Improvised Fighting Vehicle – 1 built
A one-man rampage
In 2004, the resort town of Granby, Colorado was terrorized by a man named Marvin John Heemeyer. A costly amount of property and vehicles were destroyed by a single man and his retrofitted Komatsu D355A bulldozer. Heemeyer’s bulldozer (also known as the Killdozer) was an engineering marvel for a single man and managed to take explosives and armor piercing ammunition. Not much is known about the man, but he claimed to be influenced by God. He recorded himself prior to the rampage explaining his motives and his targets. However, even though the recordings were released to the news reporters, they were never fully released to the public. Only bits and pieces can be found online.
Heemeye’s Killdozer at the end of its rampage
Marvin John Heemeyer (born in South Dakota, October 28,1951), a successful welder, owned two muffler shops named “Mountain View Muffler” in Granby and nearby Boulder, Colorado. He was known by the town for fighting civil issues such as a failed proposal to bring gambling to Grand Lake, Colorado (where he lived) in 1994.
The town of Granby allowed a cement plant to be located near Heemeyer’s muffler shop in 2000. This angered him over the noise, dust and the limited access to his shop it could create. Heemeyer tried to convince Cody Docheff, the project’s operator, to sell his property, but ultimately failed.
In 2001, the town sided with the concrete plant. Heemeyer countered this with a lawsuit which failed again.
In 2003, he found himself involved in another conflict with the town concerning whether he should be connected to the town’s sewage system. Heemeyer was not part of the system. He was forced to pay the $2500 fine and wrote a check which he enclosed the note with “cowards” written on it.
He plotted his revenge. This involved his Komatsu D355A bulldozer. He had originally purchased it to construct roads to his shops. In March of 2003,, Heemeyer deeded his house to a friend and lived in his shop. He then sold off both of his shops and the building that housed his bulldozer.
However, he kept 185 square miles (479 square kilometers) of closed off land with a building where the bulldozer was moved to in December the same year. For six months, he used his welding skills to armor up his bulldozer so he could use it for his revenge.
The default 49 ton Komatsu D355A bulldozer is powered by a 410 hp (305 kw) engine. It had a top road speed of 7.45 mph (12 km/h) and a horsepower per ton of 8.36. Heemeyer’s armored version brought the weight up to 61 tons. This most likely slowed the bulldozer somewhat and decreased the horsepower per ton to 6.7.
The bulldozer was armed with a .50 (12.7mm) Barret M82 semi-automatic rifle at the rear, 5.56mm FN FNC semi-automatic assault rifle at the front, and a .223 (5.7mm) Ruger Mini-14 at the right. His two side arms were a .357 (9.1mm) Magnum revolver and 9mm Kel-Tec P-11. These weapons were fired from small firing ports inside the cabin.
One of the Killdozer’s weapons, a Barret M82 rifle
The armor consisted of two half inch (12.7mm) steel plates with concrete in the middle and bonded plexiglas which gave it the same benefits of composite armor. This proved very effective against small-arms fire, armor piercing ammunition and grenades.
The cameras which allowed Heemeyer to see his surroundings were connected to three monitors and protected by three inch (76.2mm) bulletproof plastic. The armored Komatsu D355A bulldozer also had a sophisticated air filtration system and air conditioning system.
On June 4, 2004, Heemeyer greased up his bulldozer to make it harder for people to climb on top before he bolted himself shut inside. He smashed through the building that housed his bulldozer and proceeded to his first target which was unsurprisingly the cement plant near his former business.
While this factory was being destroyed, the owner, Cody Docheff, drove one of his own construction vehicles to try and stop the destruction. Heemeyer saw this and quickly charged towards Docheff’s vehicle. Docheff regretted his decision. His vehicle was not big enough to stop the bulldozer so he tried to make his escape by driving away. Heemeyer rammed the rear of Docheff’s vehicle.
The armored bulldozer preparing to rip through a building
During his rampage, he managed to destroy a local bank, his former business, hardware store, the town hall, the police department building, the home of Granby’s deceased former mayor, the town’s library, local newspaper office, former judge’s home, and an enormous amount of cars. He spent a few minutes trying to ignite the Independent Propane Company’s storage tanks by firing at them with his .50 cal rifle. Luckily, they did not explode or catch fire.
Marvin Heemeyer’s armored bulldozer reconstitution by D Bocquelet
After being sealed by an industrial loader inside a group of buildings, Heemeyer in his armored Komatsu bulldozer tried to escape by ramming through buildings. The chaos stopped when the bulldozer collapsed inside a store’s basement.
Police officers charged towards the bulldozer but it was covered with grease which made it tougher for them to get on top of the machine. Colorado’s governor considered using the Apache’s Hellfire missiles from the Colorado National Guard to destroy the vehicle, but it was already bogged down inside a basement. Heemeyer committed suicide with his .357 (9.1mm) Magnum revolver. His armored bulldozer was stuck. He could see no way out and he did not want to go to jail.
Fortunately, there were no civilian or police deaths, however, Heemeyer had caused seven million dollars of damage to buildings and vehicles. It is said that killing civilians wasn’t his intentions, but his tape recordings say otherwise. Heemeyer’s recordings were released by the police department to news stations, however, only bits and pieces can be found online. It took twelve hours with a blowtorch to enter into the cabin of the armored bulldozer to retrieve his dead body.
The incident left 7 million dollars worth of damage.
Heemeyer is seen by most as just a terrorist, but some see him as a patriotic American for standing up to the government. C4, grenades, and more than 200 bullets were used against the bulldozer and had little to no effect. A few people in Granby proposed a yearly celebration of the incident to generate tourism. The idea was rejected, and the armored bulldozer was scrapped.
Luckily, insurance and state aid came to help the ravaged town of Granby and it quickly got back onto its feet. After Heemeyer’s rampage, it received the reputation as the “Killdozer”. Funny enough, this isn’t the first kind of attack in Colorado. In 1998, a man named Tom Leask conducted an attack with a government owned front end loader in Alma, Colorado. He managed to destroy the town’s post office, town hall, fire department, and water department until he was taken into custody.
Armored bulldozers are nothing new and are present in many conflicts as professionally manufactured or improvised combat vehicles. This bulldozer is particularly interesting due to how well it protected him from C4, grenades, and armor piercing ammunition. Plus, it only took one expert welder to make this impressive contraption.
The Israeli Defense Forces has different armored versions of the D9 Caterpillar with slat armor and a protected cabin; other examples include the British Centaur bulldozer, Japanese Type 75 bulldozer, American D7G Caterpillar bulldozer, armored bulldozer used by the Sri Lankan Armed Forces in Sri Lanka against the LTTE (Liberation Tigers of Tamil Eelam), and dozens of other bulldozers.
An article by Joshua Martinez
Suburban Legends: True Tales of Murder, Mayhem, and Minivans
The Colorado Mountain Companion
Komatsu D355A-1 specifications
News article about the event
|Dimensions||TBA m (TBA)|
|Total weight, battle ready||61 tons|
|Propulsion||Komatsu SA6D155-4A, 410 hp|
|Armament||.50 (12.7 mm) Barret M82 semi-automatic rifle
5.56 mm (0.22 in) FN FNC semi-automatic assault rifle
.223 (5.7 mm) Ruger Mini-14
|Armor||Plexiglass, Concrete, .5 inch (12.7 mm) steel plates|