The "Olympic"-class ships were long, displacing normally (their draft at this displacement being ), and their tonnage was around 45–46,000 GRT. "Olympic" became the largest ship in the world when it was completed in May, 1911 before losing the title to its sister "Titanic" when she was completed in April, 1912. After the loss of "Titanic" the third sister ship "Britannic" claimed the title of largest British-built ship until her own sinking in November 1916. After this "Olympic" would enjoy the title for 20 years until the commissioning of in 1936. All three vessels sported four funnels, with the fourth being a dummy which was used for ventilation and aesthetic purposes. Smoke from the galleys and Smoking Room fireplaces and fumes from the engine rooms was exhausted through a chimney up the forward portion of this funnel. On the one hand it was a decoration to establish a symmetry in the ships' profile, on the other hand, acting as a huge ventilation shaft, it prevented the large amount of ventilation cowls on deck as on Cunard's "Lusitania" and "Mauretania".