The Deep Draft

The turning gear is a reversible electric motor which drives a worm gear which can be connected with the toothed flywheel to turn a large diesel engine. It is used in following cases.

• A slow-speed drive is thus provided to enable positioning of the engine parts for overhaul purposes.
• The turning gear is also used to turn the engine one or two revolutions prior to starting. This is a safety check to ensure that the engine is free to turn and that no water has collected in the cylinders.
• Turning the engine using the gear removes any waste products of combustion, water, unburned fuel etc before putting starting air into the cylinder. This is a precaution to avoid water damaging the engine, or a pre-detonation doing similar damage. It also allows cylinder lubrication to be spread onto the cylinder walls by manually working the lubricators prior to starting.
• If the engine is to be in lay-up for some time, it will be turned one and a quarter turns every so often to avoid the crankshaft sagging or bearings being damaged.
• Turning gear must be engaged before working on or inside the engine as wake from other ship in port or waves may cause the propeller to turn.

So guys, its not a very big deal if an engineer asks you for a permission to turn the engine using turning gear. This is really slow and a requisite for engine room pre departure safety checks.

ShipHappens !