It is indeed the Bulwark being towed out of Portmouth bound for Cairn Ryan. I was a junior officer on the Robust. The Robust and Rollicker did a double headed tow around the south coast and up the North Sea. Jerry Nicholls was the towing master who was my skipper on the Robust. It was an uneventful tow accept that we missed the tide at Cairn Ryan and has to loiter off the Irish coast for about 11 hours to wait for the next one. Albert Hannon, I think he was called, was a retired Admiralty Pilot who was contracted to pilot the whole shebang into harbour which he did, again without incident. Fellow officers on the bridge of the Robust were Doug Turner and Jim Richmond.