People who have followed Shell’s distressing exploration experience in the Arctic, which resulted finally in the grounding the semi-submersible Kulluk during its tow from Alaska to Seattle in 2012, and subsequently its departure to the breakers on a heavy lift ship (See my book “A Catalogue of Disasters”),  might not realise that the rig had been part of the Beaudrill fleet originally constructed in 1979 to carry out exploration drilling in the Canadian Beaufort Sea. The company, which was based in Calgary, also built a mobile caisson, the Molipaq, capable, according to the specification for the unit of being able to accept ice loads of 100,000 tons. They also built four icebreaking support vessels to tow and supply these rigs. Two were massive, very powerful and even for those of us who have become used to the unusual shapes of supply vessels, very unattractive. The other two, the Ikaluk and the Miscaroo, were designed by Robert Allen, more or less taking into account what a good looking anchor-handler should be like, while catering for the extremes of climate and the need to conform with the Canadian Coast Guard requirement for “Arctic Class 4” vessels. They were 79 metres long and were powered by four engines giving 15,000 bhp with the relevant levels of bollard pull. The Ikaluk was built at Nippon Kokan in Japan and the Miscaroo at Vancouver Shipyards.  By the 1983 standards, even though they were not as large as the German and Milne designs, they were still as large as, and as powerful as, anything else available at the time.  They were, according to the specification, capable of  travelling continuously through ice 1.2 metres thick at three knots, the double drum winch was totally enclosed and could be viewed from the bridge on CCTV and the bowthruster was designed to avoid being clogged up with ice, the intake being positioned under the hull. After the failure of the Arctic drilling activity the Ikaluk was briefly seen in Aberdeen, which exposed it to two design failings, one was the fact that the deck was not wood sheathed, and therefore the cargo tended to move about as the ship rolled, and the other was the very high fuel consumption which put off potential charterers. But fortunately for their continued employment, offshore oilfields were being developed at Sakhalin and so the two ships migrated there, as did the Molipaq, and incidentally one of the larger ships, the Kalvik. At the time of writing both the Miscaroo, now the Smit Sakhalin, and the Ikaluk which has been the Smit Sibu but is now the Ikaluk again, are both working in support of the offshore oil and gas fields at Sakhalin. 

The Miscaroo, as the Smit Sakhalin in the Russian ice. Photo Alexander Fedoseev