TerraPro Truck Targets Mining, Off-Road Duties

Diesel Progress North American Edition, April, 2001 by Brent Haight

Bearing a passing resemblance to AM General's well-known Hummer, the TerraPro IT 650 industrial truck is a mid-or rear-engine rear-wheel drive rough terrain vehicle with full air ride suspension and 18 in. of wheel travel designed to operate and survive in off-road environments. Initially created for the mining industry, other applications, such as forestry, off-road utility work and agriculture are lining up quickly, according to Andy King, owner of TerraPro LLC.

"We started out in the mining market because many on-road trucks just don't cut it," said King. "Within weeks, mines often have to replace the front end, brakes and driveline of the on-road trucks. Some mines have reported spending in excess of $30,000 per year, per vehicle, just to keep a pickup truck running in the mining environment."

The TerraPro vehicle has been in development since 1995, King said, and has gone through five prototypes. "The one we have now, the IT 650, is built for high profile coal mines," he said. "This is the end of the research and development for that vehicle and now we are going into the production phase."

The IT 650 truck has a top speed of 31 mph. However future models will be designed to reach 45 mph, King said. The vehicle incorporates a Linde hydrostatic drive system in which speed is controlled by the swashplate angle of the transmission. "Another feature of the transmission is our ability to match the transmission's output to the engine's power curve," said King. "Synchronizing the engine and transmission reduces emissions and engine damage due to operator error.

"We vary the transmission's output based upon direct input from the operator. We slow the vehicle using no brakes. Basically the operator takes his foot off the accelerator pedal and the transmission will bring the machine to a stop. The brakes basically operate as a secondary, emergency or park brake system.

"In order to comply with the new MSHA underground coal regulations we have incorporated hydraulic-released, spring-applied, fail-safe wet disc brakes on the rear wheel motors and conventional disc brakes on the front axle"

According to King, TerraPro's goal is to produce a standardized chassis and drivetrain designed for the application and can be powered by a customer specified engine that meets MSHA emissions standards.

"Any engine will work on this vehicle," King said. "If the customer's fleet uses Perkins, we'll put in a Perkins engine; if it's Deutz, we'll use Deutz. All we have to do is bolt the engine into the chassis. With the hydrostatic transmission, we don't have driveline configuration problems to worry about."

"We drive the unit with a 5.98 cu.in./rev Linde HPV 105 hydrostatic transmission," said King. "But that can be changed based on the operating parameters -- speed, weight and the hills it would have to climb." Other Linde hydrostatic units could be selected, based on speeds needed, he said.

The pump drives Poclain MS05 cam lobe wheel motors, but larger MS08 motors can be used if the application requires the ability to climb steep hills with heavy loads. "We base the vehicle performance to the customer's specific needs," King said.

"It's important to note that this will not go where a true four-wheel drive vehicle will go because it's only two-wheel drive," King added. "But for most mining applications, because of how we drive it and distribute the weight on the axles, we don't have a problem going into most areas of the mine."

The chassis and frame of the IT 650 are designed so they can be built on a production scale. The main frame is 3/16 in. wall 4 in. x 6 in. rectangular steel tubing, fabricated in a rigid ladder type design. The frame can accept a variety of bodies including, a personnel carrier bed, work truck bed and lube truck. "Our goal is to provide a whole fleet of vehicles with all the same commonality of parts," said King. "The bed will reflect what the vehicle does. The bed is bolted on, so it can easily be changed from a personnel carrier, to an ambulance, to a work truck, etc."

The suspension is a rough terrain full air--ride suspension. In front is a solid front axle air-ride suspension with 14 in. of travel. The rear is an independent trailing arm air-ride suspension with 18 in. of travel. The front axle is a modified Dana 44 or Dana 70 axle, depending on weight and operational requirements.

The IT 650 truck body is made up of high molecular weight polyethylene panels that bolt on and off.