November 2, 2005: The Singapore Army has developed the Singapore Lightweight Howitzer (SLWH) Pegasus. Weighing in at a measly (for a heavy artillery piece) 5.4 tons (4898.9 kg), Pegasus is probably the world's lightest 155mm 39 caliber artillery piece with self-propelled capability, and was specially designed for helimobile operations. It's abilities were demonstrated at a media event to mark its official service introduction, when a CH-47D Chinook heavy-lift helicopter dropped off an underslung Pegasus and then landed to disembark an 8 man crew. The crew then used the Pegasus's Auxiliary Power Unit ( APU) system to drive it to a firing location, and then proceeded to bring the weapon to battery within 2.5 minutes.

The SLWH Pegasus is part of a recent trend by many armies to move from helimobile 105mm howitzers towards those of 155mm caliber, and it will replace GIAT 105mm Light Guns currently in service. The primary reasons for the shift to 155mm for 'light' guns is that this will allow armies to standardize all their gun artillery to one caliber, thus reducing supply complications, as well as providing helimobile forces artillery with greater range and lethality For example, the M1 High Explosive round used by the M119A1 105mm Light Gun, currently in US Army service, will deliver 7lbs (3.2kg) of explosives to a range of 7 miles (11.5km), while the M795 155mm HE round, when fired by a 39 caliber howitzer like the US Army's M198, will deliver 23.8lbs (10.8kg) of explosives to 14.3 miles (23km).

The US Army and US Marine Corps, for example, will soon field the British developed M777A1 155mm 39 caliber Ultralightweight Field Howitzer (UFH), which at 4.1 tons (3745kg) is more than a ton lighter than the SLWH Pegasus. While both these howitzers use light materials such as titanium and aluminum to keep their weights low, the Pegasus' 'extra' weight comes from an APU that not only gives it a short-range self-deploy capability, with a maximum speed of 12kmh (8mph) but also powers the Pegasus's ammunition loading system to reduce the manual workload of the Pegasus' crew.

The 155mm 39calibre SLWH Pegasus is actually the fifth homegrown 155mm artillery system that has been developed in Singapore since the 1980s by Singapore Technologies Kinetics (STK) and its predecessor, Chartered Industries of Singapore (CIS). The first weapon was the CIS FH-77, a 155mm 39 caliber towed howitzer. This was followed by the STK 52 caliber FH-2000 in the late 1990s, which also had an APU for short range self-deployment and automated ammunition loading. In 2002, STK unveiled a 7 ton wheeled vehicle mounted 39 caliber weapon called the 155mm Light Weight Self Propelled Howitzer (LWSPH), which never entered Singapore Army service, and in late 2003, the 23 ton 39 caliber Primus Self Propelled Howitzer (SPH) was unveiled. The SLWH Pegasus will join both the FH-2000 and the Primus SPH in Singapore Army service. -- Shawn Chung

For details on the Pegasus:
http://www.mindef.gov.sg/imindef/mindef_websites/topics/Weapons/slwh/home.html
http://www.stengg.com/CoyCapPro/detail.aspx?pdid=270
For details on the Primus:
http://www.mindef.gov.sg/weapons/sph/
For details on the LWSPH:
http://www.stengg.com/CoyCapPro/detail.aspx?pdid=140