4-2 Attempt to Reduce Weight of Hatch Cover
Tsuji also provides a number of variations of hatch covers for bulk carriers, as shown below:
● Open hatch bulk carrier: Pontoon type/Piggy back type
● Handy bulk carrier: Folding type
● Panamax + Cape size: Side rolling type
The study of weight reduction is in progress from the standpoints of the adoption of the light weight and high speed ship body structure typified by a recent TSL and the reduction in material costs for competitive prices.
a) Analysis Method
Design by Regulation → DBA: Design by Analysis (by CAE)
Skin plate thickness determination according to the regulations by each ship class association → Analysis by the finite element method based on the external force and the conditions of working environment
An example of DBA is shown in Fig.9. This analysis method can be applied in a wider range, for example, to the ramps of car ferries, etc.
b) Feasibility of Reduction in Weight
b-1) Hatch Cover Body
Use of light weight material
CFRP (Carbon Fiber Reinforcement Plastic)
GFRP (Glass Fiber Reinforcement Plastic)
There exists a problem of the total cost in the case of the application of plastic or any other material which exceeds high tension steel in tension.
