.Each year from 1995 to 2001, an average of 408 tankers break
apart at sea or barely escaped that fate, according to the International
Association of Independent Tanker Owners, known as Intertanko. The leading cause
was collision, but nearly as many suffered unknown structural failures ot technical prblems.
Management and Ship building.
MIG and flux cored Weld Issues and Weld Resolutions:
Canadian frigates and MIG and flux cored weld Issues:
This Eastern Canadian ship yard management and engineers, were not aware that their yard
was in a state of Weld Process Chaos: During
the nineteen nineties, I was invited to provide a weld evaluation for a Canadian Ship Yard. The yard was building Frigates for the Canadian
Navy. At the ship yard, most of the welding practices could only be defined "as beyond chaos."
The weld engineers
and management at the Canadian ship yard had allowed the use of poor weld practices and did not appear to understand the
concepts of process controls or even the fundamentals of the MIG and flux cored weld processes utilized for most of the welds on the Navy Frigates. It was also interesting
for me to find out out that thanks to the management apathy and lack of management Process Ownership, the few weld engineers that were employed in the yard were not allowed to tell
the welders what to do.
The bottom line was the ship yard weld quality and productivity was run by the yard welders, and the majority of these welders lacked an
understanding of the MIG and flux cored processes utilized.
Incorrect weld process choices and weld settings for the Canadian Navy Frigates.
When you weld a 1/4 (6mm) horizontal fillet weld with MIG or flux cored wire you use a "single pass weld" with either a MIG Spray weld, or a flux cored wire using a a high wire feed - volt setting. Both of these weld processes would provide
a typical weld deposition range of approx. 9 to 12 lb/hr. In a ship yard, welding fillets, multipass fillets or groove welds, (good groove welds use fillet wire feed settings), and with a 30% hourly weld duty cycle, any welder who is well managed, would deposit on average 20 to 25 pounds of MIG or flux cored weld wire per shift.
Note. You will find that most ship yards only average 8 to 15 lbs of wire per-eight hr. shift
WHEN IT COMES TO WELD COSTS, HOW GOOD IS THE MIG or FLUX CORED WELD PRODUCTION
EFFICIENCY AT YOUR PROJECT?
An acceptable average MIG and Flux Cored weld wire usage per eight shift day for weld shops welding parts > 4 mm should be 20 pounds / per-shift. A highly effiicient weld shop would be depositing > 24 pounds per-shift. Those shops that weld thinner parts < 4 mm, should be depositing on average between 8 - 10 pounds per shift.
To compete in a global weld market in which the Chinese are now welding bridges for the state of California, management should have the capability to understand both the weld quality requirements and the weld deposition rate potential per welder. In a large weld shop where welders weld and someone else does the fitting on parts > 4 mm, if you multiply the total welder man hours by 3, you will see how many pounds of MIG or flux cored weld wire should be deposited daily. Then call the purchasing manager, ask them to let you know how much wire was purchased and used in the previous year. With this information you will quickly get a grasp of where you are reference the weld you are depositing and your real weld production potential.
Most of the large MIG - flux cored weld projects that I visited in 13 countries were only achieving 40 - 60% of the welds that they should have been daily deposited. To be aware of how to attain the weld production goals and train the weld personnel on how to achieve these weld production goals, please visit my manual MIG - Flux Cored Process Control Programs.
Note: Single pass welds are fine with horizontal fillet welds up to 5/16 (8mm). When the horizontal fillet weld size required is larger than 5/16, the weld shop would have concern for side wall fusion. The solution is to then weld the large fillet using 1/4 (6mm) stringers. Do not allow manual weaves to be used for single pass fillet welds above 5/16 as lack of fusion may occur and excess weld heat (weaker HAZ - distortion ) will be generated.
In the poorly run Canadian ship yard, the two prime weld processes that were daily utilized were on the majority of the welds using INCORRECT weld PARAMETERS & INCORRECT WELL PRACTICES. For example to
make the 1/4, (6.4mm) carbon steel, horizontal fillet welds on the Navy Frigates, the
welders would typically apply TWO WELDS that were carried out with TWO DIFFERENT WELD PROCESSES, MIG and Gas Shielded Flux Cored.
To make a simple horizontal, steel 1/4 fillet weld ON > 6 mm steel parts, the welders would first make a cold, MIG "Short Circuit close to globular weld" that deposited 5 - 7 lb/hr. This cold weld was better suited to welding thin gauge 0.080 (1.8 mm) sheet metal.
This first weld pass had to result in Frigate welds that had extensive lack of weld fusion.
To finish the 1/4 fillet welds, the welders would do something which revealed the complete lack of weld control in this Canadian Navy yard. For the second weld pass on the fillet weld, the welders changed their weld process to gas shielded flux cored. With the flux cored wire they used the same wire feed and voltag as they had used with the MIG wire, (no playing around with these guys they just ued one incorrect setting for any weld).
The flux cored wire feed and volt settings used ensured that the welders were placing a cold flux cored weld over the top of the cold short circuit - glob welds.
SOMEONE FORGOT TO TELL THE CANADIAN NAVY FRIGATE SHIP BUILDING MANAGEMENT, "THAT
WHEN THEI WELDERS USE INCORRECT, COLD WELD PARAMETERS, THEY WILL
END UP WITH A COSTLY WELD DEFECT, AND WE THAT HAVE SOME PRIDE LEFT IN THE WELD PROFESSION, CALL THAT DEFECT "LACK OF WELD FUSION."
The majority of the two fillet pass welds on the Canadian Frigates would reveal extensive lack of weld fusion and weld porosity. Also the cold flux cored welds would result also in extensive lack of fusion and slag entrapment. Each day using inappropriate weld settins and practices, the 200 - 300 ship yard welders would have produced hundreds or thousands of feet of single - multiipass welds on each Navy frigate. It
should come as no surprise to those reading this, that as I walked around the yard and talked to the key weld decision makers and too many welders I did not manage to talk to anyone who knew what MIG Short Circuit, Globular or Spray Transfer was, and even fewer understood the optimum working parameter range and best weld practices required for the E71T-1 flux cored wires..
Note: Many of Canadian Frigate welds under discussion only required visual surface examination, and this is the crutch that enables poor poor weld management to pick up a pay check.
COSTS: THE AVERAGE WELD DEPOSITION RATE AT THE CANADIAN YARD WAS 4 - 7 LB/HR.
The MIG short circuit
- globular parameters that were used with the 0.045 (1.2mm) wires were set at a the SC typical wire feed
rate of 210 to 280 ipm, (average 5 - 7 lb/hr) which typically produced 180 to 230 amps with 19 to 22 volts,
(20 plus volts promotes glob and excess spatter).. Without question, the majority of these welds would result in extensive lack of weld fusion, on
any carbon steel
parts > 4 mm. The flux cored data that also use these settings was better suited to a poor quality "vertical up weld," The average flux cored weld deposition would have been 4 - 6 lb/hr.
Ed's MIG Spray, Single Pass fillet. 045 wire. 450 ipm - 28 volts. 12 lb/hr
COSTS: THE AVERAGE DEPOSITION RATE AT A WELL RUN WELD SHOP THAT WELDS THE SAME PARTS WOULD BE 9 - 12 LB/HR.
Ffor those few mgrs, engineers or supervisors . that have an interest with weld process control and cost info. To make a single pass, horizontal,1/4 fillet with the 0.045 flux cored wire, you would typically set approx. 500 inch/min, (average 9 - 10 lb/hr) with 27 - 28 volts. For the MIG process a wire feed rate of approx. 420 - 450 inch/min, (average 11 - 12 lb/hr).
The more one learns about ship welds,
the less one is inclined to go on a ship.
Its possible that your Navy's worst enemy
may be the welds on its ships..
IF MANAGEMENT, ENGINEERS & THEIR WELD SUPERVISION DO NOT FULLY UNDERSTAND "WELD COSTS", THE SUBJECT IS NOT LIKELY LIKELY TO BE PART OF THE DAY TO DAY WELD SHOP CONVERSATION:
To put salt in the Canadian Frigates ship yard management wounds, every weld produced with
the low wire feed (low deposition rate) settings, took each of the 250 - 300 welders approx. 30 to 400% longer than it should have.
Canadian yard simply had no effective weld management and ironically spent over a million dollars annually on "welder training" which resulted in extraordinary poor weld productivity and quality. Not that anyone gives a dam, but the low weld deposition rates and unnecessary weld rework could readilyy result in Canadian tax payers paying > 10 plus MILLION dollars per year on unnecessary weld labor costs.
I delivered my weld report to the yard management. The report provided the required data and practices for the yard to get it's
welds to the quality and productivity that they should have been attaining.
was later informed that my weld report never got as far as the first manager who reviewed
it. The report then disappeared into the nearest garbage container. I was later told by the key weld suppler to the yard that the manager was too embarrassed to present the report to his executive
team, and also he did not want the Canadian Navy Brass to be aware of the weld quality
produced and the unnecessary yard over costs generated by the welds.
ALL WELD DECISION MAKERS SHOULD FOCUS ON THEIR BEST WELD PRACTICES - PROCESS CONROL EXPERTISE.
USING MY SELF TEACHING - TRAINING RESOURCES, IT'S
EASY TO GENERATE MULTI-MILLION
DOLLAR COST SAVINGS WITH ANY LARGE SCALE WELD PROJECTS:
.Each year from 1995 to 2001, an average of 408 tankers break
apart at sea or barely escaped that fate, according to the International
Association of Independent Tanker Owners, known as Intertanko. The leading cause
was collision, but nearly as many suffered structural/technical failures
often a euphemism in industry circles for excessive corrosion or structural problems.
INTHIS USA SHIP YARD, I PROVIDED PROCESS CONTROL - BEST PRACTICE TRAINING WHICH REDUCED THE OIL TANKER
CONSTRUCTION WELD REPAIR COSTS BY > 6 MILLION DOLLARS PER SHIP.
In building a fleet of oil tankers in Philadelphia, Aker Kvaerner, a global ship building company had budgeted a few hundred thousand dollars per-ship for its projected ship weld repairs. In 2007, I was called in to help this yard with it's weld quality and productivity problems. At this time the weld repair costs per oil tanker was approx. eight million dollars.
The prime manual weld process at this USA ship yard, was the Gas Shielded Flux Cored weld process. Most of the 300 welders in the yard used E71T-1 (1.2 mm)
flux cored wires to weld all position, Vee Groove,
9 to 25mm, steel joints that used
ceramic backing for the open roots.
many ship yards, the Aker management, engineers and QA personnel knew little about the flux cored and MIG processes, their experience was usually with the SMAW (stick) process, a process in which weld skills is the prime requirement and minimal weld process expertise is requied.
In this yard, as it is with too many large scale weld projects, the flux cored welder training focus was on the "welder's skills", and the skills taught had more to do with the SMAW process and were not the optimum skills - practices required for flux cored. As is common in most ship yards, the training provided no best weld practices and process controls, both of which are essential to optimize both flux cored and MIG weld quality and productivity.
To work at the yard, the welders had to pass an all position, flux cored
weld tests with ceramic backed vee groove welds, (6 mm root gaps) The welds were to be made in accordance with the yards weld procedures.
TOO OFTEN, "WELD QUALIFICATION TESTS" ARE IRRELEVANT TO THE WELDS MADE ON THE ACTUAL WELD APPLICATIONS.
It's important to emphasize, that like many code quality weld applications, the weld - welder qualification tests will too often have little in common with
the real world weld joints typically found
in the weld shop or the yard.
This ship yard was managed by managers - engineers and supervisors who while comfortable around a box of stick electrodes, lacked the awareness - expertise of the unique requirements necessary to attain consistent
optimum manual or automated flux cored weld quality for those ceramic backed steel groove welds. In the last five decades, the lack of valuable weld process control - best practice expertise appears to be common on large scale weld projects, and it does not take a rocket scientist to figure out the future weld liability and the weld cost consequences.
THE EXTRAORDINARY OVER BUDGET SHIP YARD WELD REWORK COSTS WOULD NOT CHANGE TILL I INSISTED THAT ALL
THOSE INVOLVED, INCLUDING THE FRONT OFFICE PERSONNEL ATTEND MY TRAINING SO THEY WOULD ALL FULLY UNDERSTAND THE WELD PROCESSES
For the Flux Cored Weld Best Practices - Process
Control Training Program that I was to present, I insisted that all the welders, supervisors, engineers, managers and QA personnel in the yard participate in my unique
Note for the bean counters: This weld process training program requires approx. ten hours, "five hours classroom and five hours hands on".
With my best friend Tom O'Malley assisting, Tom in light blue jkt on right died in Feb. 2015.. RIP TOM and keep your eye on me. In a few weeks, we completd the training for approx. 300 welders and the yards newly eductated weld decision makers.
After the training was complete, the ship yard QA department was given the responsibility to evaluate the weld cost saving results through the weekly reductions with the ship's weld rework. Three
months after the training, the ship yard
QA department indicated a 50 - 60% reduction
in the required weld rework per-ship. The
ship yard management reported that the reduced weld rework, labour and NDT costs,
would result "at that time" in a weld cost savings of approx. 4 million dollars per-ship. As the weld rework was still decreasing further cost reductions were projected and dont forget I have not discussed the increased weld productivity that was attained from the welders using the correct (higher) wire feed settings.
Ed's MIG and flux cored self teaching or training programs are available at this site
HOW MANY MORE DECADES WILL WE REQUIRE FOR MANAGERS TO REALIZE THAT SMAW HAS NOTHING IN COMMON WITH MIG OR FLUX CORED AND THESE TWO PROCESSES HAVE UNIQUE REQUIREMENTS?
It's not unusual
for weld personnel to have many weeks of flux cored hands on training at global ship yards, and then
at the training completion find that when it comes to MIG and flux cored welds, the weld personnel that have under gone weld training will do the following;
PLAY AROUND: Many welders will play around with two simple MIG or flux cored weld controls that have not changed in sixty years, The welders and their supervisors will rarely be able to dial in the optimum flux cored weld settings
Vee groove root, hot pass, fill pass and cap passes. And don't ask that welder to tell you the optimum MIG settings for that common horizontal 1/4 fillet weld.
[b] NOT BE AWARE OF PROCESS CONTROLS AND LIMIT THEIR WELD ADJUSTMENTS: Instead of optimizing the welds through the MIG weld equipment controls, many welders will typically find one weld setting and if they cant find one, the welder may copy the settings of another welder although that welder is doing a very different weld. A welder should be able to make optimum weld parameter changes that suit the conditions they have to deal with. Imagine how annoyed a machine shop supervisor would be, if his lath and milling machine operators used one control setting for every different job they were given.
[c] NOT BE AWARE OF THE BEST WELD PRACTICES? As they have rarely received best practice training, it should be no surprise that most MIG and flux cored welders will not utilize the optimum weld practices - techniques required for either the MIG or flux cored process.
[d] NOT BE AWARE OF THEIR INFLUENCE ON WELD COSTS? Lack of management, engineer, supervisor and welder awareness of the wire feed to weld
deposition relationship and the weld deposition rate potential for the common flux cored or MIG welds certainly makes it difficult to be competitive and to control weld costs.
A BREAK DOWN OF THE WELD COST SAVINGS GENERATED FOR THIS USA SHIP YARD:
the following ship yard weld cost reduction and the weld benefits attained from my unique process
control training program. Many mangers may not be keen on training as in the past the weld training did not improve the weld quality or productivity. (Managers, if you dont provide the right training you don't get the results). Training cost money, and the larger the weld shop the greater the training costs. With this in mind it should be no surprise to find some one in management that may be worried about the production man hours lost for training their employees.
Weld Best Practices - Process Control Training Costs:
The Acker training program I produced, required 300 x 8 man/hrs. = 2400
man hours at an approx. weld labor overhead cost of $30/hr. The base labour training cost for the ship yard training was $72,000. To this add the actual training and material costs was approx. $100,000.
Total training costs for the 300 welders was approx. $172,000.
Shipi Yard Weld Rework Cost Reduction Savings Per-Ship:
The initial weld improvement results revealed an instant savings of four million dollars. With management - engineering and supervision focus on maintaining the skills - process control expertise required, the reduction in weld rework costs will continue and could easily reach 7 million dollars on each oil tanker produced.
Ship Yard Weld Cost Reduction from Increased Weld Productivity:
An unreported weld cost fact from the Aker yard was the changes that I created in the
development of the new weld procedures. My weld procedures generated a dramatic increase in the gas shielded flux cored wire feed rates,
(increasing the weld deposition rates). The new weld procedures increased the daily weld productivity
potential per-man in the range from 25 to 35%. If the managers and supervisors kept their focus on weld deposition potential, it would be easy for the yard to attain a weld labor cost reduction per ship of between four and five million dollars.
Ship Yard Weld Cost Reductions from welding the Correct Size Weld Joints:
If this ship yard manufacturing management, engineers, supervisors and fitters, decided to provide the weld joints in accoradance with the design dimensions and tolerances it would be easy to reduce the weld labor and rework by another 1 to 2 million dollars per-ship.
Ship Yard Management - Ownership - Responsibility - Accountability.
The weld quality - labor cost reduction savings for each oil tanker could if well managed readily achieve "8 to 13 million dollars" per-ship. Larger ships built at this yard would provide increased weld cost savings. The welders have the skills which when combined with the best practices and process control training they recieved has given them the resources they require. To sustain the weld cost savings and weld quality, a commitement is required from the yard management to ensure that they and their engineers and supervisors maintain ownership of the weld processes utilized and be responsible and accountable for the weld quality and productivity attained.
Note I took > 2500 - 3000 hours to develop both the Flux Cored - MIG training programs available at this site. My unique Weld Control Clock Method simplifies the training or self teaching, this is a method I developed over three decades. This program can be used for any gas shielded flux cored alloys or applications. The program is available here
thanks to the Aker Kvaerner management
to be their short term catalyst for welding change.
1945 0R 2015, When will they ever learn ?
the good old STICK (SMAW) weld days which for some projects is ongoing, some steel ships broke apart at the welds before they left the dry dock.
These and the catastrophic structural failures that occurred at sea, were often a result of
low hydrogen cracking, poor weld practices, steels with poor chemistry (high impurities) and design ignorance of plate - weld mechanical
properties and the influence of cold temperatures.
the 1980's the majority of ships have been built from high quality,low carbon
steels and welded with low hydrogen SMAW - MIG and flux cored consumables. You would
have thought these two important attributes would have resolved the catastrophic
ship failure issues that occur in >2008.
face it, welds on low carbon steels, are typically supposed to surpass the strength
and ductility of the base steels and if the welds are applied correctly,
the welds and surrounding base metals are not supposed to fail.
The reality is however different, while many ships and oil platforms have plate and pipe
that will be affected by rust, during unforeseen circumstances or severe weather
while the steel parts impregnated with rust stay intact, the welds and weld heat affected zones will tear apart like a wet paper
2007: Is it possible that the global ship building flux cored, lack of best weld
practices and lack of weld process controls are partially responsible for many of the catastrophic
failures that sink many ships each year?
ABOVE, A COMMON FABRICATION ATTITUDE.
THE USA SHIP YARD HAD EUROPEAN, HIGHLY QUALIFIED SHIP BUILDING MANAGEMENT, AND A LARGE QA AND ENGINEERING DEPARTMENT, YET THEY ALLOWED WELD JOINTS LIKE THIS..
a weld reality that the QA departments in many ship yards and oil platform yards,
while looking for weld defects the QA department personnel will place minimal focus on the design fit tolerances and the quality standards that are supposed to be applied
to the part fit and weld edge preparations. Its also a fact that pre-heat and interpass weld temperatures are often not utilized when they could provide good weld / part benefits.
picture on the left is a flux cored weld edge prep (made in 2007) at a major USA ship yard. Yes the gap opening is larger than one inch and that is ice and water surrounding the weld joint. On this joint there was no weld preheat applied and no interpass weld temperatures applied during the numerous welds. To add to this pathetic weld situation, the mill scale was left on the groove edges and cutting oxides were left on the groove surfaces. Weld joints like this shoud never be
allowed especially in these industries.
The increased root openings not only dramatically adds to the weld labor costs and increased potential for weld defects, the weld heat from the additional weld passes has a tremendous negative influence on the weld's HAZ (heat affected zones).
2007: WE SHOULD ALL KNOW THE ANSWER TO THIS QUESTION.
DOES A STEEL BACKED, 6 mm ROOT GAP ON SHIPS PLATE, PROVIDE THE SAME HAZ MECHANICAL PROPERTIES, WHEN THAT ROOT GAP IS ALLOWED TO INCREASE IN THE RANGE OF 8 TO 25 mm.?
WITH THE EXTRA WELD PASSES FROM THE OVER SIZED ROOT WELDS, THE RESULTING , INCREASED WELD HEAT AND INCREASED WELD DEFECTS WILL HAVE DRAMATIC NEGATIVE RESULTS FOR BOTH THE WELD AND WELD JOINT INTEGRITY. WITH THIS IN MIND, YOU WOULD EXPECT THE SHIP YARD ENGINEERS TO PROVIDE STRICTER SHIP YARD WELD REQUIREMENTS AND ENSURE THE CORRECT FABRICATION AND WELD CONTROLS ARE APPLIED.
Weld - steel qualification tests for critcal ship weld plate joints are typically taken from optimum weld joints with specified max root gap openings. It would be of interest, if the navy and ship building industry, both of which turn a blind eye or enable welds that allow extensive, plus, open root tolerances, would provide the necessay research to find out the following;
what the negative weld heat influence will be from the numerous extra weld passes.
[b] what the negative consequences will be from the combinations of the extra weld defect buildup and extra weld heat would be on the mechanical properties,
[c] what is the real world maximum root gap cut off point before the mechanical properties will be outside those specified by the ship's designers? After this research, I would anticipate a dramatic reduction in the open root tolerances, more focus on interpass temperature controls and and stricter part fit controls in the fab shops.
The additional HAZ weld heat provides many questions about the mechanical properties being achieved with many weld joints. Every time I see photos of ships that unexpectantly tear apart at sea, and you see that nice clean straight tear where the welds HAZ is located I think about these weld situations.
|Quick, before it sinks, examine how nice and clean the catastrophic
right down the weld seams and their HAZs...
weld failures on this ship occurred in the locations in which
the welds should
have been sound, as they would have be subject to NDT. With ship welds we need more focus on the weld quality that is being accepted and on the mechanical properties being attained in the weld's HAZ.
2007: It's a weld reality that in ship yards and on other mega oil and natural gas projects, that many unacceptable variables will
happen to the weld joints and welds and those "variables that impact the welds are typically not considered in
the pre-qualification welder procedures generated".
When the weld personnel are not supplied with the
process control training necessary to deal with the weld shop variables, the welders will typically play
with the weld controls and not provide optimum weld settings to deal with the weld situations.
Weld Quality Standards will have a different meaning for each
company that builds ships or oil platforms. One thing most QA departments will have in common, is their weld quality focus will be on "finding rather than preventing weld defects".
Have we learnt anything about welding ships in the last six decades?
29/07 Note from Ed:
and metallurgists will typically look to the ship's design, steel - alloy compositions,
environment, water temp, weather and the formation of rust for the causes of
many catastrophic ship failures. I wonder how many designers will take into account
that on any global built ship the NDT that examines the internal weld quality is only applied to a small percentage of the ships welds.
IRRESPECTIVE OF THE WELD CODES, COMMON SENSE WOULD ENSURE THAT ENGINEERS CREATE PRE- QUALIFICATION WELD TESTS THAT ALLOW FOR THE REAL WORLD "WORSE CASE WELD SITUATIONS THAT ARE LIKELY TO TAKE PLACE WITH THE INTENDED WELD APPLICATIONS".
Poor Welds and the Consequences.
Shit, it broke apart right along the bloody weld seams, and it was not much of a storm.
Many ship yards forget that oversized
weld joints require many more weld passes producing extra weld heat (larger HAZ) and more internal weld defects. An increase in weld defects with a weaker plate HAZ is not a combination any organization should accept.
While the ABS code, Navy or any ship builder will stipulate a maximum root gap allowance in most instances its rarely adhered to. The weld reality is weld and material metallurgical weld qualification tests should always be carried out with the maximum allowable root gaps and those root gap dimensions must have strict min and max tolerances that must be followed.
Unfortunately as the photo on the left indicates this is the real world weld joints that are rarely shown in the engineers office.
When building merchant or naval vessesls, the too common poor control of the weld joint will often leave edge preps that have irregular, oxide and scale laden surfaces. The edge preps may also not have the required pre-heat on those cold or wet days. The wet plates or cold plates, lack of pre-heat combined, oxides - scale and frequent lack of interpass controls with innapropriate weld parameters, techniques and practices, and the usual lack of care of the consumables leads to extensive lack of weld fusion, weld slag inclusions, porosity and lower than required plate / weld mechanical properties..
As only a small portion of a ship's welds are typically subject to NDT, both the navy and merchant navy would do well to put a renewed focus on weld process control training that is directed at weld defect prevention and good weld practices. All managers need to be aware that it's just as easy to produce optimum quality welds as it is to produce poor welds.
The following are a sample of recent news paper or web reports
typical weld and related issues that have occured in ship yards. It's true that with large scale weld fabrications it should be no surprise that they are extensive weld issues. It just seems strange that few managers today seem to want to take opportunity to take ownership ot their processes and control of the many variables that can provide dramatic weld cost reductions for their organizations.
When building the USS Nimitz, as reported by the Navy, only
one weld out of
approximately 100 tested passed the NDT.
the ship's or OIL platform demise from a freak
of nature, or from poor welds?
DESIGNERS ASSUME THAT THE SHIPS OR OIL PLATFORMS THAT THEY DESIGN,
WILL BE BUILT IN ACCORDANCE WITH
THE WELD SPECIFICATIONS PROVIDED.
THE WELD REALITY IS
FEW ARE. THE REASON WHY MANAGEMENT - ENGINEERS GET AWAY WITH POOR WELD CONTROLS AND PRACTICES IS, IT'S DIFFICULT TO TEST AND CONFIRM THE OVERALL WELD INTEGRITY ONCE THE SHIP YARD OR OIL PLATFORM IS ON THE OCEAN FLOOR.
amount or type of weld defects typically found in a ship's construction
in 2015, has hardly changed
from the defects found six decades ago.
the 1940's, poor quality stick (SMAW) welds were the norm. The weld quality was further influenced by electrode issues combined with poor quality steels and poor
weld practices. The end result was numerous Liberty ships suffered from catastrophic weld & steel failures.
Seventy years later, in general (there are of course exceptions) in the weld industry we have achieved what.? Today we have a superior flux cored wires for those all position ship plate - pipe welds. We also have the MIG process and good automated weld equipment. We also weld on far superior quality steels, yet due to the global lack of weld process control expertise, the too common poor weld practices and the ineffective (we take no ownership) weld management, ships and oil
platforms are riddled with costly weld defects and these applications are still at risk for catastrophic failures.
5000 liberty ships built, 1000 catastrophic
failures right down te weld seam.
Decades later,oil platforms heading down to the ocean floor
those looking for the structural security attained from the double hull construction that
will occur when building large ships or more costly ships, keep in mind that unless ship yards change their
approach to weld best practices and process controls, the double hull ships may simply enable double the amount of bad welds.
HOW RELEVANT IS SHIP
DESIGN WITHOUT SOUND WELDS:
Each week one or two global ships sink, many as a result of weakened
structures from corrosion.Does anyone ask how many ships sink annualy as a result
of bad weld practices, and why do ships appear to get torn apart in calm waters?
The US automotive industry that this year had 60 million vehicle recalls, loves the
infamous and highly ineffective Six Sigma Crutch and this management crutch is now heading to other industries whos management also requires a crutch. Ship yards and large weld fab
shops are showing interest in the SS even after it has failed with the majority of manual and robot MIG and flux
cored weld applications found in US automotive and truck plants. Remember when it comes to welding MANAGEMENT does not need a crutch, they do need weld best practices and process expertise.
THE QA SYTEM (typically finds, rather than prevents weld defects) USED THROUGHOUT THE WELD INDUSTRY OFTEN DOES LITTLE TO REDUCE THE LIABILITY POTENTIAL..... While
the QA manager focuses on the ISO and his never ending after the weld fact inspection reports, the lack of
affective process control training, the lack of weld best practices and the lack of management - supervision process
expertise in his organization leaves many
of the ships welds in a
Be a professional with the processes and consumables utilized.
A note from Ed
yard may use half to a million pounds of flux cored weld wire each year,
however it's rare to find a ship yard that has management and engineers who have established Best Weld Practices
and implemented effective Flux Cored Weld Process Control Training for the weld personnel.
How many ship yard managers and supervisors
are aware of
decades the global shipyard focus has been on the welder's "stick welding
skills while the majority of global ship yard welders that weld with the flux
cored - MIG process, lack weld best practices - process control and consumable expertise.
many weld personnel in ship yards will daily use the unsuitable techniques and skills they learnt
with the lower weld energy, lower weld deposition stick welding process.
flux cored process, the variable size root gaps and the placement of weld across none
conductive ceramic backing requires unique weld considerations and specific instructions
for the all position, root, fill and cap weld passes. A visit to any global ship
yard, would reveal that few welders, supervisors or "engineers" are
aware of the flux cored process and ceramic requirements necessary for consistent
It's a sad comment in a time when MIG and flux cored weld defects inundate ships
and oil platform construction, that at many global ship yards, weld apprentices
will spend more time practicing with stick electrodes than they will with MIG
and flux cored consumables. It's also a weld reality that many weld instructors
when providing MIG and flux cored training, will teach the apprentices inappropriate
stick welding practices and techniques. You dont want to ask any weld instructor in a ship yard this fundamental MIG question. " What is the wire feed and current start point of spray transfer with the world's most common 0.045, E70S-6 MIG wire and argon - 20% CO2"..
YOU CANNOT CONTROL THE WELD QUALITY - PRODUCTIVITY
IF YOU CANNOT CONTROL THE PROCESS.
Try the following fundamental weld process questions.
Process Control Weld Test
Fundamental Flux Cored Process Control Weld Test.
Ed's Unique, MIG and Flux Cored Weld
Process Control Training Resources
It looks like someone needs a lesson in ship building.
Accountability - Responsibility - Ownership....36 million in repairs and 400 million
over budget & the seniior management and engineers are still on the job.
HOW "NOT" TO BUILD A SHIP, BUT HEY WHO CARES,? IT'S ONLY TAX PAYERS DOLLARS:
- The new amphibious ship San Antonio failed to complete a series of sea trials
in late March, and faces $36 million in repairs during the next three months. The
San Antonio has been plagued by mechanical and structural problems since the Navy
took ownership two years late, in July 2005. Northrup Grumman Ship Systems in
Pascagoula, Miss, built the ship at
a cost of $1.2 billion, roughly $400
million over budget.
With optimum flux cored weld consumables and extensive use of a grinder, the gas shielded flux cored process
is perfectly able to produce optimum, all position quality welds on any steel
applications as long as those applications have weld joints that meet the design and code criteria.
The bottom line is MIG or flux cored welds on any ship
should be the strongest part of the ship. The reality with too many structures welds are creating the weakest
IF I MANAGED A SHIP YARD THE FIRST EASY THING TO FIX WOULD BE THE QA DEPARTMENT. For
decades, on many mega
weld projects, a typical
QA / CWI primary function has been to "find fault after the weld completion". With minimal cost managers could provide my Weld Process Control - Best Weld Practice Training Program and demand that their weld inspection personnel learn the requirements necessay to prevent the MIG or flux cored weld defects. The reduction in weld defects, less weld rework and much lower NDT costs, has to have a big impact on the companies bottom line.
If the guys in the front office don't fully understand weld costs, who is going to understand the requirements necessary to attain optimum quality welds at the lowest possible cost?.
There are ten individuals comprising of managers, engineers and supervisors having a weld meeting in the ship yard managers office. The meeting was called to discuss the reasons for the increasing weld costs associated with the weld rework. Most of the welds are made on fabricated components that require simple 1/4 flux cored fillet welds. The weld procedure is passed around with information on the consumable type and size, the wire feed rate and the volts being utilized. There is much finger pointing at the afternoon shift guys on the shop floor The discussion is heated and tempers are on the rise. The manager is a pragmatic individual who admits he knows little about weld costs, he stands hits the table, looks around the room and says, "gentlemen there appears to be much confusion here and little expertise, is there one of us in this room that can tell us the real cost of a 1/4
fillet weld one meter in length"?.
You know that if you were in that meeting,
instead of the few minutes to provide the correct answer, it would likely take many hours of more discussion and then the answers provided will be all over the place. Then again, possibly the manager should never have asked the question in the first place as he is part of the problem.
from Ed, please don't shoot the messanger.
Sometimes I feel that my comments
on this site may be seen by some as a little too critical, however there is a reason
this site is called "weld reality" and I don't just criticize, I provide
highly effective practical weld quality - productivity and cost solutions. To those who are interested in weld best practices
and process controls or weld cost simplification, click
Concerned about weld costs and weld liability consequences?
those weld shop managers and engineers that live behind glass walls and are rearing up in defensive exasperation
at my hands off, inexperienced manager - supervision and engineer comments, and my criticism for the general lack of global lack of process control - best practice expertise,
please remember that their will be thousands of weld shops this year that will have to deal with lower weld labor costs from other companies in other states / provinces or countries, over
budget weld costs, inconsistent and poor weld production efficiency, over budget NDT costs,
and extra weld rework costs.
The typical common unexpected weld - part issues will of course lead to tighter
production schedules which typically makes the weld situation worse as the weld shop supervision now has to drive
more production before quality. And lets not forget, the lack of process ownership ensures all involved will continue to work
too many hours and loose too much sleep.
WELD LIABILITY CONSEQUENCES ARE MANY..
person who makes a weld decision, should learn weld process
controls and understand the requirements to prevent defective welds
all the money Ed makes from
his weld consulting, he has made
the down payment on his dream "house
wonder how many weld shop managers, supervisors and engineers would last
in their jobs, if every weld they were responsible for, was given a 100% UT
or radiograph examination?
ship yard welder was allowed to weld USA oil tankers for three years,
and this was his best attempt at a welder requalification test.
The weld equipment and consuambles purchased in a weld shop are
always a reflection of the weld or fabrication managers expertise.
PURCHASE OF RIDICULOUS WELD EQUIPMENT
AND LACK OF FUNDAMENTAL
PRACTICES AND PROCESS EXPERTISE..
Take a moment look around your weld shop. Watch as the weld personnel "play with their MIG and flux cored weld controls". Evaluate
why you are using a wide variety of unnecessary weld consumables and weld equipment.
Go to your gas cylinder rack and ask your self whay there are more than two gas mixes. Chat with the purchasing mgr and find out how much was spent last year on grinding wheels and other equipment used for cleaning welds. And last, find out how much was paid last year for service, repair and maintenance costs" associated with the electronically sensitive
welding equipment and weld guns purchased.
THERE BE DOUBLE STANDARDS APPLIED TO WELDS AND
SO CALLED CRITICAL SHIP WELDS BE MANUAL OR AUTOMATIC?
In my world every weld produced on a ship or used to fabricate a work bench should be considered critical, after all, whats the purpose of a weld? and why would you not ensure every weld produced is optimum. Also why would any manager allow double standards for welds:
In the ship yard, the structural welds in the center area of the ships are considered critical and subject to internal NDT weld evaluation. When NDT finds defects in these welds, then more weld area is subject to the NDT. This has great weld cost repercussions for the ship builder so these welds are given extra consideration and often the best welders are used on these joints. The point is in any facility that welds, if the correct training is provided there should be no best welders. Welding is not rocket science and there is only one standard that can be applied to all welds. If after the proper training is provided, you get rid of the welders who cannot meet that standard.
many of the weld facilities that I visit, I note manual welders typically will make
long fillet or vee groove welds, when low cost, easy to set up, automatic weld carriage equipment is on a shelf gathering dust. Controlling weld speed, weld weaves and wire stickout is essential if you want to attain consistent, optimum, uniform weld quality.
In the encouragement for flux cored or MIG weld automation,
one of the problems ship and oil platform companies have, is that due to lack
of weld process expertise, especially with the supervisors who should be providing the automation weld training, many welders do not know the correct data to
dial in for the common 3/16 - 1/4 - 5/16 fillet welds.
Ask 10 welders in a yard what
is the MIG or flux cored "wire feed and weld travel rate settings" are for a 1/4 (6 mm) fillet weld and I guarantee you will get 10 different answers.
I have assisted ship yards in the USA, and Canada and in Europe. At the yards I worked with Norwegian, Swedish,
Danish, German, Polish Italian. English, Korean, Japanese, Yanks and Canadians
and and don't forget those tenacious thick skinned, highly intelligent, hairy, canny
Scottish weld personnel. My experiences with these hard working, great
characters indicated that the majority played around with their weld controls
and none had ever received MIG or flux cored weld best practice - process control training, or training in dealing with ceramic backed welds.
From my ship yard experiences,
i developed thicker skin, an increased sense of humour and also developed the
following flux cored, CD. Best Practices - Process Control Training Resources. This program is applicable to all position, open root, steel and ceramic backed, pipe and
plate, fillets and vee groove welds.
Ed's "MIG and Flux Cored" Weld Best Practices - Process Control
WELD MANAGEMENT STARTS WITH "PROCESS - EQUIPMENT AWARENESS":
The first step for ship yard management is be aware of the level of weld process control expertise and reponsibility of the key weld decision makers in the yard. Lets face it, If these guys knew what was needed to minimize weld defects and optimize weld productivity, then the weld and rework costs would not be out of control.
Weld quality responsibility should be in the hands of managers, engineers, technicians and supervisors. Typically the weak link in this chain are the weld or fabrication supervisors. The irony is the supervisors are given more responsibilty for the welders than the engineers and technicians get. Notice that QA persons who find weld defects after the welds are complete are not included.
IF AN ENGINEER IN A SHIP YARD THINKS A WELDER IS NOT CAPABLE OF PRODUCING
THE WELD QUALITY DESIRED, HIS OPINION ON THAT WELDER WILL HAVE LESS MEANINING THAN WHAT THE LESS QUALIFIED SUPERVISOR'S OPINION MIGHT BE.
The second step for ship yard management is the managers have to be aware that the weld equipment, process
and consumables used in their yard rarely reach their full weld quality and productivity
potential. The soution to this is in the training programs provided. Yard management have to be aware that the MIG and flux cored welder training programs provided for weld personnel are obviously not effective, therefore training changes are required and training focus is necessary on teaching all weld personnel best weld practices and weld process controls
The ship yard management needs to be aware that the stick
(SMAW) weldesr with 20 years experience typically only brings incorrect techniques and
bad weld practices to the MIG and flux cored process? There is a global shortage of welders. If the weld management was aware that
when new welders walk into their
yard, few will have seen a ceramic backed root gap.
If something like ceramic backing is unique or rarely utilized in other industries, that means welder's need to undersatnd the best practices and process controls necessary for welding on none conductive ceramics.
As its difficult to hire drug free welders, I dont want to waste ship yard money on testing welders to fail. Before testing welders I would give them a one day training on the best practice and process controls necessary for the process and consumable used in the weld test. I would also provide the welders with the optimum weld settings. With this logic ship yards would have less issues hiring welders?
As a matter of interest to the few managers that read this stuff please note. Any "none welding person" with the right attitude and provided with the correct skills, best practices and process control weld training, should with "ten days training" be able to meet the all position code weld quality requirements necessary for the majority of MIG and flux cored welds in any ship yard.
MANAGEMENT ENSURES SHIP YARD WELDER TRAINING DEALS WITH THE YARD WELD VARIABLES:
While the ship yard management
complains that their weld over cost per-ship is one to ten million dollars, they allow the ship yards fitters to produce oversize weld preps that typically add 30 to a 100% more weld.
In ship yards, thanks to lack of management / engineering focus on providing weld joints that are in compliance with the design, its not uncommon to find weld joints outside the code requirements with variable root weld gaps
8 to 25 mm. These welds will be made. How will the welders react to the techniques and parameter changes
required when welding across the extra size ceramic root gap.
 How does
the welder react when the weld procedure does not require
preheat but the steel is either wet or cold.
 How does the welder react when
they have to put in twice as many welds that are specified in the procedure but
there are no interpass temp controls or information about additional weld passes?
ship and oil platform welders are daily offered unique challenges by fabrication supervisors
who frequently know little about the flux cored or MIG process, supervisors who deliver weld joints that are simply not acceptable. To make their job
a little more complex, ship yard welders often have to make the challenging welds
on the poor oversized edge preps in 20 mph winds, 50 feet up on a scaffold, at minus 20
FOLLOWING ARE A FEW WELD VARIABLES FOUND ON SHIPS AND OIL PLATFORM PROJECTS. THESE
VARIABLES ARE THE REASONS WHY WELDERS REQUIRE THE ABILITY TO WALK UP TO THEIR WELD EQUIPMENT AND INSTANTLY SELECT OPTIMUM WELD
PARAMETERS FOR THE THINGS THAT ARE ABOUT TO IMPACT THEIR WELD QUALITY OR PRODUCTIVITY POTENTIAL.
 narrow, inconsistent root gaps,
variable and excess root gaps,
 a lack of understanding of the unique weld requirements
for ceramic backed
roots with variable gaps,
 poor weld edge preparations,
welding on primer, paint, rust and cutting oxides,
 welding in an inconsistent
daily changing environment,
 difficult weld access,
 extensive difficult, vertical and over head welds,
 recieving weld joints from ship yard fitters who have never
been educated on the cost consequences, the quality liability potential or difficulties
of welding poor weld joints,
 supervisors, managers and engineers making
flux cored and MIG process and equipment welding decisions, when the reality is,
weld knowledge never got past a E7018 stick electrode.
about those ships being built with the higher strength and low alloy steels? My
gut instinct tells me that if a ship yard cannot control the weld issues that
occur with the common low carbon steels, that ship yard will not provide any better controls
on the higher strength or low alloy steels.
In the good old days when
welders deposited a leisurely three or four pounds of stick electrode a shift,
they would be concerned about the sponge like flux on the stick electrodes and it's attraction for The stick electrodes would be protected
(sometimes) in a heated storage oven or electric portable heater.
Most welders on large projects typically only produce 50 - 60%
of the weld they should be producing.
MIG and flux cored welders on large projects should be depositing a minimum of 20 - 23
pounds of weld wire a shift, (few do). The reality is during the construction
of many ships and oil platforms, that due to the lack of
supervision - management focus on attaining weld deposition rates, most welders will typically deposit only
10 to 15 pound of flux cored weld per shift.
Due to lack of logical flux cored weld best practices,
few weld facilities ask the welders to date and time tag new wire reels utilized. Whats normal is the flux cored wires are left out in cold, damp or humid conditions for god knows who knows
contrast to stick welding, which has the flux on the surface of the electrode,
a primary benefit of the flux cored wire is the wire's flux is protected by an
outer steel sheath. Some wire sheaths have a straight butt seam and it's easy
for them to allow moisture through the seam, other wires like the one in the picture
have seams that are designed with a little more consideration for keeping moisture
away from the flux.
With flux cored wires you get what you pay for.
shielded flux cored wires are supposed to be low hydrogen products, however that definition only applies as long as the weld wire is sealed in it's container. The flux in these
wires or the wire surface can readily be be contaminated with moisture, and show me a ship yard where moisture is not an issue.
flux cored, process control training program available on a CD also
with the weld practices necessary for all weld
IT TAKES TO GET HYDROGEN CRACKS STARTED:
High strength steels.
 Large root gaps, plate misalignment, anything
that results in excess weld heat and excess stresses.
 Lack of control on the steel
 Lack of control with preheat and interpass temp
 Lack of history and protection for the flux cored weld consumables
 Lack of awareness of the potential for moisture
in the welding gases utilized
 Lack of process and weld technique knowledge
that could help minimize the effects of moisture
 Lack of concern for
the quality of the weld gases used. Many cylinders and pipes supplying MIG and
flux cored weld gas mixes, will contain moisture.
BEST WELD PRACTICES AND PROCESS
THOSE WELD CRACKS WILL HAPPEN.
It's inevitable that on that on that one billion
dollar naval vessel,containing high strength steels, that when that vessel leaves
the docks, it will leave with hydrogen cracks.
add misery to misery, the cracks will typically be in the weakened weld's heat
affected zones, along side welds that are bound to contain lack of fusion, slag
inclusions and extensive porosity.
|Please remember when building a ship,
or an oil plat form, a failed weld can have the same consequence
as those weapons of mass
OF FRACTURED STEEL PLATES REMOVED
FROM WELDING SHIPS.
Author : PENNSYLVANIA STATE UNIV UNIVERSITY PARK
Author(s) : Williams, M. L. ; Meyerson, M. R. ; Kluge, G. L. ; Dale, L. R.
: Samples of fractured plates from 72 ships were examined, and various laboratory
examinations and tests were made on 113 plates selected from these samples. Information
regarding the structural failures involved was obtained from the cooperating agencies,
and the failures were analysed on the basis of this information combined with
the results of the laboratory investigations. The ship
weld failures usually occurred at low temperatures, and the origin of the fractures
could be traced, invariably, to a point of stress concentration at a geometrical
or metallurgical notch resulting from design details or from welding defects.
Note from me: Fifty
six years have passed since the above reports. When will ship yards get
control of the common welding processes they utilize?
SUPERSTRUCTURE ON FFG 7 CLASS SHIPS HAS EXPERIENCED EXTENSIVE CRACKING. THE CAUSE
OF THE CRACKING HAS BEEN DETERMINED TO BE A COMBINATION OF HIGH DESIGN STRESS
COUPLED WITH POOR WELD QUALITY
I had a good laugh in 2005 when I read in the AWS
magazine about some VP in a ship yard looking at purchasing a CO2 laser for ship welding applications.
This was a yard I was familer with. It was a yard in which the management and engineers were unable to get control of the simple to use, two control, MIG - flux cored process.
This was a yard where the managers had a difficult
time getting their weld personnel to feel comfortable with simple Bug-O welds, (mechanized
MIG or flux cored carriage welds). This was a yard in which none of the weld management understood the cost of a weld. This was a yard in which the managers and supervisors lacked the ability to provide
edge preps and weld gaps that meet the design specifications for flux cored weld, and now this is a yard in which the management wants to to bring a laser into their yard.
IN MY WORLD, A SHIP YARD WOULD BE RUN LIKE A NAVY SHIP:
yard management would do well to compare themselves with the way the navy runs a ship
and submarine. A captain or engineer on these vessels typically has the ability to operate or take apart most things on the ship. I
am not suggesting that today that this comprehensive, technical expertise
should be part of this generation's
manufacturing managers job description, (it should however be part of an engineers job description). I am suggesting that in 2012
the global weld industry would benefit from a compromise in which managers and
engineers have less reliance on salesmen or weld equipment rep and show more ownership interest in
the equipment responsible for building their products.
get manufacturing management and engineers back into the weld equipment process control
loop, an important first step would be for these individuals to show the workers
that when they open their mouths on the subject of welding, they can provide welders
on the shop floor something most don't have "weld process control knowledge".
If you are looking
for excellent MIG and flux cored weld process control knowledge resource, it's here.
IF MANAGERS, ENGINEERS AND SUPERVISORS LACK THE ABILITY TO CONTROL
THEIR WELD PROCESSES, THEY WILL TYPICALLY LEAVE IT THE THOSE LOWER PAID
GUYS IN THE WELD
SHOP TO EVALUATE NEW OR DIFFERENT WELD TECHNOLOGY.
evolution from the shielded metal arc welding (stick) process, to the gas shielded
flux cored welding process has for many pressure vessel shops, pipe shops
and pipe line contractors been painful and slow. The flux cored wires that
offered many practical benefits for all position welds were developed > twenty five ago.
The weld reality for those industries that weld pipe lines or and code projects with the SMAW process, is the gas shielded flux cored weld process evolution for most all position code application should have taken a few weeks.
Note: When the management and engineers don't provide weld process ownership, the so called weld decision makers will leave it to their welders to test new weld wires or gas mixes.
Some of the greatest resistance to the uses of flux cored wires came from the global pipe weld shops that supply the oil industry. These weld shops like ship yards were entrenched in SMAW (stick) weld practices, and the unqualified reps who were selling the flux cored wires lacked the process expertise necessary to optimize the flux cored weld performance and therefore could not convince
the stick pipe welders to accept the superior flux
The majority of welders will lack the best practices and process control expertise necessary for weld consumable evaluation, and therefore the new consumable weld test results will often be poor.
Also what motivation will welders have for going outside their comfort zones and recommending something new that would require major learning curve changes for the shop?
HAPPY WITH A PROCESS THAT REQUIRES MINIMAL PROCESS CONTROL EXPERTISE:
As the SMAW equipment provides
a single weld current control, the
STICK welder simply increases or decreases the weld current and therefore needs minimal weld process control expertise. In most instances even the choice
of the electrode is made for the welder. In contrast to the SMAW process,
the MIG equipment that's also used for flux cored welding allows a welder to use
seven distinct modes of weld transfer for MIG - FCA welds..
The reality today in 2012 is that most of the weld shops that use the common MIG and flux cored processes will have focus on the welder's skills rather than on the
welder's weld process control expertise. Every day in these weld shops you will find that the MIG equipment and consumables are rarely used to provide their full weld quality - productivity potential and therefore every day weld costs are more than they need to be. The upside is in most weld shops there is always good potential for dramatic weld cost savings.
WELDERS WILL NOT FEEL COMFORTABLE WITH WIRE FEED PROCESSES UNTIL SOME INDIVIDUAL STEPS UP TO THE PLATE AND TEACHES THEM THE BEST PRACTICES AND PROCESS CONTROLS NECESSARY TO OPTIMIZE THESE TWO PROCESSES. PLEASE NOTE. YOU DO NOT NEED WELD EXPERTISE TO PRESENT MY UNIQUE WELD PROCESS CONTROL TRAINING RESOURCES.
HOW BAD WELDS
of USS Thresher (SSN-593)
company with Skylark (ASR-20), the USS Thresher put to sea on 10 April 1963 for
deep-diving exercises. In addition to her 16 officers and 96 enlisted men, the
submarine carried 17 civilian technicians to observe her performance during the
deep-diving tests. Fifteen minutes after reaching her assigned test depth, the
submarine communicated with Skylark by underwater telephone, appraising the submarine
rescue ship of difficulties. Garbled transmissions indicated that--far below the
surface--things were going wrong. Suddenly, listeners in Skylark heard a noise
"like air rushing into an air tank"--then, silence.
to reestablish contact with Thresher failed, and a search group was formed in
an attempt to locate the submarine. Rescue ship Recovery (ASR-43) subsequently
recovered bits of debris, including gloves and bits of internal insulation. Photographs
taken by bathyscaph Trieste proved that the submarine had broken up, taking all
hands on board to their deaths in 5,500 of water, some 220 miles east of Boston.
Thresher was officially declared lost in April 1963.
a Court of Inquiry was convened and, after studying pictures and other data, they said that the loss of Thresher was in all probability due to
a casting, piping, or weld failures that flooded the engine room with
water. This water probably caused electrical failures that automatically shutdown
the nuclear reactor, causing an initial power loss and the eventual loss of the
How lack of metallurgical expertise
cold water helped destroy the Titanic.
Eight More Ships with Structural - Weld Problems.
Marine Log Home Page:
classification society RINA, Genoa, says its initial findings on the causes of
the sinking of the Maltese-flag tanker Erika during a major storm in December
point to a small structural failure or leak low down in the hull structure. This
was followed by cracking that eventually led to the collapse of the hull.
says its investigations prove that the calculated residual strength of the vessel
at the time of the casualty should have been sufficient
to withstand normal operation of the vessel in the prevailing weather. The residual strength was within IACS limits.
investigations show that the hull structure initially failed at some point low
in the hull, and that complete failure occurred only after cracks had propagated
from that source.
is continue its investigations to determine the cause of that initial failure
and the results of the subsequent actions of the master, owners and other parties
involved. RINA will focus on several potential causes of the initial failure,
possible poor loading or poor ship handling,
 poor workmanship during weld repairs,
 failure of welds due to poor design and poor weld practices during it's construction.
RINA has appointed Three Quays Marine Service and Studio Tecnico Navale Ansaldo
to conduct further independent investigations covering: design and construction
of the Erika and its seven sister ships. "Eight sister ships of the Erika
class were built, under two different class societies, and have been classed by
five different IACS classification societies at some time in their lives. All of these ships had suffered structural problems. Three of them, other
than the Erika, were serious. No information on this history of problems was available
to RINA," he says.
Note: It appears that in the case of the Prestige and the Erika tankers that the
structural failures occurred a few months after welding
repairs were carried out on the hulls. This would suggest that welding
could be a factor in the structural failures.
IF THE BAD WELDS DONT GET YOU, MAYBE THE RUST WILL:
NEW SUPERTANKER PLAGUE
By Richard Martin
it on super-rust, a virulent form of corrosion that has destroyed hundreds of
ships and could sink the oil industry.
December 7, 1999, the oil tanker Erika set sail from Dunkirk, France, bound for
Sicily, carrying 10 million gallons of heavy fuel oil. A few days later, the ship
headed south around the coast of Brittany and cruised directly into a powerful
The Erika battled swells of more than 20 feet as it steamed
across the Bay of Biscay. Soon the ship began to list, and 11-foot cracks appeared
in the deck and hull. The Erika was breaking apart. A helicopter evacuated the
crew just before the vessel split in half and sank in 400 feet of water, spreading
tarlike petroleum across more than 250 miles of the Loire-Atlantic coastline
Europes largest oil spill in two decades.
Built in Japan in
1975, the Erika was typical of todays older tankers. Sailing under the flag
of Malta, it was managed by an Italian operator and chartered by a Bahamian company
headquartered in Switzerland. Its Maltese owner was itself owned by two Liberian
firms. Deemed seaworthy by Registro Italiano Navale one of many organizations,
known as classification societies, responsible for inspecting and certifying commercial
vessels the Erika had passed every inspection over the year prior to its
The final report on the disaster, issued in January 2000
by the French investigative agency Bureau dEnquetes sur les Accidents en
Mer, concluded that severe corrosion had weakened the Erikas hull, causing
the ship to flex in the storm and eventually to fracture.
of oil moving by ship is soaring. And in traditional tankers, accelerated corrosion
is engineered right into the body of the vessel.
Erika was neither the first nor the last tanker to succumb unexpectedly to corrosion.
Each year from 1995 to 2001, an average of 408 tankers broke
apart at sea or barely escaped that fate, according to the International
Association of Independent Tanker Owners, known as Intertanko. The leading cause
was collision, but nearly as many suffered structural / technical failures
often a euphemism in industry circles for excessive corrosion and bad welds
Ships have been corroding since the late 18th century, when
wooden hulls were first covered with copper to protect against worms. Mariners
have recognized the threat to steel tankers in particular since the 1950s, and
classification societies have established a regime of inspections and maintenance
to keep corrosion at bay. But the system has failed. Ships that cost hundreds
of millions of dollars to build are falling apart on the open sea, endangering
the lives of crew members and spilling millions of gallons of oil each year.
instance, the Nakhodka went down two years before the Erika sank. This 27-year-old
tanker broke apart off the coast of Japan, spilling 1.3 million gallons of crude
and killing one sailor. The Japanese Ministry of Transport found that portions
of the ships hull had rusted 20 to 50 percent. In December 2000, the Castor,
carrying 8.7 million gallons of unleaded gasoline across the Mediterranean, developed
cracks in its deck and had to be drained of its cargo in a risky ship-to-ship
Preliminary findings in the Castor case rocked the industry.
According to the American Bureau of Shipping, the classification society that
certified the vessel, the Castor had fallen prey to hyper-accelerated corrosion
swiftly dubbed super-rust in the trade press. The ABS downgraded
its assessment to excessive corrosion in its final report, issued
this past October. Nonetheless, that document noted that the vessels steel
had disintegrated at rates of up to 0.71 millimeter a year more than seven
times the nominal rate expected by the bureau. (The ABS declined numerous
requests for an interview. David Olson, the Colorado School of Mines professor
who served as the independent metallurgist for the Castor report,
also refused to comment.)
Super-rust was initially explained as an
unprecedented phenomenon, a highly evolved form of corrosion neither foreseeable
nor preventable. The truth is less mysterious: Hyper-accelerated corrosion is
the inevitable result when unforgiving chemistry meets the harsh economics and
tangled industry politics of transporting fossil fuels.
steel from the moment the metal encounters moisture. To keep that from happening,
ship owners paint steel surfaces with corrosion-resistant coatings. The coatings
break down with age; conventional maintenance protocols dictate that tankers be
recoated periodically. If all this is done properly,
any ship should carry cargo for 30 years or so and then retire to the scrap yard
But first-class ship maintenance has become
increasingly rare in recent decades. Since the 1970s when the Erika, Nakhodka,
and Castor were built profit margins in the tanker business have fallen
steadily. Today, tankers change hands two or three times before theyre taken
out of service. Temporary owners of second or third hand ships tend
to be less interested in maintaining their vessels than maximizing the return
on their investments. Whats more, the classification societies lack the
authority to enforce rigorous standards. These nongovernmental agencies depend
for revenue on their clients: shipbuilders, owners, and operators, who can and
often do shop their business to competing societies. For instance, the Erikas
owners switched to Registro Italiano Navale after the French agency Bureau Veritas,
which had certified the ship for the previous five years, refused to overlook
its deterioration. The Erika went down just 18 months later.
far, super-rust has destroyed only old ships at the end of their useful lives,
allowing many in the industry to maintain that the problem is contained. This
complacency has become increasingly dangerous in the face of evidence that the
latest generation of tankers is even more vulnerable than its predecessors. Ever
since the Exxon Valdez ran aground in 1989 the worst spill in US history,
dumping 11 million gallons of crude into Alaskas Prince William Sound
shipbuilders have focused on constructing tankers that would be impervious to
grounding and collision. The solution has been
to wrap a second hull around the first; the Oil Pollution Act of 1990 mandates
that, by 2015, all tankers operating in the US have double hulls. This innovation
has prevented dozens of spills, but it has inadvertently propelled corrosion to
Tales of double hulls rusting far more
rapidly than expected began to circulate in the early 90s, not long after
the first such vessels entered the water. The 5-year-old Mobil tanker Eagle, for
example, spent almost three months dry-docked in Singapore in 1998, reportedly
having her cargo tanks treated for corrosion. According to Seatrends, a leading
trade magazine, the Eagle had leaked oil into the space between its inner and
outer hulls. (Contacted earlier this year, an ExxonMobil spokesperson repeated
the companys assertion that the ship docked in Singapore for routine
maintenance and that no leakage had occurred.)
Fearful of government
regulation, the shipping world has attempted, as Seatrends editor Ian Middleton
put it in a 1999 editorial, to keep a lid on such incidents. But inspections
keep turning up severe corrosion in new tankers. A 2000 Intertanko report concluded
that excessive rust is afflicting double hulls within two years of launch. Without
a serious shift in industry practice, it wont be long before the first double
hull goes the way of the Erika.
Rust arises from an intricate subatomic
dance in which waters oxygen and hydrogen atoms snatch electrons from atoms
of iron. Because saltwater conducts electricity better than freshwater, the iron
in steel oxidizes more quickly in seawater up to 0.10 millimeter per year,
as foreseen in classification-society manuals. Given enough time, this process
can eat through even the thickest hull.
The way corrosion attacks
the interior of a tanker, however, is more insidious. It can be seen most vividly
in the cargo tanks, which line up along the ships backbone beneath the deck,
and in the ballast tanks that cushion the cargo tanks along their outer edges.
In these areas, steel deteriorates at five, ten, even thirty times the nominal
In the ballast tanks, which are normally filled with seawater
when the cargo tanks are empty, water conducts electrons between plates on either
side, and between separate areas of a single plate that is, the tanks become
huge, if weak, batteries. The increased electrical activity hastens the metals
degradation. To combat the problem, shipbuilders have traditionally installed
bars of reactive metal like zinc or aluminum inside the tanks. The added metal
becomes a sacrificial anode, which corrodes in place of the ships
steel. Known as cathodic protection, this method has become less popular as paint
manufacturers have developed rust-resistant coatings over the past 20 years or
so. In the absence of cathodic protection, however, corrosion sets in when coatings
break down. Shoddy repairs can also play a role. In the
Castor, corroded plates discovered during inspections were replaced with new plates
of uncoated steel, turning the uncoated metal into a sacrificial anode. Thus,
the patches rusted even faster than the original metal had.
processes that drive ballast-tank corrosion hasten the familiar action of oxidation.
What happens in cargo tanks, on the other hand, involves more ruinous chemical
and biological forces.
At the top of the cargo tanks, the vapor space
between the oils surface and the underside of the deck traps highly acidic
gases products of the reaction between petroleum, oxygen, and water
that condense against the metal. The deck flexes at sea, causing degraded steel
to flake off the ceilings of the tanks, exposing more bare steel for the acid
to attack. Examining this area isnt easy. Scaffolding must be constructed
inside empty, unlit tanks, and even then inspectors can view only small portions
At the bottoms of the tanks, in the water that
settles under the oil, corrosive bacteria thrive. Consuming hydrocarbons, microbes
like Desulfovibrio desulferican produce acids that dissolve the tanks floors
and lower sides at rates as high as 2 millimeters per year. Some microorganisms
even feed on the coatings that protect the tanks from rust. Essentially, a tanker
is a gigantic floating petri dish for a peculiarly vicious sort of steel-eating
sludge the ultimate metallivore.
in aging single-hull vessels can be blamed on an industry in denial. In
double hulls, accelerated corrosion is engineered right into the ships themselves.
The extra layer of steel gives rust many more square feet of surface area to attack,
much of it hidden in cramped, inaccessible crawl spaces. Whats more, these
crawl spaces form an insulating layer that keeps the internal temperature much
higher than it would be in a single-hull tanker. Corrosion rates tend to double
with each 20-degree Fahrenheit increase.
the same time, manufacturing efficiencies have reduced the thickness of hulls
and decks. Guided by software modeling, designers put plenty of steel where its
needed for strength, while reducing it in the rest of the structure. The
advent of high-tensile steel stronger than conventional steel but no more
rustproof has allowed naval architects to further pare down the metal structure.
developments have led many shipbuilders to trade corrosion-resistance for lower
cost. Every ounce of steel saved in the construction of a new ship translates
into greater profits for the builder and reduced fuel bills for the owner. Between
1970 and 1990, the amount of steel used to construct a tanker declined by almost
one-fifth, according to Tankers Full of Trouble, a 1994 book by Eric Nalder based
on his Pulitzer Prize-winning Seattle Times series. Modern
tanker walls are only 14 to 16 millimetres thick, compared with 25 millimeters
a generation ago. Assuming a microbial corrosion rate of 1.5 millimeters a year,
rusted-out pits would reach halfway through those hulls in five years.
without a spill, the consequences of an internal breach leaking oil into a double
hull could be catastrophic. Asked what might result, shipbuilding consultant Rong
Huang gives a one-word answer: Explosion.
All ships look old unless
theyre freshly painted. At the Avondale Shipyard, upriver from New Orleans,
the only unblemished metal surfaces are rails that support rolling dockside cranes
and the gleaming blue sides of the state-of-the-art tanker Polar Resolution. Every
other steel surface in the yard is dusted with flash rust, a ruddy patina that
appears almost as soon as the steel is exposed to air. This superficial oxidation
is sandblasted away before the metal is painted and coated. Some surfaces, however,
never get coated at all. These unprotected areas invite the risk of destruction
Contracted by Polar Tankers, a division of Phillips
Petroleum, the Polar Resolution is one of four $230 million ships designed for
the iceberg and reef-strewn run from Valdez, Alaska, to Puget Sound. The 895-foot
vessel has not only a two-layer hull but duplicate engine rooms, navigation systems,
and propellers. Its 12 cargo tanks hold 42 million gallons of oil. When its sister
ship, Polar Endeavor, set sail last spring, Professional Mariner magazine named
it Ship of the Year.
A series of ladders and stairways descends steeply
to the floor of the Polar Resolutions empty cargo tank number five. The
walls rise 100 feet to the main deck. A band of light streams from the hatch high
above. From the inside, the tank is like a vast steel cathedral, a shrine to mans
thirst for oil.
The tank floor is covered with epoxy.
But overhead, the vapor space is uncoated contrary to classification-society
This expanse of bare metal is a stark emblem
of the industrys failure to face up to the hazard of corrosion. With each
disaster or near-disaster, authorities have launched an investigation. When corrosion
has been implicated, the result has been a litany of recommendations that hardly
varies from year to year: Coat the vulnerable surfaces of the ballast and cargo
tanks, inspect them frequently, and remove substandard tankers from service. But
these guidelines are honored mostly in the breach. According to the ABS report
on the Castor, the ships last inspections failed to adequately represent
the condition of the vessels structure. In other words, the investigators
missed the damage.
Supertankers are the
biggest moving structures ever built, yet the system for constructing, inspecting,
and certifying them is a relic of the 19th century.
time, the classification societies were adjuncts to the marine insurance business.
Today, they call themselves the self-regulating arm of the shipping world; the
avowed mission of the ABS, for instance, is to serve the public interest
as well as the needs of our clients by promoting the security of life, property,
and the natural environment. In practice, the societies serve the shipowners.
The leading organizations, which include the ABS, Lloyds Register in London,
and Det Norske Veritas of Norway, are staffed by conscientious experts, but they work within a system where no one is answerable for the condition of
the ships. There is no FAA for tankers.
the tanker industry is overrun with so many holding companies, limited-liability
partnerships, and owners-of-record that even determining who bears ultimate responsibility
for a ship can be difficult. Authorities investigating the Erika found the owners
capital structure so opaque that it was nearly impossible to figure out who controlled
the company. Following the inquiry, Paul Slater, chair of shipping conglomerate
First International Group and a member of Intertankos Communications Committee,
declared the current inspection system monstrously outdated.
Most American tax payers are rarely aware of where their taxes go and some goverment weld - bld rework costs can be extraordinary.
to the program office the LPD 17 Amphibious Transport Dock, which was delivered
to the Navy in July 2005, experienced numerous quality problems
of varying degrees that significantly impacted the ships mission. These problems contributed to a delay of 3 years in the delivery of the ship and a cost increase of $846 million.
In June 2007,
the Secretary of the Navy sent a letter to the Chairman of the Board of Northrop
Grumman expressing his concerns for the contractors ability to construct
and deliver ships that conform to the quality standards maintained by the Navy
and that adhere to the cost and schedule commitments agreed upon. Northrop Grummans
Chairman acknowledged that the company was aware of the problems and is working
on improving its processes.
LPD 17 encountered a problem with the isolators on titanium piping. The isolators
are used to separate different types of metals to keep them from corroding. The
problem was discovered in 2006, about a year after the launch of the first ship.
According to DOD program officials, the titanium piping is used throughout the
ship because it is lighter than the traditional copper-nickel piping and has a
longer service life. However, it has not been used much in naval surface ships
or by the American shipbuilding industry, and therefore required new manufacturing
and installation processes. According to the program office, these processes were
being developed as Northrop Grumman Ship Systems was building the ship. In addition,
designs for the piping hangers, which hold the piping in place, as well as tests
of the isolators were subsequently delayed. When the titanium piping on the ship
was changed, the hanger design had to be modified as well. The final hanger design
was not completed until about 90 percent of the titanium piping was already on
the ship, which resulted in additional rework and schedule delays.
from Ed. Welding Titanium. It would have been an easy task with TIP TIG which was available at this time.
ship alsp encountered problems with faulty welds on P-1 piping
systems, a designation used in high-temperature, high-pressure, and other
critical systems. This class of piping is used primarily in hydraulic applications
in engineering and machinery spaces. P-1 piping systems require more extensive
weld documentation than other pipes as they are part of critical systems and could
cause significant damage to the ship and crew if they failed. Welds of this nature
must be documented to ensure they were completed by qualified personnel and inspected
for structural integrity. Further investigation revealed that weld inspection
documentation was incomplete. As a result, increased rework levels were necessary
to correct deficiencies and to re-inspect all the welds. Failure to complete this
work would have increased the risk of weld failure and potentially presented a
hazard to the ship and crew. According to the program office, a contributing factor
was turnover in production personnel and their lack of knowledge on how to complete
the proper documentation.
Note from Ed. If people
are not doing their job, not qualified to do the job, it's time to hire qualified managers who can rectify these situations.
THE FOLLOWING IS A REASON YOU CANNOT APPLY DOUBLE
TO SHIP OR OIL PLATFORM WELDS:
AS THIS NEXT ARTICLE INDICATES. EVERY WELD SHOULD BE CONSIDERED A CRITICAL
Authors KITUNAI, Yoshio
(Japan Crane Association)
KOBAYASHI, Hideo (Yokohama National University)
March 27th, 1980, the semi-submersible platform Alexander
Kielland suddenly capsized during a storm in the North Sea, because one of its
five vertical columns supporting the platform was broken off. 123
workers among the 212 people on board were killed in the accident.
investigation showed that a fatigue crack had propagated
from the double fillet weld near the
hydrophone mounted to the tubular bracing D6. As a result, the five other tubular
bracings connecting to the vertical column D broke off due to overload, and the
column D became separated from the platform. Consequently, the platform became
unbalanced and capsized. After the accident, the offshore design rules were revised
and some countermeasures were added to maintain a reserve of buoyancy and stability
for a platform under a storm.
Cause (1) Fracture features
circular hole was introduced to the underside of the D6 bracing, and a pipe, which
is called a hydrophone, was mounted into the circular hole by welding. The hydrophone
was 325 mm in diameter with a 26 mm wall thickness. The hydrophone was welded
using a double fillet weld with a weld throat thickness of 6 mm. A drain of the
bracing D6 had to be installed at a location 270 mm away from the hydrophone.
a result of examination of the welds of the D6 bracing, some cracks related to
lamellar tearing were found in the heat affected zone (HAZ) of the weld around
the hydrophone. Traces of paint coinciding with the paint used on the platform
were recognized on the fracture surface of the fillet weld around the hydrophone
in the bracing D6.
The paint traces show that the cracks
were already formed before the D6 bracing was painted. Examination of the
fracture surface also showed that the fatigue cracks propagated from two initiation
sites near the fillet weld of the hydrophone to the direction circumferential
to the D6 bracing. Moreover, the fatigue fracture surface occupied more than 60%
of the circumference of the D6 bracing (Fig. 7), and beach marks were formed on
the fracture surface, which was about 60 to 100 mm away from the hydrophone. Striations
with spacing of 0.25E-3 to 1.0 E-3 mm were observed in patches on the fracture
surface of the D6 bracing.
(2) Characteristics of the welds of the hydrophone. Considering
of the importance of the strength of the D6 bracing, welding of the drain into
the bracing was carried out carefully according to the design rules. In the case
of the installation of the hydrophone, however, a circular hole was made on the
D6 bracing by gas cutting, and the surface of the hole was
not treated by some process, such as a grinding. After cutting, a pipe,
which was made by cold bending and welding using a plate with 20 mm thickness,
was mounted into the hole of the bracing, and the pipe was attached by welded
around the hole by double fillet welding with a throat thickness of 6 mm.
the hydrophone was installed by welding, the weld defects, such as incomplete penetration,
slag inclusion, and root cracks, were introduced in the welds, because of the
poor gas cutting and welding practices. Moreover, lamellar
tearing related to inclusions in the material used was found near the HAZ of the
hydrophone. The stress concentration factor, Kt, of the fillet weld of the hydrophone
was in the range of 2.5 to 3.0, which is higher than the average value of Kt of
1.6 for a fillet weld performed under normal conditions.
Chemical composition and mechanical properties of materials
The chemical composition
of the materials was found to be within the specified limits. A comparison of
the mechanical properties between the specification and the test results for the
fractured materials is shown in Table 2. The yield strength of the D6 bracing
in the longitudinal direction is slightly lower than the specified minimum values. In case of the hydrophone, the
Charpy impact energy is lower than the required value of 39 J at -40 C. Moreover,
the reduction of area of the hydrophone for the through-thickness direction is
markedly reduced because of the large amount of weld inclusions.
(1) Although the D6 bracing was
one of primary components of the platform, little attention was given to the installation
of the hydrophone into the bracing. Hence, a crack with
a length of about 70 mm was introduced in the fillet weld around the hydrophone,
before the D6 bracing was painted.
(2) Fatigue cracks propagated
from two initiation sites near the fillet weld of the hydrophone in the direction
circumferential to the D6 bracing at the early stage of the life of the platform.
The five other bracings connected to the column D broke off due to overload, and
the column D was separated from the platform. Consequently, the platform became
unbalanced and capsized
(4) Inspection of the D6 bracing had not been carried
This is a partial report found on the web and it enpahasizes that all welds should be considered critical.
Date August 10, 2001. Revised Nov 20
Vist all of Eds MIG and Flux cored programs.