In 1945, after a long and convoluted development process, the T26E1 – that lead to the M26 Pershing – entered service, and saw action in the closing months of the Second World War in Europe. The T26/M26 was armed with a powerful, high-velocity 90 mm gun that was perfect for engaging armored targets but was not practical in infantry support roles.
One of the most successful Sherman types to see service in the Second World War was the M4 (105). As the name suggests, these M4s were armed with the 105 mm Howitzer M4. These tanks provided infantry teams with a mean of knocking out enemy positions or obstructions with their powerful High-Explosive (HE) rounds. With a new tank coming into service, it was only logical to develop a similar vehicle based upon it. After all, vehicles based on the same base chassis helped ease production, crew training and ensured a plentiful supply of spare parts.
What would emerge can be described simply as a howitzer-armed version of the T26E1, with a few other, smaller modifications. This vehicle was initially known as the T26E2, but would later receive the designation Medium Tank M45. Only a small number of these vehicles were produced, and they would arrive too late to see action in World War II. They would, however, go on to see limited service during the Korean War.
The M26 Pershing was the result of a request for a new tank for the United States Army. The development process was long and complicated with numerous changes of direction. The initial request was for the tank to be armed with a 76 mm (3 in) gun from the start, but this was later changed to a 90 mm. There were three separate experimental vehicles, the T23, T25, and T26. Of course, it was the T26E3 that became the serialized vehicle, and would later be designated as the M26 Pershing, after General John J. Pershing, the Commander of American Forces in the First World War. The T26 started out as a Medium Tank, was reclassified as a Heavy Tank in 1944, and was then returned to Medium Tank status in 1945.
Other than the replacement of the T26/M26’s 90mm Tank Gun M3 with the 105mm Howitzer M4, very little changed between the M26 and M45. The hull, powertrain and suspension remained identical.
The tank was 20 ft 9.5 in (6.34 m) long, 11 ft 6 in (3.51 m) wide and 9 ft 1.5 in (2.78 m) tall and weighed 46-tons (41.7 tonnes). It was operated by a five-man crew, consisting of the commander, loader, gunner, driver, and bow gunner. It was propelled by the 450-500 hp Ford GAF 8-cylinder, gasoline engine. This and the transmission were placed at the rear of the tank. With this engine, the tank could achieve a top speed of 30 mph (48 km/h). The suspension consisted of a torsion bar system, with six paired road-wheels and five return rollers per-side. The drive sprocket was at the rear with the idler at the front.
Development of the T26E2
In 1944, designers initially turned to the T23 prototype for this new howitzer-armed tank. Work on this went as far as the development and construction of a new combination gun mount (a mount that includes the primary sight and coaxial machine gun) for the 105 mm Howitzer, based on that of the T23’s 76 mm gun. However, with attention turning to the T26E1, work on a T23-based howitzer-armed tank ceased.
This new development of the T26 was initially designated as the Heavy Tank T26E2. The new design incorporated a heavier gun shield. As the 105 mm was so much lighter the 90 mm, extra metal on the mantlet was required to properly balance the turret. The mantlet was also re-worked to protect the trunnions and trunnion bearings from the force of a shell impact.
Drawings of the howitzer mount, turret, and fighting compartment were prepared and sent to the builders of the T26/M26, Fisher Tank Arsenal and Chrysler, based at the Detroit Tank Arsenal, in October 1944. Wooden mockups of the new internal layout of the turret were also provided. There were a number of new internal features such as a stabilizer for the gun and new ammunition stowage. Fisher then went on to produce a pilot turret that would be tested on a chassis provided by the Detroit Arsenal.
The M45 in Focus
The 105mm Howitzer M4
The howitzer chosen for the M45 was carried over from the 105 mm-armed Shermans. This was the 105 mm Howitzer M4. This was simply a rework of the M2A1 towed artillery piece. It underwent a rework to allow it to be mounted and operated inside the confines of the turret. The biggest modification to the artillery piece was the breech block which was rotated 90-degrees. The vertically sliding breech block was also replaced with a horizontal one. The breech was of the manual type. Placing a round into the chamber would trigger it to start closing, but the loader would have to finish the job with the breech operating handle. The single recuperator located atop the barrel of the field gun was also replaced by two smaller ones on each side of the barrel. The barrel had a length of 22.5 calibers (93.05 inches/2.3 meters) and was fully rifled. Depending on the shell type used, maximum muzzle-velocity of the gun was 1,550 feet-per-second (470 meters-per-second).
A new mount for the gun was developed for installation in the T26E2. This included the coaxial machine gun and M76G gun site. It was initially designated the Combination Mount T117, but was later serialized as the Combination Mount M71. In this mount, the gun had an elevation range of +35 to -10 degrees. Unlike, the regular 90mm-armed T26E1, the T26E2 was equipped with a vertical stabilizer.
The ammunition used with the howitzer was semi-fixed, meaning the projectile is only loosely attached to the propellant case. This allowed the projectile to be removed and the propellant charge to be adjusted as required. A number of shell types were available: M1 HE (High Explosive), M67 HEAT (High-Explosive Anti-Tank), and M60 WP (White Phosphorus ‘Willie Pete’). The M67 HEAT shell was capable of penetrating 4 inches (100 mm) of armor.
Secondary armament consisted of a coaxial Browning M1919A4 .30 Cal. (7.62mm) machine gun and a Browning M2 .50 Cal. (12.7mm) heavy machine gun placed on a pintle-mount towards the rear of the turret roof. This could also be placed in a similar mount in front of the commander’s cupola. There was also the bow machine gun which, again, consisted of a Browning M1919A4.
As mentioned above, the howitzer was lighter than the 90 mm gun. The M4 Howitzer weighed 1,140 pounds (520 kg) while the M3 Gun weighed 2,260 lb (1,030 kg). This unbalanced the turret. To remedy this and rebalance the turret, the mantlet was thickened from 4.5 inches (114 mm) to 8 inches (203 mm). The turret face was also thickened from 4 inches (101 mm) to 5 inches (127 mm), as was the armor on the side of the turret, which was increased from 3 inches (76 mm) to 5 inches (127 mm). This additional armor, of course, increased the tank’s overall weight by 645 pounds (292 kg).
The biggest internal change to the turret was the ammunition stowage. Room was found for 74 rounds of 105mm. These were stored in eight separate bins (4-per side) aligned perpendicular to the hull, versus the three longitudinal bin layout of the M26.
Limited Production and Service
It had been anticipated that the pilot T26E2 would be completed by April of 1945. However, interest in 105 mm Howitzer armed tanks had somewhat dropped at this point and it was not delivered to Aberdeen Proving Grounds (APG) until July, almost 2 months after the end of the War in Europe. Remarkably, the original plan was to produce more howitzer tanks than gun tanks. Battle experience in Europe soon highlighted the effectiveness of the high-velocity 90 mm gun, however, and as such, the trend was reversed.
Both Chrysler and Fisher had been awarded contracts to produce the T26E2. With the end of the conflict in Europe – paired with the waning interest in howitzer tanks – Fisher’s contract was canceled and Chrysler’s was heavily reduced in number. Serial production started in July 1945 at the Detroit Tank Arsenal. During production, the order was cut back even further and by the end of production, and the year 1945, only 185 vehicles had been built.
Like its T26/M26 brother, the vehicle went through a period reclassification. During development, it was classified as a heavy tank (it received this classification in June 1944), and was designated ‘Heavy Tank T26E2’. After the war, it was reclassified as a medium tank. Following this, when the tank finally received its type-classification in May 1946, it was designated as the ‘Medium Tank M45’.
The only combat service the M45 would ever see would be during the Korean War (1950-53), alongside its M26 brother and, later, its M46 nephew. Here, 105mm Howitzer tanks found a place as mobile light artillery and were used for indirect fire-missions. The M45’s compatriots, such as the M4A3 (105) and the M4A3 POA-CWS-H5 flame tank (this had a 105mm Howitzer with a coaxial flame gun) were often used in this role. They were dug into special positions in groups. Grooves were cut into the ground with a berm at the front that the tanks would sit on to increase their elevation angle. It is likely that the M45 was also used in this way. Unfortunately, information about their time in service on the Korean Peninsula is extremely scarce. It is known that the tanks were used solely by the US Army 6th Tank Battalion, 24th Division.
Thanks to a personal account, we do know that at least a few M45’s remained in Korea after the war:
“I saw two at Tongduchon in 1956, about a mile down the road from our unit (Tank Company 31st Inf. 7 Div). Supposedly, they were not on anyone’s property books and looked pretty ragged. They had belonged to the 6th Tank Battalion, who were supposed to turn them in for scrapping after the ceasefire. No one knew how they got to us and the crews had no information. According to a crew member of one of the tanks, the Ford V8 was ‘old and beat’ and used almost as much oil as gasoline. It was covered in jerry cans full of spare oil cans. I just wish they had considered converting a few M46s. With their better engine and transmission, they would’ve been an ideal infantry support tank.”
– Specialist William Campbel, 31st Infantry, 7th Division, US Army
The M45 was one of the last howitzer armed tanks to be produced by the United States. It may appear to some as a wasted effort. It was designed for the European theatre of the Second World War but arrived too late, then had to wait 5 years to see combat, by which time it was showing its age. Nonetheless, in its short, approximately 10-year career, it found a place although it never performed the role it was intended for.
Unfortunately, probably due to its extremely short production run, it is widely thought that no M45s survive today.
Pre-production pilot of the ‘Heavy Tank T26E2’ during testing in 1945, with the stenciling on the fenders. The Gun and mantlet are protected from the elements with the weather-proof canvas cover. The roof-mounted .50 Cal (12.7mm) machine gun is in the standard position for a T26/M26 type of tank.
A Medium Tank M45 as it served in the Korean War during the early-1950s. The .50 Cal machine gun has been moved to the position in front of the commander’s cupola and the fenders have been lost. This illustration is based on the description given by a Korean War veteran, William Campbell. All details are as he recalls, apart from the ’45’ number – this is speculation as he has forgotten the exact number of the tank he saw.
Both of these illustrations were produced by Tank Encyclopedia’s own David Bocquelet.
|Dimensions (L-w-H)||20 ft 9.5 in x 11 ft 6 in x 9 ft 1.5 in (6.34 x 3.51 m x 2.78 m)|
|Total weight, battle ready||46 tons (47.7 long tonnes)|
|Crew||5 (commander, driver, assistant driver, loader)|
|Propulsion||Ford GAF 8 cyl. gasoline, 450-500 hp (340-370 kW)|
|Maximum speed||22 mph (35 km/h) on road|
|Suspensions||Individual torsion arms with bumper springs and shock absorbers|
|Range||160 km (100 mi)|
|Armament||105mm Howitzer M4
Cal.50 M2Hb (12.7 mm)
2x Cal.30 (7.62 mm) M1919A4
|Armor||Glacis front 100 mm (3.94 in), sides 75 mm (2.95 in), turret face 203 mm (8 in)|
The Author wishes to extend his thanks to William Campbel, US Army, Retired
R. P. Hunnicutt, Pershing: A History of the American T20 Tank Series, Presidio Press
Osprey Publishing, New Vanguard #35: M26/M46 Pershing Tank 1943-53
Jim Mesko, Armor in Korea, A Pictorial History, Squadron/Signal Publications
The Chieftain’s Hatch
Armored Fighting Vehicle Database