The M40 became the most powerful Allied SPG of WWII. The M40 fought in the battle for Cologne in 1945. Both the M40 and M43 were used during the Korean War.
The M40/M43 SPG was built on a widened and lengthened M4A3 medium tank chassis. The vehicle is designated as the M40 Gun Motor Carriage in a version that mounts the 155mm M1A1 "Long Tom" gun. The version that mounts the 8-inch (203mm) Howitzer is designated the M43 Howitzer Motor Carriage.
The M40/M43 leads to the M53/M55.
Pros and Cons
- Fast and mobile
- Nice gun arc
- Impressive damage.
- Low HP
- Bad accuracy and slow aim time
- Slow RoF
- Horrid Camouflage Rating
The M40/M43 has an excellent traverse speed compared to the GW Tiger and Object 212 and its top speed is good as well. The M40/M43 has a lower damage output than both those SPGs but makes up for this with its mobility, giving it the ability to relocate quickly if it is spotted by enemy tanks.
- Both upgrade engines and both upgrade radios carry over from the M12 if researched there.
- The suspension upgrade is necessary to handle the weight of the top engine and gun.
- Stock vehicle is the M40 version with 155mm gun.
- With the 8-inch Howitzer mounted the vehicle becomes the M43 version.
- Size matters in selection of arty guns. Get the big one. It adds 10 seconds to reload time, but little aim time difference.
The 155 mm Gun Motor Carriage M40 was a US self-propelled artillery vehicle built on a widened and lengthened Medium Tank M4A3 chassis, but with a Continental engine and HVSS (Horizontal Volute Spring Suspension) that was introduced at the end of the Second World War. Equipped with a 155 mm M2 gun, it was designed to replace the earlier M12 Gun Motor Carriage. Its prototype designation was the T83, but this was changed to the M40 in March 1945.
A single pilot vehicle was used in the European Theatre in 1945 by the 991st Field Artillery Battalion, along with a related 8-inch Howitzer Motor Carriage T89, which was sometimes also equipped with a 155 mm barrel. From there, it was deployed during the Korean War.
After World War II, the M40 was used by the British Army, who designated it the 155mm SP M40.
A version on the same chassis mounted an 8-inch (203 mm) howitzer and was designated the M43 Howitzer Motor Carriage. It was standardized in August 1945, 48 were built. The M43 saw action in the Korean War.
The Army planned to use the same T38 chassis for a family of SP artillery:
- Cargo Carrier T30- a few built before cancellation in December 1944 to make more chassis' available for GMCs.
- 8 inch Howitzer Motor Carriage M43- 8 in (203 mm) HMC, standardized August 1945, 48 were built.
- M40 Gun Motor Carriage and M43 Howitzer Motor Carriage Photos & history.