The M10 tank destroyer was a United States tank destroyer of World War II
based on the chassis of the M4 Sherman tank fitted with the 3-inch Gun M7.
Formally 3-inch Gun Motor Carriage, M10, it was numerically the most important
U.S. tank destroyer of World War II and combined a reasonably potent anti-tank
weapon with a turreted platform. Despite the introduction of more-powerful types
as replacements, it remained in service until the end of the war, and its
chassis was later reused with a new turret to create the M36 Jackson, which
used a 90mm gun instead of the 76.2mm gun.
It was christened the Wolverine by the British, although unlike other vehicle
names such as the M4 Sherman, the name was not adopted by American soldiers,
who called it TD beyond its formal designation.
Development US combined-arms doctrine on the eve of
World War II held that tanks should be designed to fulfill the infantry support
and exploitation roles. The anti-tank warfare mission was assigned to a new
branch, the tank destroyer force. Tank destroyer units were meant to counter
German blitzkrieg tactics. Tank destroyer units were to be held as a
reserve at the corps or army level, and were to move quickly to the site of any
enemy tank breakthrough, maneuvering aggressively to destroy enemy tanks.
This led to a requirement for very fast, well-armed vehicles. Though equipped
with turrets, the typical American design was more heavily gunned, but more
lightly armored, and thus more maneuverable, than a contemporary tank.
The idea was to use speed and agility as a defense, rather than thick armor, to
bring a powerful self-propelled gun into action against enemy tanks.
The 3-inch Gun Motor Carriage T35 was the prototype of the M10. It was
equipped with a 3-inch gun in a sloped, circular, open-topped turret, developed
from the Heavy Tank T1/M6 turret, and mounted on an early-production Medium
Tank M4A2 hull. At Tank Destroyer Command request, the
design was modified to give a lower silhouette and "angled hull
superstructure". This was built with thinner but sloped armor on the sides
and rear, again using an M4A2 chassis; the test vehicle designated as 3-inch
Gun Motor Carriage T35E1. The turret was then changed for a pentagonal welded
one. In June 1942 the T35E1 was finalized as the 3-inch Gun Motor
Carriage M10 and ordered into full production.
In order to get more production, a design on the M4A3 chassis was also
authorized as the M10A1 GMC. Towards the end of production the 76 mm
gun M1 was installed in the last 300 or so M10s, as it was being fitted into the
new production M4 Sherman tank at the time. The 76 mm M1 offered slightly
better anti-armor performance than the previous 3" gun M7.
The British converted some M10s to use their successful 17-pounder anti-tank
gun, which they designated as "17pdr SP Achilles". The turret needed
modification to take the longer gun. The 17-pounder was of a similar bore, but
longer and using a larger propellant charge had far superior armor
penetration capability. It was used by the British, Canadian and Polish armies
in Italy and northwest Europe. After World War II, a batch was acquired
by the Republic of China Army as demilitarized surplus items. The
vehicles' main guns were rendered useless prior to delivery and
consequently replaced in 1949 with ex-Imperial Japanese Army 105mm infantry
howitzers. Production
Production of 4,993 M10s at General Motors' Fisher Tank Arsenal in Grand
Blanc, Michigan ran from September 1942 through December 1943.
In September-November 1943, Fisher also built 375 M10A1s, and a further 300
M10A1s which were completed with new turrets as the M36 tank destroyer.
Ford Motor Company built 1,028 of the M10A1 variant from October 1942 until
September 1943. Some of the M10A1 vehicles were
subsequently converted to M35 Full Track Prime Mover by removing the turret and
adding the necessary equipment for them to tow 155 mm and 240 mm artillery.
Armament The M10 used a Medium Tank M4A2 chassis
with an open-topped turret mounting a 3" gun M7. This gun fired the Armor
Piercing M79 shot that could penetrate 3 inches of armor at 1,000 yards at 30
degrees from vertical. Other types of ammunition carried throughout its
service life included the Armor Piercing Capped Ballistic Cap M62 projectile,
High Velocity Armor Piercing M93 shot, and Armor Piercing High Explosive; 54
rounds of 3-inch ammunition were carried. The rear of the turret carried
two large counterweights which gave it a distinctive shape. The main shortcoming
of the 3 inch gun was its APHE round, which was the round most commonly used
for engaging tanks. The 3 inch APHE round was based on the naval 3 inch
round and had a small charge in the rear of the round which was supposed to
explode after penetration of the target's armor plating. Unfortunately it
was discovered that it exploded on impact or shortly thereafter, causing
the round not to penetrate. It is still a puzzling mystery as to why this
problem was never addressed with a better base fuse or by deleting the
small HE charge in the rear of the round. This was also a problem with the
towed version of the 3 inch gun, the M5, in the antitank role.
A .50 caliber Browning M2HB machine gun could be mounted on the top rear of the
turret for use against enemy infantry and for anti-aircraft use, along with
300 rounds of ammunition. The crew were also equipped with their own personal
weapons for self-defense. Combat use
In its combat debut in Tunisia in 1943 during the North African campaign, the
M10 was successful as its M7 3 inch gun could destroy most German tanks then in
service. The M10's heavy chassis did not conform to the quickly evolving tank
destroyer doctrine of employing very light high-speed vehicles, and starting
in mid-1944 it began to be supplemented by the 76mm Gun Motor Carriage M18
"Hellcat". Later in the Battle of Normandy, the M10's gun proved to be
ineffective against the frontal armor of the newer German Tiger and Panther tanks
unless firing HVAP rounds, but was effective against the most common tanks
such as the Panzer IV medium tank and other lighter vehicles and
self-propelled guns. Tank destroyer units had been supplemented with 90mm
towed guns in partial anticipation of heavier German tanks, but their lack of
mobility made employing them difficult. By the fall of 1944, the improved 90mm
Gun Motor Carriage M36 began to arrive in Europe as well. In the Pacific war,
US Army M10s were used for infantry support, but were unpopular due to their
open-topped turrets, which made them more vulnerable than a fully enclosed
tank to Japanese close-in infantry attacks.
Approximately 54 M10s were supplied to the Soviet Union, though their use by
the Red Army is largely unrecorded. The M10 also equipped units of the Free
French Army; one M10 named Sirocco, part of the Régiment Blindé de Fusiliers
Marins composed of French sailors, famously disabled a Panther on the Place
de la Concorde during the liberation of Paris.
The British were supplied with M10 and M10A1 vehicles. British M10s were
designated as 3 inch Self Propelled or "M10 3 in SP" and, as with all British
self-propelled anti-tank guns, were operated by Royal Artillery units. They
saw action in Italy and France. Many in France were upgunned with the more
effective 17-pounder gun from 1944 onwards. These were designated "17pdr SP
Achilles Mk IC" for the M10 and "17pdr SP Achilles Mk IIC" for the M10A1. As
well as service in the British forces in North West Europe they were retained
post-war. Those not upgunned were stripped of their turrets and used as
artillery tractors. The M10's open-topped turret left the
crew vulnerable to artillery and mortar fire and fragments. The crew is also
exposed to long distance sniper fire and infantry close assault, such as thrown
grenades, or attacks from upper story windows, especially in urban combat and
wooded areas. Based on US infantry doctrine, this was not considered a
major flaw as American infantry were supposed to have carried significant
support firepower when supporting the vehicles in the type of combat that made
them most vulnerable. However, the open-topped turret gave excellent
visibility, which was valuable for a vehicle that was tasked with finding
enemy armored vehicles and other targets. The open top also made escape
easier when the vehicle was hit and improved communications with
accompanying infantry. Though other nations such as the Soviet
Union and Germany deployed TDs according to the same inter-war era mobility
doctrine as the US, their TDs were low, slow vehicles with very large guns in
limited traverse casemates. In order to compensate for its deficiencies, some
individual US crews improvised overhead turret armor in Normandy to protect
against mortars and grenades. One M10 was photographed with an almost complete
roof fitted to a raised edge which had vision slits, all manufactured out of
captured German plating. In UK service, one M10 in the 86th Anti-Tank Regiment
in Normandy drove back out of action three separate times with the entire
turret crew dead. Two turret crews had been killed by 88mm air bursts or
mortars exploding in treetops, one crew were killed by a direct hit through the
turret. The same driver survived each time. When this driver was placed with a
new crew, his fourth, he was declared to be a 'Jonah' and they refused to drive
with him. He was transferred to another unit and told to keep quiet about his
history. By the end of the war its armor was
clearly too thin to provide protection from the newer German tanks, anti-tank
guns, and infantry anti-tank weaponry. M10s in Europe were fitted with layers
of sandbags or baulks of timber attached to front and side armor to detonate
Panzerschreck rockets and Panzerfausts before they struck the main plate. The
M10 had a very slow turret rotation speed, as the turret traverse was
unpowered and the crew had to use a hand crank to rotate the turret around. It
took approximately two minutes to rotate a full 360 degrees. However, this slow
rotation speed may have been again more a theoretical flaw than real as compared
to German armored fighting vehicles, as the M10 was generally more mobile than
its turreted opponents in the most common tactical situations in Europe and
had far better traverse than turretless German tank destroyers with virtually no
traverse and which were much less mobile. The German Panzer IV Ausf. J,
produced exclusively in 1944-45 also had manual-only turret traverse, which was
twice as fast as the M10, with the Tiger I having the same speed as the J's.
Panthers and Tiger IIs could traverse four times as fast as the M10. It was
more important that US AFVs would generally operate in greater numbers in
tactical situations, and therefore had more firing angles and greater firepower
in battle than their German opponents. Consequently, the Germans in the West
lost more AFVs than they could afford. The Western European terrain permitted
very little in the way of long distance tank engagements where the heavy German
tank's high velocity guns and thick frontal armor could be used to their
advantage. The lack of German AFV numbers is indicated by the fact that
U.S. tank destroyers fired many more high-explosive shells than anti-tank
ammunition, indicating that they were employed much like the tanks they were
assigned to support. In UK service, the M10 was normally
issued to four-battery regiments of the Royal Artillery. Typically they were
re-armed with the more powerful 17-pounder gun and, typically, two
batteries had M10s while two batteries had the towed 17-pounder gun. One
tactical theory was that the two towed batteries would form a gun line while an
M10 battery remained mobile on each flank and drove or led enemy tanks on to
the static gun line. In practice, UK batteries were frequently separated in
Normandy, with the M10 batteries often being seconded to British tank brigades
which operated within infantry divisions; these brigades were equipped
with Churchill tanks with the general purpose 75 mm gun.
In the final analysis, the M10, although it was clearly not a superior weapons
system in Europe in 1944-45, proved to be useful, effective, and survivable
enough to maintain unit strengths through replacement and repair.
The most decorated American soldier, Audie Murphy, earned his Medal of Honor
at the Battle of the Colmar Pocket, when he used the heavy machine gun of an
abandoned and burning M10 to repel German infantry. He was reportedly very
disappointed when an M10 was not available for his reenactment of the
event in the post-war film To Hell and Back and he had to use a Sherman in its
place. Ten German Panther tanks were modified
to look like M10s in the Ardennes Offensive.
Variants 3-inch Gun Motor Carriage T35: Early
production Medium Tank M4A2 chassis. 3-inch Gun Motor Carriage T35E1
Redesign of T35 with thinner armor and round turret on M4A2 chassis. Turret
changed and standardized as M10. 3-inch Gun Motor Carriage M10): Diesel
engine 3-inch Gun Motor Carriage M10A1: M4A3
chassis, Ford GAA gasoline engine 17pdr SP Achilles: M10 equipped with an
Ordnance QF 17 pounder Mark V gun as used on the Sherman Firefly and British
tanks. They can be identified by the muzzle brake at the end of the barrel
and a counterweight behind the muzzle brake.
Diesel-engined M10 became 17pdr SP Achilles IC,
Gasoline-engined M10A1 became 17pdr SP Achilles IIC
Full-Track Prime Mover M35: Turretless M10A1 used as an artillery tractor
3in SP Wolverine: Proposed Canadian-built version using a Ram tank
chassis — a single prototype was built in 1942.
M10 Self-Propelled Howitzer: Previously-demilitarized M10 transferred
to China and then in 1949 rearmed with modified ex-IJA 105mm infantry
howitzers. Other modifications included a permanent turret roof with crew
access/observation hatches, lighter but more impact-resistant armor plating, and
a bow machine gun port. One prototype and 16 follow-on vehicles were made.
* SP = Self-Propelled See also
List of U.S. military vehicles by model number
SP 17pdr, A30 - British tank destroyer of 1945
Notes References
Peter Chamberlain & Chris Ellis British and American Tanks Of World War Two: The
Complete illustrated history of British, American and Commonwealth tanks:
1939–1945 1969. Arco Publishing US Army Technical Manuals
TM 9-2800 Standard Military Motor Vehicles. dated 1 sept. 1943
TM 9-323 - M7 Gun. TM 9-752A - Carriage, Motor, 3-inch, M10
TM 9-1750 - Power train unit TM 9-1750B - Power train unit
TM 9-1750G - General Motors twin diesel US Army Supply Catalogue "Standard
Nomenclature List" SNL G130 - for Carriage, Motor, 3-inch,
M10 SNL C-43 - M7 gun.
External links 3" Gun Motor Carriage M10 - AFV Database
M10 3" Gun Motor Carriage - World War II Vehicles
(French) M35 Prime Mover - 2iemeguerre.com
I Am A Tank Destroyer Commander large detailed 1943 article
Tankdestroyer.net Flames Of War: Tanks Destroyers An
analysis of the capacities of tanks Destroyers for a wargame