Warrior Maven Video Above: Army 2-Star Outlines Strategy for Future Infantry Combat Vehicles
By Sebastien Roblin, War Is Boring
During the 1940s, the U.S. Army developed a special weapon to counter the tanks of the German Wehrmacht. Most of these vehicles had the hull of a Sherman tank and a turret with a long-barrel cannon.
But don’t dare call them tanks. These were tank-destroyers.
After the war, the U.S. Army concluded tank destroyers were a waste of time. Official histories excoriated the failure of the program.
But a look at historical records shows that tank destroyers actually did their job well.
The tank-destroyer force was the Army’s response to the wild successes of German armor in Poland and France in 1939 and 1940. Panzer divisions would concentrate more than a hundred tanks on a narrow front, overwhelming the local anti-tank weapons of defending troops and rolling deep into enemy lines.
In 1941, the Army concluded that it needed mobile anti-tank units to intercept and defeat German armored spearheads. Towed anti-tank guns took too long to deploy on the move and it was difficult to guess where the enemy would concentrate for an attack. Instead, self-propelled anti-tank battalions would wait behind friendly lines.
When the German armor inevitably broke through the infantry, the battalions would deploy en masse to ambush the advancing tank columns.
The Army didn’t intend for its own tanks to specialize in defending against enemy panzers. The new armor branch wanted to focus on the same kind of bold armored attacks the Germans were famous for.
The Army tested the concept out in war games at Louisiana in September 1941. Tank-destroyers performed extremely well against tanks — perhaps because, as the armor branch alleged, the “umpire rules” were unfairly tilted in their favor. Tanks could only take out anti-tank units by overrunning them, rather than with direct fire.
With the support of the Army’s chief of training and doctrine Lt. Gen. Leslie McNair, tank-destroyers became their own branch in the army, just like armor and artillery already were. A tank-destroyer center began training units at Fort Hood, Texas. Fifty-three battalions of 842 men each initially mobilized, with plans to grow the force to 220 battalions.
Each battalion had 36 tank-destroyers divided into three companies, as well as a reconnaissance company of jeeps and armored scout cars to help ferret out the disposition of enemy armor so that the battalions could move into position. The recon company also had an engineer platoon to deal with obstacles and to lay mines.
The first tank-destroyer units made do with hastily improvised vehicles. The M6 was basically an outdated 37-millimeter anti-tank gun mounted on a three-quarter-ton truck.
The M3 Gun Motor Carriage, or GMC, was an overloaded M3 halftrack — a vehicle with wheels in the front and tracks in the rear — toting a French 75-millimeter howitzer on top. Both types were lightly armored and lacked turrets.
Though some M3 GMCs resisted the Japanese invasion of The Philippines, tank-destroyer battalions first saw action in the deserts of North Africa starting in 1942.
Their most important engagement pitted the M3s of the 601st Tank Destroyer Battalion against the entire 10th Panzer Division in the battle of El Guettar in Tunisia early in the morning on March 23, 1943.
Deployed in defense of the 1st Infantry Division just behind the crest of Keddab ridge, the 601’st 31 gun-laden halftracks moved forward and potted off shots at the panzers as they rolled down Highway 15, then scooted back and found new firing positions. They were bolstered only by divisional artillery and a minefield prepared by their engineers.
Two companies from the 899th Tank Destroyer Battalion reinforced them at the last minute, one of them suffering heavy losses while approaching.
The panzers advanced within 100 meters of the 601st’s position before finally withdrawing, leaving 38 wrecked tanks behind. However, the 601st had lost 21 of its M3s and the 899th lost seven of its new M10 vehicles.
The heavy losses did not endear the tank-destroyers to Allied commanders. Gen. George Patton said the tank-destroyers had proved “unsuccessful.”
In fact, the battle of El Guettar marked the only occasion in which U.S. tank-destroyers were used in the manner intended — deployed as an entire battalion to stop a German armored breakthrough concentrated on a narrow front.
The German army remained largely on the defensive in the second half of World War II, and failed to achieve armored breakthroughs like those in Poland, France and Russia. As a result, the U.S. Army scaled back the number of tank-destroyer battalions to 106. Fifty-two deployed to the European theater and 10 to the Pacific.
Another problem was that tank-destroyer doctrine presupposed moving into ambush positions after the German tanks had already overrun defending infantry. In practice, nobody wanted to consign the infantry to such a fate, so tank-destroyers deployed closer to the front line for forward defense.
The first proper tank-destroyer was the M10 Wolverine, which featured the hull of the M4 Sherman tank and a new pentagonal turret. General Motors and Ford produced 6,400 M10s.
The Wolverine mounted a long-barrel high-velocity 76-millimeter gun thought to have good armor-piercing performance. However, it had less effective high-explosive shells for use against enemy infantry — at least, compared to the 75-millimeter shells fired by Sherman tanks.
Naturally, tank-destroyer units carried more armor-piercing shells than high explosive shells, while the reverse was true in tank units.
Germany, Italy, Japan and Russia all fielded tank-destroyer vehicles, as well. Some were simply anti-tank guns mounted on a lightly-armored chassis, such as the Marder and Su-76, while others were heavily-armored monstrosities with enormous guns, such as the Jagdpanther and the JSU-152.
None had turrets. These were seen as expensive luxuries unnecessary for the defensive anti-tank role. American doctrine envisioned a more active role, thus the turrets. However, the M10’s hand-cranked turret was so slow it took 80 seconds to complete a rotation.
While Sherman tanks had three machine guns, the M10 had just one pintle-mounted .50-caliber machine gun that could only be fired if the commander exposed himself over the turret. Movie star Audie Murphy won the Medal of Honor when he repelled a German assault near Colmar, France using the machine gun of a burning Wolverine.
The M10’s biggest deficit lay in armor protection. The Wolverine had an open-top turret, meaning the crew was exposed to shrapnel and small-arms fire from above. Its armor was also thinner overall than the Sherman’s was.
These shortcomings had their rationales. Even the heavier armor on a Sherman could be reliably penetrated by the long 75-millimeter guns of the standard German Panzer IV tank, let alone the more potent guns on German Panther and Tiger tanks.
Therefore, the Wolverine’s inferior protection made little difference against those vehicles. It did leave the M10 more vulnerable than the Sherman to lighter anti-tank weapons, but these were no longer very common.
Likewise, the M10’s open top gave the crew a better chance of spotting the enemy tanks first — usually the factor determining the winner of armor engagements. It would rarely be a weakness when only fighting tanks. Of course, it would be a problem when engaging enemy infantry and artillery, but that was meant to be the Sherman’s job.
The M10 fully replaced the M3 GMC by 1943, but its superior gun proved less of a panacea than the Army had hoped. The Sherman tank’s short 75-millimeter gun was unable to penetrate the frontal armor of German Tiger and Panther tanks, which accounted for roughly half the Wehrmacht tank force by 1944.
The Wolverine’s 76-millimeter gun supposedly could — but experience in combat showed it failed to penetrate the frontal armor of Germany heavy tanks at ranges greater than 400 meters. A problem known as shatter-gap meant that the tip of the 76-millimeter shell deformed when it hit face-hardened armor plate at long distances, causing it to explode before penetrating.
The tank-destroyer’s inability to take out the best enemy tanks heightened the branch’s generally negative reputation.
In the Italian campaign that began in 1943, German armor was rarely encountered in large numbers, and M10s were often asked to provide fire support for the infantry. They were even used as indirect-fire artillery. Though firing lighter shells, a tank-destroyer battalion had twice as many gun tubes as 105-millimeter artillery battalion did, and longer range.
Instead of holding tank-destroyers in corps reserve, it became standard practice for commanders to attach a tank-destroyer battalion to front-line infantry divisions. Rather than fighting as unified battalions, companies or platoons of tank-destroyers would detach to provide direct support to infantry and combined arms task forces. For every anti-tank round the tank-destroyers fired, they fired 11 high-explosive rounds.
Doctrinaire officers complained that the M10s, vehicles in most respects similar to a tank, were being employed as if they were tanks. Gen. Omar Bradley suggested that the Army should instead use heavy towed anti-tank guns, which could be more effectively concealed in dense terrain.
As a result, half of the battalions converted to towed, 76-millimeter M5 guns similar in effectiveness to the M10’s own gun. These supplemented the companies of lighter 57-millimeter guns integrated in each infantry regiment.
As tank-destroyers were drawn increasingly into infantry support roles that exposed them to artillery and infantry fire, their crews piled sandbags on top of them in order to detonate Panzerfaust anti-tank rockets. Other field-modifications included additional machine guns and even armored panels covering the tank-destroyers’ vulnerable open tops.
The arrival of new Sherman tanks in 1944 sporting their own 76-millimeter guns further blurred the distinction between tank-destroyers and tanks. There were now Sherman tanks just as effective at tank-hunting.
Busting panzers in Normandy
Tank-destroyers fought in two major engagements in Normandy in addition to numerous smaller skirmishes. On July 11, 1944, three panzer battalions of the Panzer Lehr Division, supported by mechanized infantry, launched a counterattack to relieve Allied pressure on the city of Saint Lo.
The two wings of the attack ran into dispersed M10 platoons of the 799th and 823rd Tank Destroyer Battalions near the village of Le Désert, supported by abundant air power. In a series of sharp engagements in the claustrophobic hedgerow corridors of the Normandy countryside, the Panzer Lehr division lost 30 Panther tanks.
Three weeks later, four panzer divisions attempted to pinch off the Allied breakout from Normandy in the Mortain counteroffensive. The Panzers ran into the towed guns of the 823rd Tank Destroyer Battalion. In the dense early morning fog of the opening engagement, the 823rd was forced to fire at the muzzle flashes of equally-blind Panther tanks.
Unable to pull back the entrenched weapons, the 823rd lost 11 guns but succeeded in taking out 14 tanks. Self-propelled tank-destroyer battalions rushed into help. U.S. forces held Mortain and the German armies in northern France collapsed into a full retreat.
New tungsten-core, high-velocity, armor-piercing ammunition began to arrive for the 76-millimter guns in September 1944. The new rounds could reliably pierce German armor at range. Each Wolverine received only a few rounds of the rare ammunition, but it at least gave them a fighting chance at penetrating the German heavies.
Eleven tank-destroyer battalions were designated “colored” units. They were manned by African-American enlisted men and, mostly, white officers. The third platoon of the 614th Tank Destroyer Battalion, equipped with towed guns, won a Distinguished Unit Citation for beating back a German infantry counterattack after losing three of its four towed guns.
Charles Thomas, then a captain, being awarded the Distinguished Service Cross in 1945
Its commander, Lt. Charles Thomas, stayed to direct the fight even after his M20 scout car was knocked out and his legs were raked with machine-gun fire. He was awarded a Distinguished Cross that was upgraded to a Medal of Honor in 1997. By contrast, the 827th Tank Destroyer Battalion was infamously plagued by poor leadership.
M10s and M18s also saw action in the Pacific, serving notably at Kwajalein Atoll, Peleliu, The Philippines and Okinawa. Facing only limited enemy armor, they specialized in destroying Japanese pillboxes, though some apparently took out tanks in the Battle of Saipan.
More than 1,600 M10s would also serve in Royal Artillery anti-tank regiments of the British Army. Almost two-thirds were eventually given extra armor plates and up-gunned with the superior 17-pound anti-tank gun, and were known as M10C Achilles. The 17-pound — also 76 millimeters in caliber — was a reliable Tiger- and Panther-killer. British doctrine treated the Achilles as a fast-deploying defensive weapon rather than as an active tank-hunter.
The Achilles acquitted themselves well. In a battle near Buron, France, they knocked out 13 Panzer IV and Panther tanks for the loss of four of their number. They often escorted heavily-armored Churchill tanks that lacked adequate anti-tank firepower.
Some 200 Wolverines served in the Free French Army, where they were well-liked. Famously, the French M10 Sirocco fired across the two-kilometer-long Champs-Élysées boulevard of Paris from near the Arc de Triomphe to knock out a Panther tank at the Place de la Concorde.
Even the Soviet Union operated 52 M10s received through Lend Lease. These served in two battalions that saw action in Belarus.
The new blood
In 1944, two additional tank-destroyer types entered service. Buick designed the M18 Hellcat for pure speed. Lightweight and powered by a radial aircraft engine, it could zoom along at 50 miles per hour in an era that tanks rarely exceeded 35 miles per hour.
However, it had only an inch of armor and was armed with a 76-millimeter M1 gun that was little more effective than that on the M10. Several units in Italy refused the upgrade to the M18 — armor was more important than speed in the cramped mountainous terrain. But the M18 was popular in Patton’s hard-charging 3rd Army.
While speed is useful for getting armored vehicles where they’re needed, accounts differ as to whether it provided the M18 much benefit at the tactical level. An Army study concluded it was unimportant in tactical combat. Other sources maintain the Hellcat’s speed enabled it in using hit-and-run tactics.
The M36 Jackson — or Slugger — on the other hand, had the hull of the M10 with additional armor and finally upgraded the armament to a heavy 90-millimeter gun. Not only were the heavy shells effective Tiger- and Panther-killers at long ranges — one once knocked out a Panther nearly four kilometers away — but they were significantly more effective against infantry.
2,324 were converted by the end of the war from various M10 and M4A3 vehicle hulls.
The new tank-destroyers acquitted themselves well in combat. In the Battle of Arracourt, two platoons of Hellcats — eight in total — from the 704th Tank Destroyer Battalion moved swiftly into ambush positions behind a low ridge on a foggy day, only their turrets poking over the rise.
When a battalion of Panther tanks from the 113th Panzer Brigade entered their sights, they knocked out 19 for the loss of three of their own number. At the Siegfried Line, M36s excelled at knocking out fortifications and helped beat back Tiger tanks that had decimated Shermans of the 9th Armored Division.
The Battle of the Bulge, a massive German counteroffensive in the frozen Ardennes forest, was the swan song of U.S. tank-destroyers. The Hellcats of the 705th Tank Destroyer Battalion helped the 101st Airborne repel German armored assaults at Bastogne.
A detached platoon of M18s escorting Team Desobry helped take out 30German tanks in Noville. M36 Jacksons of the 814th Tank Destroyer Battalion took 50-percent casualties in a delaying action at Saint Vith, knocking out 30 Panther tanks in the process.
The towed tank-destroyer battalions didn’t fare so well. Several battalions had to abandon their guns in the face of the German advance. Others got stuck in the mud and snow. While M10s of the 644th Tank Destroyer Battalion destroyed 17 tanks in two days in the ill-fated defense of Elsenborn ridge, the towed guns of the 801st fighting in the same battle lost 17 guns.
Of the 119 tank destroyers lost in the Battle of the Bulge, 86 were towed guns. Meanwhile, the tank-destroyers claimed 306 enemy tanks. In January 1945, it was decided to re-convert the towed units to self-propelled battalions.
By the end of the war, the writing was on the wall for the tank-destroyer — particularly when the first of the early M-26 Pershing tanks armed with the same 90-millimeter guns as on the M36 began to see action in early 1945.
Tank-destroyers were pretty much just tanks with inferior armor and better guns. Contrary to doctrine, commanders in the field asked them to perform most of the same tasks as regular tanks. Why invest in a whole separate branch of the army and different class of vehicles when you could simply give tanks the same gun?
Just three months after the end of World War II the Army disbanded the tank-destroyer branch. While the U.S. military did develop a few more specialized anti-tank vehicles, such as the M56 ONTOS, Army doctrine would go on to assert “the best means of taking out a tank is another tank.”
World War II was not quite the end of the line for U.S. tank destroyers. The M36 Jackson and its 90-millimeter gun were hastily called back for use in the Korean War five years later to counter North Korean T-34/85 tanks.
Surviving tank destroyers were resold all over the world. M10s and M18s saw action with the Nationalist army in the Chinese civil war. Wolverines cropped up in the Arab-Israeli conflict and Pakistani M36s battled Indian tanks in 1965. Croatia and Serbia used M36s and M18s in the Yugoslav civil war of the early to mid-1990s. Yugoslavia even deployed M36s as decoys against NATO airstrikes during the Kosovo War. Upgraded M18s remain in Venezuelan service today.
The shortcomings of U.S. tank destroyers are clear. They were intended to fight in a specific context that largely failed to materialize. They had inferior armor protection. With the exception of the M36, they weren’t reliably capable of taking out the scariest enemy tanks.
Post-war Army historians roundly lashed them for these shortcomings. Yet here’s the funny thing. Operational records show that the tank-destroyers actually rocked.
Active, self-propelled tank-destroyer battalions were judged to have killed 34 tanks each on average, and about half as many guns and pillboxes. Some units, such as the 601st, reported more than 100 enemy tanks destroyed. This led to an average kill ratio of two or three enemy tanks destroyed for every tank-destroyer lost.
The ultra-lightly-armored M18, with its unexceptional gun, had the bestratio of kills to losses for any vehicle type in the Army!
Why? Ultimately, it may come down to how tank-destroyers were employed, even though it was not the manner intended by Army strategists. While Sherman tank units sometimes embarked on risky assaults and unsupported rapid advances, tank-destroyers usually deployed in support of combined arms task forces with infantry.
This cooperation with friendly forces meant they showed just where they needed to be, spotted the enemy first and got off the first shot. And being the first to shoot usually determined the outcome of armored engagements in World War II, regardless of the quality of the vehicles involved.
Tank-destroyers also taught the Army not to over-specialize. There was no need for multiple classes of tanks that were strong in one respect and weak in another. The post-war concept of the main battle tank embraced this idea to the fullest.
As such, the U.S. tank destroyer branch constitutes one of the most curiously successful failures in U.S. military history.
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