Trailer jacks

Place trailer jacks imder the front end of a trailer if the tractor is not attached. 

Figure 28 Rack <5 pinion trailer jack used to raise and lower platen. 

Figure 41 Normal rack <4 pinion style trailer jack before it has been modified.

Figure 42 Trailer jack after first modification. The jade shaft has been turned end for end. Lock pin hole for trailer vdieel is located at the top.

According to 1910.178(k)(3), you may need to use fixed jacks to support a semitrailer and prevent upending dming the loading or unloading when the trailer is not coupled to a tractor. 

A lighter weight pallet jack may have to be used to load or unload trailers if floor conditions warrant that the heavier lift truck stay out of the trailer. 

The operator should inspect the floor of the truck or trailer to make sure that it is safe. Check for any weak, rotten, or otherwise unsafe areas. If any are found, the forklift should not be driven onto it. Instead, a pallet jack may have to be used to load or unload these vehicles. 

Thank you for your letter of September 13, 2007, to the Occupational Safety and Health Administration s (OSHA s) regional office in Atlanta, Georgia. Your letter has been forwarded to OSHA s Directorate of Enforcement Programs (DEP). You had a question concerning OSHA s Powered industrial trucks standard, 29 CFR 1910.178, and the use of jack stands in the stabilization of semi-trailers. Your paraphrased question and our response follow. 

Question Are two jack stands, placed one on each side of the uncoupled end of a semitrailer, sufficient to support the trailer and prevent it from upending during loading and unloading using powered industrial trucks Is one jack stand placed in the middle of the uncoupled trailer sufficient ... 

The brakes of highway trucks must be set and wheel chocks placed vmder the rear wheels to prevent the movement of trucks, trailers, or railroad cars while loading or unloading. Fixed jacks may be necessary to support a semitrailer during loading or unloading when the trailer is not coupled to a tractor. The flooring of trucks, trailers, and railroad cars must be checked for breaks and weakness before they are driven onto. 

Are fixed jacks used under semi-trailers ... 

An added measure of security for trailer safety is the positioning of jacks under the nose of the trailer. Landing wheels of trailers have been known to fail, which allows the trailer to tip nose-down at the dock. Trailer occupants could be injured by this incident. 

Trailers, railcars, and dockboards (including the use of wheel chocks, jacks, and other securing devices)... 

Inspect truck trailers before entering. Pallet jacks are heavier than they look and combined with a load can fall through a worn floor. 

We discussed the platen jack at the beginning of the book. It is simply a trailer tongue Jack that is modified for our purpose. It must be the rack and pinion type with the inside of the Jack shaft being hollow. 

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