RMS Olympic to Belfast where the passengers disembarked. Following "Olympic"s return to Britain, the White Star Line intended to lay her up in Belfast until the war was over, but in May 1915 she was requisitioned by the Admiralty, to be used as a troop transport, along with the Cunard liners and . The Admiralty had initially been reluctant to use large ocean liners as troop transports because of their vulnerability to enemy attack, however a shortage of ships gave them little choice. At the same time, "Olympic"s other sister ship "Britannic", which had not yet been completed, was requisitioned as a
Hecla-class bomb vessel a survey ship, while "Aetna" and "Thunder" were both used as survey ships. "Sulphur" was also used as a survey ship, at one time being commanded by Edward Belcher who later commanded an expedition in search of John Franklin (though not in "Sulphur"). "Erebus" was one of two ships commanded by James Clark Ross during his exploration of Antarctica and by Franklin on his ill-fated search for the Northwest Passage. The other was the "Vesuvius"-class bomb vessel "Terror". Both ships were lost during this last voyage. Hecla-class bomb vessel The "Hecla" class was a class of bomb vessels of the