In establishing the articulated dump truck as a North American jobsite hauling solution, major equipment manufacturers have mostly stuck to the 25- to 40-ton-capacity range. Truck models offered at tidy 5-ton increments in that range comprise the norm.
Now that ADTs have found their place, the next step for the full-line manufacturers may very well be the stretching out of the standard hauling capacities offered.
At the Bauma 2007 show in Germany, two 50-ton-class trucks were debuted. At least one of those, the Moxy MT51, will be coming to Conexpo-Con/Agg in Las Vegas next March.
At the other end, manufacturers established in the European market, such as JCB and Hydrema, continue to provide North America with smaller-capacity ADTs (those up to 22 tons in capacity).
"We see movement in increasing payload capacities, so we are working on larger trucks," says K.C. Clarendon, articulated dump truck product consultant with John Deere Construction & Forestry. "On the flip side, over the past couple of months, in the market for a smaller truck in the 18- to 20-ton range we've seen a good bit of interest from customers as well.
"But I'd have to say even more so in the 50-ton class."
With 250D, 300D, 350D and 400D models, John Deere is among the major manufacturers that cover the core 25- to 40-ton range.
Likewise for Caterpillar, which offers the 725, 730, 735 and 740 models.
"We're always looking at where our customers want to go with these trucks," says Ann Schreifels, articulated trucks product specialist with Caterpillar.
But when a customer asks for a larger articulated truck, there are pressing questions that need to be answered first, she says.
"Does he want a bigger version of the truck he has right now, meaning the same gradeability, same top speed, same mobility?" asks Schreifels. "Or, if you go bigger, would it be dedicated to one job, since transport issues would come into play? Would you expect to climb a grade as steep with a 50-ton truck as you do with a 40-ton truck?
"These are all questions we are looking at," she says, "and determining if the market is there for it and what exactly are they asking for."
No doubt, product-development professionals with Volvo, Komatsu and Case — all of which have made significant product-line upgrades up to the 40-ton line — are doing the same type of analysis.
While other equipment types have hit the North American marketing brick wall thrown up by the housing downturn, ADTs motor along at a pace of a little under 4,000, albeit a tad slower than the "vertical" market of a year ago.
"We haven't seen it drop that much," says Deere's Clarendon. "I think it's more about the jobs where these are going. The housing market took a pretty good crash, but where these are used are in roadbuilding and mass-excavating jobs mostly, and I haven't seen them really drop down. There's actually a good number of them out there for bid right now."
ADT applications are expanding, too.
"We've made some in-roads into markets that they weren't used too much for in the past — quarrying and mining applications," says Clarendon. "A lot of that has been driven by rigid-frame-truck availability — or not being available. That's helped us get in there, and also to show the customers the versatility of these trucks, in terms of everything from haul-road maintenance to inclement weather and how they work through all that."
More and more users, says Caterpillar's Schreifels, do see the articulated trucks as "more versatile than if they had a construction truck or a rigid-frame truck.
"There you have to prepare for the trucks to arrive," she says, "where here the articulated trucks are usually breaking new ground."
Schreifels is likewise seeing her company's articulated trucks going into different surroundings. In Nebraska, for instance, a feedlot operation is using the trucks to haul manure.
"Probably where people get the most creative is with our Ejector trucks," she says. "We have a job right now in Missouri where they are actually filling the truck with wet concrete, and pushing the concrete out for a dam construction job."
In addition to the standard-dump 730 and 740 models, Caterpillar offers two corresponding ejector-body models. With their ability to push out the load as compared to dumping, the 730 Ejector and 740 Ejector are suited for spreading material on the go.
"We've got one guy who's actually put a divider down the middle," says Schreifels. "He puts one type of material on one side, another type on the other, and then he can spread them side by side, so that there ends up being two windrows. Then, he comes back with a stabilizer, because he has to put that particular mix down for some stabilization. I call that truck 'the epoxy model.'"
Others have been enhanced with funnels and wings.
While the Ejector models would still represent less than 20 percent of the total turned out by Caterpillar in the respective class sizes, "we've seen in the last couple of years a real surge in demand for them," says Schreifels. "People are starting to get over those, 'Oh, this is new and different' kind of jitters. They're more accepting now and more willing to take a look at them."
Ejector-body articulated trucks require less jobsite support equipment, and they offer a safer system when working with restricted overhead clearance or soft underfoot conditions, she says. Then there are the faster cycle times.
"It takes you the 12 seconds to eject the load, and then you're up to full speed on your way back to get reloaded," says Schreifels. "You're not waiting for the bed to raise, you're not waiting for the bed to lower, or putting the parking brake on. You're going however fast you want to go, and then you retract the blade on your way back."
While ADT manufacturers consider an expansion of the traditional product size offering, they have been busy upgrading their established products, too.
Case completed the B-Series updating of the line this year with the rollout of the 335B and 340B models, following up on the 2006 debut of the 330B and a new model size, the 327B. Along with the swing-out fenders, Case added a tilt cab that provides technicians with easy access to the drivelines, transmission, hydraulic valves and lines, for ground-level preventative maintenance checks. An automatic-lubrication system continuously greases all lube points from a central distribution block.
With three model sizes covering the 30- to 40-ton-capacity range, Komatsu has over the past 18 months rolled out the -2 Series of the HM trucks, offering increased horsepower and improved fuel economy based on transmission control, steering and hydraulic-system upgrades. Komatsu offers full hydro-pneumatic suspension in both the front and rear.
As part of its new E-Series, Volvo used the backdrop of Bauma to introduce a Full Suspension option for the two largest of its four established model sizes. The new A35E FS and A40E FS models employ shock absorbers at each wheel position that are linked to microprocessors that automatically control the truck's stability.
On the compact side, Hydrema recently introduced the D-Series model of the 912, the smallest ADT on the market, also available in a side-dump MultiTip version. The 912D MultiTip has an "auto bed return" option that allows the truck to turn and lower the bed automatically.
As with Hydrema, JCB offers a 22-ton-capacity model. The tri-axle, constant six-wheel-drive JCB 722 is equipped with a transmission and intermediate axle differential lock that can be engaged to provide equal torque distribution to each of the three axles in poor ground conditions.
JCB also offers the smaller 714 and 718 models, which can be switched between four- and two-wheel-drive, depending on terrain conditions. All three of JCB's models are equipped with limited-slip axles.
Indeed, the ADT market is here to stay.
"Generally speaking," says Clarendon, "they'll go in quantities of 2, 4, 8, 20 — a fleet — to be loaded by excavators and wheel loaders."
As a choice among hauling systems, says Schreifels, "people know what articulated trucks are and know what they can do. They are a 'go-anywhere' kind of vehicle."
|The Cost of Ownership|
|Size||List Price||*Hourly Rate|
|* Hourly rate represents the monthly ownership costs divided by 176, plus operating cost. Adjusted operating unit prices used in the calculation are diesel fuel at $2.83 per gallon, mechanic's wage at $43.07 per hour, and money costs at 5.75 percent.|
|Source: EquipmentWatch.com , phone 800/669-3282|
|Up to 19 M Tons||$152,626||$50.22|
|20 – 25 M Tons||$328,722||$83.24|
|26 – 29 M Tons||$396,759||$93.88|
|30 – 34 M Tons||$484,725||$110.03|
|35 M Tons & Over||$569,661||$123.62|
|Model||Payload (lb.)||Heaped Capacity SAE 2:1 (cu. yd.)||Full Cycle Dump (sec.)||Dump Angle (degrees)||Net HP|
|Source: Spec-Check Xpanded Specs (as of September/07)|
|Hydrema 912D MultiTip||22,000||7.3||n/a||75||131|
|John Deere 250D||51,150||18.0||17.9||70||265|
|Volvo A25D 4x4||52,911||17.0||14||59||293|
|John Deere 300D||60,190||21.7||17.9||70||285|
|Caterpillar 730 Ejector||62,000||22.1||27||n/a||317|
|John Deere 350D||71,650||26.3||20.6||70||380|
|John Deere 400D||81,570||29.4||20.6||70||413|
|Caterpillar 740 Ejector||83,775||30.2||38||n/a||436|