A vessel owner’s team set out to increase the refrigeration capacity of the vessel. Among other new components, this required the installation of several additional 250-amp breakers identical to ones already on the vessel. The owner’s staff read the part number for the existing breakers, and directed the shipyard to order additional breakers using that part number to ensure commonality. What arrived, however, were only the casings for the breakers, not fitted with the internals. A separate part number was need for the internals, or an alternate part number for the combination of the internals plus casing. A last-minute contract amendment and extra installation costs were incurred.
The lesson learned: the owner’s specification writers should confirm from the vendor that the identified part number is the appropriate one and that the product is currently being manufactured.