PT boat

PT658 underway September 2005

A PT boat was a motor torpedo boat (hull classification symbol "PT", for "Patrol Torpedo"), a small, fast vessel used by the United States Navy in World War II to attack larger surface ships. The PT boat squadrons were nicknamed "the mosquito fleet".

Among the famous PT boats, was PT-109, commanded by future United States President John F. Kennedy, a PT-103 class torpedo boat, hundreds of which were built between 1942 and 1945 by Elco Naval Division of Electric Boat Company at Bayonne, New Jersey. Another famous PT Boat was the PT41, a 77 foot Elco boat Commanded by LT John D Bulkeley, who rescued General Douglas McArthur from certain capture by the Japanese in a daring escape from Corregidor Island, Philippines and was awarded the Congressional Medal of Honor for his exploits. This story inspired both a book, "They were Expendable" and a movie of the same name. This story of the diminutive PT boats beating overwhelming odds went a long way in propping up sagging American morale in the dark days after the attack on Pearl Harbor.

Class history

The first 3 PT boat designs were the results of two respected naval architects and the Navy. This led to 8 boats built - none of which were up to the necessary performance specifications. The Electric Boat Company (ELCO), which had no experience in small boats, had visited the UK to see their Motor Torpedo Boat designs and purchased an example of a British Powerboats 70 foot design, designed by Hubert Scott-Paine. This was demonstrated and led to a contract for 10 boats based on it. These were tested and determined to be too light for open sea work but Elco got a contract for 24 larger boats based on a lengthened design.

The design competition for the PT boat was nicknamed "The Plywood Derby" and took place just prior to the United States entering the war, in early 1941. The Navy Department held these competition trials around New York Harbor. This was a shakedown to see which company would be contracted to build the Navy PT boats. At the completion of the trials the Navy was impressed with all three designs, with the ELCO 77 footer coming out on top, followed by the HIGGINS 76 footer and HUCKINS 72 foot boat. Although ELCO came in first, the Navy saw the merits of the other two boats and decided to offer all three companies contracts. ELCO received the lion's share of the contract (385 boats by the end of the war), HIGGINS was second (199 boats by the end of the war) and HUCKINS with the smallest contract (18 boats by the end of the war). Huckins was a tiny yacht building company based out of Jacksonville FL and was unable to build the number of boats needed by the Navy. Although the Huckins Yacht Company built a few 78-foot (24 m) boats of the PT-95 class, the 80-foot (24.4 m) Elco boats, and the 78-foot (24 m) Higgins boats became the standard American motor torpedo boats of World War II. Huckins eventually produced just 18 PT boats, none of which would see combat. They were assigned however, to home defense squadrons in the Panama Canal Zone, Miami, FL and in Hawaii at Pearl Harbour.

Elco

The Elco boats were the largest in size of the three types of PT boats built for US Navy used during World War II. Wooden-hulled, 80 feet (24.4 m) long with a 20 ft 8 in. (6.3 m) beam, the Elco PT boats had three 12-cylinder gasoline fueled engines. These were Packard built, a modified design of the 3A-2500 V-12 liquid-cooled aircraft engine. The "3A" was itself an improved version of the "2A" engine used on the Huff-Daland Keystone LB-1 "Liberty" bomber of World War One vintage. When the engines were designed for use in the PT Boats, Packard modified them for marine use, hence the "M" designation instead of "A". (ie 3A-2500 then 4M-2500). The aircraft engine roots of the Packard engine gave it many features of aircraft engines such as supercharger, intercooler, dual magnetos, two spark plugs per cylinder, etc. The Packard Engine factory simultaneously built the Rolls Royce Merlin aero engine under licence in a production line side by side with the PT Boat engine production line but the Merlin was never used in any PT Boats. These Packard 4M-2500 engines generated a total of 1,500 hp (1,150 kW) each for a designed speed of 41 knots (76 km/h). The gasoline consumption of these engines was phenomenal - a PT Boat carried 3,000 gallons (11 360 litres) of 100 octane AVGAS. A normal patrol for these boats would last for a maximum of 12 hours. Consumption rate for each engine at cruising speed of 23 knots was about 66 gallons (250 l) per hour.(200 gallons (760 l) per hour for all 3 engines) However, when going at top speed the gasoline consumption increased to 166 gallons (250 l) per hour per engine (or 500 gallons [1 890 l] per hour for all 3 engines). At the top speed of 41+ knots, the 3000 gallons (11 360 l) of gas would be used in only about 6 hours. With accommodations for 3 officers and 14 men, the crew varied from 12 to 14. Its full-load displacement was 56 tons.

Early Elco boats had two 20 mm Oerlikon cannons, four M2 .50-caliber machine guns or four .30-caliber Lewis Guns, and two or four 21 inch (533 mm) torpedo tubes launching Mark 8 torpedoes. Some of them carried 2 to 4 US Navy Mark 6 depth charges in roll off racks, or mine racks. Later boats mounted one 40 mm Bofors gun aft and four 22.5 inch diameter Mark 13 torpedo launching racks, two along each side. Some PTs later received two 8-cell 5 inch spin stabilized flat trajectory rocket launchers, giving them 16 rockets and as much firepower for a short time as a destroyer mounting 5 inch guns. The PT boat had become by the wars end in 1945, the most heavily armed vessel for its small size (56 tons) than any other vessel in the US Navy. One other addition that the US Navy PT Boats had was their Raytheon SO type radar, with about a 25 nm range. Since PT boats operated mainly at night, having radar gave them an advantage over the enemy in being able to locate and engage them even in zero visibility conditions. Although radar is not specifically a weapon, its use by the PT boats made the other weapons much more effective.

In addition, many boats received ad hoc refits at advanced bases, mounting such weapons as 37 mm aircraft guns and even captured Japanese 23 mm guns. One famous example was Kennedy's PT-109 which was equipped with a 37 mm single shot anti-tank cannon that the crew had commandeered and bolted to the foredeck. Another similar type of weapon that gained widespread use as the war progressed was the 37 mm Oldsmobile M4 and M9 aircraft automatic cannon. Originally cannibalized from crashed P39 Airacobra fighter planes on Guadalcanal, and then later manufactured and installed at the boat's Elco and Higgins factories, the M4/M9 cannon had a relatively high rate of fire (125 rounds/minute) and large magazine (30 rounds) making this weapon highly desireable due to the PT boat's ever increasing need for a larger "punch" to deal effectively with the Japanese "daihatsu" barges which were immune to torpedoes due to their shallow draft. By the war's end, most of the PT boats had been fitted with these efficient weapons.

Although more 80-foot Elco boats were built than any other type of motor torpedo boat, other types were built by the U. S. In addition to 326 of their 80-foot boats, Elco also produced 49 of their 77-foot boats and ten 70-foot boats.

Higgins

Higgins produced 199 78-foot boats. The Higgins boats, built by Higgins Industries in New Orleans, Louisiana, were 78-foot (24 m) boats of the PT-71 class. The Higgins boats had the same beam, full load displacement, engine, generators, shaft power, trial speed, armament, and crew accommodations as the 80-foot (24 m) Elco boats. Numerous Higgins boats were sent to the USSR and Great Britain at the beginning of the war, so many of the lower squadrons in the USN were made up exclusively of Elcos. The first Higgins boats for the US Navy were used in the Battle for the Aleutian Islands (Attu and Kiska) as part of Squadron 13, and others in the Mediteranean against the Germans.

Others

The Canadian Scott-Paine Company produced five PT boats for the US Navy. The British-designed 70 foot (21 m) Vosper boats, 146 of which were built for Lend Lease, carried 18-inch (457 mm) torpedoes. Since the US produced the heavier and longer 21-inch torpedoes, the US Navy wanted a larger PT boat. After experimentation, the first PT boat built in any quantity was the 77-foot (23 m) type built by Elco. These boats were used early in World War II. Total production of all types, including experimental designs, was 768. [1]

Service

Originally conceived as anti-ship weapons, the PT boats of Squadron 3 were publicly (but some say erroneously) credited with sinking several Japanese warships during the period of Dec 1941-March 1942 during the fall of the Philipines to the Japanese.

During the long Solomon Islands campaign, they operated effectively at night and at times of low visibility against Japanese shipborne resupply efforts dubbed by ADM William "Bull" Halsey as "The Tokyo Express" in "the Slot", a narrow seaward channel linking the Japanese stronghold at Bougainville to the island of Guadalcanal. Throughout World War II, PTs operated in the southern, western, and northern Pacific, as well as in the Mediterranean Sea and the English Channel. Some served during the Battle of Normandy. Perhaps the most effective use of PT Boats was in the role of "Barge Busters". Since both the Japanese in the New Guinea area and the Germans in the Mediterranean had lost numerous resupply vessels to Allied airpower during daylight hours, they both attempted to resupply their troop concentrations by using shallow draft barges at night in very shallow waters. The shallow waters were such that Allied destroyers were unable to follow them due to the risk of running aground and the barges could be protected by an umbrella of shore batteries. The PT Boats were also a shallow draft vessel that could follow the barges into the shallows and sink them. Using torpedoes was ineffective against these sometimes heavily armed barges, since the minimum depth setting of the torpedo was about ten feet (3 m) and the barge was only 5 feet (1.5 m) in draft. This was the reason that PT Boats started installing more and heavier guns/cannons, which were able to sink the barges by the sheer weight of firepower. One captured Japanese soldier's diary decribed their fear of the US PT boats by describing them as "the monster that roars, flaps it wings, and shoots torpedoes in all directions".

Though their primary mission continued to be seen as attack of surface ships and craft, PT boats were also used effectively to lay mines and smoke screens, to rescue downed aviators, and to carry out intelligence or raider operations. In 1943 in the Solomon Islands, three 77-foot (23 m) PT boats, PT-59, PT-60, and PT-61, were even converted into gunboats by stripping the boat of all original armament except for the two twin .50 caliber (~12.7 mm) gun mounts, and then adding two 40 mm guns and four more twin .50 caliber (~12.7 mm) machine guns. LTJG John F. Kennedy was the first commanding officer of PT-59 after the conversion.

Almost all surviving Elco PTs were disposed of shortly after V-J Day. Two PTs survive in World War II configuration on static display: the Elco boat PT-617 and PT-796, a 78-foot Higgins. The two are exhibited at the PT Boat Museum in Fall River, Massachusetts. These boats are owned by PT Boats, Inc., a WWII PT veterans organization headquartered in a suburb of Memphis, Tennessee.

Additionally, a 78 foot Higgins PT Boat, USS PT658, has been completely restored between 1995 and 2005 and is now in operational condition. It is the only 100% authentically restored US Navy PT Boat that is operational today in the world. The USS PT658 is located in Portland, Oregon at the Swan Island Naval Reserve Center Pier. She is floating in the water and has 3 operational 1850 Hp Packard Model 5M-2500 V12 gasoline engines. A dedicated group of PT Boat veterans, formed the organization Save the PT Boat, Inc., and then obtained and restored the boat, to include a full armament of 4 Mark 13 Torpedoes, 2 twin .50 caliber Browning M2 MGs, a 40 mm Bofors cannon, two 20 mm Oerlikon cannons, and 2 Mark 6 300 pound TNT depth charges. There is also another non-operational restored 78 foot Higgins PT Boat, the USS PT309, located at the "Nimitz Museum of the Pacific War" in Fredericksburg, Texas. The group that restored the PT309 is called "The of America.org." The USS PT309 is currently inside a static diorama display without engines installed. Its external restoration was completed by the Texas group in 2002, and is very well done.

Some examples of famous PT boats:

PT-41 - Flagship of Motor Torpedo Boat Squadron Three, based in the Philippine Islands 1941–1942 (PT's 41,31,32,33,34,35). Commanded by LT. John D. Bulkeley USN
PT-34 - Part of Motor Torpedo Boat Squadron Three
PT-109 - Commanded by LTJG John F. Kennedy, USNR

Cultural Impact

The story of Motor Torpedo Boat Squadron Three in the retreat from the Philippines early in World War II was documented in the book They Were Expendable by W.L. White, ISBN 1557509484, originally published in 1942 soon after the events depicted. Later, in 1945 John Ford made it into a notable war film starring John Wayne. One of the most famous PT boats, PT-41, was part of this squadron.

The JFK story is told in PT 109: John F. Kennedy in WWII by Robert J. Donovan, published in 1961, ISBN 0071376437. PT 109 was also a 1963 film starring Cliff Robertson. While he was President, JFK handed out PT-109 tieclasps to favored guests and associates.

The TV situation comedy, and later film, McHale's Navy was set in a PT boat squadron.

In the 1980s, a video game simulation called PT 109 was popular on early personal computers.

External links