Today’s shuttle car designs are not new, but are gaining viability as seams get thinner and markets tighten
by jesse morton, technical writer
If this article were on strictly the latest shuttle car innovations, it would be brief. The solutions on the market right now have been there for some time, and, apart from minor updates, they have not changed much over the last decade.
What may be changing is the economic and geologic environments in which the solutions now operate. As both markets and seams become more challenging, some of the existing solutions, though they may have been around a while, are gaining new viability.
Lower Operating Costs
Joy Global invented the shuttle car in 1938. With an astounding 18,000 units sold since then, the company long ago mastered the knowledge base on which its current designs are founded, Joy leadership told Coal Age.
Those designs are described as “the mainstay of the industry for batch haulage vehicles. Their exceptional reliability, low operating cost and sustained high levels of productivity are unmatched.”
Joy shuttle cars now come equipped with suspension and the Optidrive AC Variable Frequency Drive System. The system offers increased tramming speed, regenerative braking, improved speed control and less maintenance.
Units equipped with both technologies have been proven to outperform predecessor units, and to increase operator comfort and safety.
“The combination of suspension and the VFD was a game changer in terms of something that forced customers to buy new,” Toby Cressman, global product manager, room-and-pillar products, Komatsu, said. “It was ergonomics, too,” he said. The technologies sold shuttle cars because they were “operator focused.”
That focus also drove the development of the 10SC42, Joy’s latest design, which has been sold exclusively in Australia for much of the last decade. It features a rotating operator’s cab and joystick controls.
The Joy brand offers a host of benefits.
Foremost is cost savings, Cressman said. “The reliability and the component exchange programs drive down the operating costs,” he added.
Next is Joy’s systems approach, which gives it the ability to best serve data-oriented customers.
“Because we sell the whole suite of equipment, you have the opportunity to have a Joy miner with a Joy shuttle car with a Joy feeder with a Joy conveyor,” Cressman said. “If you are one of those customers that is very data driven and analytical, we can pull data from all those different points for optimization purposes.”
The company has a robust rebuild program with several offerings. “You can get different levels of repair to manage costs,” Cressman said. “On main component rebuilds, like wheel unit motors, we offer the same warranty in the exchange program. A customer can come in and exchange out a wheel unit. We rebuild the unit” to like-new, and it is then available for exchange.
More recently, the company has assembled a team of mining engineers to help potential customers with more than just the decision tree on purchasing Joy equipment. The new personnel consult on some mine planning tasks and how they play into purchase decisions.
“Launching the Application Team was a good step,” Cressman said.
The team basically travels the world consulting on mine plans, haulage and material handling. “Kind of think of it as a hotshot team,” said Chuck Fickter, project manager, underground, Komatsu. It specializes in detailed time studies, and “works with miners on routings and best practices for material handling.”
The service is free and comes with no obligations. “We’ll look at the numbers and the capital costs, and try to give them an overall view of what would be best for their mine from a productivity standpoint and a costs standpoint, depending on what is most important to them,” Cressman said.
The Applications Team is a natural outgrowth of the Joy business model, he said.
“It really started when we got into the battery hauler business,” Cressman said. “For our customer’s sake, we needed to be able to tell them what haulage is best for them.”
Historically, that was typically done in-house by the miners that could afford to do it themselves or by third-party contractors.
“Then we started to acquire some mining engineers in the industry,” Cressman said. “Generally, we try to hire engineers that have had five to 10 years in the industry. The last one we hired worked in the industry and then worked for MSHA (the U.S. Mine Safety and Health Administration) on the ventilation team. Now we have someone equipped to talk about best ventilation requirements and related topics.”
The team does not consult much on mining methods. “We are not into mine design. We will not tell you bolting requirements,” Cressman said. “We will tell you how to effectively use the equipment you have.”
Or what equipment would help achieve “the next level of efficiency or productivity,” he said. “Maybe a battery hauler is better, or maybe a shuttle car is right for you.”
With the current market slump and uncertainty, Joy shuttle cars speak to some of the more pressing needs of miners, he said.
“Shuttle cars are a flexible option,” Cressman said. “They are easy to put in and fairly simple to run. Low operating costs make the Joy shuttle car one of the most viable options on the market.”
To that end, Joy solutions now come with the full backing of the Komatsu network, Cressman said.
“It is a combination of two strong name brands,” he added.
Phillips Machine Services reported that bigger payloads is how the High Capacity (HC) Freedom Cars increase customer productivity.
“Wherever a shuttle car is used, the Phillips HC chassis can increase the tons per trip, which will increase profit over time,” C.R. Allen, sales director, Phillips Machine Services, said.
“The HC chassis, with its payload increase of 12% means it takes less roundtrips per shift to achieve the same production volume as a normal shuttle car would do,” he said. “More tons per trip means more profit.”
One direct effect of the higher payload is better utilization of the continuous miner.
“The miner changes places more times each shift, which is directly related to a production increase in the same time period,” Allen said. “The tonnage produced in a given time period is directly tied to the cost per ton. More tons produced in a given period will reduce costs and increase profits.”
Phillips shuttle cars feature an electronics system that uses variable speed motor controls for the traction and the conveyor drive motors. “The advantages of the variable speed motors also have the effect of reducing operating costs as the precise motor control reduces the wear and tear on mechanical parts in each of the systems,” Allen said.
The OEM offers 10 models that range in size and capabilities, and that include battery-powered, diesel electric and trailing cable units.
The biggest is the battery-powered FC30B, also known as the HC Freedom Car, with a payload capacity of 30 metric tons (mt). The unit is roughly 10 m long, 4.5 m wide, and is designed for a minimum seam height of about 3 m. It comes with DC or AC motor controls, and has halogen lighting with automatic controls, an elevating conveyor discharge boom, and full-time four-wheel drive. Four-wheel independent suspension, a dual-loader conveyor chain and a mineSMART technology package come optional.
The model’s evolution and development traces back to a conversation that occurred on a flight home to West Virginia after a Midwestern customer mine visit in Q1 2000. “The customer wanted a haulage vehicle that was more productive,” Tom Cushman, former owner and current board adviser, Phillips Machine Services, said.
“To do so, the machine needed to carry a larger payload in the same space allotted to the normal shuttle car,” he said. “Payload is always the No. 1 topic.”
The customer wanted a battery-powered solution.
The day after the flight, company leadership met and conceptualized what would become the first Freedom Car model, a battery-powered shuttle car. The goal to have a showpiece by MINExpo was achieved.
The display unit drew plenty of attention. Orders followed. Soon thereafter the model received MSHA approval and a prototype was deployed. “We have considered ourselves an OEM ever since,” Cushman said.
The first big order was for 24 machines, half of which were battery powered and half trailing cable powered. The company sold machines in the U.S., Canada, China, India, Mexico and Russia.
“The machine we showed at the 2012 MINExpo in Las Vegas earned us the order for 18 OEM machines in South Africa,” Allen said.
Repeat orders provided the proof of concept of the Freedom Cars, he said. Field results provided the proof for the HC models. “The first Freedom Car with a HC chassis reduced the number of trips per cut from 22 to 18, which increased the number of 40-ft cuts per day from nine to 11.”
Which is to say the shuttle cars disproved the misconception that increasing speed is the best way to increase production. “Time studies where operational data is entered into a computer model show that payload is the key component to increased production,” Allen said. Conversely, “as long as there is a shuttle car at the change-out point, then increased tram speeds do not improve production at the end of the day.”
Truck-and-shovel surface mining solutions suppliers illustrate the point, Cushman said. “Most big truck makers are searching for ways to increase payload and not necessarily the tram speed.”
Miners interested in deploying Freedom Cars should be familiar with batteries, change-out methods and battery maintenance, Allen said.
He said they should have an interest in mining more coal and making more money. “Mine more, haul more and make more,” he added.
Lower Loading Height
Highland Machinery Co. said with current market conditions, the 10/21K is ascendant. It is a machine whose time has come, Bill McClanahan, Highland Machinery Co., said.
“This machine is becoming more and more desirable each day with a less-than-ideal coal market and costs dictating for operations to continually mine thinner seams and to reduce the amount of reject that they are having to cut,” he said.
For many operations, mining those thinner seams can no longer be pushed into the future, and lower seams call for lower equipment.
“The ‘easy’ coal with large seams is more and more being mined out and we are left with thinner seams,” McClanahan said. “These thinner seams are leaving companies with two main options.”
“One, cut more rock to have higher mines that do nothing more than cost the company money and unnecessary wear on every piece of equipment from the continuous miner to the preparation plant. Or, two, cut lower and use smaller equipment,” he said. “The problem is that 21SC shuttle cars are not as durable as 10SC and do not have robust components due to the small nature of the machine.”
For some seams, the 10SC is simply not low enough, and the 21SC does not offer the desired capacity.
“The 10/21K is able to operate in conditions lower than any other 10SC shuttle car produced by any other company,” McClanahan said. “The 10/21K in all actuality has a lower loading height than what other manufacturers produce in a 21SC shuttle car.”
It is available in eight models that vary in haulage capacity and other capabilities.
Company literature described it as “a center-operated shuttle car for low-coal seams 48 in. and above. It is available in standard, off-standard or S-model configurations. It features “more robust components,” which reduces parts breakage, “lowering downtime, reducing maintenance costs,” and lengthening the time between complete rebuilds.
McClanahan describes it as robust, dependable and offering lower cost of ownership. “It also increases production by allowing for larger load capacities compared to other machines that could operate in such low heights.”
In the 15 years since the 10/21K was introduced, the company has relied on feedback from the field and the lessons gained doing rebuilds to guide updates. “We have never stopped learning from our customers,” McClanahan said.
“Every time that we get a machine back in for rebuild, we dissect the machine to see what we can learn from the amount of time that it has been in the field,” he said. “We analyze every aspect of the machine to see where we need to improve even further to continually develop.”
One such customer that provided very early feedback was Cumberland Resources. The company’s Virginia operations needed a shuttle car that could work in a 50- to 55-in. seam. The mine manager, Gail Kiser, worked closely with Highland Machinery’s Jim Baily and McClanahan on the conceptualization and then the development of the 10/21K.
“The 10/21K completely changed the operations of Cumberland Resources,” McClanahan said. “They were immediately able to increase production, reduce maintenance costs, increase visibility, and increase the life of miner conveyor booms from not being damaged from loading while in cross cuts.”
Ultimately, the mine and then Cumberland Resources “would go on to order 10/21K shuttle cars to replace their existing fleet one mine at a time,” he said.
More recently, a miner in Buchannan County, Virginia, ordered 14 new 10/21K shuttle cars as part of a fleet replacement effort. “It was over three years after the new 10/21K shuttle cars went into service before they ever experienced a failure on a shuttle car wheel unit,” McClanahan said.
“The math is pretty easy here: in the first three years of ownership, the 10/21K shuttle cars saved their operations between $3.6 to $5.4 million in savings in wheel units alone,” he said. Add to that “the increased production from higher load capacity compared to the machines they were previously running and the additional availability from the machines being new.”
Savings like that can contribute substantially to helping a coal miner turn a profit. Such is proof that the unit, while still featuring “old design principles from earlier generations,” is “ahead of its time,” McClanahan said. “The coal market and industry has changed dramatically over the past 15 years and this machine is needed now more than ever.”
The Strongest Link
In a soft market, it is not uncommon for some maintenance tasks to be pushed back to cut costs. Shuttle car chain replacement, for example, often gets postponed, Bobby Stenger Jr., marketing manager, Cincinnati Mine Machinery Co., said.
“As the market has tightened, we have seen customers running chains longer than anticipated, and up to 25% more in some applications,” he said.
That means that for many miners operating shuttle cars, now is the time to adopt the DA-5504-H chain, Stenger said. “This is the ideal chain for replacing OEM chains,” he added.
The DA-5504-H has been on the market for more than a decade, and in that time has been deployed to more than 100 machines.
Stenger said the topmost benefit is increased uptime. “We used high-alloy forged parts that are heat treated,” he said. “Our chain has flight articulation that allows flexibility for deflection of debris compared to the solid fixed connector style that is standard.”
The DA-5504-H runs on a five-tooth sprockets. Compared to a chain that runs on a four-tooth sprocket, it “allows for more engagement of the teeth and a smoother transition,” Stenger said. “That means longer wear life, more uptime and less stoppage. And availability is always the top priority.”
The chain can replace OEM chains, but delivers superior performance, he said. The company does supply a number of OEM-standard chains, but “this, unfortunately, is not one of them.”
The DA-5504-H is usually installed during an overhaul or rebuild. “The OEM chain is usually changed out every two to four years, depending on the cutting conditions,” Stenger said.
“Cincinnati markets the strongest chain currently on the market,” he said. “Our products are the strongest link in the mining industry.”