Extended Range Guided Munition
The Extended Range Guided Munition was a precision guided rocket-assisted 5-inch (127 mm) shell (projectile) development by Raytheon for the U.S. Navy. The program was cancelled in March 2008 after twelve years of development and over 600 million dollars in funding.[1] The developmental round was designated EX 171.[2]
ERGM consisted of three major subsections: propulsion (rocket motor), warhead, and Guidance, Navigation and Control section. ERGM is fired from the 127 mm (5-inch) 62-caliber Mark 45 gun Mod 4, at which point the fins would deploy and the rocket motor would ignite, lifting the munition to at least 80,000 feet (24 km), after which the canards would deploy and guide the ERGM to the target using GPS guidance. It was to be used on Arleigh Burke-class destroyers hulls DDG-81 onward.[3]
Synopsis
[edit ]Despite the long development time, the ERGM never worked as reliably as the older but significantly less expensive laser-guided M712 Copperhead. During development, the ERGM failed several tests in which the tail fins failed to deploy at launch, rocket motors did not ignite, or the electronic components did not survive the stress of being fired from a gun.[4] In February 2008, guidance components, rocket motors, and tail fins all failed in tests; Raytheon claimed they were testing specific functionalities rather than overall functionality and that they were "on the verge" of making the whole system operate reliably, but the Navy had lost confidence after years of issues and were no longer expecting a return on investment. Rising cost was another factor in cancellation. The unit cost of the shell more than quadrupled, from US$45,000 in 1997 to 191,000ドル by 2006 (the Copperhead unit production price was about 30,000ドル), reducing the projected buy from 8,500 to about 3,150. Program research-and-development costs had increased from 80ドル million to 400ドル million between 1997 and 2004, with total program costs increasing from 400ドル million to 600ドル million. The Navy formally cancelled the ERGM program on 19 March 2008.[5] BTERM was another U.S. Navy developmental round that included GPS guidance in an artillery shell; it too was terminated in 2008 after over four years of development by ATK.
Specifications
[edit ]- Caliber: 127 mm (5 in)
- Length: 1.55 m (5 ft 1 in)
- Weight: 50 kg (110 lb)
- Speed: >3000 km/h (1860 mph)
- Range: 110 km (60 nm)
- Guidance: GPS/INS
- Accuracy: < 20 m CEP independent of range.
- Propulsion: Solid-propellant rocket motor.
- Warhead: 72 DPICM submunitions (EX 1) or unitary high-explosive.
Program timeline
[edit ]- 1996 - Program started.[2]
- December 2001 - All-up round guided test flight of an ERGM at White Sands Missile Range, NM.[6]
- February 2005 - Successfully test-fired two tactical ERGM rounds.[6]
- April 2005 - U.S. Navy closes original ERGM program and re-opens new competition to meet the requirement.[7]
- March 2008 - Navy ends funding to Raytheon, effectively killing the program.[8]
See also
[edit ]- Ballistic Trajectory Extended Range Munition
- Long Range Land Attack Projectile
- Rocket Assisted Projectile
- M982 Excalibur
References
[edit ]- ^ Torres, Rene. "Raising the Iowa: Reactivating the Iowa Class Battleships to Fill the Current Naval Surface Fire Support Vacancy" (PDF). Marine Corps Combat Development Command. p. 9. Archived (PDF) from the original on 2021年11月21日. Retrieved 2023年01月07日.
- ^ a b Raytheon ERGM (5" Projectile MK 171) - Designation Systems
- ^ Wertheim, Eric (2005). The Naval Institute Guide to Combat Fleets of the World, 2005–2006: Their Ships, Aircraft, and Systems . Annapolis, Maryland: Naval Institute Press. p. 946. ISBN 978-1591149347.
- ^ Guided munition may be canceled - Navy Times
- ^ End of ERGM spotlights other future guns - Navy Times
- ^ a b EX-171 ERGM Extended-Range Guided Munition - Global Security
- ^ Navy Smart Shell Does a Crash and Burn - Strategy Page
- ^ Navy ends ERGM funding - Navy Times
External links
[edit ]- [1]
- Raytheon Company: Products & Services: ERGM
- Missile Systems - Precision Guided Projectiles - Raytheon
- Graham, Major Jeff (June 2004). "Extended Range Guided Munition (ERGM) Program" (PDF). Brief for the NDIA International Armaments Technology Symposium and Exhibition. Naval Surface Fire Support Program Office. Archived from the original (PDF) on 2012年09月27日.