Editing Engine room (section)

==Equipment==
===Engines===
[[File:Vesikko engine room view aft.JPG|thumb|Engine room of the [[Finnish submarine Vesikko|Finnish submarine ''Vesikko'']] in 2010]]
The engine room of a motor vessel typically contains several engines for different purposes. Main, or propulsion, engines are used to turn the ship's [[propeller]] and move the ship through the water. They typically burn [[Diesel fuel|diesel oil]] or [[Fuel oil|heavy fuel oil]], and may be able to switch between the two. There are many propulsion arrangements for motor vessels, some including multiple engines, propellers, and gearboxes.{{citation needed|date=October 2015}}

Smaller, but still large engines drive electrical generators that provide power for the ship's electrical systems. Large ships typically have three or more [[Synchronization (alternating current)|synchronized]] generators to ensure smooth operation. The combined output of a ship's generators is well above the actual power requirement to accommodate maintenance or the loss of one generator.{{citation needed|date=October 2015}}

On a steamship, power for both electricity and propulsion is provided by one or more large [[Water-tube boiler|boiler]]s giving rise to the alternate name '''boiler room'''. High pressure steam from the boiler is used to drive [[reciprocating engine]]s or [[turbine]]s for propulsion, and also [[turbo generator]]s for electricity. Besides propulsion and auxiliary engines, a typical engine room contains many smaller engines, including [[Electric generator|generators]], air compressors, feed pumps, and fuel pumps. Today, these machines are usually powered by small diesel engines or electric motors, but may also use low-pressure steam.{{citation needed|date=October 2015}}

===Engine cooling===
{{Main|Engine cooling}}
The engine(s) get required cooling from [[Heat exchanger|liquid-to-liquid heat exchangers]] connected to fresh seawater or divertible to recirculate through tanks of seawater in the engine room. Both supplies draw heat from the engines via the coolant and oil lines. Heat exchangers are plumbed in so that oil is represented by a yellow mark on the flange of the pipes, and relies on paper type gaskets to seal the mating faces of the pipes. Sea water, or brine, is represented by a green mark on the flanges and internal coolant is represented by blue marks on the flanges.{{citation needed|date=October 2015}}

===Thrusters===
In addition to this array of equipment is the ship's thruster system (on modern vessels fitted with this equipment), typically operated by [[electric motor]]s controlled from the bridge. These thrusters are laterally mounted propellers that can suck or blow water from port to starboard (i.e. left to right) or vice versa. They are normally used only in maneuvering, e.g. docking operations, and are often banned in tight confines, e.g. [[drydocks]].{{citation needed|date=October 2015}}

Thrusters, like main propellers, are reversible by hydraulic operation. Small embedded hydraulic motors rotate the blades up to 180 degrees to reverse the direction of the thrust.{{citation needed|date=October 2015}} A variant on this is the [[azipod]], which are propellers mounted in a swiveling pod that can rotate to direct thrust in any direction, making fine steering easier, and allowing a ship to move sideways up to a dock, when used in conjunction with a [[bow thruster]].