In the past, the bulkhead and floor adjacent to the cargo compartment and engine room or fuel oil compartment of most ships were covered by wood guard boards. However, wood guard boards were rarely seen in the cabin of ships. One board was difficult to dry after washing. On the other hand, they are prone to insects, which often make it impossible for the inspection of the capsule to pass, so that the grain cannot be packed.
But the frequent grain loss is also produced. A ship cargo holds and engine room daily fuel tank adjacent tank walls are thick wood plate, but underneath the tank depth exchange (to) with Ma Pan welding on the tank wall and the precipitation and daily calories to fuel oil tank is through such a small iron Ma Pan conduction to the sounding pipe, could make the scattered around sounding pipe valley of wheat in the long-term heat agglomeration and stick on the sounding pipe.