Monday 8 May 2023

Sherman's African Debut

The Medium Tank M4A1 that arrived in the UK in the summer of 1942 was much more promising than the Medium Tank M3 that had arrived shortly prior. The layout of the armament was much more conventional, the armour was tougher, and the crew's workspaces were more comfortable. Before too long, these tanks were on their way to North Africa, where they would have to fight against the harsh environment in addition to an experienced enemy. The Sherman's career was not going to be an easy one.

First blood on the sand

The tanks that arrived in North Africa were not prepared for desert warfare. They were modernized in field workshops, where British technicians added dust shields, brackets for the Sunshield camouflage tarps, racks for canisters with water and fuel, stowage bins, and other equipment necessary for life in the desert. Desert camouflage was applied over top of the olive drab paint. 252 Shermans were ready by the Second Battle of El Alamein: 92 in the 1st Armoured Division, 124 in the 10th Armoured Division, and 36 in the 9th Armoured Brigade.

The situation with the delivery was far from ideal. The tanks arrived only weeks before the planned offensive. The lack of time to train had an impact not only on the skills of the crews, but also on the cohesion with the forces fighting alongside the tanks. Since the Shermans were going to attack at night through minefields, cooperation with infantry and engineers was quite important.

Shermans of the 9th Hussars, 9th Armoured Brigade, September 15th, 1942. The tank is likely already painted in desert yellow, but disruptive camouflage has not yet been applied.

Sherman tanks first went into battle at dawn on October 24th, 1942. The wager placed on these new tanks paid off. Long barreled 75 mm guns could confidently penetrate German tanks at ranges of up to two kilometers and the thick angled front armour could handle a hit from nearly any German gun. Unfortunately, the new tanks were far from invincible and could not punch through the German defenses all on their own. Sherman tanks trapped in narrow corridors made in mine fields in the open desert were perfect targets for enemy artillery and aircraft.

Nevertheless, the amount of Sherman tanks on the front line kept increasing. After a week of fighting, the 1st Armoured Division had 113 Shermans on hand and the 9th Brigade had 39. The 10th division was recalled into the reserve by that point. The tanks played an important role in the battle that turned the tide of the war in North Africa. Flattering reports rolled in one after another. A cable received by the British attache in Washington read:
"Confirmation has been received by reports from the Western Desert, indicating great satisfaction with the M4 Medium Tank (Sherman).

The position of the main gun in the turret has made possible the advantage of maximum cover in “hull down” position in addition to good observation by the tank commander. There is concrete evidence that the enemy tanks, including the special PzKw IV (with the long-barrelled higher velocity 75mm gun) has been destroyed up to ranges of 2,000 yards. All troops are indicating that there should be more Shermans sent out at the earliest opportunity."
The Germans also judged the new tank highly. A document captured by the Americans stated that "Tommy is using an American tank (M4 medium) which has incredible armor and very good armament." An unnamed German general claimed at an interrogation that Tiger tanks were hurriedly deployed in Africa specifically to counter the Sherman.

Nevertheless, the tanks were not presented as invincible phantoms as new enemy vehicles often are. German anti-tank combat instructions suggested firing at the sides from 75 mm anti-tank guns from 1600 meters or from 50 mm guns at a range of 1300 meters. If in ambush, fire should be opened at just 800 meters. If firing from the front, the differential cover made for the best target.

Sherman tanks ready for battle with disruptive camouflage applied.

The opinion of British testers that studied a Sherman tank at Tell El Kebir was published in the monthly AFV Technical Report only after the Shermans first saw battle. The first combat impressions were also published in the same issue. These reports were a lot more grounded than the limitless praise sent through diplomatic channels. The report indicated that many of the tanks were used, with one having travelled for 700 miles (1100 km) before delivery. The tanks had to undergo a complete technical inspection before they could be allowed to fight. Many suffered from leaky radiators.

The armour was indeed quite tough. No penetrations were found in the sloped parts of the hull. Holes from 75 and 88 mm shells were only present in the differential cover and other vertical components. The quality of the armour was high. Cracks and spalling were rare. The turret armour spalled a little worse than the hull, but also performed well.

The report noted that the driver's vision port and the turret pistol port are easily penetrated, as a result of which some crews preferred to weld spare track links over their direct vision ports and look through their periscopes instead. The vertical sides of the hull were also criticized. The flammable fuel and ammunition were stored directly behind them, which made the tank quite vulnerable when hit in the side. Road wheels and tracks were destroyed when the tank was hit with HE shells, but the bogeys stayed on. An HE shell could also tear off the exhaust manifold, which increased the chance of fire due to flames that shot out when the engine backfired.

The report made note of the fact that the Shermans burned easily, even more easily than the Grant and Lee. The problem was not with the gasoline engine, which many post-war writers were quick to blame, but the location of the ammunition. One of the report authors theorized that a 32 round ammo rack positioned along the right side of the fighting compartment floor would make the tank much tougher. The fact that the British often carried 140-150 rounds into battle with an authorized complement of just 96 shots didn't help matters. When a tank so heavily laden with ammo was penetrated, a fire was nearly guaranteed. 

There was another reason for the fires. Opening the driver or his assistant's hatch caused a gust of wind to enter the tank, which helped fan the flames. These crewmen had no other choice, as climbing into the fighting compartment and exiting through the turret was difficult due to the turret basket. The tank's loader also had a difficult time leaving a burning tank, as he didn't have his own hatch in the roof.

War Daddy II, a captured M4A1 tank at the Kummersdorf proving grounds. The tank still has early suspension bogeys with one return roller in the middle, a narrow gun mantlet, and direct vision ports for the driver and his assistant.

Crews reported that the gun was powerful and easy to load, but they didn't like the periscopic sight. It was still better than the Grant's sight, but it had poor light transmission. The upper prism of the periscopic sight was completely open, as a result of which it was easily damaged not only by the enemy in battle, but also by the crewmen that climbed on the tank. The prism also had no protection from lens flare, which was unpleasant in the desert. Periscopic sights also quickly lost zero during travel.

Due to the thick sight markings, the gun was useless at ranges over 2500 yards (2300 meters) since the markings covered up the target completely. This was a shame, since the gun remained lethal at an even greater range. One commander acquired a rangefinder and managed to guide his tank's gun at a Pz.Kpfw.III tank, destroying it at a range of 2800 yards (2560 meters). The Shermans already received the latest M61 APCBC shells that could destroy German tanks at virtually any range, unlike the older M72. The HE shells with the M48 fuse set to 0.05 seconds also showed themselves well, much better than the old unpredictable M54s. The British preferred their own smoke shells to the ones sent by the Americans. Generally, the Shermans carried a complement only 10% smoke and 40-50% HE shells, with AP taking up the rest. 

The position of the gun in the turret was well received. Tanks could be hidden behind dunes, showing just their turrets. Indirect fire with HE and AP was also practiced. One commander knocked out five German tanks by standing on the roof of his Sherman and correcting fire through his binoculars. Others aimed using improvised clinometers.

A British soldier examines a knocked out Sherman II tank. A white countershading stripe can be seen on the bottom of the barrel. In this case, the camouflage didn't help. An enemy shell landed right at the base of the gun. Another hit above the machine gun port can be seen.

The machine gun mounts were not liked by the crews. The coaxial machine gun quickly loosened. The hull machine gun was impossible to aim due to a lack of sights, so the assistant driver's job largely consisted of handing ammunition to the loader. Opinions about the .50 cal AA machine gun differed. Some crews wanted to get rid of it altogether, others thought that a lighter machine gun could be preferable. Some considered it useful on the march, but suggested stowing it behind the turret during combat.

There was another drawback when it came to the armament: a lack of 2" bomb thrower. The British made an adapter to install it instead of the hull machine gun, but it wasn't very useful in this position. With a maximum elevation of just 21 degrees, its maximum range capped out at 100 yards (90 meters).

The British also didn't like the gun stabilizer. Since British tankers normally fired from short stops at long ranges, there was no reason to have this big and bulky mechanism in the turret. The Americans disagreed and even sent their experts to teach British crews. No demonstrations swayed them. An American crew hit 50% of their shots at a range of 300 yard while moving, but the tank drove at a low speed on even terrain. The Americans were also more skilled with the Sherman than the average British gunner. Each American instructor fired at least 300 shots from the Sherman, which the British considered excessive when training gunners.

The British liked all three types of traverse mechanisms (Westinghouse, Oilgear, and Logansport). They were only used to traverse the turret to face in the right direction. Fine aiming the aim was always done by hand.

A burned out Sherman tank with a grave next to it. Even the most successful tanks are not invincible.

The crew's workspaces received plenty of criticism. The commander had two seats instead of one, one for the upper position and one for the lower. Both were too small. The loader's seat was also too small and positioned too high up to load the gun while sitting. The gunner's seat back got in the way when he had to leave his position, blocking access to half of the fighting compartment. The driver and assistant driver's seat backs were also very large, making it almost impossible to pull them out if they were wounded. It was also difficult to put a harness on them to pull them out through the top. A suggestion for each crewman to put on a harness before getting into the tank was met without enthusiasm.

Without a hatch of his own, the loader was forced to climb under the gun's recoil guard to escape the tank, which could cost him his life. Many crews took off the guard, preferring the risk of injury when the gun was fired to burning to death. 

A crew from the 2nd Dragoons, 1st Armoured Division, refills their tank with ammunition. November 1942.

The tank carried enough gasoline to drive for 60 miles (100 km) in the desert at a speed of 15 mph (24 kph) or 90 miles (145 km) on a road at a speed of 25 mph (40 kph). The reverse speed was judged too low. The British wanted a tank to be able to reverse at a speed of at least 10 mph (16 kph) to retreat quickly.

The engine lasted for 700-900 miles of driving (1130-1450 km) or 180-200 hours of operation. The engine had to be inspected and serviced after 100 hours, but there was often no time for this procedure. The tankers also saw little value in this. The reliability of the engines was not sufficient, which is evidenced by various fruitless modifications carried out by the 8th Army. There were also complaints about torn wiring, broken ignition systems, and broken control rods.

The bogey with a return roller brought backwards performed much better than the bogey with a roller in the middle that the Sherman inherited from the Grant. A report for February 1943 describes a visit to a unit where not a single volute spring was broken after a 1000 mile (1600 km) march. The track links did not perform as well. The rubber began to peel off and the tracks became useless after 600 miles (970 km) of driving. Some units continued to drive around on damaged tracks, but this resulted in rapid wearing down of the road wheels. These were also a weak point in the tank's reliability. Introduction of road wheel tires with radial grooves helped to cool them in the desert, but the tires still began to layer and crack after 300 miles (480 km).

The quality of the radio station was very high. Unlike British tanks, the commander's radio and regular radios did not create noise for each other. As a result, the commanders could communicate with their own units and superior commanders simultaneously. 

A Sherman tank on a Scammell Pioneer transporter, October 1942. The automotive components of these tanks were very reliable, but the tank's usage was limited by the lifespan of wheels and tracks.

The Americans did not have as good an experience with their own tanks as the British. The 1st Armored Division was the first to use these tanks during Operation Torch in November of 1942. The American tankers were unprepared for fighting in the desert. The tanks arrived painted in olive drab, which did not help hide them in the sand. Enough paint for all of them could not be procured and some had to simply be slathered in mud.

The Germans yearned for revenge after being beaten by the British, and the inexperienced Americans were the perfect target for their frustration. The Shermans of the 1st Armored clashed with the German 5th Tank Division. By this point, the German tankers knew what to do against this new enemy. Sherman tanks sent into a counterattack by Lieutenant Colonel Loius Louis Hightower on February 14th, 1943, ran into an ambush and were shot up by 88 mm AA guns. Tiger tanks attached to the 5th Tank Division also performed well, claiming to have destroyed 20 Shermans. Hightower lost 37 tanks out of 44 in this battle.

The Americans' misfortune continued on the next day, when Lieutenant Colonel Alger's attempted to stop a German attack without having carried out appropriate reconnaissance. This time the Shermans were reinforces with tank destroyers, but this didn't help as the Germans had a five fold numerical advantage. Only four tanks from the battalion survived. Such a disappointing debut of Sherman tanks under American command proved yet again that good equipment on its own cannot be the decisive factor in a battle. The Americans still needed to learn how to fight.

A Sherman tank with an American crew. Given the same tank as the British tankers, the Americans achieved much less due to inexperience.

The price of conservatism

A whole separate drama broke out around ammunition. The quality of American M72 shot was worse than that of its British equivalents. Experienced tankers tried to avoid it. German 75 mm ammunition placed in an American casing was used instead. Thanks to frequent victories over the Germans, captured ammo was in no short supply and these conversions were common.

An alternative appeared by the winter of 1942-43. The M61 shell was higher in quality and had an HE filler. A shell that exploded after penetrating the enemy tank's armour did a lot of damage to its crew and components. British solid shot had a minimal effect, especially if the projectile did not shatter upon penetration. The British reported cases where German crews would leave their knocked out tanks unharmed. Nevertheless, the British opted to use American shells without a fuse or filler.

The proponents of shot had an ironclad argument on their side: if the fuse went off prematurely, the shell would not penetrate regardless of its quality. The British considered these premature detonations common when firing against thick armour at close range.

The weight of this argument began to wane by February of 1943. Trials against a captured Pz.Kpfw.III tank were the last nail in its coffin. At a range of 1000 yards, 75 mm shot penetrated the 50 mm thick armour positioned at 20 degrees and fell on the driver's seat. The testers noted that if this was a shell filled with HE, the German crew would have suffered much more damage.

The advantage of HE filler became obvious. No decrease in penetration was observed, plus the typical target for an HE shell in North Africa was a relatively thinly armoured tank at a range of about 900 yards (800 meters). British tankers asked not only to return the fuses for the M61 shell, but develop a 57 mm shell for the 6-pounder gun with HE. According to one report, without an AP-HE shell the upcoming Cromwell tank would be inherently inferior to the Sherman. A recommendation for a 57 mm HE shell for firing at anti-tank guns at a range of up to 3000 yards (2700 meters) was also given.

These suggestions were tested in thorough trials both in the US and in Great Britain. By November of 1943, the British were in possession of a thorough report on the effect of 75 mm shells on Medium Tanks M3A5.

Camouflage diagram for Sherman tanks. White stripes helped knock off the contrast formed by shadows under the barrel and on the lower hull.

The precision of M61 shells was the same regardless of whether or not a fuse was installed. The tip of the shell remained intact when the fuse went off, which helped with penetration. The fuse worked flawlessly when the shell hit a tank, but not if it hit dirt. The penetration of the shell was high; all shells that hit their target at 2500 yards (2300 meters) went through the upper front hull, differential cover, sides, and sponsons. The the turret was a tougher target. The front was not penetrated at all and the side was not penetrated consistently.

The shell was deemed suitable for firing at armoured targets at ranges of up to 3000 yards (2750 meters). At this range the problem was hitting the target, since only 21 shots out of 52 hit at 2600 yards (2400 meters). It was hard to miss at close range. The Americans bragged that at 1000 yards (920 meters) a group of six shells was only 20" (50 cm) across.

The M48 HE shell could also be used against armoured targets. Impacting shells tore of hatch flaps and pistol port covers, popped rivets, and made gaps between plates. The report noted that the primary cause of damage is the explosion and the velocity of the shell was secondary. Only direct hits made a difference. Near misses couldn't even tear the tracks.

Fragments of the M48 shell spread at an angle of 50-80 degrees from its trajectory. For more effective shooting, it was recommended to ricochet the shell off the ground, setting the fuse delay to 0.05 seconds.

The M48 was much more effective than the older M46 shell. While the M48 detonated when hitting any kind of terrain including sand, the M46 worked only half the time. The M48's more sensitive fuse allowed shooting with ricochets, showering the target with fragments.

The British carried out their own trials against a Matilda tank by the end of December of 1943. These trials were more interesting, since the 25 mm spaced side armour could result in premature detonation. To start, the Matilda was shot with an inert shell. The shell penetrated the 25 mm thick spaced armour and 45 mm thick main armour from a range of 1500 yards (1370 meters). A shell with a fuse fired from the same range hit a suspension spring and burst without a penetration.

The testers moved to the turret. From 1500 yards, one shell penetrated the 75 mm thick armour and smashed against the opposite side. The fuse didn't work. One penetrated the commander's cupola and burst inside it. At 1000 yards (920 meters) one shell ricocheted upwards from the side and burst against the turret. The second penetrated the turret without bursting. It was clear that the fuse needed work, but the testers still cleared it. The biggest complaint against the fuses, namely premature detonation, was not observed.

In addition to AP and HE, the tanks carried a small amount (usually 10%) of M89 smoke shells. Trials with these shells had rather poor results. The shell carried three smoke bombs that were scattered by an explosive charge. The charge was too powerful and the bombs flew up to 500 meters, which made the smoke screen uneven.

Burn,  baby, burn

The Sherman turned out to be quite a good tank. Its speed was only slightly lower than that of a Crusader, but its armour and firepower were closer to that of the heavy Churchill. The only thing that marred its reputation was the high risk of fire. Examination of burned out tanks confirmed the crews' suspicions: the fault lay with the ammunition stored in the sponsons and the turret basket, which were almost always struck with shell and armour fragments upon penetration.

Ammunition stowage inside a Sherman tank. It was easy to pull out of the racks, but also very vulnerable to being hit.

The British began modernizing their Sherman's ammo racks back in the fall of 1942. The Sherman held 60 rounds of ammo under the turret basket floor, 8 on top of the floor, 11 vertically along the sides of the basket, and 17 in the left sponson. The British protected the sponson rack with an extra inch of armour. Three openings were cut out in the turret basket to get to the ammo: a 120 degree wide one in the front and two 60 degree wide ones on the sides. The assistant driver could use it to hand the loader ammunition. This left only 19 rounds that were vulnerable when the tank was penetrated. Unfortunately, even this modificaton could not be performed in large numbers by field workshops.

The Americans took their own swing at improving ammunition stowage. Work began in early 1943 when the Armor Board recommended an investigation into the cause of fires, ordering two Sherman tanks and ammunition to conduct practical trials. One of the tanks was loaded with ammunition and carefully wiped clean from any fuel or oil. The second was fueled and oiled, but had no ammo. Shooting up both tanks would answer the question of whether the fuel or ammo was the cause of fires.

Penetration trials took place on May 24th, 1943, at Fort Knox. Shooting with 37 mm and 75 mm rounds at a range of 300 yards showed that penetration of the hull or turret led to an ammunition fire in 90% of the cases. Hitting a box of machine gun ammunition didn't do anything, but shell fragments penetrating the casing of 75 mm round had catastrophic consequences.

A solution to this problem was also tested. In addition to the regular ammunition racks, new ones were tried out. These were crates with double walls filled in with water. If a shell fragment struck the crate, the water would spill and prevent a fire from breaking out. A clever design with an air gap prevented the whole thing from being blown apart by a single hit. Trials showed that this was an effective way to protect ammunition even after multiple hits. This improvement came at a cost. The fighting compartment had to be reshaped, raising the turret basket floor up by 6 inches. A quarter-inch thick armour plate was welded to the floor in order to protect the crew from individual shells bursting. Since the rounds stored vertically in the turret basket were the most vulnerable, the ready rack was reduced to 6 rounds. The new fighting compartment allowed 150 75 mm rounds to be carried in total. The sides of the turret basket were removed altogether to ease loading. The floor was now held on with tubular supports. A Medium Tank M4 with wet ammunition racks was shot up in June. The results were good: out of 14 hits, only two resulted in a fire. The very fact that most ammunition was now stored on the floor of the tank helped, since inspection of damaged tanks showed that 60% of hits landed above the tracks.

Wet ammo rack diagram. The space between cells was filled with water.

Existing tanks were also modernized to reduce the chance of fire. Ammo racks were armoured with quarter-inch thick plates and another inch thick plate was welded to the outside of the tank. This extra armour improved the protection of the sides, although only locally. If the regular 75 mm shell could penetrate the side of the Sherman from five kilometers, the area with extra armour could only be penetrated from 2280 yards (2084 meters).

This armouring method was called Quick-Fix, but the British complained that it wasn't particularly quick, nor was it an effective fix. The upgrade was quite time consuming, taking up 200 man-hours per tank, most of which required skilled welders. The protection it offered was also very localized. The applique armour only protected the ammunition racks from a limited arc and the thin armour around the racks themselves didn't help against a direct hit. Nevertheless, this modernization was very common.

Medium Tank M4A1 with applique armour opposite its ammunition racks.

It is rare for any weapon to go through a trial by fire without showing some kind of weakness. Even the legendary Sherman tank was no exception. Nevertheless, it proved itself to be an effective weapon in the hands of an experienced tank crew. The drawbacks that were revealed in battle could be solved without a radical alteration of the entire design and without stopping production. The Sherman had a lot of room for modernization. Unlike most German or British tanks that were incapable of substantial upgrades, the Sherman continued to change throughout the whole war, remaining a potent fighting machine.

Sources:
  • Canadian Military Headquarters, London (1939–1947) RG 24 C 2
  • D. Oliver, M. Stramer, The New Breed Part 1, North Africa
  • Pier Paolo Battistelli. Battle Story: El Alamein 1942 — Spellmount, 2012
This article was originally published on Warspot.ru.

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