Wednesday, April 27, 2011


In our post of 4 August 2010 we provided details of how the ‘Joint Panel of Experts’ (JPE) had, in the Trident Re-opened Formal Investigation (RFI), slyly manipulated official data in order to modify the Trident’s indicated reserves of stability. Subsequently, in our post of 28 February 2011, after reviewing the evidence and conclusions that emerged from the Trident RFI we refuted Sheriff Young’s final report. As a follow up to those posts, we would now like to re-emphasise the following critical factors and add further details:

The Sheriff’s conclusions, as to why the Trident was lost, were merely an endorsement of the views of the ‘joint panel of experts’, who, in turn, had based their own conclusions upon the results of a series of model tests carried out on a ‘scale version’ of FV Trident by MARIN in Holland. Unfortunately, it is now evident that the stability characteristics of the Trident model (- constructed to meet the JPE’s technical specification), as tested by MARIN, did not correspond or correlate with the stability characteristics of the Trident on her final voyage.

Thus, most of the ‘new’ evidence and ‘expert analysis’, that was aired at great length throughout the Court proceedings in 2009/10, and which underpinned the Sheriff’s final conclusions, was based upon a fallacy:

 – i.e. that the observed capsize behaviour of the RFI’s ‘scale’ model in waves, would accurately replicate Trident’s capsize in 1974.

The principal incongruity between the JPE/RFI model of the Trident and the Trident herself relates to her calculated lightship and deadweight particulars. The JPE’s estimates for both lightship and deadweight differ significantly from those that were utilised in previous official investigations.

The original formal investigation (OFI)

In 1974/5, in the absence of reliable and accurate data [1] as to Trident’s displacement and the position of her centre of gravity, the official investigating panel decided to obtain such data by carrying out an inclining experiment on the Trident’s sister vessel (Silver Lining). The experiment they carried out was an official inclining test in that it was performed under controlled conditions and was witnessed and supervised by the Department of Transport (DOT) and the owner’s consultant. The data the test provided was valid for both Trident and Silver Lining. Detailed comparative calculations were subsequently carried out and this enabled more or less definitive values for the Trident’s lightship and deadweight to be obtained.

The information derived by official investigators in 1974/5 was thus the best that was available at that time and it was obtained using calculation procedures that were accurate and accepted internationally. In fact, the same calculation procedures are invariably used to obtain stability data for ships today.

The re-opened formal investigation (RFI)

Thirty years later, even though they had no additional or more accurate sources of data, the JPE decided to come up with new estimates for Trident’s displacement, centre of gravity and deadweight, estimates which, co-incidentally, would favour a no-liability outcome - always preferred by our officials.

We have checked through their calculations and can advise that, in addition to noting a number of dubious assumptions and approximations, the JPE have utilised inappropriate source data [2] to arrive at something they call ‘a best mean estimate’ for the Trident’s lightship and deadweight at the time of her loss.

Unfortunately, in arriving at this ‘best mean estimate’ the ‘experts’ have deliberately ignored accurate data of known provenance (the official inclining experiment on Silver Lining), using instead data that had been recognized to be valueless. In fact, during the 1975 formal investigation, when the DOT Surveyor was presented with inclining check information (similar to that used by the JPE), he gave the response which can now be read in the OFI transcripts of evidence:

OFI Day 10 (page 2)

Q. – I think that you have endeavoured to discover whether, from the figures there, any useful information can be obtained to assist the court to carry out an exercise to determine the stability characteristics of the Trident
A. - Yes
Q. - Are you able from those figures to obtain any assistance at all?
A. – It is my considered opinion that on examination of this particular document which has been presented to me that it is of no value at all to this court.

Thus the rough inclining data used by the JPE to determine Trident’s stability for the RFI was also available to, and rejected by, official investigators in 1974/5. However, it is this discredited data that has enabled the JPE to calculate better stability reserves for Trident than was actually the case.
The Sheriff’s conclusions as to why Trident capsized are thus based upon test results from a model that was not a true representation of Trident. This, in our view, renders the outcome from the RFI invalid.

(To be continued)
[1] Although the vessel’s designer had carried out a number of rough inclining checks on both Trident and her sister the ‘Silver lining’, the sketchy records that survived from these tests were of no real practical value as they lacked detail, did not exhibit the required degree of accuracy and essential data was either omitted or not recorded.

NB: For an inclining experiment to yield realistic and valid data, it has to be conducted by competent personnel, follow strict procedures and generate accurate measurements and data for use in centre of gravity and displacement calculations.  For UK fishing vessels, built since 1975, inclining experiments are required to be conducted by qualified consultants and be witnessed by the (DOT(MCA)) the authority responsible for reviewing and approving the vessel’s stability.

[2] In 1974/5, official investigators quite properly rejected the same rough data that was resurrected and utilised by the JPE to estimate the lightship and deadweight particulars (and stability) of Trident for the MARIN model tests.

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