Understanding about marine diesel engine is the basic foundation for a marine engineer. Bedplate is like a foundation stone we put during construction of a home. Similarly bedplate is the foundation of an engine. In this blog we are going to explain all the things which you need to know about bedplate of a marine diesel engine. 


Topic discussed are 


1. Main Functions of bedplate 

2. Material used in bedplate 

3. Components of a bedplate

4. Types of a bedplate


A. Main Functions of Bedplate ?


There are mainly 3 functions of Bedplate, Which are :- 

1. For supporting the entire weight of the engine. 

2. To maintain the crankshaft alignment. 

3. For resisting the torque reaction couple forces from propeller that will tries to rotate the engine around the crankshaft. 


B. Material used in bedplate ?


The material used in bedplate is 0.23% CARBON STEEL. 

The carbon provides the vibration absorbtion property and the steel provides strength, corrosion, resistance, oxidation resistance etc.


C. Components of a bedplate ?


1. Longitudinal girders 

2. Transverse girders 

3. Stiffening member

4. Double bottom support with solid plate


1. Longitudinal girders :- The girders are build in longitudinal direction and provide resistance against longitudinal stresses of the ship(hogging and sagging). 

2. Transverse girders :- It is used to resist the transverse forces, usually transverse girders are placed on the bearing portion where the crankshaft is seated. 

3. Stiffening member :- An additional member which provides resistance again hogging, sagging and weight of the engine. 

4. Double bottom support with solid plate floor :- There is an additional bottom is provided to support the whole weight of the engine. 


D. Types of Bedplate ? 


1. Trestle type bedplate 

2. Box type bedplate


1. Trestle type bedplate

The bedplate is provided at an elevated position, i.e above the tank top. The main advantage of trestle type bedplate is that at the  time of damage of the bedplate the elevated seat can be removed and bedplate can be fixed or replaced. So, trestle provide less financial loss and will be more robust. 


2. Box type bedplate 

They are in box shaped structure, which having a double bottom support with solid plate. They also have a longitudinal and transverse girders.