Trucks are always a prominent part of the annual World of Concrete show in Las Vegas, and to me the most impressive ones are the chassis carrying concrete pumper bodies. The bodies are big and bulky, and exhibitors extend their multi-section booms toward the tall ceiling and sometimes far away, over adjoining booths.

Pumper bodies are also heavy, so chassis toting larger units need six, seven or more axles to support the loads. Almost invariably they are straight trucks, but while roaming a section of the show on Tuesday I came upon a tractor-trailer unit displayed by Putzmeister America. Its body was a 70 M (M for meters, or about 227 feet, the maximum vertical reach of the five-section boom), and it was mounted on a five-axle semitrailer hitched to a four-axle tractor. This must be something new, I thought.

The unit is being bought by Western Concrete Pumping, based in southern California, and was built by Putzmeister of Germany. It recently arrived by ship and was hauled to Las Vegas for the show, said Steve Delamarian, Western’s VP of business development. The tractor, a Mercedes-Benz Actros cabover – a popular model in Europe but not seen here -- couldn’t legally run in California because its diesel isn’t emissions-certified. So it had to be hauled up to ‘Vegas.

With the M-B gone, the pump trailer, which weighs about 150,000 pounds, couldn’t be towed by just any other tractor. So it was trucked up to ‘Vegas aboard onto a high-capacity lowboy, said Dave Wright, a Putzmeister product manager. When the show is over, he will store the trailer nearby, then strip the tractor of specialized equipment before shipping it back to Germany (or maybe the Middle East, for which it was built, because its engine meets Euro 2 emissions specs and the European Union is now at Euro 5).

Meanwhile, he’s ordered an American-built tractor to mate to the trailer. It will be a conventional-cab model; a specs sheet shows a Kenworth C500B, but Wright said it’ll be a Mack Granite. It will have twin steer axles and a live tridem (aka “tri-drive”). That will be sent to a Fontaine Modification facility near Putzmeister America’s plant in Sturtevant, Wis., where the equipment from the M-B will be installed. Then the Mack and the 70 M pump trailer will be sent to Texas, where Western will put it to work.

Gross combination weight for the rig is 175,300 pounds, according to its specs sheet (Delamarian estimated the GCW with the M-B cabover at 178,500 pounds). Three of its five axles hydraulically self-steer, with wheel cut electronically controlled based on sensor readings at the fifth wheel.

Road-ready, the pump trailer looks bigger than it is. The specs sheet says it’s about 50 feet long (46 feet, 10 inches from its kingpin to its rear), 98 inches wide and 13 feet, 2 inches high. Overall length with a conventional-cab tractor is 70 feet, 4 inches .

When set up to work, outriggers are deployed, of course. And a pair of pull pins, one on either side of the fifth wheel, lock the trailer’s nose to the tractor, Wright explained. The nose rises as outrigger feet push into the ground, and the tractor’s weight acts as ballast to further stabilize the pumper as it churns away. The unit's pumps are powered by a large pony engine, a Deutz diesel rated at 500 hp.

The unit is capable of pumping 200 cubic yards an hour, but a contractor who happened by said in actual operation it’d handle 100 to 110 yards. That’s still a lot of work, and it’s doable because while one mixer truck is off-loading into the big rear-mounted hopper, another can back into position and get set up.  

This vehicle is unusual but not unique. Wright said several others have been built for Europe. And in the ‘90s, his company built some trailer-mounted concrete pumpers with smaller bodies for customers who preferred that configuration.

Articulation of a tractor-trailer makes it more maneuverable than a long straight truck in some situations. But in this case, the long vehicle length on 10 axles spreads out weight enough so it can run in bridge-formula states like California without a special permit for each trip.  So far it’s the biggest rig I’ve seen at the concrete show.