With tractors getting heavier, Monarch Distributing in Indianapolis needed to lighten up its trailers to recapture payload capacity. Its latest group of 53-foot vans from Great Dane accomplish this by scaling 2,000 pounds lighter than previous units.
Wine-toting Great Dane vans use aluminum crossmembers, wide-base single tires and wheels, and aluminum roof sheeting to cut 2,000 pounds from each one. Small portholes along the top of each side let in sunlight that fiberglass translucent roofs do on older, heavier trailers. Cheap natural gas motor fuel lessons the need for heavy side skirts.
E.F. Transit, Monarch’s trucking arm, uses vans to haul palletized cases of beer to the Chicago area, where they pick up loads of wine and return to a large distribution center in northeast Indianapolis, according to Fred Dufour, executive vice president, operations.
Last year it began replacing its diesel road tractors with new ones equipped with natural gas engines. It’s saving big money with gas, but the high-pressure compressed-gas tanks on each one add 2,000 to 3,000 pounds.
The vans usually back against loading docks, but occasionally drivers and mechanics need to climb up from the ground. A vertical grab handle on one door helps them do this safely.
To compensate, Dufour’s people looked at how these trailers are built, and decided to change some key specs: Aluminum crossmembers replace steel, and wide-base single tires on aluminum rims now support the trailers’ rear ends instead of traditional duals.
Air pressure is more critical in big singles, so inflation devices were spec’d for the first time on Monarch trailers. These are Hendrickson TireMaax Pro systems that monitor pressure and reduce it when tires are hot as well as pump it up when they cool. So far they’re working well, Monarch’s shop managers say.
Finally, translucent fiberglass roofs were omitted in favor of lighter aluminum sheeting. Sunlight was not entirely lost, though, as the new trailers have small portholes along the top -- three groups of three windows on each side -- to let in some rays during loading and unloading.
Hendrickson TireMaax Pro inflation systems protect air pressure in the wide-base single radials. Big singles themselves cut about 400 pounds vs. standard duals.
Omitting the fiberglass roofs also precludes the possible problem of cracking. If not caught, cracked roof sheeting weakens a trailer’s monocoque structure because the roof carries some of the vehicle’s weight, like a bridge truss. Trailers have been known to collapse when a roof fails, Dufour said.
Conspicuous by their absence are side skirts, which would’ve added about 300 pounds. The cheaper cost of gas – now about $1.20 per diesel-gallon-equivalent -- makes the skirts’ fuel savings less important, he said.
The 2,000-pound weight savings join with a 2,000-pound weight allowance granted gas-powered trucks by legislatures in Indiana and Ohio, where Monarch’s rigs also go, he said. Sometimes this means a net gain to payload for a gas-fired rig versus one pulled by a diesel tractor.