especially useful where there are sharp objects and other
debris on the ground. It’s also possible to insert foam into
air-filled pneumatics to reduce the impact of punctures or
other damage to the tire.
Cushion tires are made of smooth, solid rubber that is
fitted around a metal band. Their small profile facilitates a
tight turning radius. But they do not have the same degree
of traction as pneumatics, so they’re mostly used on smooth
indoor surfaces and on loading docks. They can also handle a well-maintained flat outdoor surface. Still, caution is
in order: Cushion-tire trucks may sink into asphalt that’s
been softened by high heat and sun exposure, warns Bob
McGowan, director of industry sales for forklift manufacturer Hyster Co.
Power and fuel. Historically, cushion-tire electric forklifts,
which don’t emit harmful fumes and pollutants, have been
used indoors; cushion-tire internal combustion (IC) trucks
powered by propane, a type of liquefied petroleum (LP)
gas, were considered indoor/outdoor models; and IC pneu-
matic-tire trucks powered by diesel or propane were used
outdoors, say the experts at Mitsubishi Caterpillar Forklift
America (MCFA), which manufactures and distributes
Mitsubishi, Cat, and Jungheinrich forklifts. But those tra-
ditional distinctions are no longer set in stone, and buyers
have more options than ever before, they say.
A major reason for that shift is that today’s IC forklift
engines “are really clean,” says Scott Johnson, vice presi-
dent of sales and marketing at lift truck manufacturer Clark
Material Handling Co. “You still have to ensure proper
ventilation and air flow,” he says, but lower emissions allow
some trucks that had been relegated to outdoor use to now
operate indoors too. He credits improved engineering and
better-quality fuel for the lower emissions. In particular,
he cites efforts by the Propane Education and Research
Council (PERC) to ensure that propane distributors filter
the fuel properly and that tanks are clean and free of con-
taminants. “The quality of the fuel today is by far the best
we’ve ever seen,” Johnson says.
In addition, U.S. federal regulations have required lift
truck makers to slash emissions from diesel-powered fork-
lifts. Because they are much cleaner-burning than in the
past, even these outdoor heavy lifters may be used in
some well-ventilated indoor environments now, says Craig
Seager, director, industry sales, for lift truck manufacturer
Yale Materials Handling Corp.
Another significant change is that heavy-duty bat-
