Truck design philosophy
Truck design philosophy


By Caterpillar | Posted July 15, 2022

With offerings in both electric and mechanical drive and payloads ranging from 143 to 372 tonnes (157 to 410 tons), Caterpillar offers a truck for every type of mining application.

But one thing all the models have in common, Caterpillar truck experts say, is the philosophy the company follows in their design. “Whatever measurement you use for material movement, our goal as an engineering and design team is to help you optimize that cycle — to help you do it the best you possibly can for the lowest cost per unit volume moved,” says Kent Foster, manager of the company’s truck engineering organization.

“Every truck we make is designed to deliver a better bottom line,” he continues. “Whether you measure that in cost per ton, cost per unit of material moved, better Net Present Value, higher return on investment — however you define it, our job is to deliver it. It all starts with you.”



When it comes to developing products for the mining industry, Caterpillar relies on its customers for direction. “It all starts with you” is a common theme when the manufacturer communicates to the industry.

But “it all starts with you” goes well beyond listening to the requirements and challenges of mining companies and building machines to meet those needs. Without the work that miners do, there wouldn’t be any heavy equipment at all.

“Without that miner providing us the raw materials we need — like steel, power and rubber — we couldn’t manufacture machines,” says Foster. “So, it truly does start with our customers.”

Foster explains the philosophy Caterpillar follows in its development of products, with a specific focus on mining trucks:

“Think about the materials we use to build these trucks,” he says. “We create our own recipes for steel, rubber, couplings, oils, gears. We need miners to give us the ingredients for these recipes so we can develop the best-in-class, gold standard haul trucks they expect.”

Caterpillar follows a “design philosophy” — the steps that are taken and the strategies that are executed when it comes to designing and engineering a Cat® truck, says Foster. “It’s a very complex process we use, to go from that recipe of steel to hauling dirt in the mine.”

Truck manufactruing process



Whether Caterpillar is working on a new mining truck design or enhancing an existing model, the process always begins with research and development (R&D). And that R&D can’t begin without an investment.

Foster says Caterpillar is committed to a continued investment in R&D whatever the economic challenges in the industries it serves.

“The economic cycle that surrounds mining and commodities, and the demand cycles for these materials, vary so greatly from year to year to year,” he said. “We’ve come out of some pretty challenging times and we’ve had some pretty booming times. But the Caterpillar approach is to make a constant investment in R&D no matter the environment. This helps us sustain the innovative developments necessary to create our world-class trucks.”

A strong team

One of the most significant R&D investments Caterpillar makes is in its people, putting together the world-class team responsible for the engineering and development of new products. “We spend a tremendous amount of time and effort to recruit the best and the brightest,” says Foster. “They come from all over the world. We continually seek the right people to execute our design model and build the best trucks.”

A robust training process is a key component. Caterpillar truck design engineers are located in Tucson, where that training can include in-the-iron time with machines at the nearby Caterpillar Proving Ground.

“This facility allows our engineers to get dirt under their fingernails and actually feel, from the seat of their pants, the dynamics around hauling 800,000 pounds at 40 miles per hour while going through a turn,” says Foster. “It’s important for an engineer to really feel that. It helps them better understand what they have to do to create the most optimized machine to haul material from Point A to Point B.”

The location in Arizona also gives the engineering team access to a number of mine sites. There are about 650 in the state alone, and Arizona is in close proximity to mines in Central America. Engineers have the opportunity to travel to see different environments, applications, mining methods and materials.

“Getting the engineers close to the mine sites, close to the materials and close to our customers is a key element of our philosophy,” says Foster.

A disciplined approach

Caterpillar follows a very disciplined approach to new product development. While there are several different New Product Introduction (NPI) processes available for use within the company, all are structured, thorough, gate-driven and proven.

NPI teams work together to improve quality, performance, durability and reliability of all Cat products. The process requires rigorous gate reviews, stakeholder updates and validation processes.

“Our NPI process starts well before we begin actually designing a machine,” Foster says. “It starts with the strategic development of our product line. Where do we want to be? What do our customers need today? What will they need in the future? When we’re developing a new truck, we’re already thinking about the next generation.”

In tandem with NPI is the development of new technologies. Across the company, engineers are at work on New Technology Introduction (NTI) projects, Foster says, researching technologies that are perhaps years away from being launched.

“New technology research and development takes a lot of time. So we can’t take new technologies and add them right into our product development programs and send them out and validate them in production” he says. “When they’re ready we put them into our gate reviews and put them as new content in our programs. But only when they’re ready.”

798 AC on haul road


A mining industry focus

Understanding mining trends is essential to truck development. “We look at where the industry is going. We listen to our customers and make sure we understand what they need in order to achieve that lowest cost per ton, that better bottom line,” Foster says. “Their answers vary depending on the location, or the type of material they’re pulling out of the pit. So, we spend a tremendous amount of time just listening.”

Once the customer requirements are defined, “we as engineers take those, filter them, put them into the specifications of the machine and create documents that have to be reviewed by multiple people. We put them in front of the industry experts within our organization to make sure that what we’re doing is actually aligning with where our customers are taking their businesses.”

Recent truck development has focused on key trends that are most important to customers today. A number of these issues are centered on environmental and social impact — such as emissions reductions, alternative fuels and machine electrification.

“Over the last decade, we’ve transitioned through the emissions programs, working to make our trucks compliant with the most stringent regulations in North American and Europe. And while we were focusing on meeting those requirements, we wanted to make sure we delivered the fuel economy our customers need as well,” says Foster.

Lessons learned during emissions development has led to advancements in fuel economy for all truck models, including those available for use in lesser regulated countries (LRCs). “We’ve improved overall fuel economy by 5 to 10 percent,” he says.

Caterpillar is seeing interest around the world for alternative fuels and continues to research various solutions both in the lab and in the field. One solution, Liquefied Natural Gas (LNG), is a clean-burning fuel that is readily available and has the capability to reduce fuel costs for mines with access to LNG. The company currently offers several trucks that run on this alternative fuel.

793F and 796 AC hauling


Electrification is another focus area. The newest truck models are diesel electric-drive, and the company has several customers using these trucks in a trolley environment. “While trolley has a very limited set of applications that are economically viable, it is an example of how Caterpillar’s full integration and more advanced electric drive technologies are benefiting customers over what was previously available to them in the marketplace,” says Foster.

However, advancement in electrification doesn't slow development on the company's industry-leading mechanical drive trucks. "We continue to invest in and advance our mechanical drive trucks," says Foster. "They set the standard for efficiency and lowest cost per ton with technologies like Advance Productivity Electronic Control Strategy, which allows for exceptionally smooth shifting, faster cycles, and ease of operation.”

Reducing required maintenance has also been a development goal. “We know that periodic maintenance has to happen. Our goal as engineers is to design new processes and systems that reduce the amount of time required for that maintenance. We’re extending the life of components, filters and fluids. We’re providing easier, ground-level service. Anything we can do to keep that truck out in the field where it is producing.”

Having engineers close to the iron helps in this effort. “They really need to understand what it’s like to go from a computer screen, which is where most of them spend their time designing, to truly working on the iron,” Foster says. “They need to feel how far it is to reach around to remove a component. How much torque they have to put on that tool to get a filter off in a reasonable amount of time. How the fluids are traveling down their systems in order to drain them out, get them to the reclamation area and get that truck out of the maintenance bay.”

A validated product

Before a new truck is ever delivered to a customer site, it has already been operated for thousands of hours. Some of that work is performed in the robust testing environment of the Tucson Proving Ground. “We’ve got a fully flexible and functional environment to test products from one end of the spectrum to the other,” says Foster. The Proving Ground offers a variety of different grades for testing as well as a structures course that can evaluate how loads impact the trucks in different haul road conditions.

In recent years, simulation has taken on an even greater role in product development. “We’re getting to the point where we use the Proving Ground to validate the models we’ve developed through simulation,” says Foster. “By that point we’ve already run thousands of simulations to analyze individual systems.”

The testing and validation process relies heavily on information provided by the machines themselves. This information comes from machines already on customer sites as well as those currently in development. “We instrument our machines in the field and are continually collecting data. This helps us understand how different applications can vary the behavior of the loads and affect performance,” he says. That data is correlated with what is happening on the machines at the Proving Ground.

Data is also used in simulations to solve problems and identify opportunities for enhancement. For example, data showed a problem with a front tire that was overheating — the result of air flow that was coming in through the radiator and blowing on the tire. Through this analysis, the design team developed baffles to direct air flow away and enhance tire life.

Cat trucks are tested and validated in multiple ways for many months. “There are many gates that we go through. There are design reviews, we bring in experts, we bring in mechanics, and we bring in manufacturing folks, who make sure they can actually build what we’re designing," says Foster. "We want our customers to get the full value of our products over the life of the machine."



While a lot of attention is paid to the development of every Cat truck, just as much attention is spent on the individual components that go inside. One of the company’s key differentiators, Foster says, is the fact that all components are manufactured by Caterpillar and supported and serviced by the global Cat dealer network.

“Vertical integration is a big advantage we can deliver,” says Foster. “It’s not just the iron. It’s the software. It’s how the engine talks to the alternator, or how the transmission talks to the final drive and differential. It’s how the tires interact with the ground. And it’s the speed-sensing components that we have, and what they tell the engine and the transmission to do. That’s how we optimize the machine to really give you the lowest cost per ton.”

Foster further explains the importance of the company developing its own software to run on machines: “It’s one thing to write code and run software. How do you process that software on board? Well, we create our own Engine Control Modules (ECMs), our own computers to put on those machines. The data we can read and react to is all Caterpillar.”

In addition to optimizing engine performance, vertical integration also leads to an optimized electronic architecture. “The electronic architecture is the nerve system of the whole truck, so we’re really working hard in our engineering organization and investing a pretty substantial amount right now to look at our electronic architectures,” he says. “We want to get everything on the same platform. That feeds into the whole machine. It optimizes the haul profile based on the strut characteristics. It makes sure that your payload is monitored properly so you know how much you’re hauling.”

These fully integrated trucks offer a distinct advantage when it comes to autonomous haulage. “When we say our trucks leave the factory autonomy-ready, we mean that they are already optimized to operate in an autonomous capacity,” says Foster. “In an autonomous environment, you have to simulate what an operator would see or think or do. You have to program the truck to tell it how fast to go and when to apply the brakes. We make sure we know everything there is to know about how our trucks perform when there’s an operator on board. So when it comes time to automate them, we are already ahead of the game.”

Trucks working in the pit



Foster points out that the Caterpillar focus on integration extends beyond components. “Consider our truck bodies,” he says. “The way the bodies interact with the trucks is important — making sure we get the right weight distribution and extending tire life by paying attention to where those loads are on the machine. We want to ensure our customers can get the loads into the machine properly and get them out of the machine quickly to optimize production.”

Optimization of body designs is primarily done via simulation. “We have programs that can simulate cohesive materials and non-cohesive materials, large rocks and small rocks — or a mix of it all,” says Foster. “When we talk about optimizing the dump cycle, we use that information heavily when we’re developing our bodies.”

Integrating tires is another important focus. “We know our customers around the world are sensitive to tire life, so we do a lot of work with our tire manufacturers,” Foster says. “They actually join us at our Proving Ground. We work with tire engineers on their concepts, putting their tires on our machines. We simulate haul cycles, load-out areas and high-speed turns. We understand the dynamics of our trucks, so we can model that and validate it in the dirt.”



Foster says the goal of the Caterpillar truck design philosophy is to deliver a better bottom line. And the way that value is delivered is through performance.

“What this all boils down to is delivering iron that performs,” he says. “We really don’t compromise when it comes to the quality that we build in and the time that we spend developing these machines. We want to deliver trucks that do what they were designed to do and that deliver the value we’ve promised. Because of vertical integration, including technology, we get performance and efficiency. And our customers get a better bottom line.”

However, that focus on development doesn’t stop once a new truck model is launched. “Our engineers always reserve the right to enhance our products,” he says. “We look at things that are happening in the industry and on our customers’ sites all the time and continue to look for new ways to make our trucks even better.”



As an engineering manager, Foster admits he is a little bit biased when it comes to describing engineering expertise as one of the company’s key differentiators. But when it comes to delivering performance, he is quick to share credit with the Cat global dealer network.

“We can’t do what we do without the dealer and our teams out in the regions and the interaction and support we get from them,” he says. “Our dealers are on site working alongside our customers, and they have been working in the mining industry for generations. That’s where we get a lot of the information that allows us to do our jobs.”

World-class truck support


“When an issue arises with one of our products, the dealer is on call for the solution,” he continues. “They are constantly monitoring fleets and doing what they can to improve uptime and availability. The information that they gather flows through our regional teams and product support teams and right back to the engineers so we can react. We want to make any changes we need to make as quickly as possible so we’re not affecting availability. We want our engineers involved and our dealers help us do that.”

Alongside dealers, Caterpillar engineers work with customers on very specific projects to help them increase the productivity they’re getting out of Cat trucks, as well as to improve their availability.

“Our trucks have very long owning and operating cycles. There is going to be a need for maintenance and repair,” he says. “We want to optimize those repairs so they’re easier and faster and more effective.”

Foster says Cat trucks are designed to last 100,000 hours, and some are going well beyond that. “Our trucks are designed for multiple lives,” says Foster. “They’re optimized to go the distance. We’ve spent years of development and simulation and validation to deliver this value. Components, power trains, engines — Cat trucks are designed to be rebuilt from end to end.”

The “rebuildability” of Cat machines is built into the design process. “We design for rebuild,” says Foster. “And at the same time we’re designing for retrofits. When we go through a design cycle, our engineers are always thinking about how that improvement or enhancement can be put on a previous model, or the one before that. We want our customers, during the rebuild process, to be able to optimize their existing fleets. We can enhance them so they will perform even better than they did when they were new.”


With a wide variety of sizes, bodies, configurations and even electric-drive models, Caterpillar offers a truck to meet every application. And they're backed by industry-leading technology and world-class dealer support.

Mining Trucks
Mining Trucks