Showing posts with label design fault. Show all posts
Showing posts with label design fault. Show all posts

Sunday, February 21, 2010

The combined effects of the Gaul’s stability shortfalls and duff and offal chute design faults

The principal finding of the 2004 Re-opened Formal Investigation (RFI) into the loss of the Gaul was that flooding of the factory space had occurred through two hull openings in the side of the vessel and that it was probable that this ingress of water led to the capsize and sinking of the Gaul.
Up until December of last year this blog focussed on a number of obvious design faults and flaws in the construction of the duff and offal chutes on the Gaul, and criticised the conduct and outcome of the 2004 RFI which, ignoring these facts had concluded that the flooding and loss of the vessel had been caused by the crew’s failure to close the inner covers of the duff and offal chute hull openings. Recently, however, we have added a summary of the results of a separate investigation, which has revealed significant stability shortfalls (on IMCO’s minimum stability standards [*]) that would have affected the Gaul in a number of her normal operating conditions.
As far the capsize and loss of the vessel is concerned, it should be noted that, while the stability shortfalls and flooding of the factory space through the duff and offal hull openings (facilitated by defective closing arrangements) are two different matters, they do not suggest differing causes for the loss of the Gaul; in fact, the impact of each is complementary to the chain of events which led to the loss of the vessel.
The stability reserves of a trawler may be regarded as a finite but variable quantity, dependent upon the vessel’s condition of loading, disposition of fuel, water etc. If seawater is allowed to flood into the hull, the stability of that trawler is reduced and the possibility of capsizes rises.
The 2004 RFI concluded that an ingress of about 100 tonnes of seawater (entering through her duff and offal chute openings) would have been necessary before the Gaul’s stability reserves would have been depleted to a level where capsize was probable in the weather the vessel encountered.
Our investigation has shown that, because the Gaul’s actual stability reserves were initially much lower than those assumed by the RFI, capsize would have been probable after only a modest ingress of seawater.
However, regardless of the design faults in the chutes’ closing arrangements, the Gaul’s stability problems and their combined effect on the safety of the vessel, the 2004 RFI was still content to attribute her loss to a failure on the part of the crew to close and secure the duff and offal lids during the storm they encountered on 8 February 1974.
Their conclusion, however, appears now extremely far-fetched.
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[*] One of the most important safety standards for a sea-going trawler is that it should meet the IMCO minimum stability criteria, however:

- Compliance with the IMCO minimum stability standard does not guarantee that a trawler will be safe from capsize in severe weather
- A trawler having stability reserves that significantly exceed the IMCO minimum standard is unlikely to capsize in severe weather
- Non-compliance with the IMCO minimum stability standard does not automatically mean that a trawler is likely to capsize in severe weather
- A trawler having stability reserves that fall significantly below the IMCO minimum standard is likely to capsize in severe weather.

Thursday, October 02, 2008

Why no search for the Gaul?

Although the approximate position of the Gaul had been well known, both in official and unofficial circles, in the 23 years that preceded its discovery, successive governments were reluctant to survey the area in question, and to locate and identify the wreck.
It was only in 1997, when TV producer Norman Fenton chartered a vessel and launched a search in the Barents Sea, that the position and identity of the wreck could be confirmed. Finding the wreck took him no longer than six hours. His discovery triggered an obvious question: why had a search for the wreck not been carried out earlier, this would have put an end to much of the speculation and rumours that had surrounded the vessel’s loss and, more importantly, would have helped to ease the grief, frustration and anger felt by the families and friends of those who had perished with the Gaul.
The discovery of the wreck obliged the Government to answer this question; hence, in April 1999, the Deputy Prime Minister, John Prescott, asked Mr Roger Clark, Head of Shipping Policy in the DETR, to conduct an ‘independent’ [1] investigation into why there had been no search for the Gaul after her disappearance in 1974.
Mr Clark applied himself to the task and, a year later, his findings were published in a 60 pages DETR report (see Annex 1).

In brief, the Government’s justification, presented within Mr Clark’s report, claimed that:
Initially we didn’t really know where the vessel was and it would have cost too much to find her and, even if we were to find the vessel, the expense of carrying out an underwater survey of the wreck could not be justified in terms of the benefits it would bring for marine safety.
John Prescott lauded Mr Clark’s conclusions and expressed his total confidence in their soundness and objectivity.

During the 2004 Re-opened Formal Investigation, in response to the victims’ families’ dissatisfaction with Mr Clarke’s explanations, justice David Steel, the Wreck Commissioner, re-examined the arguments, then endorsed, in his turn, Mr Clarke’s earlier conclusions (see the final report of the RFI [2]).

While the official reasoning may appear quite plausible, we have reasons to believe that, in fact, the Government had never been too keen to discover the location of the wreck, not on the grounds advocated by Roger Clarke, but for an entirely different reason: i.e. because a survey of the wreck and an analysis of the evidence that it revealed would have raised questions as to the adequacy of her design. The DfT’s marine experts, it now appears, had long suspected that the arrangement of the duff and offal chutes on the Gaul were a weakness in her design and that this weakness might have been a causal factor in her loss.

(Further details to follow)

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[1] As head of the DfT’s shipping policy section, Roger Clarke could hardly be considered independent of the government whose actions he was asked to investigate

[2] “We accept the Department’s submission that its actions were solely directed to balancing the interests of those immediately affected by the loss of the GAUL with the wider public interest and the resources available

Thursday, May 10, 2007

More about the main design fault on the Gaul
In an earlier posting we gave details of the main design fault that was present in the closing arrangements for the duff and offal chute openings on the Gaul (i.e. that that non-return flap plates opened the wrong way). In that posting we suggested that, if for any reason the flap valve was not fully closed, it could be opened by the action of the sea.
In fact, those comments did not reveal the full extent of the problem; the design of the flap valve was such that even if the valve had been in the fully closed position, the forces of the sea could have opened it.
Furthermore, this is not a just a hypothetical scenario, the partial print from one of the Gaul’s drawings (below), shows that there was a lip or ‘free edge’ at the end of the flap for the sea to act on.

And the VIDEO CLIP in our previous post shows in graphic detail just how easy it would have been for this “non-return” flap valve to open and for the seawater to flood into the factory deck of the vessel.

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If the above link does not work, please try HERE

Monday, May 07, 2007

Back garden model testing
At the end of the 2004 RFI, the wreck commissioner opined: “[…] it is important to note that although both chutes were found on the wreck to be open both in way of the non-return flap and the internal top cover, there is no known mechanical reason why this was so.[1]
This viewpoint has recently been echoed by the the Treasury Solicitor who said: “there was no evidence that the chutes had been forced open by wave or water action so this was not advanced as a loss scenario by the experts
Having enjoyed the benefits of a sunny weekend, we decided to construct a small-scale (and cheap) model of the chutes and test them with a hose. The results of this simple experiment provide a clear illustration of the SCENARIO whereby the design fault in the duff and offal chutes on the Gaul caused the flooding and loss of the vessel.
Simple mechanics!
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[1] Report of the Re-opened Formal Investigation into the Loss of the FV Gaul
The video file can be dowloaded from this SITE (2.9 Mb)

Thursday, January 04, 2007

Another design fault

In our previous post we provided a LINK to a factor tree diagram, which presented the various alternative explanations as to why the outer non-return flaps in the duff and offal chutes were found in the open position during the 2002 underwater survey on the Gaul.
We have also published a simple pictorial explanation of the PRIMARY DESIGN FAULT in the vessel's chutes.
Now we are publishing a document, which reveals a second design fault in the construction of these chutes (please click SECOND DESIGN FAULT to view it).
This additional design fault, demonstrated in the above-mentioned paper, gives weight to the possibility that the bolted flap assemblies within the duff and offal chutes became twisted due to wave loading and remained open thereafter. (See item (14) on the factor tree diagram).
Are the conclusions arrived at by the Gaul investigation panel (i.e. that the vessel’s chutes had been left open by the crew and shore staff for 59 days before the accident occurred) supported by any credible proof?
We would be interested to hear it.

Friday, November 24, 2006

The Design Defect


For a pictorial explanation of the design defect on the Gaul, please follow this link: http://webzoom.freewebs.com/inconvenientcitizen/Gaul%20design%20fault.pdf

Sunday, October 15, 2006

"If I take refuge in ambiguity, I assure you that it's quite conscious" (1)

In a recent message, the Treasury Solicitor writes:You have indicated that in your view the chutes were a design fault. This is your view but appears not to have been accepted as such by any of the retained experts.

Having contacted one of the retained experts, I learned that the design fault they had considered was in fact related to the difficulty of maintenance of the non-return flaps (2) (3), and that they had not identified or even seen, within the documentation that had been made available to them, any reference to a design fault in terms of inadequate strength of the inner covers and possible malfunction of the non-return flaps.
There is definitely a difference in perception here. Could some occlusion of the communication lines between those involved in the 2004 investigation be the explanation for that?
Anyway, that the vessel had a design fault in the construction and arrangement of the duff and offal chutes is an engineering fact (see the technical report on our website).
Why this has not also become a legal fact, is something that should be explained – plainly and without procrastination.
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(1) Kingman Brewster

(2)
Concluding remarks from Mr Meeson (Investigation transcript) suggesting answers to the formal questions:
“………Although the design of the non-return flap was deficient, in that it was liable to seize over time and had no real means whereby it could be maintained, proper use……..”


(3) This was also questioned in the technical report published on our website:
http://www.freewebs.com/inconvenientcitizen/fulltechnicalreportpdf.htm.