United States Navy submarines, surface ships, and aircraft launch torpedoes, missiles, and autonomous undersea vehicles as part of training exercises. Typically, these training munitions have no warhead and are recovered from the sea and reused. Similarly, new naval weapons under development are launched at sea in performance trials. These experimental units also need to be recovered, in their case to obtain evaluation data. At various points in history, newly manufactured torpedoes were fired as a quality control measure and these, too, had to be recovered before issuing them to the fleet. The U.S. Navy has used a variety of boats to accomplish the retrieval of these test and training munitions. As their missions evolved over the last century they have been variously known as torpedo retrievers, torpedo weapon retrievers, torpedo recovery boats, range support craft, and multi-purpose craft.

These vessels have usually been confined to firing ranges close to port and have not engaged in combat. The individual service histories of these boats are consequently modest, undramatic, and frequently undocumented. While their individual histories may be lost, as a class they have been part of the Navy for a century and have served around the world. Their modern types remain in service with the Navy today, continuing to provide an essential function.

History and operation

The first sinking of a ship by a self-propelled torpedo occurred in 1878, and by World War I, torpedoes played a pivotal role in naval warfare as German U-boats sought to close the North Atlantic to allied shipping. While the United States had experimented with early torpedoes, the U-boat threat in World War I focused undersea warfare efforts on anti-submarine technologies rather than torpedoes. At the close of World War I, U.S. defense spending was reduced, further curtailing the development of torpedo systems. Consequently, U.S. Navy experience with torpedoes was quite limited prior to World War II. At the start of the conflict there was no one in the Navy who had ever seen or heard a torpedo detonate either in test or war. No U.S. submarine sank a vessel using a torpedo until 1941. In this environment of economy, testing and trainining were limited. Only two types of small purpose-built torpedo retrievers, 40' and 42' boats, were built. There were few enough of these that it was common for unspecialized motorboats to recover exercise torpedoes.World War II brought about a large increase in U.S. Navy use of torpedoes. Prior to the war, about 60 torpedoes per month were manufactured. Over the next four years nearly 50,000 were produced. Training and testing capabilities expanded significantly, including new, more capable torpedo retrievers, notably the 63' vessels converted from aviation crash boats. Even so, other small vessels continued to be pressed into service as retrievers. For example, during March 1945 the rescue tug ATR-63 was detailed to retrieve exercise torpedoes off Pearl Harbor five times. Two exercises were aborted due to high winds and seas, and in the other three exercises she recovered 25 torpedoes, including some dropped by aircraft and others fired by submarines USS Cod and USS Cero.

The most recent generations of torpedo retrievers are much more than that, as their designations suggest. They are now categorized as range support craft, and multi-purpose craft. They not only retrieve torpedoes, but new classes of weapons including missiles, and autonomous undersea vehicles. They launch drones and other targets. They tow various targets and lower sound transducers into the sea to simulate enemy vessels. They are capable of extended operation away from port, sailing independently, and have capacity to retrieve many exercise weapons without having to return to base.

For most of their history, torpedo retrievers have been manned by Navy enlisted personnel. A recent development is the outsourcing of operation and maintenance of these vessels. While the Navy continues to own the boats, civilian contractors and crew will run many of them. The Pacific Missile Range Facility, the Southern California Offshore Range, and the Naval Submarine Support Command at Pearl Harbor have all moved toward placing civilian crews aboard their range support craft.

Torpedo retrieval techniques Exercise torpedoes are intended to float on the surface when they reach the end of their runs. Various techniques have been used to achieve this. For example, the submarine-launched Mark 14 torpedo of World War II replaced its warhead with an exercise head filled with water. At the end of the torpedo's run, compressed air would expel the water, lightening the weapon sufficiently to float.

In order to recover a floating torpedo it is first necessary to find it. Prior to the advent of electric torpedoes, which first reached the U.S. fleet in September 1943, torpedo recovery boats could follow the stream of bubbles generated by the weapon's propulsion system. Also aiding the retrievers was that early torpedoes were primarily used against surface ships, so they ran at a set, shallow depth. They ran straight, with no ability to change course once fired, making their ultimate destination somewhat predictable. Exercise torpedoes have typically been painted in bright colors, often international orange, to stand out in the water.

Modern torpedoes have electric propulsion systems that leave no trail of bubbles for a retriever to follow. They also rely on homing and other technologies that can change a weapon's course once fired. Further complicating location is that torpedoes are more likely to be used against deep-diving submarines, rather than surface ships, so not only is their course less predictable, but also the depth at which they run. Today, finding spent torpedoes is aided by dye packets that vividly color the sea where they complete their run. Some torpedoes have also been equipped with an electronic end-of-run locator, a "pinger" producing a high-frequency sound that can be detected by hydrophone equipment.

Once a torpedo has been located, the next step in retrieval is to attach a line to it. A variety of snares and slings that encircle the body of the weapon, and various nosepieces have been used to attach lines to the otherwise smooth object. Slings and nose cages have been attached to the weapons either by swimmers, by sailors working from a small boat, or by sailors operating from the torpedo retriever itself.

Having located and captured a spent torpedo, it could now be recovered. The early 40' and 42' torpedo retrievers had no ability to bring a weapon on board. Their crews would snare a floating torpedo, tie a line to it, and tow it to a dock or ship where it could be craned out of the water. In the absence of purpose-built torpedo retrievers, a wide variety of small boats performed similarly. Disadvantages of these early vessels included their inability to operate in difficult sea conditions, to stay on station overnight, to navigate on their own, and to recover more than one torpedo per trip. These early retrievers had no radios. They would communicate by raising a "bravo" signal flag to indicate they were recovering a torpedo. Beginning with the 63' boats and continuing to the present day, all U.S. Navy torpedo retrievers have an inclined aft deck or ramp equipped with rollers that allow torpedoes to be winched aboard directly from the sea. These larger vessels could recover multiple torpedoes before off-loading to a shore facility or ship.

Torpedo retriever alternatives Torpedo retriever boats are but one of the ways spent exercise and test weapons have been recovered by the Navy. Malfunctioning torpedoes that sink require different approaches. Divers, nets, grapples, and magnetic detectors have been used to search for lost weapons starting as early as 1919. A descendant of these early methods, recovering munitions as deep as , were a series of increasingly sophisticated cable-controlled robots called CURV. Beginning in the 1950s, the Navy experimented with training a variety of marine mammals to recover sunken torpedoes. Orca, beluga whales, pilot whales, and bottle-nosed dolphins were all trained with some level of success. As robots became more capable and cheaper, this program was discontinued.

Helicopters are also capable of recovering floating torpedoes using specialized nets, but they suffer from a number of disadvantages compared to torpedo recovery boats. They are in short supply, have limited flight times, are expensive, have limited lifting capacity, and can pick up just a single torpedo per trip.

The United States Air Force has also operated drone and missile retriever boats to support its own training and development requirements and continues to do so to the present day.

U.S. Navy torpedo retrievers The Navy's rules regarding these non-commissioned vessels have varied over the decades, but for much of their history they were not entitled to an official name or even a pennant number painted on their bow. These nameless vessels have simply been known by their hull number. Unofficial pennant numbers and names have been assigned from time to time at their bases. This has led to historical confusion since vessels with the same unofficial name or pennant number have been in service simultaneously. The vessels described below are listed in order of their introduction to the fleet.

40' Torpedo retriever The navy built a number of these small, wooden torpedo retrievers as early as 1924. They were driven by twin 150 horsepower Palmer Marine gasoline engines. Many were declared surplus after World War II and sold to the public for prices as low as $250.

42' Torpedo retriever These boats had white cedar hulls framed with oak. After World War II many of these vessels were declared surplus and sold to the public for prices as low as $750. Nonetheless, a few of them served into the 1950s.

63' Torpedo retriever

This class of torpedo retrievers began as conversions from 63' aviation crash boats, designated auxiliary vessel - rescue (AVR) by the Navy. Their aft cockpits were modified with a ramp down to the water. Hand-cranked winches were installed on deck to haul torpedoes out of the water and onto the ramps. The configuration of these boats varied based on the model of AVR from which they were converted. Some gasoline powered boats could reach 20 knots, while others powered by twin Gray Marine 165 diesel engines, reached a speed of 11 knots. They sailed with a crew of six.

One of these vessels was converted into the base fishing boat, Big Wheel, at Naval Station Key West. This former torpedo retriever hosted President Harry S. Truman on fishing trips in 1949 and 1951. +63' Torpedo retrieversPennant #NotesOne assigned to Naval Station Key WestThree assigned to Submarine Base Pearl HarborFour were assigned to the Montauk Naval Torpedo Testing Range. In November 1956, one of them, "22", sank in heavy seas between Montauk and Block Island while exercising with USS Becuna, which rescued the torpedo retriever's crew.TRB-8Assigned to the Long Beach Sea Range, a detachment of the Naval Ordnance Test Station.TRB-9Assigned to the Long Beach Sea Range, a detachment of the Naval Ordnance Test Station.TRB-11Assigned to the Long Beach Sea Range, a detachment of the Naval Ordnance Test Station.

72' Torpedo recovery boat