Rough-terrain forklifts are specialized machines used for many types of construction applications. They can go where other load-handling equipment can't, thanks to high ground clearance and features that control frame and pallet carriage level and sway. Many models offer four-wheel drive, as well as four-wheel steering, which increases maneuverability.

Variable reach is another feature that sets rough-terrain forklifts apart from traditional lift equipment. Fork pallets are mounted on an adjustable boom that can be extended both horizontally and vertically to handle materials in areas inaccessible to standard forklifts. Some models also can reach below ground level. For many users, the variable reach capability of these units is as important as the ability to work on uneven surfaces.

Rough-terrain equipment routinely handles lumber, framing, steel, brick and concrete blocks, masonry, roofing, sheets of drywall - building materials of all kinds. Specialized attachments make the machine's material-handling capabilities virtually unlimited.

"Carriages designed for framers and masons, rotating carriages, buckets, jib booms, grapplers and hay bale attachments allow rough-terrain forklifts to handle about anything," says Scott Nicklas, Terex Handlers, Baraga, Mich.

"We believe that the increased versatility through attachments brings limitless unexplored opportunities for this type equipment," says John Graham, Lull International, St. Paul, Minn. "Anyone needing the capabilities of a skid-steer loader with the added dimension of reach is a possible rental customer."

"New markets and uses for rough-terrain forklifts are limited only by the imagination of the rental store operator," says Tom Pranka, Ardco/Traverse Lift Co., Houston.

Basic categories of potential customers for rough-terrain equipment are clearly defined, but the versatility of these machines opens the door to many applications.

"For the most part, rental centers are keeping their fleets busy," says Terex's Nicklas, "but there may be more markets than are currently being utilized. Examples are agriculture, forestry and lumberyards."

Renters of rough-terrain forklifts generally are involved in construction and material handling. General contractors, residential and commercial contractors, steel construction specialists, road and bridge builders, large warehouse operations, building material supply companies, industrial and manufacturing companies, military installations and other agencies of government use rough-terrain forklifts. It's really not a homeowner market - you want to have experienced personnel at the controls.

While these machines are built for rough terrain, inexperienced users can get in trouble quickly by not knowing the limits of equipment. There are surface conditions and loading situations that can cause vehicles to overturn. Rental store personnel must be prepared to provide complete operational and safety instructions with each rental.

"Basic safety points include traveling with the boom retracted and in the lowest possible position and never exceeding load ratings," says Earl Bashaw, CareLift Equipment, Breslau, Ontario, Canada. "Remember that load capacities are rated on a firm surface with frame level, wheels straight and tires properly inflated. Use manufacturer's charts to determine allowable loads."

Companies that regularly conduct safety training may be able to reduce insurance premiums.

"Rental centers that provide operator training can promote this benefit," says Dan Lang, senior instructor for forklifts at the John Deere Training Center in Moline, Ill.

The most popular machines for rental are those with maximum load capacities in the 6,000-lb. range, with about 37-ft. lift height and 30-ft. horizontal extension. Machines in this class average around 100 hp. Rental centers also carry units with 8,000- and 10,000-lb. capacities and extended boom heights of just under 50 ft. For all sizes of equipment, load limits with booms fully extended are significantly less than published maximums. Extended loads must be kept within limits specified by the manufacturer - given the reach and load capacity of these machines plus the fact that they may be on uneven ground or negotiating obstacles around a job site, operators must respect these limits and not risk destabilizing the machine.