M777 155 mm Lightweight Towed Howitzer (United Kingdom / United States)
Channel: Main Battle Tank
Date: 2023-01-12

The BAe (British Aerospace) M777 howitzer is the primary towed artillery piece of the US armed forces, and has effectively replaced the preceding M198 howitzer. It is one of the smallest and lightest weapons of its type ever constructed, due to a combination of a titanium alloy construction and a methodical elimination of as much mass as possible. Though presently produced in the US, the M777 is actually a development of a British design.

The origins of the M777 date back to the early 1980s, as a private venture by Vickers (which later merged with BAe, the current manufacturer) to develop an exceptionally lightweight 155 mm howitzer for the export market. The primary market for this new weapon was the US Army, who has recently fielded the M198 howitzer, but found it wanting; the primary purpose of the M198 had been maximum mobility and air transportability, but at over 7 000 kg, it was still a rather hefty artillery piece. Vickers was convinced that by simplifying the configuration of a 155 mm howitzer and making expansive use of lightweight materials in its construction, they could make a weapon of equal firepower that was just over half the weight of the M198.

Needless to say, figuring-out how to make a 4-ton 155mm/L39 towed howitzer took some time and effort (most weapons of this type are significantly heavier), and the preliminary design wasn't ready until the spring of 1987. The main issue had been figuring out how to apply titanium alloys to the construction of the new weapon, in place to traditional steel, as titanium's impressive strength is also equaled by an impressive price tag, and a very high level of hardness that makes it notoriously difficult to machine. The design was presented soon after to the US Army, who were intrigued by the possibility of fielding such a weapon, and they authorized the construction of 2 prototypes in September of 1987. As the federal law prohibits the US military from procuring weapons of foreign manufacture, Vickers teamed-up with Textron to build this weapon in the US. There was also a competing design submitted by Royal Ordnance, whose development roughly paralleled the Vickers design.

Two prototypes were constructed of the Vickers design, now dubbed the LW155 (shorthand for 155 mm Lightweight Howitzer), which were delivered to the Army for testing and evaluation late in 1989. The US Marine Corps had also taken an interest in the LW155 in this timeframe, seeing potential for such a weapon in their operations, where the weight of an artillery system was at a premium. The USMC evaluated the LW155 as well in 1990.

In the late 1990s there was a formal competition in which the LW155 was pitted directly against the Royal Ordnance design (by this time named the "Light Towed Howitzer"), with the former ultimately being declared the winner. Following this decision, the US Army formally designated the LW155 as the XM777.