We could go on and on. The down ratchet works everywhere. Rudder stock dimensions, steering gear torque, propeller blades, awkward and dangerous outfitting including pump room ventilation ducts that don't go to the pump room bottom, etc, etc. Table 15.1 shows one last example: main engine shaft couplings.
|Power||45,000 SHP||44,640 BHP|
|Engine Torque Pulse||nil||80%|
|Flange Thickness||220 mm||140 mm|
|Coupling Bolts||14 x 150 mm conical||12 x 95 mm reamer|
Table 15.1 is an extreme case, but it is very difficult to find any scantling or parameter that is not at least 15% weaker on the new ships than the old. As a result, large tankers built to current Class rules are far less safe and less reliable vessels than those built 25 years ago. And the mid-70's ships as a group were not over-built. They were at best just good enough. Yet in the same period the potential liabilities associated with large tanker casualties have increased one hundred fold. It simply makes no sense. If the classification society system is to continue to exist, if it should be allowed to continue to exist, the Rules must be rewritten returning at a minimum to the standards of the 1970's. And the direct computation down ratchet must be eliminated.