An old theory re-surfaces

At the beginning of December, a new book saw the light of the day. Fishing Explorer – authored by Ernest Suddaby, a former skipper of the Gaul, and published by Maritime Info UK Ltd - makes a very pleasurable read.
Put together with brilliant literary skill, printed in excellent graphic conditions and warmly prefaced by Alan Johnson MP, the book offers the reader a rich source of documentary information and photographic material.
The book carries two main narrative threads: one which depicts the author’s trip to the Falklands and one recounting his time as skipper onboard the Gaul, interspersed with personal memories and anecdotes.

In his account of the Gaul, along with his impressions and recollections of past events and more recent developments in the Gaul saga – many of which are well worthy of note - the author also shares with us his disagreement with the results of the 2004 Formal Investigation, and his personal opinions as to the causes that might have led to the loss of the vessel.In the author’s view, the sinking of the Gaul was caused by foul weather and bad luck, which led to flooding through the two fish loading hatches cut into the trawl deck. These hatches, it is suggested, could have been opened by the pull of gravity, when the vessel rolled beyond 90 degrees in heavy seas.

Mr Suddaby’s hypothesis is not that new, in fact it has been, if we may say so, previously enjoyed. It is what the results of the first formal inquiry, held in 1974, implied. The MAIB also flirted with this theory for a while, although, after the 2002 underwater survey and further reflection, they decided to abandon it. They did not, however, explain very well why.

Therefore, we have taken it upon ourselves to try and present the reasons why this loss scenario is merely a conception (so as not to say mis-conception) rather than a real possibility.
To elucidate matters, we have compiled the video clip below, which, in a simplified manner, attempts to show how the fish loading hatches on the Gaul would have behaved under various roll conditions. The model presented therein shows that gravity – which inexorably acts downwards at all times and circumstances - would have had the effect of keeping the hatch covers closed and prevented seawater from getting inside the ship, when the ship rolled to an angle of 90 degrees from its vertical position. The model also shows that, when the ship rolled beyond 90 degrees, the hatch covers would have still been kept closed by seawater pressure, and that this would have happened even without taking into account the effects of the hydraulic ram system, which was connected to the hatches.

Enjoy!

Laying the blame on those who cannot defend themselves

(click to enlarge)

The areas coloured in orange represent the critical down-flooding openings, which were deemed to have played a part in the loss of the Gaul.
The areas coloured in blue (the funnel vents) are also critical in the down-flooding scenario, although these are meant to be kept open at all times.

The duff and offal chutes were found open on the wreck. The 2004 RFI concluded therefore that they had been left open by the crew.
As we have attempted to demonstrate on these pages and in the attached documents, the chutes’ outer flaps had a design fault, while their inner covers could not provide sufficient protection against flooding.

The fish loading hatches and the net store hatch, as our previous post explained, could have been opened by air pressure or by the force of internal floodwater acting on them from inside the vessel.
The RFI panel’s opinion, however, was that these hatches, also, had been left unsecured by the crew and had opened due to gravity when the vessel was sinking.

The engine room escape door, the RFI surmised, had been opened by one of the crew when trying to escape from the lower deck at the time of the incident.
In the absence of any contrary evidence, the hypothesis that this door had been opened by air pressure is again more probable.

The RFI panel concluded that the access door to the accommodation space, also, had been left open by the crew; and we can contend again that trapped air pressure or internal floodwater pressure could have opened it just as well.

As to the factory deck access door the RFI concluded, this time on the basis of some tangible evidence, that the crew had failed to secure it in the closed position.

All in all, the only conclusion we can draw from the dubious RFI findings is that the 2004 investigation panel was too eager to suggest a pattern of widespread crew negligence and to lay the blame for the loss of the Gaul on the victims to bother about plausibility.
Ignoring the existence of alternative explanations, underpinned by simple scientific principles, the RFI panel chose to put forward a loss scenario that was not only unsupported by any credible evidence, but also defied common sense.

The fish loading hatches on the Gaul

In 1999, in the year following their first underwater survey of the wreck of the Gaul, the MAIB produced their Marine Accident Report no. 4/99.
Amongst other things, this report put forward the MAIB’s hypothesis as to why the two large fish loading hatches on the Gaul had been found open during the survey. This stated that, at the time of the loss, the hatches had been unsecured and that they had therefore fallen open during the vessel’s capsize and sinking ’by the stern’.

As we have attempted to demonstrate in the document published at this LINK, the MAIB analysis, taken as read by the 2004 RFI panel, appears to have been seriously flawed.
The error it contains relates to one of the possible mechanisms that could have opened the fish loading hatches, namely, an increase in pressure of the air trapped between the water that was flooding into the vessel and the under side of the closed hatches.The MAIB report stated that the maximum lifting pressure on the underside of the fish loading hatches was only 478 N/m² (49 kg/m²), and that this would occur, for some unknown reason, when the vessel was exactly 80m below the sea surface. (!?)

A simple calculation can show, however, that if the Gaul had had a trim by the head of only 5º [1] and had been submerged to merely two metres below the sea’s surface, the lifting pressure on the underside of each fish-loading hatch could have been of the order of 900 kg/m² (i.e. approximately 3.5 tonnes per hatch), while the self-weight of each hatch was approximately 0.9 tonnes.

This ‘error’ meant that one plausible scenario for the opening of the hatches was incorrectly eliminated from the formal investigation, while another similarly plausible hypothesis – the possibility of the hatches having been opened by the force of internal floodwater acting on the hatches from inside the vessel – was not even mentioned.

Here again, as in the case of the duff and offal chutes, the preferred explanation was crew error.

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[1] Although both the MAIB and RFI experts have concluded that the Gaul sank initially and sedately by the stern, this theory cannot be relied upon with any degree of certainty, as it does not take into account the dynamic loads and ship motions that the vessel would undoubtedly have experienced, whilst at or near to the sea’s surface and following the redistribution and loss of buoyancy that would have occurred, as it flooded and sank. At the time of the loss the weather was extreme, with a significant wave height of circa 10m and with infrequent individual waves of up to 19m in height.