Olympic-class ocean liner so, the "Olympic"-class ships were built to surpass rival Cunard's largest ships, "Lusitania" and "Mauretania", in size and luxury. "Olympic", along with "Titanic" and the soon to be built "Britannic", were intended to be the largest and most luxurious ships to operate on the North Atlantic, but not the fastest, as the White Star Line had already switched from high speed to size and luxury. The three vessels were designed by Thomas Andrews and Alexander Carlisle. Construction of "Olympic" started in December 1908 and "Titanic" in March 1909. The two ships were built side by side. The construction of "Britannic"
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