UTB
大型汎用艇


満載排水量:9.75t(1951年時、1980年時には10.77t) 全長:12.19m 幅:3.40m(最大) 吃水:0.96m(最大、1951年時) 主機/軸数:GMC 6-71ディーゼル2基/2軸 出力:380制動馬力 速力:26.0kt(Mk. I、鋼製、1951年時) 航続力(1951年時):15.0ktで190浬(1953年には18.0ktで450浬) 乗員:3名
A New Beginning For CG 40394. buoyjumper.
↑By the end of the 1940s, the original 38' cabin picket boats and 30' motor rescue boats were rapidly wearing out and had become obsolete given the significant increase in missions for the Coast Guard, including general marine law enforcement, recreational boating safety, environmental protection, and port security. Newer and faster designs were needed with better towing capabilities in order to respond to these operational requirements. The first new design to be developed by the Coast Guard in 1949 for this purpose was the 40' utility boat (UTB). This design was first tested by means of an extensive modification of a 38' cabin picket boat, rebuilding it to simulate the layout of the proposed 40' design. The first of these boats CG 40369 was completed in 1950. It was powered by a single GMC 6-110 Diesel 275 HP engine. Sea trials resulted in very favorable reviews and the new boat was put in service at Sandy Hook NJ Lifeboat Station. A second boat in this configuration was built but these boats were only capable of achieving a speed of 18.5 knots when 20 knots was the design criteria. Following these trials, the Coast Guard Engineering Staff decided to switch to a twin screw configuration and install 2 GMC 6-71 engines of 190 HP each. In February 1951 the wood hull CG 40371 and steel hull CG 40375 utility boats were put into service. They were turned over to The Coast Guard Field Testing and Development Unit for evaluation. The trials revealed that the steel hulled boat should be modified because the wood hulled boat provided superior comfort and resistance to pounding in heavy seas as well as drier deck surfaces. It also had better visibility for the Coxswain. The steel boat was capable of 22.5 knots and the wooden boat a little over 20 knots. With the trials completed both boats were delivered to operating units. At this point all Engineering efforts were directed to designing a steel boat with sea qualities approaching those of the wooden boat. This was accomplished by pinching in and adding a little greater flare to the bow. These simple modifications achieved a boat with better sea-riding qualities as well as an improved underwater fineness. This concluded the 40-foot Mark I design program. Mark I Utility Boat Production The Coast Guard Yard had a requirement to build 125 boats to replace those in service and to meet new requirements. The Yard had never built boats in large quantities or to a tight schedule. Therefore they set up a production line with prefabricated sub-assemblies. This assembly line technique commenced operation in June 1951. The planned rate of delivery was one boat per day and this was reached in July 1951 and continued for the construction of over 100 boats. During this time 15 Model 1 wooden boats were built as well and additional steel boats for the US Navy and the Military Assistance Program. In 1951, the Coast Guard Yard built 27 Mark I Model 2 boats for the French Navy for service in Viet Nam. No interior control station was installed, a 50 Cal. Machine gun mount on bow and a 20 mm Cannon on the stern in place of tow bit. In 1955, the remainders of these boats were transferred to start the South Viet Nam Navy. Mark II Utility Boat. The Coast Guard Yard built one twin screw 40-foot Utility boat with a marine plywood hull in November 1951. The mechanical components of the Mark I boats were installed: Twin GMC 6-71 Diesel engines and 20" x 18" propellers. She had a cruise speed of 18.5 knots and a 192 mile range. She was attached to the Yard's Testing and Development Division of the Office of Engineering for evaluation. Mark III Utility Boat In 1952 and 1953, the Coast Guard contracted with Anchorage Plastics Corp. of Warren, RI to build 3 single screw plastic 40-foot Utility boats. The mechanical components of the Mark I boats were installed: Twin 3 GMC 6-71 Diesel engines and 20" x 18" propellers. She had a cruise speed of 20 knots and a 192 mile range. One of these boats was attached to the Yard's Testing and Development Division of the Office of Engineering for evaluation. 40-foot Utility Boat Competition In May 1952 a comparative operational test was conducted by the Coast Guard Yard's Testing and Development Unit utilizing one Mark I Steel UTB, one Mark II Plywood UTB, and one Mark III Plastic UTB. These boats were comparison tested during the period of 9 June through 4 July between Norfolk, VA and Cape May, NJ. These tests concluded that although there were certain areas where each boat excelled, the steel boat's superior ruggedness made it capable of withstanding the greatest amount of abuse. Mark IV Utility Boat In 1954, the Utility boats had been in service for 18 months. The Office of Search and Rescue had recommended certain configuration changes. The Coast Guard Naval Engineering section drafted plans for a Mark IV version of the 40-foot UTB. The changes incorporated in the Mar IV version were: Engines and Pilothouse were moved 2 feet aft. Refinement to the propeller shaft struts, rudders, and aft parts of the hull bottom. Enlarged fuel tanks increasing capacity from 228 gallons to 370 gallons. (Subsequent trials indicated that this increased the boats speed by 4 knots and range by 175 miles.) Canvas Canopy installed over the outside steering station. Mark IV Mod 1 Utility Boat In 1955, the Mark IV Mod. 1 was developed. The modification included: Redesign Cabin Windows. Remove Engine Box Louvers Lighted Instrument Panels. Use of Plexiglas discontinued. Coxswain's platform on outside station raised. Pilothouse door hinged to swing outward. The steel 40-foot utility boat building program was completed in 1959. Mark V Utility Boat In 1959, the Coast Guard contracted with W.R. Chance and Associates of Waldorf, MD to build one plastic and fiberglass single screw utility boat of Coast Guard design. The boat was designed for Captain of the Port (COTP) surveillance and inshore rescue duties. This boat was attached to the Yard's Testing and Development Division of the Office of Engineering for evaluation. Following sea trials, she was assigned to an operating unit. Mark V Mod. 1 Utility Boat In 1961, the Coast Guard contracted with Universal Molded Fiberglass to build seven Mark V Mod. 1 single screw plastic and fiberglass boats. She was powered by a GMC 6-71 Model 612IT 300 HP @ 2300 RPM with a V-drive. The single screw boat proved not to be as efficient as the twin screw boats. The single engine V-drive proved not to be reliable. Mark VI Utility Boat In 1962, the unreliability of the Mark V, Mod. 1 led to the development of the Mark VI plastic boat. The Mark VI was designed with twin Cummins V-6 Turbo-charged diesel engines producing 260 HP @3000 RPM to increase speed and durability. She had a speed of 25 knots and a range of 200 miles. The Coast Guard Yard constructed 13 Mark VI boats between 1962 and 1966. The UTB building program ended in 1966. Image courtesy of Shipbucket.
船名 NAME 船種記号 建造所 就役日 退役日 除籍日 備考
40369、40370 ◎2隻、1950年9月8日竣工、木製、1軸、プロトタイプ
40371 ◎1隻、1951年竣工、木製、2軸、プロトタイプ
40372、40373、40376〜40390 ◎17隻、1951年竣工、Mk. Iモデル1、木製、2軸
40375 ◎1隻、1951年竣工、鋼製、2軸、プロトタイプ
40391〜40491、40493〜40501、40505〜40518 ◎131隻、1951年〜1952年竣工、Mk. I、鋼製、2軸
40492 ◎1隻、1951年竣工、Mk. II、合板製、2軸
40502〜40504 ◎3隻、1952年〜1953年竣工、Mk. III、プラスチック製、2軸
40519〜40547 ◎26隻、1953年〜1954年竣工、Mk. IV、鋼製、2軸
40548〜40589 ◎40隻、1955年〜1959年竣工、Mk. IV Mod. 1、鋼製、2軸
CG-40585は1958年8月10日に喪失
40043 ◎1隻、1959年竣工、Mk. Vプロトタイプ、プラスチック製、1軸
40590〜40596 ◎7隻、1961年竣工、Mk. V Mod. 1、プラスチック製、1軸
40597〜40609 ◎13隻、1962年〜1966年5月16日竣工、Mk. VI、プラスチック製、2軸


満載排水量:15t 全長:12.60m 主機/軸数:ディーゼル2基/2軸 出力:636馬力 速力:26.0kt 乗員:3名
↑41-foot Utility Boat (No. 41353)
船名 NAME 船種記号 建造所 就役日 退役日 除籍日 備考
41300〜41507 Coast Guard Yard ◎208隻、1971年〜1983年建造。後に41327、41403、41405は船種を航空機練習艇に改める
41410は退役後、Sturgeon Bay Maritime Museumにて展示


Update 16/10/28