Haul Truck of All Trades:
Rear-Eject Equipment Offers Increased Versatility for Mining Applications
Written by Josh Swank, Vice President of Sales & Marketing at Philippi-Hagenbuch
In mining, as in any industry, selecting the right tool for the job is the key to efficient operation. Using a screwdriver to hammer in a nail might work (eventually) but only after a lot of wasted effort. For a number of primary applications, such as drilling, screening, or hauling ore, single-purpose machines help producers maximize productivity and output by doing one task and doing it well. When it comes to support equipment, though, the solution lies in a multi-tool. Rear-eject bodies offer a number of benefits to enhance productivity on a job site.
Keeping it Level
In certain underground mining applications, such as gold, oil shale, aggregate, or salt, rear-eject haul trucks are an essential link in the production line. Producers simply drive the vehicle into the mine, load, and return to the surface. This much could be done with a traditional end-dump vehicle, if size allows. But it’s the next step, offloading, that sets the rear-eject apart in terms of productivity.
As the name implies, rear-eject bodies use an ejector blade to discharge material. Without moving or raising the truck bed, the blade pushes material toward the rear of the truck. As the blade moves to the rear of the body, the unit’s tailgate lowers. To reduce maintenance and the risk of breakdown, some rear-eject models incorporate the tailgate mechanism in the sides of the body. These units use simple mechanics, supplemented by gravity, to lower the tailgate without the need for additional hydraulic cylinders. Some manufacturers also design their rear-eject bodies to feature a unique sweeping action that virtually eliminates carry back — even with materials prone to sticking to the sides or floor of the truck bed. This effective dumping action makes rear-ejects an ideal solution for increased productivity in a number of challenging hauling applications.
When considering the efficiency benefits of a rear-eject body in hauling applications, time savings is probably the most obvious. It takes roughly 12 seconds for an end-dump body to lift, a few seconds for the material to flow out, and another seven seconds to drop back down. With a rear-eject, there is no need to lift the body, saving producers at least 19 seconds per offload.
The rear-eject’s stationary body also provides an even greater benefit for both underground and open pit mining operations — consistent clearance. In both operations, there are a number of overhead obstacles. Room height, legacy structures, bridges, conveyors and other equipment can all make access difficult — or impossible — for traditional end-dump bodies. In situations where height restrictions rule out raising an end-dump body — such as offloading materials inside a building, near existing structures, or underground — operators must rely on loaders and other smaller support equipment to move materials, which significantly reduces efficiency for these tasks. Additionally, operations that use end-dump haul trucks risk accidents while moving around low-clearance structures if the bodies are not completely lowered every time.
However, a rear-eject body removes the height variable and allows operators to safely access limited-clearance areas and manoeuvre around the mine. This boosts productivity for applications like reclamation, both above and below ground, where large amounts of material need to be moved. Now producers are able to quickly deposit overburden materials right where they need them, without worrying about lifting the body of the truck. This saves valuable time and can increase efficiency for these support tasks by up to 25 per cent.
Minimizing Downtime, Maximizing Productivity
Switching to a rear-eject body can boost productivity and streamline an operation’s entire process by reducing the need for additional support equipment and labour. With so much relying on a single piece of equipment, though, durability and maintenance requirements must be key considerations when selecting a manufacturer.
Anytime equipment is unavailable due to maintenance, productivity suffers. But when that piece of equipment is responsible for several jobs, maintenance downtime is especially detrimental. Staying up to date on routine maintenance is essential and rear-eject equipment that requires little maintenance goes a long way to minimize costly downtime.
When selecting a rear-eject manufacturer, producers should keep in mind less is more. Rear-eject bodies constructed with a single hydraulic cylinder to operate both the ejector blade and the rear tailgate mechanism, minimize maintenance, and maximize uptime. Ejector guides integrated into the inside of the body also decrease overall maintenance requirements on certain rear-eject designs. This feature eliminates rollers that typically break or bind while providing smooth operation. Additionally, bodies constructed of high-strength, abrasion-resistant steel can withstand years of use with little maintenance for optimum longevity.
Multiplying Opportunities
Support equipment might not be doing the heavy lifting when it comes to mining operations, but there’s no denying the role these machines play in overall efficiency. The versatility of rear eject bodies offers producers an opportunity to streamline small-scale hauling operations with a single piece of equipment for increased productivity and long-term success.