American self propelled artillery developed on its own terms, especially tank destroyers. After a series of experiments, American tank destroyers became very similar to their own tanks. As a rule they were based on tank chassis, but had thinner armour and higher mobility. The first such vehicle was the GMC M10, which made its debut in March of 1943. Its replacement, the M36, appeared on the battlefield a year and a half later. This was the best of American tank destroyers. Like the Soviet SU-100 its career spanned more than a decade. The last conflict it took part in was the Yugoslavian Civil War in the 1990s.
Attempt at improvement
It just so happened that development of the GMC M10 started to cross paths with the Medium Tank T20, a prospective medium tank that was supposed to replace the Medium Tank M4. This had to do with the armament first and foremost. Both vehicles were developed with a 76 mm gun based on the 3" AA gun in mind. One of the prospective weapons for the T20 was the T12 gun, later standardized as the M7.
This coincidence in armament is no surprise. Both the GMC M10 and Medium Tank T20 were developed by the Tank-automotive Center that was organized in Detroit in 1942. The TAC was headed by Joseph Colby and included a number of engineers who used to work for the Ordnance Department. Most of these were military men, and Colby himself retired with the rank of Brigadier.
Experimental GMC T72 vehicle, March 1943.
It just so happened that at some point the GMC M10 and Medium Tank T20 diverged again. The SPG was going to use the M7 gun designed by Captain Quentin Berg, the T20 settled on the T9 gun that was later accepted into service as the M1. Both guns had their advantages and drawbacks. The T9/M1 gun was lighter, but the T79 gun mount based on the 75 mm M34 gun mount had a number of drawbacks, which largely had to do with protection. The T79 was attached with bolts that were not protected from enemy fire. Furthermore, the gun mantlet could at best resist 37 mm shells. The M7 gun mount and gun were heavier and larger then the M1 and T79, but the SPG's gun was superior. Its mantlet covered the entire turret front and there were no exposed bolts. The mantlet was also angled.
The turret was smaller than on the GMC M10.
Both guns had the same issue that turned up in the fall of 1942 when the GMC M10 was first issued. The same issue came up during trials of the Medium Tank T23. The turret balance was poor. In both cases the turret was front-heavy, which made the gunner's work much more difficult. The GMC M10 was given counterweights, but in case of the T23 the solution was in a new turret, or rather turrets.
The idea of reworking the gun mount came up in parallel. Analogous work began on the GMC M10. There are two schools of thought regarding this: one claims that a new turret was developed for the Medium Tank T23 and later, in March of 1943, a version of it was designed for the GMC M10. This opinion clashes with documents, as work on this turret began at the latest on February 22nd, 1943. The second theory states that the turret was created for the GMC M10. Since work on the two variants proceeded in parallel, both theories have merit. This confusion arises from the fact that in later reports the start of the work is given as March 18th, 1943.
The overall concept of the turret was similar to the one on the Medium Tank T23. This is not surprising, since the same people were responsible for both designs.
The turret developed at the TAC was very similar to the E6194 welded turret used on the first Medium Tank T23 prototype. This should not be a surprise, since both turrets were designed by the same people. The idea of the new turret lent itself to a further development of an existing design. The new turret, gun, and mount were expected to reduce the overall mass of the GMC M10 by 2722 kg. This mass included not just the turret, but also the counterweight that was required to balance the overloaded front. Such a radical decrease in mass may have looked bold, but was actually quite reasonable. First, the gun mount indeed weighed much less than the M7. Second, this turret had thinner armour than the E6194 and no roof.
The turret bustle was used to carry 27 rounds for the 76 mm M1 gun.
The GMC M10 with a new turret and gun mount was indexed GMC T72. A production Gun Motor Carriage M10A1 with the Ford GAA engine was used as a chassis. The new turret was produced very quickly and the GMC T72 was ready to head to the Aberdeen Proving Grounds in March of 1943. The weight decrease was smaller than expected, just 1973 kg. To put it in conext, the mass decreased to 27,955 kg. This was just half a ton more than the initial GMC T35 and less than 300 kg more than the initial GMC M10.
As planned, the GMC T72 turret was similar to the welded E6194 turret. More changes were introduced as the project went on. The new gun mount, indexed T2, lost its coaxial machine gun, as the Americans thought that a tank destroyer doesn't need one. Second, the turret gained a large bustle. It acted as a counterweight and provided space for ammunition. The bustle held 27 rounds of ammunition, increasing the overall capacity to 97 rounds. The TAC solved one of the issues of turreted SPGs: small ammunition capacity.
The new turret decreased the weight of the SPG to 27,955 kg.
Trials of the GMC T72 began in March of 1943. A second vehicle joined it in April. The changes to the new vehicle no doubt improved its performance. The tank gun mount had better sights and aiming mechanisms. There were some complaints about protection. The gun mantlet was just 38 mm thick, and unlike the M10's mantlet it was not sloped. The sides were just 28.5 mm thick, and also vertical. These complaints seem strange, since even the M10's armour could be penetrated by any towed or self propelled gun still in service by the spring of 1943.
Fighting compartment of the GMC T72. Despite its advantages, this design was rejected.
The crew's placement was a definite boon. Since the ammunition was now stored in the bustle and the gun mount was more compact, the fighting compartment was roomier than the GMC M10, even though the turret of the GMC T72 was narrower. The reduced mass also had a positive effect on the supension. One would think that the logical conclusion would be correction of minor defects and mass production. The chassis was the same as the GMC M10/M10A1 and the turret had many advantages. However, the American military (especially General Andrew Bruce) had their own ideas on the subject. The GMC T70 entered trials in the spring of 1943. It seemed more promising, since the chassis was lower and faster, and the torsion bar suspension offered a smoother ride. The GMC T70 was recommended for production and the GMC T72 was left in the dust. Officially work ended on February 17th, 1944, but in reality the project was abandoned earlier.
Later on the T72 turret was used to test the T116 recoilless gun mount.
The GMC T72 was used as a test lab for the T116 recoilless gun mount. Work began in December of 1943. This project's goal was to develop a gun that took up less space in the fighting compartment. A 75 mm M3 gun barrel was used. Since the load on the turret increased, it was reinforced. Work continued in 1944-45, but results were few. The idea of installing the GMC M18 turret on the GMC M10 chassis was also a dead end. There were many complaints about the M18 turret as is and this idea was senseless to begin with. The primary requirement at the time was improving firepower, not mobility. Work on this topic began in parallel with the GMC T72 and partially used the materials developed for this project. The GMC T72 was not a waste of time after all.
Conversion for a large caliber
The 76 mm gun with ballistics of the AA gun was a priority development, but a competitor arrived in 1942. The Americans inspected the German 88 mm Flak 18. The 3" M3 gun was close to it in firepower, but the German system was still more powerful. The Americans had their own powerful 90 mm M1A1 AA gun. The Americans were thinking of installing this gun on a self propelled chassis as early as April 1942. Putting these ideas in practice came some time later, in October of 1942.
Trials of the GMC M10 with a 90 mm gun T7, November 1942.
American SPGs usually had to play catch-up when it came to guns, but this was not the case this time. The 90 mm gun indexed T7 was initially supposed to be installed in the turret of the Heavy Tank T1E1, so it would have to wait for a chassis. Meanwhile, there was already a perfectly good chassis for it: the GMC M10. There were no real issues with installing the 90 mm gun, only the gun mount had to be changed slightly.
The larger gun fit into the existing fighting compartment perfectly well, but this version did not go into production.
The first GMC M10 to receive this weapon had the registration number U.S.A. W-4040705. This vehicle was already located at the Aberdeen Proving Grounds where trials took place. The trials showed that the turret was out of balance, but the installation of the 90 mm gun didn't create any serious problems. A modified GMC M10 entered trials by the end of November. The ammunition capacity decreased, but not much. The SPG still carried 42 rounds of ammunition, 6 of them in the turret, which was a decent ammunition capacity for this kind of vehicle. For comparison, the SU-100 had only 33 100 mm rounds on board.
The first GMC T71, September 1943.
Gunnery trials were also successful. Issues with balance became worse since the 90 mm T7 was 132 kg heavier than the 3" M7, but theoretically the conversion to the more powerful gun was not too difficult. Issues with balance were solved using a tried and true method: a counterweight. The Aberdeen Proving Grounds approved the rearmament to a 90 mm gun and recommended starting a conversion program. Due to the small number of required changes this could even be done in field workshops.
Several improvements were made on the second prototype after trials of the first.
This program was never launched. There were a number of complaints lodged against the GMC M10 itself, some of which were not resolved even after it went into production. The gunner's job was difficult, there was no powered turret traverse, and there were also complaints about the sights and observation devices. These issues were corrected in the new GMC T72 turret. The Ordnance Committee chose the correct way forward and decided to create a new turret rather than simply rearm the old vehicle.
The AA machine gun moved from the cupola to a more conventional location.
Official work on the new SPG started in March of 1943. The vehicle was indexed Gun Motor Carriage T71. Don't be surprised that the number was lower than the GMC T72, in practice work on the new turret started much earlier than the official start date of March 18th, 1943. In any case, work on the T71 and T72 turrets started at around the same time, which is seen in the overall concept. As with the GMC T72, the starting point was the E6194 turret. The biggest differences were in the front and the rear. These were directly connected to the more powerful gun. The turret bustle was enlarged and the gun mount was completely reworked. The turret had to be built first. Chevrolet was initially chosen as the subcontractor, later the order was moved to Ford since the GMC M10A1 was planned to be the chassis for the new SPG.
The experimental GMC T71 with a canvas roof.
The experimental GMC T71 with a mild steel turret was built in September of 1943. The turret was generally welded, but had a complex shape. This was caused by the massive counterweight that doubled as a ready rack. The GMC T71 was influenced by another SPG, the GMC T70 (it also had a large bustle that doubled as a counterweight). The GMC T70's AA machine gun cupola was also copied, as it was more comfortable than the pintle mount.
Inside the fighting compartment. The hydraulic traverse was a big boon. Thanks to it the maximum traverse speed increased to 24 degrees per second.
Trials went slowly, in part due to bureaucracy. Army Ground Forces prioritized tanks, and trials began in October of 1943 only due to Barnes' insistence. The two prototypes were not tested at Aberdeen, but at Fort Knox. A list of issues was composed after the first prototype was tested, which were corrected on the second vehicle. The AA cupola was not the best solution, so it was removed alongside the bulge on the left side. Improvements were also made to the pannier racks.
Several organizations argued about other improvements. For instance, a muzzle brake that reduced recoil but also revealed the vehicle's location when it fired. In any case, AGF, Tank Destroyer Command, and the Ordnance Department agreed: the vehicle was good. The only question was when production would start and how many would be built. Production began in April of 1944 and two month later, on June 1st, the vehicle was standardized as the GMC M36.
Changing chassis
The situation with GMC T71 production gradually changed as prototypes were tested. Ford ended production of the GMC M10A1 in September of 1943, and not just the M10A1; production of the M4A3 ended at Ford as well. The obvious choice for production disappeared. The automotive giant remained a participant in the building of this SPG, but only as the supplier of engines. GMC M10A1 production continued at Fisher Tank Division, but not for long, only until November of 1943.
Production of GMC M36 turrets at Fisher Tank Division.
It was clear that the GMC T71 was a good vehicle in need of only minor improvements by January of 1944, and a clever plan was hatched. Fisher Tank Division received an order for 300 GMC M10A1 chassis, but there was never a plan to make them into this SPG. They were always meant to become the GMC T71. Even earlier, on December 9th, 1943, the Ordnance Committee split the GMC T71 into two. The base vehicle would be built on the GMC M10A1 chassis, the second, GMC T71E1, would be based on the GMC M10. The Ordnance Committee had a backup plan in case of issues with production, which came in handy later.
Typical GMC M36. As a rule, Fisher Tank Division's SPGs looked like this.
The GMC T71/M36 didn't enter into proper production. Instead, existing vehicles were converted. These were largely the GMC M10A1 that weren't sent to the front lines but were used in training units. These were priority chassis for the GMC M36. The idea solved a lot of problems. First, it gave purpose to the GMC M10A1 that was practically never used in combat. Second, chassis for the new tank destroyer didn't have to be built anew. Third, it was now possible to order these SPGs from factories that formerly built light tanks.
The rear turret bustle armour was the thickest, as it played the role of a counterweight.
Fisher Tank Division began producing the GMC T71 in April of 1944. No specific conversion work was required at first, since there was a reserve of 300 chassis. Only the ammunition racks in the fighting compartment had to change and a new turret was installed. Under pressure from the AGF the order grew to 500 units, and this was just the start. On May 15th, 1944, it was expanded to 600 units, 300 of which were built from refurbished GMC M10A1. Even with the benefit of using an existing chassis, the rate of production was low. 25 vehicles were delivered in April, 100 in May, 120 in June, 122 in July, and 100 in August.
Since early chassis were used to built these vehicles the hulls could differ.
Such a glacial pace can be explained by the amount of orders that flooded Fisher Tank Division. First was the start of the Medium Tank M4A2(76)W production, in February of 1944 production of the Medium Tank M4A3(75)W started, then the factory was ordered to build 254 M4A3E2 tanks. The same factory was given an order for Medium Tank T25E1, Heavy Tank T26, and later Heavy Tank T26E3. It's not surprising that the factory couldn't keep up with the rate of M36 conversions. Meanwhile, the order jumped to 1400 units on July 29th, 1944. The cause of this was the appearance of new vehicles in Normandy: the Tiger II and Jagdpanther.
Late production GMC M36. It's easy to tell them apart due to the muzzle brake.
American command knew what was happening and started to look for a backup plan in the summer of 1943. The fact that the vehicle wasn't built from scratch was a big plus. Massey Harris Co. became the first subcontractor to take over conversion. It was starting production of the Light Tank M24, but still had capacity for additional work. The company, situated in Brantford, Canada, started conversions in June of 1944. 500 vehicles were delivered between June and December of 1944. The next subcontractor was American Locomotive Company (ALCo), which at that point had no tank contracts. 413 vehicles were converted between October and December of 1944. 1213 GMC M36 were built in 1944, of which only 300 were built at Fisher Tank Division.
GMC M36B1, an original solution to a chassis shortage.
Fisher Tank Division finished its share of the order in July of 1944. A months-long pause followed. In September of 1944 not a single factory delivered a GMC M36. Only 913 GMC M10 could be obtained from training units. There were no more new chassis and production was at risk. Here is where some trickery helped. As mentioned above, Fisher Tank Division was already building the Medium Tank M4A3(75)W with an identical turret ring diameter. The thought to install the GMC M36 turret on this tank was logical. The ammunition capacity with the new hull remained the same, 47 rounds. The mass increased to 30,844 kg (compared to the GMC M36's 28,576 kg) but mobility was essentially the same.
There weren't that many GMC M36B1 built, only 187 units.
This conversion was standardized as the GMC M36B1 in October of 1944. Only Fisher Tank Division built this variant. 50 vehicles were delivered in October of 1944, 93 in November, 44 in December. ALCo and Massey Harris built 75, 290, and 348 vehicles respectivel. The contract for 1400 tank destroyers in 1944 was filled. Turrets for all of them came from Fisher Tank Division.
There were few M36B1s built, but they still saw combat.
GMC M36 production didn't end here. A contract for 200 vehicles was signed in the spring of 1945. It used 200 chassis that were found during the lull. This contract went to Montreal Locomotive Works. 10 vehicles were delivered in May of 1945 and the contract was finished in July.
M36B2, the final batch of GMC M10 hulls converted.
The look of the M36 produced in 1944 deserves a separate description. Since production relied on refurbished GMC M10A1 chassis there was a variety of hulls used. Mounts for spaced armour disappeared from production in July of 1943, as they were never used in practice. M36es built at Fisher Tank Division in 1944 didn't have them either since they were built on new chassis, but other manufacturers could use hulls where they were still present.
The guns also changed. The order for 600 SPGs made on May 15th, 1944, called for 600 M36es with no muzzle brakes. The muzzle brake was introduced in October of 1944, but some GMC M36B1 had no muzzle brakes. Extended End Connectors that lowered ground pressure were introduced in late 1944.
Hulls from various production periods were used to build the M36B2 as well.
A decision was made to produce additional GMC M36es towards the end of the awr. The GMC M10A1 hulls ran out, so the GMC T71E1 was dusted off. This variant used GMC M10 hulls and was indexed M36B2. This vehicle was slightly heavier than the GMC M36 at 29,937 kg. The top speed was limited at 40 kph. Nevertheless, the production program was approved in January of 1945. These vehicles were built at ALCo and MLW. The first 50 vehicles of this type were delivered in May of 1945, production ended in September of the same year. 724 M36B2 were built, of them 52 at MLW and 672 at ALCo.
The GMC M36B2 came with a roof.
1945 production vehicles also had a variety of equipment. As with those built in 1944, some had refurbished chassis with spaced armour mounts. A light roof for the fighting compartment was also developed as a result of fighting experience. It was developed for the GMC M10 but chiefly used on the GMC M36. The roof weighed an extra 363 kg, but it solved the problem of crews getting hit with shrapnel and bullets from above.
High caliber long-liver
It usually took about 4-5 months from the start of production for American armoured vehicles to see battle. Mass production of the GMC M36 essentially began in May of 1944, so it could be expected to reach the front lines by September. This estimate was approximately correct. Many things happened in the time between the start of production and the first battles, namely the landings at Normandy. It's not that the Allies weren't ready for them, but Germany still had the advantage in armoured vehicles. Of course, there were many units that were using obsolete tanks, but also quite a few with top of the line equipment. Allied tankers quickly encountered new German tanks in large numbers. A number of these tanks were already encountered in Italy, but they were used in limited amounts and in conditions specific to Italian theatre. In Normandy there were many more opportunities for the Germans to capitalize on their advantages,
The new SPG had excellent mobility in addition to a large gun.
The conclusions from two months of fighting in Normandy were jarring. The 75 mm M3 gun in the Medium Tank M4 couldn't penetrate some of these new tanks even at point blank range. The 76 mm M1 and 3" M7 guns were better, but their abilities were limited. Even the 60 mm of sloped armour used on the Jagdpanzer IV tank destroyer was only vulnerable at a distance of half a kilometer (German diagrams claimed a distance of only 100 meters, but that was overly optimistic).
The situation with the Panther was worse. This tank could be penetrated frontally only in the lower front plate or the gun mantlet. July of 1944 also marked the combat debut of the Jagdpanther tank destroyer and Tiger II tank. These vehicles only fought against the British and had mixed success, but the Americans still drew conclusions from these encounters. It's not surprising that the order for the GMC M36 jumped from 600 to 1400 units on July 29th, 1944. This SPG was the only vehicle capable of penetrating German vehicles from medium ranges. There were no alternatives. The Medium Tank T25E1 with the same 90 mm gun was a failure, and the Heavy Tank T26 needed more work.
Battle for Metz, November 1944.
The fact that the situation was critical is reflected in the request by the 12th Army Group to rearm 20 of its 52 tank destroyer battalions to the GMC M36. It was impossible to pull this off quickly. About 40 new SPGs arrived in early September, enough for just one battalion. This led to a temporary solution; after training new crews the GMC M36 were split up into batteries. A temporary TO&E was adopted where each battalion had 24 GMC M10 and 12 GMC M36. Ironically, the Germans were doing the same thing at this time. A shortage of Jagdpanthers meant that battalions had only one battery of these vehicles.
The GMC M36 performed well during the fighting in the Ardennes.
The GMC M36 first saw battle in October of 1944. Even though three batteries were not enough to change the situation on the front lines, the Germans felt their impact. Unlike the 76 mm gun of the GMC M10, the 90 mm gun could penetrate the front of the Panther and Jagdpanther from up to half a kilometer. The 654th Tank Destroyer Battalion was one of the victims of the new American tank destroyers. The battalion recorded total loss of 20 SPGs from November 20th to December 11th. The commander, Hauptmann Karl-Heinz Noak, recorded that a number of vehicles were destroyed from the front at a range of 200-500 meters. The only vehicle capable of this was the GMC M36.
The GMC M36 and one of its main opponents, the Panther. Unlike the GMC M10 this tank destroyer could penetrate the Panther's upper front plate.
The GMC M36 and Jagdpanther clashed regularly. American tank destroyers gained numeric superiority as new shipments arrived. A comparison of these two vehicles shows that the Jagdpanther had precious few advantages over its American rival. It had a bigger gun and thicker armour, but also weighed half again as much as the M36. It also had much a poorer power to weight ratio, 13.2 hp/ton vs 17.5 hp/ton. The top speed of 42 kph on the American vehicle was an artificial limit. On trials Soviet tankers managed to accelerate the heavier GMC M10 with a weaker engine to 50 kph. It's unlikely that the GMC M36 was not capable of the same. The American vehicle carried fewer shells than the German, but its ready rack was much better designed. A drawback was the lack of a coaxial or bow machine gun, but the M36 had an AA machine gun that the Jagdpanther did not. Finally, even though the GMC M36 was almost as tall as the Sherman, it was 10 cm lower than the Jagdpanther. The visibility and agility of fire of the GMC M36 was also much better.
Jagdpanther units noticed the appearance of the GMC M36.
There were six battalions armed with the GMC M36 by the time the Germans counterattacked in the Ardennes. Combat experience showed that this SPG had an advantage over its predecessors and towed guns. By January of 1945 these SPGs also had the T33 AP shot that could penetrate the front of a Panther and Jagdpanther from 1000 meters. The T30E16 subcaliber shot was also introduced. High firepower was combined with high agility. The GMC M36 surpassed even the GMC M18 in combat effectiveness. The GMC M36 inflicted significant damage to German armoured vehicles, for instance they were the first killers of the new Jagdtiger tank destroyer on January 5th, 1945. Sure, they couldn't penetrate the front armour of these vehicles, but the sides were still very vulnerable.
The GMC M36 became the most common tank destroyer on the Western Front in February of 1945.
These successes resulted in a call for more GMC M36. Thanks to high rates of production the GMC M10 was rapidly being replaced. There were only 365 GMC M36 issued in January of 1945, but in February the number grew to 826. The GMC M36 becme the most common tank destroyer on the front lines of the Western Front. They were often used as tanks instead of as tank destroyers. This was not by choice, as the Heavy Tank T26E3 was available in very limited numbers and there were no other vehicles with 90 mm guns. The key was not even its anti-tank potential, but the power of the HE shell. It was much more potent than the 75 mm gun, not to mention the 76 mm. Losses of the GMC M36 were also low. Just 30 were lost by April, and this is with 1054 SPGs of this type issued. In the same conditions losses of the GMC M10 were much higher.
Like other vehicles, the GMC M36 was often covered in sandbags.
The summed up experience of the GMC M36 tank destroyer was very interesting. In practice, they were used as tanks. The GMC M36 also showed the limit of firepower of the Medium Tank M4 chassis. The same limit could be seen on medium tank destroyers from other nations. Calculations showed that putting a more powerful gun on the Panther would raise its mass to 51 tons. Soviet SPGs were in the same boat. The Uralmash-1 showed that improvement in firepower and armour leads to a rapid increase in weight and decrease in reliability. This is why medium tanks received very similar armament. For this reason the Americans stopped working on tank destroyers in 1946. It turned out that the best tank destroyer was a tank.
GMC M36B1 in combat.
Even though work on tank destroyers stopped, the GMC M36 remained in service for a long time. Its service was prolonged by parts commonality with the Medium Tank M4A3 and Medium Tank M26, similar to what happened to the Soviet SU-100. The Medium Tank M26 was plagued by issues that were only corrected with the Medium Tank M46. Meanwhile, a vehicle with the 90 mm gun, better mobility, and higher reliability was already in service. The M36 hung on until the 1950s when they were replaced with pattons.
The French army obtained the M36 and M36B2 after the end of teh war.
Even though there were no Lend Lease shipments of these vehicles, their service abroad was long. South Korea was the first foreign nation to receive the M36. 110 vehicles were shipped in total and they were actively used in the Korean War. Later these vehicles were shipped to France, to Pakistan, 222 were shipped to Turkey, a large number ended up in Yugoslavia. The Americans aimed to get rid of the GMC M36B2 first and foremost. The French M36es migrated to Taiwan, then ended up in Iran and Iraq. The M36 were also used by Italy and Belgium.
Vehicles from the M36 family ended up in a number of nations, including Turkey.
It turned out that the GMC M36 had a much longer career than any other American wartime SPG. Most of those did not fight after Korea, but the GMC M36 had a different fate. It was used by the French in Vietnam, then the vehicles played an active role in the India-Pakistan conflicts. They often had M3A1 guns with a muzzle brake and fume extractor instead of the old M3. A number of Pakistani tank destroyers had the even better M41 gun. The last war for the M36 was the Yugoslavian Civil War in the 1990s. In other armies the M36 was only written off in the early 21st century.
The GMC M36 was last used in battle in Yugoslavia.
The GMC M36 was a big success for American armour designers. A modern combat vehicle capable of defeating most enemy tanks of its era was created with little effort. The fact that the M36 could be built on an already existing chassis meant that it could be produced easily and solved the issue of using up old chassis. The lengthy career of the M36 speaks for itself. This tank destroyer was up to the tasks it was given.