Proper Restraint

10 Reasons to Use Restraints on Sit Down Lift Trucks

Clark revolutionized the industry by inventing the first operator restraint system for lift trucks in 1983. It was put into production on the internal combustion product then, and Clark offered a free retrofit for eligible trucks (which expired in March 2004). It was patented, but offered royalty-free to competition. Now, every manufacturer has some type of restraint system available on their forklifts.

Clark is now putting the same operator restraint system on its electric product. There have been no reported deaths or serious injuries from lateral tipovers where the operator was wearing his seatbelt and braced himself in the seat, riding the truck down.

Operator Restraint System

Very few of the injuries associated with lift trucks are due to overturns. But a disproportionate number of the very serious injuries are. In a 1980 report on lift truck accidents, (from the California Division of Labor Statistics and Research) tipovers resulted in 73 percent of the 11 total deaths listed.

Reports also disclosed that operators who remain within the confines of the truck are rarely seriously injured. The Clark Operator Restraint System is designed to keep operators in the truck during a turnover. It was developed exclusively by Clark after two years of exhaustive consideration of 11 viable solutions.

The design, which best met all of the objectives of safety, confinement, comfort, visibility, mobility, and protection is the wing seat with lap belt and deck latch. This design also allows unhampered access to all controls and permits unrestricted operator entry and exit. It further restrains and controls the upper torso while the lap belt restrains the pelvic area.

Five of the designs were selected to be tested with a GM Hybrid II anthropomorphic test device (dummy) on a Roll Over Crash Simulator, aided by and evaluated with an Automatic Dynamic Analysis of Mechanical Systems (ADAMS) computer program and verification. The simulator approximated the same effects of an actual overturn, including the "fly-swatter effect."

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The Fly-Swatter Effect

As a truck starts to roll, its initial momentum is slow. The effect "cons" the operator into thinking he or she has time to abandon the truck. At the moment the center of gravity passes the wheel line, the slow overturn rapidly accelerates. An operator who is partially off the truck at this point may very well be pinned or crushed under the overhead guard. This slow start and instant acceleration is known as the "fly-swatter effect."

The "fly-swatter effect" and the natural human reaction to escape, established the need for a device which would effectively contain the operator within the vehicle. The wing back seat and lap belt accomplish this as was proven by an actual rolflover test with a live operator.

The Moment of Truth

The final and most conclusive test was performed with a Clark 4,500 lb. (2250 kg.) rated capacity lift truck, equipped with the wing back seat, lap belt and deck latch in an actual tipover situation using a professional test driver as operator.

The operator was successfully contained within the vehicle by the restraint system with no injuries occurring. Absence of any marks on the operator's safety helmet and video replays indicated no head contact of any kind.

System Concept

The Clark Operator Restraint System consists of a vertical wing support which also serves as the back cushion support. The wings are offset from the center of the back with more area to the operator's right, offering arm and shoulder clearance for proper operation of the truck's hydraulic controls. It also provides a greater expanse to rest one's arm while turning to look backward when traveling in reverse.

The open design of the wings reduce a possible claustrophobic effect on the operator and provide visibility for smaller operators. Warning decals caution the operator to fasten the lap belt, which is provided to assist in containment and to prevent forward thrust. A deck latch is provided to secure the engine compartment cover, on which the seat is mounted.

This system is currently available as standard equipment on Clark internal combustion engine lift trucks in the 2,000 through 10,000-lb. (1000-5000 kg.) rated capacities, as well as, the ECX and TMX. The system also may be retrofitted on Clark C500 and C300 trucks of similar capacities now in the field.

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The Clark Hip Restraint System

The new Clark Hip Restraint System is the result of Clark's continued commitment to safety. Following further design and testing, CLARK engineers have developed a second generation operator restraint system for older vintage Clark forklifts. Phase II of the Clark retrofit program is directed toward older, internal combustion trucks. This release addresses the system, the model trucks for which the system has been designed and instructions for the system.

We encourage you to advise your qualifying users of the availability, and to contact your Clark dealer for more information of this safety innovation.

Operator Restraint System for Electric Models

Through continuing engineering and safety innovation, the Clark ECX and TMX now incorporate the Operator Restraint System.

The ECX series forklift was designed to replace the ECS model. The TMX is the successor to the TM. As a result of Clarkcontinued commitment to safety and design innovation, the ECX and TMX forklifts have been designed to incorporate the Clark patented Operator Restraint System.

CLARK Safety Seats

The Safety Seat, pioneered by Clark, has long been proven effective in reducing operator injuries in a lateral tipover accident. Clark believes the Safety Seat is superior to that of other manufacturer's designs.

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Seats, restraints and seat belts are available for internal combustion and newer electric products.

Seats and seat belts are available for electric products prior to the ECX.

Standard Features

Seats, restraints and seat belts are available for internal combustion and newer electric products.

Seats and seat belts are available for electric products prior to the ECX.

Standard Features

  • 6 inch (152 mm) of fore/aft travel
  • Variable rate suspension
  • Atwood seat tracks
  • Operator weight adjusts from 100-270 lbs.(45-123 kg.)
  • Back angle is adjustable from 5 degrees to 15 degrees
  • Adjustable lumbar support
  • Ergonomically styled cushions with incorporated bolsters
  • Full-length polypropylene back cover with built-in manual holder
  • Non-cinching seat belt with retractor

Available Features

  • Cloth cushion
  • Seat switch shutdown

lateral Restraints

  • 1832444 - Lateral safety restraint
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Seat Belt

  • 2813876 - Universal retractor seat belt


  • 2813105 - Static, vinyl
  • 2813106 - Static, cloth
  • 2813107 - Static, cloth, switch

Suspension Seats

  • 2813108 - Suspension, vinyl
  • 2813109 - Suspension, cloth
  • 2813110 - Suspension, cloth, switch

Contact your Clark dealer.