Let’s talk tailgates: Key considerations to optimize return on investment (ROI)

Efficient hauling practices are at the heart of every successful mining operation. Maximizing capacity with each load while minimizing maintenance requirements and unnecessary downtime leads to increased profits and a healthy bottom line.

Many mining and aggregate producers have found simply adding a tailgate to their haul trucks makes a significant impact on their overall efficiency. Tailgates are not standard on rigid-frame haul trucks from any manufacturer. However, aftermarket options are available from manufacturers specializing in off-highway truck customization.

Like any piece of equipment, adding a tailgate requires careful consideration for optimal results. Some benefits can be achieved with any old tailgate, but to truly enhance their overall operation — and return on investment (ROI) — producers should look for a tailgate with features that align with their specific application. Let’s look at how tailgates can improve efficiency and what options are available.

Tailgate to the rescue

For being a relatively simple piece of equipment, tailgates can have a significant impact on how and how much material loader-operators will fill. This underhauling is often unintentional but usually results in loads that are 10% to15% below rated capacity. Sacrificing 15% of the load per trip is simply not affordable for mining and aggregate producers looking to remain profitable.

Hauling a half-full load costs relatively the same amount of money in labour, fuel, and wear on a truck as a full load. By allowing loader-operators to meet the truck’s rated capacity without fear of spillage, tailgates quickly and easily boost an operation’s profitability. For example, a 70-tonne-capacity truck with a tailgate hauls its rated payload, which is nearly 11 more tonnes per load than a 70-tonne truck without a tailgate. Underhauling costs operations millions of dollars per year. If a fleet of six trucks adds 11 tonnes to each of their respective 12 loads per day, additional 792 tonnes are hauled daily. That equates to nearly $7,049 in profits if hauling aggregates at an average of $8.90 per tonne. It is like adding another truck to your fleet without the increase in fuel, maintenance, or labour.

Even with a single truck, adding a tailgate can greatly reduce underhauling. A mining producer using a custom tailgate on its Volvo A40D articulated hauler was able to increase capacity by 17% per load. Before adding the tailgate, the Volvo A40D averaged 31.48 tonnes per load. With the tailgate, loader-operators now average 36.7 tonnes per load.

Hitting the target

Whether it is increasing productivity or reducing downtime and freeing up equipment, moving material from point A to point B in fewer trips is important for maximizing productivity. By increasing capacity with each load, the above mining producer was also able to reduce the overall number of trips back and forth with its VolvoA40D. This not only increased overall efficiency but also reduced wear and tear on the truck.

Additionally, tailgates further reduce wear and stress on trucks by providing the loader-operator a better, larger loading target. Tailgates allow loaders to safely dump materials in the middle of the body, rather than near the front, improving loading target, weight distribution, and overall truck stability. Without the added benefit of the tailgate, loader-operators avoid spillage by placing most or all the materials toward the front of the bed. This loading technique ends up overloading and stressing the front tires, axles, and hydraulic hoist cylinders of the truck, resulting in premature tire wear, body maintenance, and potential axle and hoist cylinder damage.

Typically, rigid-frame haul trucks are designed to carry one-third of the payload on their front axle and two-thirds on the back. Placing heavy materials toward the front puts excessive stress on the chassis, axles, front tires, suspensions, and hydraulic systems. Front tires are designed to support 33% of the weight, and when overloaded, rim damage may occur, or worse, they blow. Sometimes tires can be salvaged, patched or re-treaded, but even repairs are expensive, costing up to 60% of their original cost, in addition to the labour associated with repairing the tire and equipment downtime. An optimized loading target, equalized weight distribution, and reduced spillage means that trucks with tailgates can extend a tire’s service life by as much as 40% or up to 13,000 hours in some cases.

One thing to remember — even if a tailgate makes loading easier, that does not mean loader-operators should overload. A 150-tonne truck cannot haul 175 tonnes of material without operating outside of the OEM truck manufacturers guidelines; this can cause damage and safety hazards in addition to voiding the truck warranty. Squeezing an extra 25 tonnes in a load might seem like a quick way to bring in extra profits; however, repair costs far exceed the additional revenue if you blow a tire or cripple the chassis and axles. The goal of tailgates is to achieve the trucks rated payload.

Maximizing uptime

Optimizing payload capacity and reducing tire and axle wear are only the beginning. The benefits of adding a tailgate extend beyond the truck to haul roads and the other equipment, as well. Anyone who spends their day in a mine knows roads are narrow, rough, and littered with spillage, which makes them hard to navigate and poses risks to the trucks and other equipment operating at the site. All options for dealing with the challenges result in lost time or increased expenses. Deploying road grading crews to clean debris off haul roads equates to lost productivity and the added costs associated with the fuel, labour, and expense of additional equipment.

Navigating debris can damage tires as well as the truck’s suspension systems. In some large mines, more than 200 tires are replaced per month because of debris damage or overloading. Many businesses are not equipped to handle the negative impact that has on overall profitability, especially since the cost of rubber has skyrocketed over the last decade. Most mining truck tires cost upward of $50,000 apiece, with some larger models topping out at $100,000 each. Combine those extra costs with downtime caused by the repairs and replacement, and the impact can be devastating. A global tire shortage for mining-class vehicles only compounds the problem with longer-than-normal wait times just to receive replacement tires.

Weighing the options

Crunching the numbers, it does not take long to realize the benefits of a tailgate quickly add up. A tailgate enhances operations whether you are hauling aggregates, copper, coal, iron, gold, oil sands, or soupy, viscous materials. But to truly maximize profitability, certain design aspects should be considered before making a purchase decision, such as durability and versatility. There are a variety of tailgate options on the market. Finding the design that complements the specific quarry or mining operation is important.

First and foremost, work with a manufacturer that engineers their tailgates for each specific make and model of truck and truck body. Options exist for rigid and articulated frames. Some custom manufacturers have even engineered models that bolt directly to the undercarriage of the off-highway truck. Quick disconnect options, such as fluidic seals or cushion pads, are customizations that are available and should be considered, depending on the application. Operators should look for designs that do not require any welding to the frame, as welding to the frame of an off-highway truck may invalidate the OEM warranty, while making sure that the brand they choose offers stability, quality, and structural integrity.

How a tailgate opens is also important for efficiency and long-term durability. A tailgate that lifts, for example, provides increased efficiency over a model that drops down. A dropdown tailgate is sometimes slower when opening and closing and is more susceptible to damage from the dumped materials. These designs often rely on pins or hydraulic systems, and when there are more grease points, cylinders, and joints, the risk of increased maintenance and failure exists. They might seem like quick, economical solutions, but dropdown tailgates often end up costing more for repairs and replacement in the long run and are simply not an option for large ultra-class rigid frame mining trucks.

Ultimately, a lifting, scissor-style tailgate has fewer moving parts, so there is less potential maintenance. However, it is important to ensure these few parts are tough enough for the job since not all tailgates are created equal. A tailgate will not last long if it cannot withstand the breadth of material being hauled. Find a tailgate that is built with durable materials, such as high-strength steel, and features strong components including steel alloy chains and fiber bushings that do not require ongoing lubrication. Certain manufacturers design their tailgates specifically for durability, resulting in a tailgate that can take a beating but still lasts for decades with minimal maintenance.

Customizations to tailgates are also a way to tie them into the truck fleet methodology employed at any given site. Truck bodies frequently have sideboards that add height to the sides for either added volumetric capacity or to keep material within the bed. In this case, having the tailgate built up to the height of the sideboards creates a unified height around the entire bed, as opposed to a high-sided body with a low-sided tailgate.

Adding cushion pads to a tailgate will soften the blow when it is raised and lowered in harsh worksite conditions. When operations have extremely bumpy haul roads, or when mining underground, the cushion pads minimize noise and increase the tailgate service life and other truck components.

Operations that haul large amounts of wet material arguably need a tailgate more than any other operation that uses off-highway haul trucks. In these applications, a tailgate with a fluidic seal can create a near-perfect seal, resulting in minimal fluid leakage during transport. Few manufacturers can contain 100% of the liquid material, but manufacturers with years of experience have engineered designs that can contain up to 99.5% of wet materials, which are invaluable for specific applications.

For operations that require a 100% positive seal, there are specialty tailgates available from select manufacturers. These designs build up the rearmost portion of the truck body or container to create a cohesive flange from which the tailgate compresses. Two hooks on either side of the base of the flange intercept a corresponding tag on the tailgate, allowing the tailgate to pivot inward as the sidearm and over-center locking mechanism compressively lock the rear tailgate into place. This creates a water-tight seal that contains liquid materials within off-highway truck bodies or roll-off containers.

Finally, make sure the tailgate lifts high and fast enough to get out of the way before material starts to unload. The last thing you want is the tailgate to hold back the material during dumping rather than allowing it to flow freely out of the back of the truck body. Fast dumps lead to increased efficiency and productivity. Materials left behind in the bed or stuck in grease points damage hinges and overall structure, and the amount of carryback reduces the volume of the next load.

Optimizing ROI

Increasing volume, reducing maintenance, and maximizing hauling efficiency — for a simple piece of equipment, a tailgate, can sure make a big difference. Six 100-tonne-capacity trucks with tailgates hauling ore could result in approximately $10,700 in additional profits per day. Even with the average tailgate cost between $22,500 to $30,000 — based on the size of haul truck and options chosen — a producer purchasing six tailgates for his 100-tonne truck fleet would see a complete ROI on a tailgate project purchase in less than 17 days with those numbers, and that is based on profit alone. Factor in additional fuel and tire cost savings associated with the use of tailgates on a truck fleet, and the numbers really start to add up. Pay for tailgates once and reap the benefits for the truck fleets lifetime. 

Josh Swank is chief growth officer for Philippi-Hagenbuch. He oversees their global sales team.

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