Each classification society has varying views of type approval of steering systems. In general the following is true:
Steering systems can only be type approved for a specific group of vessels that remain exactly the same in all aspects relating to the steering and related components. The related components include the rudders and the required torque, the power supplies and control systems.
When type approval of the system has been granted, the charges relate to the actual plan approval. Extra charges will be made relating to the inspection of materials and witnessing of tests for each batch of systems built. This means if only one set is built; the costs of these extras will be applied to one set. If 10 sets are built at the same time and these can be inspected as one batch, then the costs can be spread over the 10 sets.
Wills Ridley have general approval on some specific items which include some of the steering components. However, there are always items that have to be tailored for the steering. These include; tillers to suit the rudder stock/s, electro-hydraulic power packs & control systems.
The prices quoted for type approved systems have to be related to the vessel type, total quantity and build frequency. Type approval is not transferable to other classification societies or other vessels. Type approval of other items such as auto pilots etc, are available because they are readily repeatable items that are not regarded by the classification societies as essential systems.
Wills Ridley has found that small quantity builds are best put through the normal plan approval system, as the type approval is normally a longer process with higher charges.