| Year | February 1945 |
| Vehicle Type | [@type] |
| Origin & Designer | [@designer] |
| Numbers Produced | 418 (24 Co |
| Crew | 8 (Commander, Gunner, Two Loaders, Two Ammunition Bearers, Radio Operator & Driver) |
| Main Armament | 1 x 155mm L/45 M1A1 or M2 Gun |
| Main Armament | [@sponson_traverse] |
| Elevation | -5° to +45° |
| Turret Traverse | 18° Left & Right (Manual) |
| Gun Traverse | [@gun_traverse] |
| Gun Mount | [@gun_mounts] |
| Maximum Range | [@maximum_range] |
| Armour Penetration | [@armour_penetration] |
| Gun Sight | 7.12m |
| Secondary Armament | None |
| Smoke Discharger | [@smoke_discharger] |
| Ammunition Carried | 20 x 155mm |
| Height | 3.30m |
| Width | 3.15m |
| Length | 7.12m |
| Combat Weight | 37.000 kg |
| Ground Clearance | 0.43m |
| Fording Depth | 1.20m |
| Trench Crossing | 2.30m |
| Obstacle Clearance | 0.61m |
| Climbing Ability | 30° |
| Radio | SCR 619 |
| Armour | Upper Hull Front: 13mm. Lower Hull Front: 13mm. Upper Hull Sides: 13mm. Lower Hull Sides: 25mm. Hull Rear: 13mm. Hull Top: 13mm. Hull Bottom: 13mm. Open Gun Compartment. |
| Engine | Continental R975 C4 (Petrol) |
| Transmission | 5 Forward & 1 Reverse |
| Maximum Road Range | 116 miles (187 km) |
| Maximum Cross Country Range | 80 miles (130 km) |
| Maximum Water Range | [@maximum_water_range] |
| Maximum Road Speed | 21 mph (34 kph) |
| Maximum Cross Country Speed | 20 mph (32 kph) |
| Maximum Water Speed | [@maximum_water_speed] |
| Variants | [@variants] |
| Notes | The M40 was developed to provide longer range support fire and replace the M12. It was based on the M4 chassis and had a wider hull and tracks. It mounted the 155mm M2 gun in an open compartment which featured a folding platform to extend out to allow for more room. A few pilot versions managed to get to Europe before the end of World War Two, but the M40 mainly saw action in the Korean War. |