OSHA COMPLIANCE ADVISORY

“Raised Cab” LockOut Procedures for Fire Shops Mechanics

Cal/OSHA requires that employees whose job duties include performing repairs on equipment be familiar with methods to “Lock Out” potentially hazardous forms of energy. While energized equipment poses the most obvious danger, many forms of energy – including the force of gravity – exist in the workplace. The following information has been prepared to alert Department mechanics of a recent fatality, outlining required safety measures for working under the raised cab of fire apparatus.

Incident:

Last month, a mechanic at Johnson Power Systems in Riverside, California was working under the raised cab of a fire truck which fell, pinning him against the truck’s tire. The incident was not witnessed by other employees, who later discovered him. Efforts to revive him were unsuccessful.

Analysis:

Hydraulic systems, such as that which elevates the cab, can fail or be deactivated during repair operations, allowing the cab to fall, often with disastrous results. For this reason, mechanics are required to manually install ‘Lock Out’ devices to secure the cab in place, preventing serious injury.

This incident also points out the importance of the ‘buddy system’ in avoiding tragedy. Those who work around heavy equipment and machinery need to be aware of facility operations at all times – including others working in the area. Fire Shops mechanics should always be prepared to lend a hand at the first sign of trouble.

A life may depend on it.

Procedure:

This notice is to review the design features developed by Manufacturers for securing the raised cab while working on apparatus. Additionally, Department procedures require that Fire Shops employees install a “lock bar” before putting their head “into the lion’s mouth.”

Lock Bars

Fire Shops’ procedures require that a Lock Bar (pictured, in circle,) be put into place before performing repairs which require that mechanics work under the raised cab of apparatus.

Once the cab has been raised and secured using the built-in restraints (See following descriptions.) the lock bar is to be installed using the cab’s securing blocks (pictured) and tightened using the ‘T’ handle until it is wedged securely between the upper and lower anchor points. The locking bar is to be installed for all ‘raised cab’ operations.

Lower Anchor Point Upper Anchor Point

When work is completed, the lock bar is removed by rotating the ‘T’ handle until the bar’s ends are clear of the anchor points.

Manufacturer’s ‘Raised Cab’ Restraints

KME (1993, 1995, 1998)

Cab is raised using controller for truck’s “Cab Jack” hydraulic system (pictured). When the cab reaches maximum height, the restraints must be manually engaged by turning and pulling handle (in photo, to left of corded wire) which lowers the restraining bar in place. When repairs are complete, the cab is raised and the restraints are retracted and by turning handle and pushing – according to the instructions posted inside the compartment for the Cab Jack controls.

KME (2006)

Similar to previous models, but with second locking arm that must be lowered into place by hand. When repairs are complete, the manual arm must be raised and secured.

Other Methods

Other brands of fire apparatus require different measures to secure the cab in an upright position. One method requires that “collars” be installed on the hydraulic pistons, which prohibit the cab from falling.

Restraining collars are heavy-walled pipe, split lengthwise (inset) and secured around the piston (see photo) by raising the cab to its full height and installed on both hydraulic pistons. The restraints prevent the cylinders from retracting, allowing work to be safely performed beneath the raised cab.

Once the collars are installed, the additional measure of installing a lock bar ensures that the cab will remain elevated while work is being performed. Restraints are removed by raising the cab using the lock bar or “Cab Jack,” and removing the pins. The lock bar then can be removed and the cab lowered.

Remember: Cal/OSHA and Department procedures require that these measures be put into place and tested before any work is performed under the raised cab of fire apparatus.

Additional information and training is available. Contact Capt. Duran or Blaise Grock in the Safety Office for assistance.