×
Aircraft / Aviation Vehicles & Artillery Infantry Arms Warships & Submarines Military Pay Scale Military Ranks
Advertisements

HOME
ARMOR
MODERN ARMIES
COUNTRIES
MANUFACTURERS
COMPARE
BY CONFLICT
BY TYPE
BY DECADE
WORLD WAR 2

240mm Caterpillar Mark IV


Self-Propelled Howitzer (SPH) (1920)


Land Systems / Battlefield

1 / 2
Image from the Public Domain.
2 / 2
Image from the Public Domain.

Jump-to: Specifications

The 240mm Caterpillar Self-Propelled Gun concept never materialized for the United States Army before the end of World War 2.



Authored By: JR Potts, AUS 173d AB | Last Edited: 09/27/2018 | Content ©www.MilitaryFactory.com | The following text is exclusive to this site.
Advertisements
During World War 1, United States Army authorities came to the conclusion that towed artillery was consistent with their current battlefield doctrine. However, large howitzers and like-artillery systems required multiple "mover" vehicles (either tractors or large trucks) to transport and much time was needed by the operating crew for the preparation of such weapons, in a sense defeating much of its tactical value. Making the artillery system self-propelled was the primary solution as less crew and time would be needed to transport and set up a firing position for the gun. The Caterpillar Mk IV was such a machine, born as a single pilot vehicle designed to propel a large-caliber 240mm howitzer.

The 240mm, 9.5-inch M1918 Schneider howitzer of French origins was the largest-caliber field gun to be deployed by US Army field artillery in World War 1 and was used to great success. The gun began life as a towed artillery piece originally designed during World War 1 and since having been updated on many occasions in increase potency and keep the type modernized for current battlefield requirements. The 9.5-inch barrel fired a hefty 356-pound shell which was propelled by a 49-pound bag of TNT and could reach out to 14,000 yards - approximately 10 miles - when fired.

The M1918 gun was towed in separate major components by no fewer than six tractors and required a full 20-man crew to transport, setup and operate. In a combat situation, the crew would have to set up the gun system in the cover of darkness, which also required reconnaissance of the ground and much training as deployment of the six tractors and the many required hours needed to set up the gun in broad day light would have drawn much attention from enemy artillery. When the precise firing position was found, a seven-man lead crew was first on the scene to layout the emplacement pit using a surveyor's transit. The crew then dug a 7x6x3 foot pit with conventional picks and shovels over the course of three hours if the ground proved fair. An additional twelve hours and the balance of the 20-man crew was needed to complete setup of the gun.

Firstly, a metal base was dropped into the prepared pit with steel ramps placed along the sides of the pit to help distribute the weight of the system. Next came the tractor towing the aiming mounts followed by another tractor bringing the recoil mechanism and, finally, another transport hauling the 11,000 pound barrel. The guns wheels alone weighed up to 1,000lbs each. When completed, the entire gun system weighed an impressive 39,920lbs. As one can see, the massive effort made a self-propelled version very desirable.

The Caterpillar Mark IV, developed in 1920, did not make use of a "true" tank chassis but instead relied upon a tractor chassis - weighing some 31,580 pounds - with an 11,000lb barrel and applicable firing system added. The tractor was based on a French design produced by the St. Chamond Company. All told, the completed Caterpillar vehicle topped 71,500 pounds. A 150 horsepower motor powered a 400 volt, 70kW generator which, itself, powered the 70 horsepower electric motors required to move the track systems. A crane, connected to the back of the gunnery platform, assisted in raising each 356-pound shell from awaiting ammunition carts. This arm then swung the projectiles into place on the loading tray. The primary tractor could transport seven crew. Testing ensued at the Aberdeen Proving Grounds of Maryland in 1921.

As a mover, the tractor chassis proved underpowered with its engine/motor arrangement for a top speed of just 9 miles per hour was possible and this only in ideal conditions. A second tractor (sans the gun and mounting), known as the "Mark IV-A", was attached to the rear of the primary mover in an attempt to help increase speeds over open ground. While towing the vehicle itself would have been an option, it would defeat the purpose of its "self-propelled" nature. Thusly, the Mk IV concept was ultimately deemed inadequate and later scrapped from US Army requirements, this after six of the kind were completed.

The heavy-caliber self-propelled gun concept was tried once again during World War 2 when, in 1944, a 240mm howitzer was mounted onto a heavy tank T26E3 tracked chassis. An extra wheel bogie had to be fitted to each track side due to the excessive weight. This new variant became the "T92 Howitzer Motor Carriage" though the war was over by September of 1945. The T92 HMC was never used in combat and later scrapped - along with the dream of a US Army large-caliber self-propelled gun. Similar gun concepts within Germany and the Soviet Union also fell to naught during the war.

Specifications



Service Year
1920

Origin
United States national flag graphic
United States

Crew
7
CREWMEN
Production
6
UNITS


State Factories - USA
National flag of the United States United States
(OPERATORS list includes past, present, and future operators when applicable)
Fire Support / Assault / Breaching
Support allied forces through direct / in-direct fire, assault forward positions, and / or breach fortified areas of the battlefield.


Length
29.9 ft
9.114 m
Width
8.5 ft
2.59 m
Height
13.0 ft
3.96 m
Weight
71,198 lb
32,295 kg
Tonnage
35.6 tons
MEDIUM
(Showcased structural values pertain to the base 240mm Caterpillar Mark IV production variant. Length typically includes main gun in forward position if applicable to the design)
Powerplant: 1 x Motor developing 150 horsepower to 1 x Generator of 400 watts driving 2 x Motors developing 70 horsepower each.
Speed
9.0 mph
(14.5 kph)
Range
34.8 mi
(56.0 km)
(Showcased performance specifications pertain to the base 240mm Caterpillar Mark IV production variant. Compare this entry against any other in our database)
1 x 240mm M1918 Schneider howitzer main gun


Supported Types


Graphical image of a tank cannon armament


(Not all weapon types may be represented in the showcase above)
Dependent upon ammunition carrier. 345lb HE shell with 40lb TNT charge.


240mm Caterpillar Mark IV - Base Series Designation.
Mark IV-A - Designation marking gun-less tractor movers.
T92 Howitzer Motor Carriage - 1944 Variant mounting 240mm gun barrel and firing system t T26E3 tank chassis.


Military lapel ribbon for the American Civil War
Military lapel ribbon for pioneering aircraft
Military lapel ribbon for the Arab-Israeli War
Military lapel ribbon for the Battle of the Bulge
Military lapel ribbon for the Battle of Kursk
Military lapel ribbon for the Cold War
Military lapel ribbon for the Falklands War
Military lapel ribbon for the Indo-Pak Wars
Military lapel ribbon for the Korean War
Military lapel ribbon for the 1991 Gulf War
Military lapel ribbon representing modern aircraft
Military lapel ribbon for the Soviet-Afghan War
Military lapel ribbon for the Spanish Civil War
Military lapel ribbon for the Vietnam War
Military lapel ribbon for the World War 1
Military lapel ribbon for the World War 2
Military lapel ribbon for the Yom Kippur War
Military lapel ribbon for experimental military vehicles


Ribbon graphics not necessarily indicative of actual historical campaign ribbons. Ribbons are clickable to their respective campaigns / operations.

Advertisements





Disclaimer | Privacy Policy | Cookies


2022 Military Pay Scale Army Ranks Navy Ranks Air Force Ranks Alphabet Code DoD Dictionary American War Deaths French Military Victories Vietnam War Casualties

The "Military Factory" name and MilitaryFactory.com logo are registered ® U.S. trademarks protected by all applicable domestic and international intellectual property laws. All written content, illustrations, and photography are unique to this website (unless where indicated) and not for reuse/reproduction in any form. Material presented throughout this website is for historical and entertainment value only and should not to be construed as usable for hardware restoration, maintenance, or general operation. We do not sell any of the items showcased on this site. Please direct all other inquiries to militaryfactory AT gmail.com.

Part of a network of sites that includes GlobalFirepower, a data-driven property used in ranking the top military powers of the world, WDMMA.org, the World Directory of Modern Military Aircraft, and SR71blackbird.org, detailing the history of the world's most iconic spyplane.


Facebook Logo YouTube Logo

www.MilitaryFactory.com • All Rights Reserved • Content ©2003-