A small cement carrier with a crew of eight was loaded with cement and underway across the North Sea on a passage plan that brought the vessel through the Pentland Firth. Having spent 24 hours heading into deteriorating weather and increasingly heavy seas, the Master first reported that there would be a two-hour delay to the arrival time at Liverpool bar buoy. The next day, in consequence of increasingly bad weather, his report stated that there would be a further 10 hours delay to the arrival time.
As the vessel entered Pentland Firth (figure below), it was on a heading of 270° (COG of 272°) and SOG of 10.6kt. Once inside the Pentland Firth, the vessel was sighted by the crew of a nearby ferry. The cement carrier appeared to be upright and making slow headway, pitching heavily into the large waves. Later that afternoon the vessel’s AIS transmissions ceased. The data from the last received transmission showed a heading of 239°, a COG of 276° and SOG of 6.3kt. Such a SOG, however, would have meant a speed through the water of less than one knot, rendering the vessel unmanageable and at the mercy of the ferocious oncoming waves.
The hull of the capsized cement carrier was spotted and reported to the local coastguard 25 hours later. The damaged vessel soon sank. Search and rescue (SAR) activities were undertaken, but no surviving crew members were found.
The official accident report found, among other things, that:
- On one past occasion when the vessel entered the Firth with an opposing flood tide, the same Master held position by stemming the stream, and waited for it to ease. From this it can be deduced that the Master understood the tidal risks and actions were normally taken to abort or avoid the unfavourable tidal conditions in the Firth.
- On another occasion of rough weather in Pentland Firth, during the alteration of course across the sea, the vessel had heeled excessively and suffered a cargo shift, resulting in a significant list to port. The vessel was brought back upright using the ballast tanks. The Master’s decision to proceed into the Firth on this (final) occasion, with very unfavourable conditions, was inconsistent with his previous actions.
- The extraordinarily violent sea conditions were created by gale force winds opposing a strong ebb tidal stream. Such conditions were predictable and passage through the Pentland Firth should not have been attempted.
- The cement carrier was loaded to its draught marks, but the density of its bulk cargo was not properly considered. As a result it is likely that its stability did not meet the minimum criteria set by the IMO. Potential reductions in its righting levers would have made the cement carrier more vulnerable to capsize in a heeling situation.
- Always adopt a conservative approach to weather – your life depends on it.
- Never bring your vessel to a point where manoeuvrability is lost.