Reference no: EM132307382
A ship needs a new platform on its main deck to support a davit, lifeboat and a winch. The maximum area of the platform is limited by the available deck area as shown in Figure 1.
Figure 1: Main Deck Plan
Height of the platform above the main deck is 2.4 m and it must be strong enough to hold the following weights;
1. new davit and lifeboat of 8 tonnes,
2. a new winch of 0.5 tonnes,
3. weight of 4 crew (average weight of a person 80 kg),
4. self-weight of the deck plate (thickness must be at least 6 mm and the area must be less than or equal to the available area).
Assume that the resultant load is acting at the centre of the platform, thus equally distributing the load on platform support columns. The material of the platform must be mild steel with the UTS = 435 MN/m2, USS = 280 MN/m2, and Modulus of Elasticity = 205 GN/m2.
1. Design a platform to support the above loads with 2.2 safety factor (see Figure 2). You can decide the plate thickness and the number and type of support columns (i.e. a pipe, rectangular section etc.) based on the calculation. Once you design the platform, calculate the strain and compression of the columns.
2. When launching the lifeboat, the platform is subjected to 100 kN lateral load as shown in Figure 2. If four mild steel bolts are supporting each column, calculate the diameter of a bolt suitable for holding the platform. FOS of a bolt must be 5.
