After WWII the US Army sought to replace the
M41 Howitzer Motor Carriage with a better SPH using the drive train of the future light tank then developed (originally T37, later T41 and finally
M41), giving it increased battlefield mobility. Unlike the M41 and the earlier
M12 Gun Motor Carriage, the T99 was to have an enclosed gun compartment, giving the five-man crew some armor protection even when firing the cannon. The 155mm cannon, designated T97, was to be a radically new design, with a
muzzle brake,
bore evacuator and new, separately-loaded ammunition with metal cartridge cases. T99 should also have had a revolutionary gun control system. When the
Korean War broke out in 1950, the US Army realized it didn’t have enough self-propelled artillery the development was sped up, and with features from T41E1 light tank, the T99E1 SPH prototype was rushed into production even before testing was complete. After 250 had already been produced by the
Massey Harris company, it was discovered that firing the howitzer discharged poisonous fumes into the gun compartment, leading to the cancellation of the order. Engineers offered a revised design called the T194E1 with a modified howitzer T186E1 (standardized as M45) based on the
M114 bagged charge ammunition and open (roofless) crew compartment that successfully vented the fumes, albeit at the cost of crew protection. The already produced vehicles were upgraded to the new standard, with the designation M44, and deployed to front line units in 1954, too late to see action in the Korean War. The M44 fleet was later upgraded with AOS-895-6 engines, and thus designated the M44A1. Production ended in 1958. The M44 served on until 1963, when it was replaced by the
M109. The M44 was exported to West Germany, Italy, the UK (where it was called the "Cardinal" under the ecclesiastical naming convention for self-propelled artillery) and Turkey.
Turkish M44T In 1986, 222 Turkish Army M44s were extensively upgraded with 36 caliber 155mm howitzers by
Rheinmetall with an increased range of 24.7 km. An MTU MB 833 Aa-501 V-6 water-cooled diesel developing 450 hp at 2,300 rpm coupled to the original Allison CD-500-3 transmission via a
ZF gearbox was fitted. There were numerous other improvements such as upgraded suspension, tracks and fire control and increased fuel capacity. The driver's position was moved into the hull. The last was delivered in 1992. Some sources claim they have now been withdrawn, but two were seen in a video by the Russian news agency
RT, allegedly firing into Northern Syria from a border post inside Turkey in 2015. ==Variants==