Accession Number : ADA306210

Title :   Seakeeping Assessment for 270 and 378 Foot Coast Guard Cutters in Alaskan Waters.

Descriptive Note : Final rept.,

Corporate Author : NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD HYDROMECHANICS DIRECT ORATE

Personal Author(s) : Thomas, William L., III ; Bachman, Robert J. ; Lee, Wah T. ; Applebee, Terrence R.

PDF Url : ADA306210

Report Date : JAN 1996

Pagination or Media Count : 82

Abstract : The question of whether or not the 270 foot WMEC might serve as a suitable replacement for the 378 foot WHEC in Alaskan Waters is addressed in this report. In comparison to the relatively benign Caribbean region, where these two vessels act in almost an interchangeable fashion, the Bering Sea and North Pacific Ocean areas experience much rougher weather, especially during the winter season. Therefore a seakeeping assessment study of the two vessels was carried out. A comparison of ship motions measured in side by side trials between USCGC HARRIET LANE, a 270 foot cutter, and the USCGC BOUTWELL, a 378 foot cutter is presented. An operability assessment for the winter season for three geographic locations which represent Alaskan waters is presented for seakeeping sensitive missions that are related to Search and Rescue and Law Enforcement. Annualized (four season) operability assessment is also presented. The findings indicate that the 270 foot cutter is less seakindly than the 378 foot cutter and is less capable in terms of maximum speed. The 270 foot cutter is projected to carry out its duties approximately 14 percent less often in the winter than the 378 foot cutter with excessive roll and pitch motions serving as the principal source of performance degradation. On an annual (four season) basis, the 270 foot cutter is projected to carry out its duties approximately 11 percent less often than the 378 foot cutter.

Descriptors :   *SEAKEEPING, *COAST GUARD SHIPS, PITCH(MOTION), WEATHER, DEGRADATION, SIZES(DIMENSIONS), COMPARISON, SHIP MOTION, SENSITIVITY, WINTER, MISSIONS, LAW ENFORCEMENT, SEARCH AND RESCUE, SEA TESTING, BERING SEA.

Subject Categories : Marine Engineering

Distribution Statement : APPROVED FOR PUBLIC RELEASE