Steam Engines are a shipbuilding part used to construct steamships. Activated by pressing E, Steam Engines require Coal to run at a rate of 1 coal per 45 seconds at full throttle, using less coal as you slow the ship. The engine speed does not add to the sail speed of the ship, so it's recommended to only use the engine when going crosswind or upwind. While the Neptune, Binglehopper and Poseidon are able to move without use of their engines, it is at a crawl due to not holding sails and so the engine must be used constantly to maintain an operational speed.
There are three types of engine parts, Steam Engine Parts, Blessed Engine Parts, and the Advanced Engine. Steam Engine Parts are craftable for 100 Steel and 50 Copper to those with Crafting level 10, however they must be blessed into Blessed Engine Parts with a Lord Gaben's Blessing before they can be used in shipbuilding. The last engine type, the Advanced Engine, is purchased for 1000 Robux from the Premium Merchant and is used exclusively to create ironclads. The Advanced Engine does not require a blessing to be used.