A bedplate is the lowermost portion of a marine engine, which supports the engine structure and is also one of the most loaded constructional parts of the engine. For large engines, the bedplate is fabricated in parts with flat bottom type construction having a high surface finish.
The bedplate is later arranged together during installation in large engines, whereas for smaller engines the bedplate is fully cast. For large bedplates, the material used can be cast or prefabricated steel or a mixture of both. The important requirement for a large engine bedplate is to use material with low carbon steel with a maximum carbon content of 0.23%.
For small bedplates, cast iron with internal vibration-damping characteristics is used, which reduces the frequency of cracks in the bedplate. The main components of any bedplate are longitudinal and cross girders.
Watch the video lesson (Bedplate) –