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Motor Torpedo Boat

The motor torpedo boat is a seagoing "Indian fighter." She seeks out her prey by night, and both stealth and high speed enable her to engage and disengage her foe. Although her adversary may be many times hersize and displacement, she is always the first to attack.

With the passing of sail and the advent of the modern machine age came a new and untried weapon - a small, fast, torpedo carrier which was destined to become our speediest and most streamlined naval vessel. However, her history had its christening in the sixth year of the twentieth century. By the beginning of the first World War, Italy, Germany and England had all taken an active part in small and fast surface torpedo craft development, and today the motor torpedo boat of one type or another forms an important part of nearly every navy.

Italy made the first progress with a successful torpedo carrying motor boat in 1906 - only 37 years ago. This initiated the development of a boat that at least partially fulfilled the desired requirements by the time the first World War started. They were of a ten-ton design and were 52 feet long. By 1916, the Italian boats were from 50 to 69 feet in length, carried from two to four small torpedoes and one or two machine guns. In general, they were capable of a speed of about 33 knots and had little freeboard. To enable them to approach their objective in silence, they were equipped with two electric motors furnished with storage batteries. These motor torpedo anti-submarine boats, MAS as the Italians called them, were used for attacking surface vessels and submarines, for coastal reconnaissance, escorting seaplanes and mine sweeping.

The significance of such vessels in naval operations can be illustrated by the exploits of the Italian MAS against the Austrian Navy. During the first World War, Austria was receiving many of its supplies from overseas; this gave Italy a good opportunity to attack its maritime communications and ports of call. However, there was considerable question as to which type vessel could best be employed for this task. This was where the idea of using the MAS came into being and, in May, 1916, the organization of the first Italian Motor Torpedo Boat program was completed. The first action was in the form of a raid on the night of June 6th, 1916, on the Bay of Durazzo, carried out by two MAS's from a Brindisi base. The boats were supported by destroyers which towed them most of the way. In the bay, they sighted a large steamer, the Lukrum, at anchor. One torpedo was fired resulting in the sinking of that vessel. During that night the Austrians did not discover the presence of the MAS and thus they were uncertain as to the method by which the Lukrum was destroyed.

It is interesting to note that the Italian MAS's used aircraft reconnaissance to keep them informed of enemy activity. This was the first instance of the coordination of aerial reconnaissance with motor torpedo boats; the possibilities still remain undeveloped. In the upper Adriatic, during November of that year, aerial reconnaissance over Pola and the Canal of Fesana (near the Austrian Fleet Base) showed important surface units anchored in the Fesana Canal, the entrance to which was protected for several days at a time by a series of logs linked together. Aided by a torpedo boat, which was equipped with apparatus to destroy such obstructions, another boat entered the Canal and made two attempts to torpedo an old battleship anchored there. Although both attempts were frustrated by anti-torpedo nets surrounding the battleship, the exit as well as the entrance to the Canal was effected without damage to the MAS.

In 1917, the MAS's were principally used for protection of surface craft from submarines, for mine laying and for reconnaissance in the vicinity of enemy restricted waters. However, it was desired to use them for work of a more offensive nature. So the Italians decided it was advisable to take the initiative and, after much night reconnaissance around Trieste, plans were developed for torpedoing the two battleships Wien and Budapest. On the night of December 9th, in a thick fog, two MAS's escorted by other light vessels reached the entrance to the Port of Trieste and, after cutting some metal cables, succeeded in forcing an entrance. After careful search, the battleships were revealed and attacked with torpedoes. The Wien was hit and went down immediately, and the Budapest, anchored nearby, was hit but only slightly damaged. The MAS's were able to escape, in the confusion that followed, by the same route in which 2 they had entered.

The year 1918 was perhaps the most successful for the Italian MAS's, as their raids did much to hamper the life line of Austrian merchant traffic. Their operations on June 8th of that year against the Canal of Otranto were also successful as they further weakened the Austrian Navy. Large units, escorted by torpedo boats, and MAS's operating independently, made up the striking forces. Two MAS's explored the waters between the rock of Gruizza and Selve. After exploring the area, they came out of the Strait at about 2:00 a.m. and headed slowly toward the open sea to join the other units. About 3:00 a.m., a large cloud of smoke was sighted to starboard and, upon investigation, they found two large warships escorted by ten or more destroyers. One MAS maneuvered into position and fired two torpedoes at the first large warship at a range of about 350 yards. The vessel was the Szent Istvan, the most recent ship of her type, and she went to the bottom two and a half hours later, despite all efforts to save her. Successful actions continued and, on October 31st, the nets were forced at Pola and a large warship, the Viribus Unitis, was sunk. This resulted in complete revolt and loss of discipline in the Austrian Navy.

The Coastal Torpedo Motor Boat (CMB) was the British version of the small, fast torpedo craft and was developed in 1916 as a result of considerable designing work. They were 40 feet long with a speed of about 30 knots, carried two small torpedoes, three machine guns and a crew of three. Those boats were mostly Thornycroft design with a singlestep hull. By the end of the last war, Britain had constructed a total of 66 CMB's, of which only six were lost.

The CMB's played an important and spectacular part in the attacks on Zeebrugge and Ostend in April, 1918. Their main task was laying smoke buoys in advanced positions and smoke screens around the harbor entrance by using chlor-sulphonic acid in their exhausts. Routine duties of CMB's were mine laying, rescue of crews from fallen planes, and patrol off the Belgian Coast. In one action, six CMB's were attacked by eight German aircraft and all the boats were temporarily put out of commission though none were lost. Motor torpedo boats were also used extensively in the raids on Kronstadt after the Russian revolution. In these most spectacular operations, two capital ships, a cruiser, two destroyers and other craft were sunk or completely disabled while only two CMB's were lost (probably by mines). The results achieved by both the British and Italian boats formed the first basis to substantiate the claims of the supporters of these vessels, and must be considered responsible for the early adoption of this type of craft by nearly every navy.

As a result of the British CMB, Germany built boats known as patrol motor boats (PMB's). Based in the harbor of Blankenberghe, they were both slow and ineffective. The design and performance of German motor torpedo boats have shown such remarkable improvements in this war that their accomplishments are worthy of mention. Before and since the battle of France, Germany had used a fast armored vessel known as the "E" boat. They have many practical uses such as attacks against convoys, escort duty, mine laying and the rescue of plane pilots. Boats of this type range in length from 80 to 110 feet, are about 65 tons displacement and have a speed of about 30 to 36 knots. They carry from two to four torpedo tubes, several heavy machine guns, and some armor. Seaworthy and capable of taking considerable punishment, they are equipped with Diesel engines that have proven satisfactory. At first, the British held the "E" boats in contempt but, when the latter started operating in packs and disrupting British channel traffic, the, British began earnestly to improve their own craft and to use motor gunboats in combating those of the enemy. Motor gunboats, incidentally, are MTB's that have had the tubes removed and more and heavier guns added, thus increasing their fire power.

The first spark of motor torpedo boat enthusiasm in this country probably resulted from the interest in the establishment of a volunteer patrol squadron of small boats in the first World War. President Roosevelt, then Assistant Secretary of the Navy, took an active interest in patrol craft and. persuaded A. Loring Swasey, now a Naval Reserve Captain in the Patrol Craft section of the Bureau of Ships, to build five volunteer sub-chasers. These and many others did considerable patrol work and established an excellent combat record.

Our early destroyers were little more than torpedo boats. They were small in size, carried torpedoes and light additional armament: Then came a gradual increase in size to 1200 tons and, later, they were stepped up to 1500 and 1850 tons. While present day destroyers increased to a size of 2100 and 2250 tons, and the entire tempo of warship construction was tuned to make the large and heavy type ships larger and heavier, there still remains the need for the fast small craft which can carry and deliver a heavy punch. The 80-foot sub-chasers (ML's) which were built for Britain in great quantities in the last war by The Electric Boat Co. also inspired an interest in the motor launch and coastal motor torpedo boat as used by Britain. Soon after the first World War, the Navy Department bought both a 40- and a 50-foot British Thornycroft boat for testing purposes, but no further progress was made with the development of such boats until 1937.

General Douglas MacArthur, upon appointment to organize and build up the Filipino Army, became cognizant of the ever threatening dangers from Japanese aggression and the rSle that small, fast motor torpedo boats might play in strengthening the Islands' defenses. He reasoned that the motor torpedo boat might provide a solution, as she could be built in a hurry at a minimum cost, and at the same time, in conjunction with air- ' craft, provide the Philippines with a good defensive and striking force. In this interest, he journeyed back to the United States to press his program for defense. In the United States, remote from any apparent danger, he found few with enthusiasm for such craft, so he appealed to his old friend Admiral Leahy, then Chief of Naval Operations, to plead his dire need of 100 small, fast boats to defend the Philippine Islands. The final and indirect outcome of this appeal was a $15,000,000 appropriation put through Congress for the development of such craft.

Thereafter, the early designs were developed without a specific employment plan in mind. One faction maintained that the size of the boat should be kept down, so that the target presented would be negligible. Another faction declared that the boats should be larger to increase their seaworthiness. A third insisted on the construction of torpedo boat catchers in an effort to counteract the effect of the motor torpedo boats being built by potential enemy countries, while the fourth held that, since the small boats could not remain at sea for any length of time and the cruising radius would be short, there would be no need for motor torpedo boat catchers as there would be nothing for them to catch. Still another claimed it was foolish to spend $200,000 to $300,000 for such a boat when a torpedo plane, costing about the same amount, could carry a torpedo much faster and further and probably be more effective. The PT proponents replied by stating that the type of weather that would normally ground aircraft - darkness, fog and low visibility - would prove ideal for PT operation and, besides, the boats could remain at sea longer than aircraft could remain in the air. The result was a compromise in design.

Thereafter the development of the PT was marked by a design contest, open to civilian naval architects, and by the further development of the types of PT's which are now a part of the United States battle fleet. For the record, it is interesting to note that one of the original Navy contracts provided for the construction of PTC's (Patrol Torpedo Boat Chasers). The difference between the PT's and the PTC's was only a matter of armament and equipment. Instead of carrying four torpedoes, the first PTC's carried about 22 depth charges in racks, and two Y guns aft. Subsequently, the construction of this type of boat was discontinued. PT's 10 to 19 were fitted with 18" torpedo tubes; PTC's 1 to 12 were rated as subchasers.

The PT's now in operation range from 77 to 80 feet in length, have three 1350 hp. engines with a full load speed in excess of 40 knots, with either four torpedo tubes or two torpedo tubes and eight depth charges or four mine racks, two .50 caliber machine guns, a 20 mm. gun and a smoke screen generator. Each boat carries a complement of eleven, two officers and nine men.

The primary mission of motor torpedo boats is to attack enemy surface vessels. Their high speed, handiness and torpedo armament make them most suitable for surprise attacks against enemy surface vessels at night or during low visibility. The secondary missions which they may be called upon at times to fulfill are: (a) Anti-submarine operations; (b) Emergency rescue vessels; c) Escort duty; (d) Mine laying; (e) Commando Missions.

We must remember that motor torpedo boats, like aircraft, are not a "cure all" and their employment for other purposes than those for which they are designed tends to reduce their life and effectiveness when called upon to fulfill their primary mission. Uses such as picket duty, anti-submarine patrol and as high speed transports place unnecessary hours of duty on the engines and other equipment, thereby reducing the boats' efficiency.

The normal motor torpedo boat squadron consists of eight to twelve boats and a complement of about 25 officers and 175 enlisted personnel. Besides the boat crews, each squadron has additional personnel for base administration, maintenance, overhaul and upkeep. Each boat has a crew's compartment forward capable of billeting eight men and two small staterooms for officers. There is also a small galley. Boats can operate away from tender or base for many hours for which full rations are carried; emergency rations carried permit subsistence for a day or two longer. In combat areas, where speed is vitally important, all excess equipment such as bunks, cooking gear, etc., is removed to cut down weight and help increase speed. Sandwiches and vacuum jugs of coffee usually provide all the sustenance when boats are operating on a mission.

Considerable publicity has given the impression that our motor torpedo boats are capable of fantastic speeds. Our present boats are a compromise between speed, seaworthiness, armament and being self-sustaining: Their main defensive power lies in small size, speed, handiness, ability to lay smoke screens and to cruise silently at low speed.

W. C. Specht, Commander, USN, and W. S. Humphrey, Lieut (jg), USNR. The opinions or assertions contained herein are the private ones of the writers and are not to be construed as official or reflecting the views of the Navy or the Naval service at large. Elco PTs In Action. The Development Of The PT. Electric Boat Co. 1943.

By a large margin, most PT boats were lost when they ran aground in enemy waters and were destroyed to prevent their capture. Grounding was a continuous threat to PT boats as they sped through coastal waters, making an attack or attempting to escape after one. Accidents also took a major toll on PT boats; their highly volatile fuel (100-octane gasoline) made the boats vulnerable to enemy gunfire as well as to mishaps.

After the war the Navy initially retained three squadrons for training: MTB Squadrons 4, 41, arid 42. However, in early 1946 the Navy Department decided to keep only four boats for experimental work, the PTs 613, 616, 619, and 620, all newly completed Elco boats. With the last squadron decommissioned in April 1946, these four boats were assigned to the Operational Test and Development Force. The hundreds of other boats were broken up or sold for commercial use.

Shortly after the war the Navy initiated the design of a new series of PT boats. Reminiscent of the late 1930s design competition, the Navy ordered four PTs with different characteristics from four yards. All would have aluminum hulls and would be powered by four Packard engines (in place of three Packards of lesser horsepower in war-built boats). All were to carry 40-mm and 20-mm guns and have four torpedo launchers. These boats were:

1. PT 809-built by the Electric Boat Company in Groton, Connecticut-featured a riveted hull 98 feet in length.
2. PT 810-built by Bath Iron Works, Bath, Maine-with a hull partially riveted and partially welded, 89 feet in length.
3. PT 811-built by John Trumpy and Sons, Annapolis, Maryland-an all-welded boat 94 feet in length.
4. PT 812-built at the Philadelphia Naval Shipyard-with an all-welded hull, configured specifically for rough seas, 105 feet in length. The PT 812 subsequently had her four Packard engines replaced by a pair of Metropolitan Vickers gas turbines on her outboard shafts with two smaller diesel engines being fitted to her inboard shafts, the latter to provide speeds up to 18 knots. This early U.S. Navy experiment with aircraft-type turbine engines was unsuccessful.

The four were completed in 1950-1951. After their initial trials, these boats operated from 1954 to 1959 as MTB Squadron 1 under the Navy's Operational Development Force. (U.S. MTB hull numbers reached PT 822, with the PT 813 through PT 822 built in Denmark with U.S. funds under the Military Defense Assistance Program.)

No PT boats operated under the American flag during the Korean War (1950-1953). The four surviving Elco boats were transferred to the South Korean Navy in 1952. The four competitive prototypes were not considered suitable for an overseas deployment in a combat environment. But they all had active careers.

The PT 809 was transferred to the White House in late 1959 for use by the Secret Service as a "chase" boat for the presidential yacht. As signed the name Guardian, she was based at the Washington Navy Yard. About 1965 she was transferred to the Central Intelligence Agency for classified work. In 1974 the craft was returned to the Navy and modified for use as a drone recovery boat, being renamed Retriever and designated DR 1. Through 1986 she supported Navy operations with remote-control aircraft, operating out of Little Creek (Norfolk), Virginia. She was then retired after 35 years of service!

The PT 812 was transferred to the U.S. Army in 1959 and, in 1968, to the South Korean Navy. The PT 809 and PT 810 were stricken from the Naval Vessel Register in late 1959. However, with the escalation of U.S. military operations in Vietnam, the craft were placed back in service in January 1963, and reclassified as PTF 1 and PTF 2, respectively. PTF - for fast patrol boat - reflected their new role.

One final "torpedo boat" was built for the U.S. Navy - the CPIC or coastal patrol and interdiction craft. This 100-foot craft was built as a prototype successor for the PT/PTF-type small combatant. The Tacoma Boatbuilding firm in the State of Washington launched the craft in 1974. The U.S. Navy carried out extensive trials. Among the CPIC's special features was a modular weapons configuration to permit rapid changeover to guns, rockets, missiles, torpedoes, and mines. Total weapons payload was ten tons (on a full load displacement of about 75 tons). The craft was propelled by two aircraft-type Avco Lycoming gas turbine engines with an auxiliary diesel; maximum speed was in excess of 40 knots.

After U.S. Navy trials, on August 1, 1975, the CPIC was transferred to South Korea. Additional craft of this type were constructed in South Korea. The CPIC was the last U.S. small combatant built with a torpedo capability-the last PT boat. Anti-ship missiles, which could be carried by rela tively small ships as well as large warships, aircraft, and even submarines, had replaced the torpedo.

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