SINGLE BOTTOM STRUCTURE
In smaller ships having single bottoms the vertical plate open floors are fitted at every frame space and are stiffened at their upper edge. A centre line girder is fitted and one side girder is fitted each side of the centre line where the beam is less than 10 m. Where the beam is between 10 and 17m two side girders are fitted and if any bottom shell panel has a width to length ratio greater than four additional continuous or intercostal stiffeners are fitted. The continuous centre and intercostal side girders are stiffened at their upper edge and extend as far forward and aft as possible.
The single bottom structure is shown in Figure 2 and for clarity a 3-dimensional representation of the structure is also provided to illustrate those members which are continuous or intercostal. Both single and double bottoms have continuous and intercostal material and there is often some confusion in the student’s mind as to what is implied by these terms.
A wood ceiling may be fitted across the top of the floors if cargoes are to be carried but this does not constitute an inner bottom offering any protection if the outer bottom shell is damaged.
Read More: SHIP CONSTRUCTION