The Mk-48 is designed to combat fast, deep-diving nuclear submarines and high performance surface ships. It is carried by all Navy submarines. The improved version, Mk-48 ADCAP, is carried by attack submarines and the OHIO class ballistic missile submarines. The Mk-48 replaced both the Mk-37 and Mk-14 torpedoes.
Background and Features:
The Mk-48 has been operational in the US Navy since 1972. MK-48 ADCAP (Advanced Capability) became operational in 1988 and was approved for full production in 1989. The USS NORFOLK (SSN 714) fired the first ADCAP torpedo on July 23, 1988, sinking the FORREST SHERMAN-class destroyer JONAS INGRAM (DD 938).
Mk-48 and Mk-48 ADCAP torpedoes can operate with or without wire guidance and use active and/or passive homing. When launched they execute programmed target search, acquisition and attack procedures. Both can conduct multiple reattacks if they miss the target.
A highly capable weapon, the Mk-48 can be used against surface ships or submarines, and has been test fired under the Arctic ice pack and in other arduous conditions. The ADCAP version, in comparison with earlier Mk-48 torpedoes, has improved target acquisition range, reduced vulnerability to enemy countermeasures, reduced shipboard constraints such as warmup and reactivation time, and enhanced effectiveness against surface ships. The Mk-48 is propelled by a piston engine with twin, contra-rotating propellers in a pump jet or shrouded configuration. The engine uses a liquid monopropellant fuel, and the torpedo has a conventional, high-explosive warhead. The Mk-48 has a sophisticated guidance system permitting a variety of attack options. As the torpedo leaves the submarine's launch tube a thin wire spins out, electronically linking the submarine and torpedo. This enables an operator in the submarine, with access to the submarine's sensitive sonar systems, initially to guide the torpedo toward the target. This helps the torpedo avoid decoys and jamming devices that might be deployed by the target. The wire is severed and the torpedo's high-powered active/passive sonar guides the torpedo during the final attack.
The Mk-48 Mod. 5 ADCAP torpedo is an improvement to the Mk-48 submarine launched torpedo. It is a heavyweight acoustic homing torpedo with sophisticated sonar and a fuzed warhead. The ADCAP enhancement includes all digital guidance and control systems, digital fuzing systems, and propulsion improvements which add speed, depth, and range capability. The Navy will produce about 1046 MODS ADCAPs, replacing an equivalent number of baseline (Mod. 5) ADCAPs, and maintaining the total inventory of ADCAP torpedoes at 1046.
The ADCAP torpedo OPEVAL was completed in August 1988, and the B-LRIP report was sent to Congress in December 1988. ADCAP was reported to be operationally effective against certain threats, but not operationally effective against other threats at that time. The system was reported operationally suitable. The Navy subsequently authorized full-rate production, but Congress constrained procurement because of the concerns identified in test reporting. Modifications were implemented by the Navy to improve performance in certain scenarios, upgrade fuzing systems, and improve reliability. These modifications were considered effective. In 1994 a second software upgrade was introduced to improve performance and reliability.
The MODS ADCAP (Mk-48 Mod. 6), when properly employed, is more effective than the ADCAP torpedo (Mk-48 Mod. 5). Unfortunately, production Mod. 6 ADCAPs have shown a significant vulnerability, differing from the test units. This production problem is typical of problems seen in the initial phases of LRIP. The program office is investigating. DOT&E will continue to follow this.
|General Characteristics - Mk-48 and Mk-48 ADCAP Torpedo|
|Primary Function||Heavyweight torpedo for submarines|
|Power Plant||Piston engine, pump jet|
|Length||19 feet (5.79 meters)|
|Weight||Mk-48: 3,434 lbs (1545.3 kg)|
Mk-48 ADCAP: 3,695 lbs (1662.75 kg)
|Diameter||21 inches (53.34 centimeters)|
|Range||"greater" than 5 miles (8 kilometers)|
|Weapon acquisition range||1,600 yards (1,463.04 meters)|
|Depth||officially: 1,200 feet+ (365.76 meters)|
reportedly: 3,000 feet (914.4 meters)
|Search/attack depth settings||Minimum: 20 yards (18.288 meters)|
Maximum: 1,500 yards (1371.6 meters)
|Speed||officially: 28+ knots; 32.2 mph; 51,52 km/h|
actual: 40 - 55 knots
|Run characteristics||6-8 minutes downward|
|Guidance System||Wire guided and passive/active acoustic homing|
|Warhead||650 lbs (292.5 kg) high explosive|
|Unit Cost||$2.5 million (Mk-48)|
|Date Deployed||Mk-48: 1972|
Mk-48 ADCAP: 1989