UK: So Why Did Those Ships Collide?

Last Updated: 8 November 2004
Article by Kevin Oram

It has long been accepted that in Admiralty matters, expert evidence as to matters of seamanship is not admissible without the leave of the court. We take a look at the use of illustrative plotting in Admiralty cases involving collisions between ships, and some of the reasons for the Admiralty Court’s cautious approach to the use of reconstructions in its effort to assess what really happened.

In his judgment in The "Pelopidas" [1999] 2 Lloyd’s Rep 681, Steel J quoted from the judgment of Lord Sumner in The "Australian" [1927] A.C. at p.152 when emphasising that:

"in questions of nautical science and skill, relating to the management and movement of ships, a Court, assisted by nautical assessors, obtains the information from them, not from sworn witnesses called by the parties…"

The Admiralty Court has traditionally had assistance from the Elder Brethren of Trinity House who sit as Nautical Assessors. One or more of the Elder Brethren will sit with the Admiralty Judge and provide what Steel J describes in his judgment as "…sound and independent advice…" on matters of and relating to nautical science and seamanship. Parties to collision proceedings are of course not precluded from obtaining their own nautical advice in preparing their submissions, but without an order of court, any costs so incurred would not, as a rule, be recoverable.

In recent years, illustrative plotting of the movements of ships in the period leading up to a collision has become increasingly sophisticated and arguably more helpful to the court. Various software programs have been developed which allow more accurate reconstructions to be made of ships’ performance and manoeuvring, taking into consideration a vast range of parameters such as tidal, sea or weather conditions and ships’ handling characteristics.

Steel J acknowledges in his judgment in The "Pelopidas" that this has had the effect of encouraging parties to furnish computerised plots prepared by experts in support of their arguments. Some of the most up to date of these may be interactive or even amount to a "video arcade" type simulation of the events leading up to the collision. Such plots are invariably backed by a substantial amount of explanatory documentation setting out the underlying calculations and assumptions made in their preparation.

The increasing use of computerised plotting and course simulation in collision cases has to some extent resulted in the presentation of material which often comes close to falling foul of the bar against admission of "seamanship evidence". It is perhaps inevitable that this should have happened given the complexity of the various software programs now available to experts, and the fact that simulations can nowadays be very accurate, depending on the amount of information available to the expert preparing the reconstruction.

The true value of reconstructions is that they should enable the court and the parties to have what Steel J calls "…a broad bird’s eye view of the events leading up to collision…". This said, he remains firm in his view that reconstructions cannot be relied upon to enable the court to determine what actually happened. There are more often than not simply too many variables to be taken into consideration to allow a simulation to be anything more than illustrative. Even on the most modern ships with state of the art integrated navigation systems in which "black box" type data is stored, assumptions will need to be made by experts when preparing any plot. By definition the results of any particular simulation will depend on what assumptions are made.

Steel J recognised this difficulty and expressed the view in his judgment in The "Pelopidas" that:

"…[the] true probative value [of reconstructions] is that they may sometimes enable the Court to determine not what may have happened, but what could not possibly have happened… the plotting is more effective if, despite assuming every margin of error in favour of a particular hypothesis, that outcome can be demonstrated to be highly improbable if not impossible….".

This accords with the long held view of judges in the Admiralty Court and chimes with the opinion expressed by Lord Reid in The "Statue of Liberty" [1971] 2 Lloyd’s Rep 277 where he made it plain that while precise measurements may be taken and margins of error may be so small that for ordinary purposes they might be ignored, in cases where a large number of measurements or variables exist, it would not as a matter of course be possible to create a plot with sufficient accuracy to show any "…strong probability..." that one particular simulation of events should be favoured over another.

In a recently reported Court of Appeal case, The "Manzanillo" [2004] EWCA Civ 1007, Lord Justice Clarke referred to the judgments in The "Pelopidas" and The "Statue of Liberty" noting that:

"…plots must be viewed with considerable caution…all plots depend for their value upon the accuracy of the assumptions on which they are drawn…often, the available data is not sufficiently precise to enable a plot to be drawn showing what precisely happened…"

In other words, in collision proceedings before the Admiralty Court, a good plot or simulation, no matter how well prepared and presented, will be treated with caution. Its true probative value will often be that it will assist the Court to determine not what happened, but rather what could not possibly have happened. What in fact happened in the collision remains, as ever, to be decided by the Admiralty Judge, with assistance from the Nautical Assessors sitting with him, after consideration of all the evidence before them.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.

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