Trailer Drop Problem and Solution

Johnson Equipment Corporation continues to lead the industry with breakthrough product innovations that address critical safety and productivity issues at the loading dock. 

Trailer Movement

  • Trailer bed can drop 4-8" with the weight of a forklift during loading/unloading.
  • Majority of trucks have air-ride suspensions - compounds the effects of trailer drop.
  • Linkage nature of air-ride suspensions is to move forward, causing trailer separation or "dock walk."
  • Catastrophic trailer separation accidents can occur when trailers are not properly secured to the dock.

Problems caused by Trailer Drop:

  • Worker back and neck injuries.
  • Forklift operator muscle fatigue.
  • Product damage.
  • Damage to equipment, including forklift and walkie wheels, dock seals and bumpers.


Solution: STR-4100 Dok-Lok Vehicle Restraint part of the Smooth Transition Dok System :

  • Stabilizes the trailer, using durable hydraulic cylinders to minimize trailer drop to 1-2".
  • Provides a smooth transition onto truck.
  • Reduces jolts to forklift operators during loading/unloading, helping to prevent injuries.
  • Minimizes product and equipment damage.
  • Helps prevent catastrophic trailer separation accidents, including: unscheduled departure, dock walk/trailer creep, trailer tip over, trailer pop up, trailer upending, landing gear collapse.


With the trailer stabilized, the leveler and trailer bed form a straight path for minimal impact and smooth transition. For the ultimate protection for your forklift operators, product and equipment, use the Smooth Dok Transition Systemby Johnson Equipment.