If the milling machine or cold planer is already considered a niche product type, then the full-lane crawler version is the niche of the niche.
Of the milling-machine manufacturers surveyed by Construction Equipment, only three are offering a full-lane product at this time. And each of those machines represents a full-lane option to the companies' respective largest half-lane milling machines, and not a dedicated full-lane model per se.
Each with 150-inch drum options, the established Wirtgen W 2200 and Roadtec RX-900 products have been joined in the full-lane game by the Terex CMI PR950, for which production begins this year.
As a market, sales of 25 to 30 would be considered a good year, notes Jeff Wiley, Wirtgen America's vice president of sales and marketing. As of the mid-point, 2007 was on target to approach that total.
While the ability of contractors to transport these machines can be limited depending on the jurisdiction, another factor of the limited market is the productivity of the machines themselves, he notes.
"They're capable of basically working you right out of work," says Wiley. "If you're on a mill-and-fill and you've got one machine that's 12 feet wide, you can get a lot of area covered in one night. So, a contractor doesn't necessarily need three or four or five of these machines in his fleet. One or two of them pretty much takes care of most all of his mill-and-fill needs."
But, says Wiley, these machines will become increasingly popular, because they offer full-lane milling width while retaining enough horsepower for mill-and-fill applications.
"Our intentions in 2005 have finally come to fruition here in 2007," says Larry Jack, Terex Roadbuilding's director of marketing. He is referring back to a Construction Equipment article on half-lane machines in early 2005, in which he outlined the company's objective to develop a high-horsepower milling machine that, at the standard configuration of three tracks and an 86-inch cutting width, would weigh in the vicinity of 75,000 pounds.
As part of a "renewed offensive on the cold-planer market," that machine, the PR950, is also available in a four-track configuration and with the full-lane cutting width of 150 inches.
The Terex CMI PR950 is powered by a 950-horsepower Cummins diesel engine. Comparatively, the Caterpillar powerplant utilized by Astec's Roadtec brand has increased from 860 to 950 horsepower on the four-track version of the RX-900, while the Wirtgen W 2200 also utilizes the Caterpillar 3412E diesel, generating 900 horsepower. According to Wirtgen America, the 12-cylinder Caterpillar engine is "overspecified" for the W 2200's maximum cutting depth of 13.7 inches and, with the resulting immense feed rate, combines with the front-loading conveyor system for a theoretical production capacity of 1,100 tons per hour.
First introduced by Germany-based Wirtgen in 2000, the W 2200 today offers a choice of three cutter spacing configurations on the full-lane drum. Along with the standard 5/8 of an inch spacing, available is a fine 5/16 option and a new, wider Eco-Drum. At spacing of an inch-and-a-quarter, the Eco-Drum is suited for deeper, aggressive excavation.
"What that gives you is greater breakout force," says Wiley. "You're going to have more horsepower per tooth, and it's going to allow you to be a little more productive. When you're doing full-depth excavation, or you're cutting deep concrete, you're not as concerned about a tight, finely spaced pattern, because you're going to overlay it back with four, five or six inches of asphalt anyway."
Versatility is the crux of the half- and full-lane optional machine, says Wiley. Being able to switch back to a 7-foot drum and take on city-street projects when full-lane work is not available is the "multi-purpose" flexibility the market looks for today.
With Roadtec, "we have seen an increase in popularity of segmented drums," reports the Astec Industries company. "These allow the contractor to change, say, from 12 feet 6 inches to 12 feet by taking off the outside foot-and-a-half and replacing it with a foot-long section. The rest of the housing stays in place, and that means much shorter change times."
With CMI and its current owner Terex for 30 years, Jack notes just how much has changed about the large milling-machine market.
"There was a time you had half-lane machines and you had full-lane machines," he recalls, "and neither one of them crossed that line." Half-lane machines went up to 8.5 feet in width for some special applications, but most were 7 feet in width to process 12- and 14-foot lanes in two passes. "And that's all these half-lane machines did," he says. "Initially, none of them had bolt-on cutters; they were built into the machines."
A change occurred in 1999.
"The then-CMI Corp. introduced the first multi-use machine," says Jack. "It was a tractor that would accommodate either a 7-foot or typically a 12-and-a-half-foot — that's the standard — cutter head.
"In typical milling, I don't know of any manufacturer today that builds a dedicated full-width-lane machine. Everybody has a tractor that will accommodate both of them."
Today, the Terex CMI PR950 offers a cut depth of 15 inches, allowing contractors to excavate the entire roadway, right down to the base material.
"We've learned over our years of experience here that the shape of the cutter housing does a lot as far as how you purge the material from the cutter housing," says Jack. "The term that's used in the industry is the head of material that you carry. The more head of material, or more bulk or mass of material that you have inside the housing, the more material that your cutter bits are running through and, of course, that creates more wear on all the components, whether it's the drum, the sliding, the holders and the teeth themselves."
To combat that, Terex CMI has carried over and enhanced from earlier machines a trapezoid-type-shaped cutter housing that reduces the amount of head.
"The shape of the cutter housing, in conjunction with the helical patterns on the drum, allows us to discharge the material faster," says Jim Holland, Jr., product manager with Terex CMI.
As a test, the company ran a 600-horsepower machine with the tapered housing against an 800-horsepower machine without the tapered housing. The smaller machine was able to keep pace in a 4-inch cut.
Quick-change tooth holder systems are the trend today.
"It costs you a lot less to own a welded-type cutter, and it can cost you a lot less to maintain it," says Terex CMI's Jack, "but if you're in New York City and it seems that every block you go into, you're going to knock one of these things off, what you're losing there is uptime and production, and that will very quickly outweigh. You can get your payback with these quick-change cutters by getting the machine back on the job quickly."
Wirtgen offers the HT11 quick-change toolholder system for large-volume milling machines as standard. With this new system, the retaining bolt is significantly larger than the one used in the former HT3 system. Enlarging the contact surface of the upper part to completely cover that of the bottom ensures an even and tight fit between the two. As a result, when the upper part needs to be quickly replaced on a jobsite, the bottom part requires only minimal cleaning, which allows for quicker and easier part changes. Additionally, the bore in the bottom part is protected against milling debris contamination by a seal.
As a product type, the cold planer or milling machine evolved back in 1976, when CMI incorporated conical-bit technology into a rear-discharge fine grader as a road surface reclaiming alternative to simply crunching up the asphalt and hauling it off with a front-end loader.
Today, with Terex CMI catching up to Roadtec and Wirtgen with the full-lane milling option to the half-lane product line, the next player in this game may well be Volvo, having recently acquired the Ingersoll Rand Road Development line.
Just prior to the sale, Ingersoll Rand had begun the completion of an all-encompassing road construction and rehabilitation product offering with the rolling out of two milling machines, including the MT-2000. A four-track, front-load machine capable of running drums up to 86 inches in width, the new Volvo MT-2000 offers four steering modes, three distinct drum cutting speeds, and active anti-spin control.
At the company's product launch late in 2006, Ingersoll Rand announced plans to expand that product offering to a total of six models. Volvo representatives have since indicated product-line expansion will include larger-width options.
