Showing posts with label corrosion. Show all posts
Showing posts with label corrosion. Show all posts

Sunday, March 16, 2008

Health and knowledge

Since we started this blog and the related Gaul website, almost two years ago, none of the experts in the 2004 RFI have deigned to comment or, in any way, express agreement or discontent with the technical propositions enunciated on these sites.
When a professional finds his opinions challenged or publicly criticised by his peers, he is normally prompted to reply either by defending his theories or by amending them. The experts in the Gaul RFI, by contrast, have buried themselves in silence, and although we have repeatedly tried to engage with them, they never replied. Don’t you find this odd?
The government didn’t even process the RFI recommendations, as customary after each major investigation, not as much because they were irrelevant, but for fear that the gilding will come off its findings at the slightest touch.

In contemporary Britain, it appears, truth is nothing more than an empty shell that can be filled with whatever meaning suits the government’s interests of the moment.
Strange events are left un-investigated, important questions are blithely ignored and, like the profane who must be prevented from defiling sacred knowledge, we are being taught to content ourselves with secrecy, half truths and disinformation.
It is best not to argue, the cynics recommend, because letting the humbug stuff you full of prunes is nowadays less harmful to your health than properly checking the facts.

Monday, February 04, 2008

The rust

In our previous posts of 30 January 2007 and 9 April 2007 (incl. the ADDITIONAL DATA document) as well as our TECHNICAL REPORT etc., we explained in detail why it was unlikely that the non-return flaps of the duff and offal chutes on the Gaul should have both been seized in the open position, due to corrosion, at the time when the vessel was lost.
The hinge assemblies of the non-return flaps contained oilite low-maintenance bearings (oil impregnated sintered bronze), which were designed for the life of the vessel and not just for the 18 months period that was the lifespan of the Gaul.
Furthermore, the extracts from the underwater survey footage presented in our 30 January post showed clearly that, even after 28 years under the sea, other structures on the Gaul, which used the same combination of materials as the flaps’ hinges, worked without problem.
Now, we are adding the statements of two witnesses who had sailed on the Gaul on her previous voyages including the last but one.
Skipper Suddaby, whom we mentioned earlier on this site, tells us in his recently published book, at page 167 that: “I believe firmly that both chutes were in perfect working order right up to the time that the Gaul was lost” and that: “there is no report of the Gaul crew having trouble dumping the duffs back”.
Also, Mr. Petty, who had been the mate of the Gaul from 18 September 1973 to January 1974, when questioned under oath during the RFI, gave the following answers:
“Q. Can you remember using that hopper on the last trip you were on when you were with Mr. Suddaby?
A. What, the Gaul?
Q. Yes.
A. Yes.
Q. What was its condition at that time, can you remember? Was it working or was --
A. It was all working, yes, everything was working perfect.
Q. Did you ever have any problems with it or did the men have any problems where it seized up and so would not open when they threw duffs on it?
A. Never. That is the gospel truth, never.” (Transcripts of evidence, day 2 page 46)
The RFI conclusions, however, stated that the non-return flaps of the chutes were seized in the open position when the vessel left Hull on her last voyage (See RFI final report, page 286).If the chutes had been working perfectly well and smoothly during the Gaul’s first four voyages, as the witnesses testified, how could the RFI panel expect the public to believe that they were seized with corrosion when the vessel left Hull at the start of her fifth and last voyage? [1]
The RFI panel of experts and justice Steel should perhaps explain to us why they chose to flagrantly ignore all these facts and testimonies and go for the ‘rust theory’, in support of which they had no proper evidence.
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[1] The question of why two separate mechanisms, which had been appropriately engineered for the marine environment, which would have been fully greased and lubricated at the vessel’s delivery, which had different operating cycles and which were operated by two separate teams of ship personnel, should both seize in the fully open position due to corrosion and at approximately the same time, is rather intriguing.
As the RFI panel was informed during the investigation, it is far more likely that the non-return valves shared some fault in their DESIGN, which manifested itself during the severe weather conditions that the vessel encountered prior to its loss.

Tuesday, January 30, 2007

Another small observation

The 2004 Formal Investigation into the sinking of the FV Gaul concluded, as we all know by now, that the cause for the loss of the vessel was the ingress of a large quantity of seawater through the two duff and offal chutes openings in the hull of the vessel.
The double-barrier protections of these openings – the inner covers and the outer flaps - were found to be in the open position during the underwater survey in 2002.
The fact that the outer flaps were found open, the investigation concluded, was due to seizure caused by corrosion in the vessel’s 16 month old flap hinges and failure on the part of the crew and shore maintenance staff to identify and rectify this problem.
The fact that the inner covers were also found open was explained away by crew negligence. However, the trouble with these findings (as we have attempted to explain in our earlier posts) is that they were based on unsubstantiated assumptions.
Let’s take, this time, the presumed corrosion at the flap hinges. (For a few more details on this issue please click HERE.)
As the same combination of materials, mild steel and brass, had been used in a number of other structures on the Gaul (e.g. for the toggles and clips on all weathertight hatches and doors), one would expect similar corrosion problems in those areas.
In reality, though, this doesn’t seem to be the case.
Quite the reverse, as the following clips[1] show, even after 28 years under the sea, the toggles and clips on the Gaul did not present such a level of corrosion and seizure that would prevent them from being easily unscrewed by the ROV[2] arm.
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[1] Extracts from the 2002 MAIB video footage - © Crown copyright
[2] Remote Operated Vehicle

weathertight hatch mild-steel clips & brass bush


weathertight hatch brass toggle & steel toggle bolt


weathertight hatch brass toggle & steel toggle bolt