Insulated Bus Pipe (IBP) for Shipboard Applications

The commercial shipbuilding industry and the U.S. Navy have decreed that the aim of the "all electric ship" power system design will be for survivability and continuity of electrical power supply. In general, ship service electric power and electric propulsion power requirements are approaching hundreds of megawatts. There are major challenges to the use of standard cable at medium voltage levels onboard due to cable stiffness, and cable bend radius requirements for distributing very high current around the ship. This paper examines the practical design and installation benefits associated with IBP as a possible alternative to shipboard electric power cable. Although IBP is widely used in the utility industry, the shipboard use of IBP is limited to several passenger cruise ships. IBP is considered a more efficient medium & high voltage transmission line over cable for integrated power system (IPS) ships due to cable size, quantity, and installation time. There are technical issues that must be resolved before advocating the use of IBP onboard Navy ships. This paper presents an overview of IBP technology, examines IBP technical issues and presents probable solutions for Navy and commercial shipboard applications. One of the probable solutions that are discussed is a new type of insulating material for IBP that should significantly enhance the Navy 3 hour gas flame circuit integrity flame test withstand capability. This paper recommends that the proven IBP prototypes and their models be the procurement specifications. The paper also recommends: (1) inclusion of IBP application recommended practices in shipbuilding standards such as IEEE-45 and IEEE-1580 (2) inclusion of IBP in ABS rules for commercial ships, ABS NVR for naval vessels, and other national and international shipbuilding rules and regulations.