Lockheed Martin designed and developed the MK 48 Mod 7 Common Broadband Advanced Sonar System (CBASS) submarine-launched heavyweight torpedo for the US Navy.
The torpedo, which has advanced counter-countermeasure capabilities, is operational with the US and its allied submarine fleet, and serves as a highly effective and lethal weapon against anti-surface and anti-submarine threats in deep and shallow waters.
The heavyweight torpedo is equipped with advanced commercial-off-the-shelf technologies to provide superior reliability and performance against challenging threats in both littoral and blue water environments, and can support multi-band operation.
MK 48 Mod 7 CBASS development details
The MK 48 Mod 7 CBASS is an upgraded version of the MK 48 Advanced Capability (ADCAP) Mod 6 Advanced Common Torpedo (ACOT), manufactured by Raytheon. The new torpedo was developed as part of an Armaments Cooperative Programme between the US Navy and the Royal Australian Navy.
MK 48 Advanced Capability (ADCAP) Mod 6
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.
|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|
MK 48 Advanced Capability (ADCAP) Mod 6 – Source navysite.de
The US Navy awarded a $70.2m contract to Raytheon for 15 MK 48 ADCAP torpedoes in support of MK 48 CBASS initial production and production engineering. Development testing of the MK 48 CBASS torpedo was completed in November 2004 and operational testing was completed in November 2005. Initial operational capability was achieved in 2006 after hardware and software upgrades.
The torpedo was successfully test-fired by HMAS Waller submarine of the Australian Navy during the Rim of the Pacific 2008 (RIMPAC 08) exercise in July 2008.
Orders and deliveries
MK 48 Mod 7 CBASS
The US Navy awarded a five-year fleet-wide CBASS programme to Lockheed Martin in 2011 to modernise a total of 1,263 MK 48 torpedoes deployed by the entire submarine fleet as anti-submarine or anti-surface warfare weapons. The company received a contract worth over $50.68m for functional item replacement kits, engineering services, spare parts and production support material in March 2011.
The upgrade kit consists of a broadband analogue sonar receiver, a guidance and control box, a pre-amplifier, guidance and control materials, and cable assemblies. It provides increased bandwidth and streamlined targeting and tracking capabilities to the heavyweight torpedo.
Lockheed Martin secured a $37m contract from the US Navy in August 2013 to provide Mod 7 CBASS replacement kits and services for the MK 48 heavyweight torpedoes in service with the US Navy and allied naval customers from Canada and the Netherlands. Polaris Contract Manufacturing, a subsidiary of Lockheed Martin, is responsible for building the circuit card and module assembly. Completion of the work is scheduled for July 2017.
Lockheed Martin was awarded a $10m contract by the Naval Sea Systems Command (NAVSEA) in April 2014 to provide maintenance support for all MK 48 torpedoes.
US Navy contracts Lockheed for MK 48 Mod 7 torpedo guidance upgrades
The U.S. Naval Sea Systems Command has awarded Lockheed Martin Sippican a $72,8 million contract for the procurement of MK 48 Mod 7 heavyweight torpedo guidance and control sections.
Under the contract, Lockheed will also provide MK 48 Mod 7 Common Broadband Advanced Sonar System upgrade kits, test equipment, spares, production support material, engineering support, and hardware repair support.
This contract includes options which, if exercised, would bring the cumulative value of this contract up to $424,7 million.
Work will be performed in Marion, Massachusetts and is expected to be completed by December 2019. Source navaltoday.com
Design and features of the MK 48 Mod 7 CBASS
The MK 48 Mod 7 CBASS torpedo has a length of 5.8m and diameter of 53cm, and can reach a maximum depth of 1,200ft. It weighs 1,676kg and carries a high explosive warhead of 292.5kg.
Active and passive homing guidance is provided by the Common Broadband Advanced Sonar System. The torpedo can effectively engage low-Doppler shallow submarines, fast deep diving submarines and high-performance surface ships.
It supports autonomous fire-and-forget operation or wire-guide capability to provide post-launch monitoring and updates through the submarine combat system. It also allows the transmission and reception over a wide frequency band. The broadband signal processing techniques ensure improved search, acquisition and attack effectiveness for the torpedo.
Mk 48 Mod 7 CBASS submarine torpedoes
The CBASS broadband sonar makes the torpedo more effective against emerging submarine classes in the harshest of acoustic environments, Lockheed Martin officials say. The Mark 48 Mod 7 CBASS torpedo uses modern commercial-off-the-shelf (COTS) technologies in an open-architecture computing environment, and can be improved with regular hardware and software upgrades.
(Edit: HD) Mk 48 Mod 7 CBASS schematic, the US Navy’s current heavyweight torpedo. Sonar transducer in front followed by the electronics, warhead, fuel tank, and engine.
The Mark 48 Mod 7 torpedo is standard armament for the Navy’s fleet of Los Angeles-, Virginia-, and Seawolf-class fast attack submarines, as well as Ohio-class ballistic-missile and cruise-missile submarines.
Mk 48 Mod 7 CBASS schematic, the US Navy’s current heavyweight torpedo. Sonar transducer in front followed by the electronics, warhead, fuel tank, and engine.
The Lockheed Martin Corp. Mission Systems and Training segment in Washington is building the Mark 48 Mod 7 CBASS heavyweight torpedo with advanced common broadband advanced sonar system for expanded operational capabilities for shallow waters along coastlines and inside harbors, as well as in the deep-water open ocean.
The CBASS torpedo also has the ability of multiband operation with active and passive homing; advanced counter-countermeasure capabilities; effectiveness against low-Doppler shallow submarines, fast deep diving submarines, and high-performance surface ships; autonomous fire-and-forget operation or wire-guide capability to enable post-launch monitoring and updates via the submarine combat system; and running Otto Fuel II as the propellant.
Detail: CBASS fuel tank containing Otto II fuel (wire reel on the right)
The Mark 48 Mod 7 CBASS torpedo can transmit and receive over a wide frequency band and use broadband signal processing techniques to improve the torpedo’s search, acquisition, and attack, Lockheed Martin officials say. Source militaryaerospace.com
Virginia-class attack submarine: Details
MK 48 Guidance and Control Section
Lockheed Martin provides the U.S. Navy the latest advancements in sonar systems for guidance and control systems for the MK 48 Mod 7 torpedo. The Lockheed Martin guidance and control systems will equip the heavyweight torpedoes with increased bandwidth and streamlined targeting and tracking capabilities. These systems will optimize the MK 48’s effectiveness as well as provide advanced counter-measure capabilities.
Lockheed Martin provides fully integrated guidance and control sections to increase the inventory of MK 48 torpedoes over several years. The expectation is that the production orders will range with the potential for more than 250 torpedoes over the next five years for the U.S. Navy, which are used by all classes of submarines as their anti-submarine warfare (ASW) and anti-surface warfare (ASuW) weapon.
The guidance and control systems for MK 48 torpedoes include the same section of the Navy’s existing heavyweight torpedoes that Lockheed Martin is upgrading under the MK 48 Common Broadband Advanced Sonar System (CBASS) awarded by the U.S. Navy in 2011. Lockheed Martin delivers to the U.S. Navy at least 20 Mod 7 CBASS kits per month and is on track to deliver all kits on schedule. Lockheed Martin also performs work intermediate maintenance of these torpedoes for fleet training, giving the Navy a critical combat advantage.
MK 48 Mod 7 CBASS
The MK 48 is designed for:
- Active and/or passive homing; Advanced counter countermeasure capabilities.
- High effectiveness against low-Doppler shallow submarines, fast deep diving submarines and high-performance surface ships.
- Autonomous fire-and-forget operation or wire-guide capability to allow post-launch monitoring and updates via the submarine combat system.
- Otto Fuel II as the propellant is an inexpensive and safe alternative to other fuels and electric propulsion.
Engine and performance
The MK 48 Mod 7 CBASS torpedo is propelled by an inexpensive Otto Fuel II Piston engine, and has a speed of more than 28kt and a range of five miles.
MK 48 Mod 7 CBASS
|MK 48 Physical Specifications|
|Weight||3,500 lbs (1, 676 kg)|
|Length||19 ft (5.8 m)|
|Diameter||21 inches (53 cm)|
|Maximum Depth||> 1,200 ft|
|Effective||> 5 miles|
|Speed||> 28 knots|
|Guidance System||Common Broadband Advanced Sonar System|
|Warhead||650-lb (292.5 kg) high explosive|
|Propulsion||Otto Fuel II Piston Engine|
Specification data for MK 48 Mod 7 CBASS lockheedmartin.com
Main material source naval-technology.com