Watertight closures have been a significant cost driver for acquisition programs, particularly for U.S. Navy ship programs that require shock qualification of watertight closures. The previous National Shipbuilding Research Program (NSRP) Research Announcement project, "Design for Maintenance and Repair," identified watertight doors as a significant driver of life cycle support cost based on multiple comments from repair yards.
The issues with watertight doors can be summarized as follows:
Navy ship specifications call for Navy standard watertight doors to be used unless some other part of the ship specifications drives a deviation. Sadly, this happens quite often, such that on a large ship there may well be dozens of unique door designs that deviate in some way from the Navy standard design, increasing part counts and procurement costs.
For ship programs that require shock qualification of watertight closures, the unique door designs that deviate in some way from the Navy standard design aren't considered to be shock qualified. In some cases, the design is similar to a previously-qualified design. Such doors may receive Navy qualification by extension. Other door designs are less similar, and the Navy will mandate testing to prove the shock resistance of the door design. In either case, the shipyard incurs additional cost to achieve shock approvals for watertight doors.
The unique door designs that deviate in some way from the Navy standard design drive higher logistics costs due to having to maintain data on the door designs and separate spare parts packages. In some cases, ship's force or other related maintenance personnel don't have the documentation on all the unique door designs and aren't sure of what parts to order when repairs must be made.
The NSRP Standardization of Watertight Closures Research Announcement project was selected for funding in December 2015 and awarded in February 2016. The objective of this project is to improve the status quo regarding the high cost of purchasing and maintaining watertight closures on U.S. Navy and U.S. Coast Guard ships. The project team will provide design documentation for previously approved doors that deviate from the current Navy standard to support new Navy standard drawings for a family of approved and qualified door designs that cover the vast majority of doors used on new construction ships. The revised documentation will also give accurate logistics data to ship maintainers and thereby support cost effective maintenance and repair.
