Caterpillar D9: Difference between revisions

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{{Short description|Large bulldozer}}{{More references|date=April 2024}}

[[he:דחפור די-9]]

[[Image:Cat_D9.GIF|thumb|Caterpillar D9 with dimensions]]

{{Use dmy dates|date=May 2018}}

The '''Caterpillar D9''' is a large track-type tractor (commonly referred to as a [[bulldozer]]) with [[caterpillar track]]s designed and manufactured by [[Caterpillar Inc.]]. The D9, with 410hp of gross power and an operating weight of 53.8 tons, is in the upper end of Caterpillar's track-type tractors, which range in size from the D3 (70hp, 8.1 tons), to the D11 (850hp, 124.3 tons). The size, durability, reliability, and low operating costs has made the D9 one of the most popular large track-type tractors in the world, with the Komatsu D275A as one of its most direct competitors.

{{Infobox tractor

| name = Caterpillar D9

| image = CatD9T.jpg

| caption = Caterpillar D9T

| manufacturer = Caterpillar

| production = 1955 -

| length = {{convert|26.5|ft|m|abbr=on}}

| width = {{convert|14.7|ft|m|abbr=on}} (blade)

| height = {{convert|13|ft|m|abbr=on}}

| weight = {{convert|108000|lb|kg|0|abbr=on}}

| propulsion = [[Continuous track]]

| type = Heavy [[bulldozer]]

| engine_model = {{unbulleted list

| CAT C18 ACERT (D9T)

| 3408 HEUI (D9R)

}}

| gross_power = {{unbulleted list

|{{convert|464|hp|kW|abbr=on}} D9T

|{{convert|474|hp|kW|abbr=on}} D9R

}}

| flywheel_power = {{unbulleted list

| {{convert|410|hp|kW|abbr=on}} D9T

| {{convert|410|hp|kW|abbr=on}} D9R

| {{convert|375|hp|kW|abbr=on}} D9N

| {{convert|460|hp|kW|abbr=on}} D9L

}}

| drawbar_pull = 71.6 tons

| speed = {{unbulleted list

| {{convert|7.3|mph|abbr=on}} Forward

| {{convert|9.1|mph|abbr=on}} Reverse

}}

| blade_capacity = {{unbulleted list

| {{convert|17.7|cuyd|m3|abbr=on}} 9 SU blade

| {{convert|21.4|cuyd|m3|abbr=on}} 9 U blade

}}

}}

[[File:CAT-D9H pic001.jpg|thumb|right|Introduced in 1974, the {{convert|410|hp|abbr=on}} D9H was the last D9 with conventional track drive]]

[[File:Bulldozers2012-Shoam 0072a.jpg|thumb|CAT D9L, the first D9 model to employ [[Caterpillar D10#High Drive system|Caterpillar's "high drive"]] configuration, which raises the drive sprocket, resulting in elevated ground clearance and a triangular track.]]

[[File:Caterpillar D9N.jpg|thumb|221x221px|The {{convert|370|hp|abbr=on}} D9N replaced D8L in 1987]]

[[File:D9T - Caterpillar Tinaja Hills Demonstration & Learning Center (22621586725).jpg|thumb|CAT D9T, the current generation of the Caterpillar D9 tracked-type tractor series]]

The '''Caterpillar D9''' is a large track-type [[tractor]] designed and manufactured by [[Caterpillar Inc.]] It is usually sold as a [[bulldozer]] equipped with a detachable large blade and a rear ripper attachment.

The D9's primary working tools are the [[blade]], affixed to the front and controlled by 4 [[hydraulic]] arms, and the optional [[ripper]], which can be attached to the back. The blade is mainly intended for earthmoving and bulk material handling: pushing up sand, dirt and rubble. It also can be used to push other heavy equipment such as earthmoving scraper pans, and in military applications, [[main battle tank]]s. The rear ripper is intended for use in loosening rockey ground and ripping out larger stones. It can also break frozen ground.

The D9, with 354 kW (474 [[horse power|hp]]) of gross power and an operating weight of {{convert|49|ST}}, is in the upper end of Caterpillar's track-type tractors, which range in size from the D2 69 kW (92 hp), {{convert|9|ST}}, to the [[Caterpillar D11|D11]] 698 kW (935 hp), {{convert|104|ST}}.

The D9 has undergone several generations of engineering enhancements. The current version is the D9R but the older models such as the D9N and D9L are still common. The L, N and R models of the D9 are visually very similar, differing primarily in the design of their internal systems.

The size, durability, reliability, and low operating costs have made the D9 one of the most popular large track-type tractors in the world.

The size and weight of the larger track-type tractors dictate that they are used primarily for major projects. The D9 is most commonly found in use in construction, forestry, mining, waste, and quarry operations.

As the size, power, and weight of the larger track-type tractors dictate that they are used primarily for major projects, the D9 is most commonly found in construction, demolition, forestry, mining, waste, and quarry operations.

<div style="float: right; margin: 0 0 1em 1em; text-align: center;">[[Image:Military_D9.jpeg|An armored military D9.]]<br>

''An armored military D9''

</div>

==Engineering and technical description==

==Military usage==

{{More citations needed section|date=August 2024}}

The D9 is a series of heavy tracked-type tractors, carried on [[continuous track]]s and usually used as [[bulldozer]]s. The series began in 1954 with a prototype tractor called the D9X. Ten D9X prototype models were built in 1954. In 1955, the {{convert|286|hp|abbr=on}} D9 was introduced to compete against the more powerful [[Euclid Trucks|Euclid TC-12]]. The D9 came equipped with a 1,473 [[Cubic inch displacement|cid]] D353, which powered the D9 until the 1980 introduction of the D9L. In 1956, the D9 had its engine power raised to {{convert|320|hp|abbr=on}}. The new {{convert|335|hp|abbr=on}} D9E replaced that model in 1959. Two years later, the legendary {{convert|385|hp|abbr=on}} D9G was introduced; it remained in production for 13 years; it became the main crawler on many job sites, testifying to its sturdiness and design.

In 1965, West Coast businessman Buster Peterson hooked up a pair of D9Gs to pushload the largest wheel tractor scrapers built. In 1968, Caterpillar bought the rights to this concept, thus the {{convert|770|hp|abbr=on}} DD9G was created (DD stands for Dual D9G).<ref>{{cite web |last1=Berry |first1=Thomas |title=The Dual D9 |url=https://www.oemoffhighway.com/home/article/20858662/the-quad-d9 |website=OEM Off Highway |date=18 April 2017 |access-date=2020-01-02}}</ref> Peterson also built the first SxS D9G, which has two D9Gs side-by-side, pushing a {{convert|24|ft|m|adj=on}}-wide bulldozer blade.

Caterpillar Inc. does not manufacture a military version of the D9 per se, but the same attributes that make the D9 popular for major construction projects make it desirable for [[military]] applications as well, and it has been found to be of particular utility by the [[Israeli Defense Force]] (IDF).

In 1969, Caterpillar introduced this new SxS D9G. In 1974, the improved {{convert|410|hp|abbr=on}} D9H was introduced to replace the D9G. The D9H is still the most powerful conventional track-type tractor in company history. The DD9H and the SxS D9H soon followed.

Armored bulldozers are a standard tool of [[Combat engineering]] battalions, and the IDF has gained some notoriety for their use of armored tractors in the [[Al-Aqsa Intifada]] , [[Operation Defensive Shield]], and their involvement in the demolition of orchards and residences and the consequential death of [[Rachel Corrie]].

In 1980, the {{convert|460|hp|abbr=on}} D9L was introduced. The unit featured the same new type of [[Caterpillar D10#High Drive system|elevated drive sprocket]] undercarriage as had been introduced on the larger [[Caterpillar D10|D10]] in 1977.{{efn-lr|The D10, and the elevated sprocket drive, was developed over several years from 1973 before its commercial debut.}} The new undercarriage design reduced strain and shock loads on the final drives<ref>{{cite web|last=Caterpillar Inc|title=D9R Track-Type Tractor|url=http://www.albahar.com/assets/products/Product%20Machines/D9R.pdf|access-date=15 November 2012|archive-date=18 April 2013|archive-url=https://web.archive.org/web/20130418133432/http://www.albahar.com/assets/products/Product%20Machines/D9R.pdf|url-status=dead}}</ref><ref>Caterpillar. [https://assets.almarwan.com/media/catalog/product/file/d9r.pdf D9R Track-Type Tractor] specifications of 2021 model. Al Marwan. Retrieved 31 July 2025.</ref> and gave the "belly pan" more ground clearance. The elevated-drive-sprocket undercarriage is a modular design. To repair the machines, one breaks down the tracks and pulls the drive sprockets out. As a result, one can pull the powershift transmission out of the rear.

The armored '''D9''', as developed and modified by the [[Israel Defense Forces|IDF]], provides armor protection to the external [[hydraulics]] and operator cabin. The operator is protected by bulletproof glass to protect against bombs, machinegun and sniper fire. The fitted armor package adds roughly 10 additional tons to the weight to a so-equipped D9. Like many customized packages, individually modified D9s may be found with disparate features, such as crew-operated machine guns, smoke projectors, or grenade launchers.

The D9L was replaced by the {{convert|520|hp|abbr=on}} D10N in 1987. The {{convert|370|hp|abbr=on}} D9N replaced D8L in 1987 (this was due to a model number/size adjustment by Caterpillar in their larger bulldozer lineup at the time, allowing them to introduce a smaller D8N model below the larger D8L size). Due to the model adjustment, the D9L is the most powerful D9 in history, with a flywheel power of {{convert|460|hp|abbr=on}}. The D9L is also the heaviest D9 in history at {{convert|130,000|lb}}.

The Israeli [[Combat engineering|Combat Engineering]] Corps are using the D9 for a wide variety of engineering tasks: digging moats, clearing terrain obstacles and openning routes to [[Armored fighting vehicle]]s. The D9's have also been used to clear [[landmine]] fields and booby-trapped areas. The heavy armour installed by the [[Israeli Defence Force|IDF]] allows the D9's to work under heavy fire in dangerous battle-zones. The Israeli armor kit proved itself well, as no D9 operator was killed during the 3-year long [[al-Aqsa Intifada]].

In 1988, Caterpillar produced their 25,000th elevated-drive-sprocket track-type tractor, a D9N. The {{convert|405|hp|abbr=on}} D9R replaced the D9N in 1996. The {{convert|410|hp|abbr=on}} D9T replaced the D9R in 2004. The main difference between the D9T and the D9R is the installment of the new [[Cat C18 ACERT]] inline-six engine in the D9T vs the V8 3408 HEUI in the D9R. The D9R has clutch and brake steering, while the D9T has differential steering. The D9T has a low-emissions ACERT diesel engine. The current model is the D9 (no letter); however, older models such as the D9T, D9R, D9N, and D9L are still commonly used. The L, N, R, and T models of the D9 are visually very similar, differing primarily in the design of their internal systems.

On the 4th of June, 2004 a Granby, Colorado resident by the name Marvin Heemeyer ran amok inside an in-house modified D9 and destroyed several houses and community buildings in the small farming village. He appeared to target his adversaries in a zoning dispute involving his muffler shop and a new concrete mixing plant. Mr. Marv has built a concrete [[sarcophagus]], reinforced with 0.50" steel plates on the inside and outside. Once a crane lowered this hood onto the D9's cockpit, the mobile bunker became his tomb, he was not going to get out. Control of the vehicle was facilitated by way of video cameras and two CRTs. The bulldozer was armed with several rifles and a 0,50" gun.

==Tools==

During the one-and-a-half hour rampage, law enforcement fired hundreds of bullets at the makeshift tank and set off explosive charges against it, apparently with no visible effect. Finally the futuristic-looking D9 came to rest trapped in the rubbles of a collapsed building. According to some reports, Mr. Merv reversed his tractor into that building to escape from a road grader that tried to pin him. Later Mr. Merv apparently comitted suicide in his cockpit, while SWAT teams were using explosives and torch welders to gain access to his hideout.

The D9's primary working tools are the blade, affixed to the front and controlled by four [[hydraulic]] cylinders, and an optional [[Bulldozer#Ripper|ripper]] in the rear.

The blade is mainly intended for earthmoving and bulk material handling: pushing up sand, soil, and rubble. It also can be used to push other heavy equipment such as earthmoving scraper pans, and in military applications, aid [[main battle tank]]s. The dozer blade usually has three variants:

Noone else was killed, but according to some reports, M. H. has fired several 0,50" shells at a propane facility, in a failed attempt to set off a massive explosion. The case could be considered domestic terorism.

* A straight blade ("S-blade") is short and has no lateral curve, with no side wings, and can be used for fine grading.

* A universal blade ("U-blade") is tall and very curved, and has large side wings to carry more material.

* A "S-U" combination blade is shorter, has less curvature, and has smaller side wings. This blade is typically used for pushing piles of large rocks, such as at a quarry.

The rear ripper is intended for use in loosening rocky ground and ripping out larger stones. It can also break frozen ground and excavate small ditches. The ripper can be replaced with a multi-shank ripper, allowing the bulldozer to comb the ground.

<div style=" right; margin: 0 0 1em 1em; text-align: center;">[[Image:D9-idf_pic214.jpg|An IDF armoured military D9 bulldozer.]]<br>

''An IDF armoured military D9 bulldozer''

</div>

Like many other bulldozers, the D9 can be fitted with other devices, such as [[mine plow]]s for clearing minefields.

The Israeli armored '''D9''', a.k.a ''Duby'' (lit. [[bear]]) has been used in standoff situations with armed Palestinians barricaded in buildings and rigged them with explosives and booby-traps. In order not to risk Israeli soldiers, the D9 shook the house until the occupants surrendered and then razed the structure in order to detonate and bury any explosives inside. This method was also employed (with great success) in [[Jenin]] after 13 Israeli soldiers were killed in an ambush. In [[Hebron]], the IDF used the armored D9 to stop the local [[Hamas]] leader, Bassal Qawasameh who was killed by the collapsing house after shooting at the D9 ([http://prozny.com/_photo/_dozer/25.jpg photo from this incident]).

==Military applications==

Armoured '''D9 bulldozer'''s are routinely employed in the [[Gaza strip]] as well. Their main task there is to detonate large [[explosive]] charges (such as improvised anti-tank [[landmine]]s or [[booby trap]]s) and clear safe way to IDF [[armored fighting vehicle]]s and troops. The D9s also demolished houses and cleared shrubbery that were used as shooting cover for Palestinian militants. The D9s are essential tool in the [[Israeli Defence Forces|IDF]] campaign against illegal [[smuggling tunnels]] in [[Rafah]], which are used by militants to smuggle weapons, explosives, [[terrorist]]s, cigarettes, drugs, and other contraband. Armoured D9 bulldozers have demolished many structures in Rafah during battles with militants and operations to uncover smuggling tunnels. The destruction of hundreds of structures in [[Rafah]] is highly contraversial issue: the [[Israeli Defence Forces]] claim the destruction is a security neccessity and that most houses destroyed were used for [[terrorist]] activity; Palestinians claim the destruction left thousands of people homeless and is done systematicly in order to create a "buffer zone" between Rafah and [[Philadelphi Route]].

[[File:IDF-D9-Zachi-Evenor-001.jpg|thumb|An armored [[IDF Caterpillar D9]]R [[bulldozer]], nicknamed "דובי" ([[Teddy bear]]) in [[Israel]].<br/> Its armor allows it to work under heavy fire.]]

[[Caterpillar Inc.]] does not manufacture a military version of the D9. However, the attributes that make the D9 popular for major construction projects make it desirable for certain military applications.

Both military armored '''D9'''s and civilian non-armored '''D9'''s are employed by Israel's [[Ministry of Defence]] in the building of the [[Israeli West Bank barrier]]. Their main application in the project are earthmoving and soil-leveling, making path for the security fence and digging trenches in front of it.

The US Army used D9 bulldozers to clear forest in the [[Vietnam War]], but after the war they were replaced with smaller and cheaper [[Caterpillar D7|Caterpillar D7G]] bulldozers. D7G bulldozers are still very common in US [[combat engineering]] battalions; currently{{when|date=March 2025}} the US Army fields around 1300 D7r’s that are a combination of armored and non armored.{{cn|date=March 2025}} A series of suggestions have been made to replace the lighter D7Gs with the newer and more heavily armored D9s.{{Citation needed|date=October 2015}}

[[Image:IsraeliBulldozers.jpg|thumb|IDF armoured Caterpillar D9 bulldozers]]

{{see also|IDF Caterpillar D9}}

The United States Army has purchased several armor kits from the IDF and used them to produce similarly equipped D9s. These have been used to clear destroyed vehicles from roads, to dig moats, erect earthen-barriers and construct field fortifications. It was also used to destroy a house which hosted snipers who shot at an American base (similar to the Israeli usage). There were some reports about the use of large [[bulldozer]]s against Iraqi trenches during the first Gulf War.

The [[Israel Defense Forces]] (IDF) have used the D9 since it was introduced.{{cn|date=March 2025}}. The armored [[IDF Caterpillar D9]] was introduced in 1986 on the D9L. Fitted with an Israeli-developed [[vehicle armor]] kit, and modified variously by the Israel Defense Forces, Israeli Military Industries and Israel Aerospace Industries, it has proven particularly effective.<ref name='Caterpillar D9 Armored'> {{cite web | url = http://www.israeli-weapons.com/weapons/vehicles/engineer_vehicles/bulldozers/d9 | title = Caterpillar D9 | access-date = 2013-07-24 | work = www.Israeli-Weapons.com website | publisher = www.Israeli-Weapons.com LTD | quote = The Israeli Armored D9 is a Caterpillar D9 bulldozer that been modified by IMI for IDF. }}{{dead link|date=August 2017 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

IDF D9 bulldozers were used during the [[Second Intifada]] (2000–2005) to [[Israeli demolition of Palestinian property|demolish Palestinian structures]] and clear [[improvised explosive device]]s. The Israeli armor provides protection from small arms and explosives, and the bulldozers were used the [[Battle of Jenin 2002]] during [[Operation Defensive Shield]]. A [[Rachel Corrie|2003 incident involving an IDF D9, in which a 23-year-old American activist was killed]], resulted in a [[Corrie v. Caterpillar|lawsuit brought against Caterpillar, Inc.]] in the United States.<ref name=":0">{{Cite web|title=FindLaw's United States Ninth Circuit case and opinions.|url=https://caselaw.findlaw.com/us-9th-circuit/1403943.html|access-date=2020-09-19|website=Findlaw|language=en-US}}</ref> The court dismissed the case on grounds that it was outside their jurisdiction, and that Israeli tort law was a sufficient avenue to pursue remedies.<ref>{{Cite web|date=2007-09-17|title=Corrie, et al. v. Caterpillar Inc.|url=https://www.chamberlitigation.com/cases/corrie-et-al-v-caterpillar-inc|access-date=2020-09-19|website=U.S. Chamber Litigation Center|language=en}}</ref><ref name=":0" />

==External links==

The D9 remains one of the main combat engineering tools of the IDF, which currently{{when|date=March 2025}} deploys the D9L, D9N, D9R, and D9T. Most of the IDF's D9 fleet today are composed of the D9R with [[slat armor]].{{Citation needed|date=August 2024}}.

The Israeli armoured '''D9 bulldozer''':

*[http://prozny.com/_photo/_dozer/index.html Photos of the IDF armoured D9 bulldozer in action]

*[http://www.idf.il/english/idf_in_pictures/2003/october/18.stm IDF D9 with machine-gun] ([[Israel Defense Forces|IDF]] Official website)

*[http://www.time.com/time/2002/jenin/ The D9s role in Jenin battle] (Time Magazine article)

*[http://www.jed.simonides.org/engineer/charlie/caterpillar-d10_series/israeli-armoured/israrm-intro.html Pictures of "Duby", IDF armoured D9] (the site mistake them for D10)

*[http://www.timesleader.com/mld/timesleader/news/7144048.htm AP: Israel to Raze With Robot Bulldozers (30 October 2003)] - "The giant Caterpillar bulldozer, used by the Israeli military to destroy Palestinian homes in the West Bank and Gaza Strip, now comes with a controversial new feature: remote control."

A similarly modified armored D9 was also used by [[KBR (company)|KBR]] in Iraq.{{citation needed|date=November 2012}}

<gallery widths="200" heights="150">

Military '''D9 bulldozer''':

File:IDF-D9-demolishes-Palestinian-structure-01.jpg|IDF Caterpillar D9L razing a Palestinian house

*[http://cndyorks.gn.apc.org/caab/articles/kuwait-dig.htm Army's new D9 bulldozer digs into duty in Kuwait] - The US army test the armoured D9R for the Iraqi campaign

File:D9-IDF-1460a.jpg|IDF Caterpillar D9R pushing soil for an [[earthworks (engineering)|earthworks]].

*[http://www.enr.com/features/bizlabor/archives/030922.asp Engineering News: Combat Engineering in Iraq] - including reviews on the D9 Dozer performance in Iraq and nice pictures of it and other [[Combat engineering vehicle|CEVs]]

</gallery>

*[http://www.jed.simonides.org/engineer/charlie/caterpillar-d9_series/d9-series.html French D9 with mine-breaching devices]

==See also==

Civilian '''D9 bulldozer''':

* [[Rome plow]]

*[http://www.cat.com Caterpillar Tractor Company - Official Website]

* [[Killdozer! (film)|''Killdozer!'' (film)]]

*[http://www.butler-machinery.com/news_33.html The new Caterpillar D9R specifications] (from Caterpillar distributor)

* Pictures of [http://www.fidenzamacchine.it/CAT%20D9G%20foto1.jpg CAT D9G bulldozer] and [http://www.atst.ru/cat9b.jpg CAT D9N bulldozer].

==References==

{{Notelist-lr}}

{{reflist}}

==External links==

{{Commons}}

*[http://www.cat.com/cda/layout?m=163632&x=7 Caterpillar D-Series Track-Type Tractors] – Official Caterpillar website

*[https://web.archive.org/web/20030926024616/http://cndyorks.gn.apc.org/caab/articles/kuwait-dig.htm Army's new D9 bulldozer digs into duty in Kuwait] – The US army tests the armoured D9R for the Iraqi campaign

{{Caterpillar}}

[[Category:Military engineering vehicles]]

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