Armored bulldozer. The armoured bulldozer is a basic tool of combat engineering. These combat engineering vehicles combine the earth moving capabilities of the bulldozer with armour which protects the vehicle and its operator in or near combat. Most are civilian bulldozers modified by addition of vehicle armour/military equipment, but some are tanks stripped of armament and fitted with a dozer blade. Some tanks (called tankdozers) have bulldozer blades while retaining their armament, but this does not make them armoured bulldozers as such, because combat remains the primary role—earth moving is a secondary task.

World War II

The first armoured bulldozer (D7A) was developed by the British during World War II. This was a conventional Caterpillar D7 bulldozer fitted with armour to protect the driver and the engine. The work was carried out by Jack Olding & Company Ltd of Hatfield. The bulldozer was one of several specialist armored vehicles that were collectively referred to as "Hobart's Funnies" and were operated by the British 79th Armoured Division in support of armoured assaults.

The bulldozers were produced in preparation for the Battle of Normandy with the tasks of clearing the invasion beaches of obstacles and quickly making roads accessible by clearing rubble and filling in bomb craters.

As Allied armies advanced through Europe, the armoured bulldozer was found to be too slow—there was a need for well-armoured, obstacle clearing vehicle that was fast enough to keep up with tank formations. This need was met by the Centaur Bulldozer—a Centaur tank with the turret removed and a bulldozer blade fitted. Centaur bulldozers were still in use with the British Army at the time of the Korean War.

Modern use

Modern armoured bulldozers are often based on the Caterpillar D7 and D9. The attributes that make the D9 popular for major construction projects make it desirable for military applications as well.  It has been particularly effective for the Israel Defense Forces (IDF) and for the United States armed forces (the Marine Corps and the US Army) and the Canadian Army  in Iraq, both using an armour kit developed and manufactured by Israel. Following the success of the armoured D9, Caterpillar Defense Products started to manufacture and sell armoured bulldozers, mainly for the United States Armed Forces.

Israel
The Israeli Armored D9 is a Caterpillar D9 bulldozer that was modified by the Israel Defense Forces, Israeli Military Industries and Israel Aerospace Industries to increase the survivability of the dozer in hostile environments and enable it to withstand heavy attacks.

The D9R, the latest generation of D9 bulldozers in IDF service, has a power of  and drawbar pull of . It has a crew of two, an operator and a commander. It is operated by the TZAMA (צמ"ה = ציוד מכני הנדסי, Mechanical Engineering Equipment) units of the Israeli Engineering Corps.

The main IDF modification is the installation of an Israeli-made armor kit, which provides armour protection to the mechanical systems and to the operator cabin. The operator and commander are protected inside an armoured cabin ("the cockpit"), with bulletproof windows to protect against bombs, machine gun, and sniper fire. The IDF also developed a slat armor add-on to deflect RPG rounds. The modified D9 bulldozers can be fitted with disparate features, such as crew-operated machine guns, smoke projectors, or grenade launchers.

The IDF uses the D9 for a wide variety of engineering tasks, including earthworks, digging moats, mounting sand barriers, building fortifications, rescuing stuck, overturned or damaged armoured fighting vehicles (along with M88 Recovery Vehicle), clearing landmines, detonating improvised explosive devices and explosives, clearing terrain obstacles and opening routes for armoured fighting vehicles and infantry, as well as structures demolition, including under fire.

During the Second Intifada the armoured D9 bulldozer was an effective tool against Palestinian fighters, as they were almost impervious to Palestinian weapons and withstood even RPGs and belly charges with more than 100 kg and even half a ton of explosive. Therefore, they were used to opening safe routes for IDF forces and detonate explosive charges. The bulldozer was used extensively to clear shrubbery and structures which could be used as cover. 

During the Battle of Jenin, armoured bulldozers were used for neutralizing the roadside bombs that would line the alleys of the camp, according to Israeli Military Intelligence. About a dozen armoured Caterpillar D-9 bulldozers were deployed, widening alleys, clearing paths for tanks, and detonating booby traps. Lieutenant Colonel Ofek Buchris continued to employ extensive use of bulldozers, developing a method to expose IDF soldiers to less risk: first, a bulldozer would ram the corner of a house, opening a hole, and then an IDF Achzarit troop carrier would arrive to disembark troops into the house, where they would clear it of any militants found inside.

Following several incidents where armed Palestinians barricaded themselves inside houses to prevent house demolition and killed soldiers attempting to breach the entries, the IDF developed "Noal Sir Lachatz" (נוהל סיר לחץ "Pressure Cooker protocol") in which D9s and other engineering vehicles were used to bring them out by razing the houses.

The Israeli military would use armoured bulldozers extensively during the Israeli invasion of the Gaza Strip. They would also be used to damage infrastructure during the 2024 Israeli military operation in the West Bank.

In 2003, American peace activist Rachel Corrie was killed by an IDF armoured bulldozer in Rafah while attempting to prevent the destruction of Palestinian homes in the Rafah Refugee Camp.

United States

During the first Gulf War the United States purchased tractor protection kits (TPK) from the Israel Military Industries (IMI) for their Caterpillar D7 bulldozers. The armored bulldozers were mainly used in mine clearing applications. During the preparation to the war in Iraq in 2003 the United States Army purchased several D9 armor kits from the IDF and used them to produce similarly fortified D9s. These have been used to clear destroyed vehicles from roads, dig moats, erect earthen-barriers, and construct field fortifications. D9s have also been used to raze houses which sheltered insurgent snipers. Military reports on the Conflict in Iraq say that the D9s were found very effective and "received highly favorable reviews from all that benefited from their use".

Other military forces
The Soviet military developed a dozer-blade-equipped armored vehicles, the IMR series, based on the T-72 platform. They would later see use by Russia and Ukraine during the 2022 Russian Invasion of Ukraine.

See also 

 Bob Semple tank
 Demining
 Engineering vehicles
 Marvin Heemeyer – known for the 2004 "Killdozer" rampage

Notes and references

External links
 , Military-today.com
 IDF Armoured D9R Dozer, Army-technology.com
 Army's new D9 bulldozer digs into duty in Kuwait - The US army tests the armored D9R for the Iraqi campaign
 Caterpillar Bulldozers Are Leading the Fight Against the Islamic State, Popular Mechanics, June 2017

Military engineering vehicles
Military vehicles of Israel
Caterpillar Inc. vehicles
Tracked vehicles