The Titanic had four giant smokestacks, but only three of them actually worked.

The Titanic was built between 1909 and 1911 at the Harland and Wolff shipyard in Belfast. Its 29 boilers only needed three funnels to release smoke and ash. Designers added a fourth funnel because people at the time believed more smokestacks meant a ship was faster and safer.Each funnel stood about 81 feet tall and tilted back at a 30-degree angle. The first three funnels connected to the boiler rooms to release exhaust. The fourth funnel sat above the turbine engine room and acted as a large vent for the kitchens and the smoking room.In old photos, thick black smoke only comes out of the first three stacks. The fourth stack only released a small amount of steam or light haze. This design helped the ship compete with other famous ships that also had four funnels.The fourth funnel also contained a ladder for workers to perform maintenance. When the ship sank on April 15, 1912, the funnels broke off as the ship tilted into the water. The fourth funnel was the last one to fall.