Keywords: leg safe safety legs legsafe
Landing Leg Safety System
The "dropping" of a trailer is caused by drivers failing to lower the landing legs during the de-coupling process; often when tired or distracted. The result is that the tractor pulls away and the front of the trailer drops a significant distance before the landing leg feet crash into the road/bay surface.
The consequences can be severe. Don-Bur carried out an assessment based on an average 26,500kgs load on a standard 13.7m long trailer. 8,050kgs of that is placed in front of the landing legs. If you allow a trailer to drop just 40mm before impact (The travel of landing legs is typically 250-300mm), the generated kinetic energy is equivalent to a weight of 64,356 kgs. Under such loads, the obvious consequence is damage to the road/bay surface, deformation of the landing leg feet and potential damage to the payload inside. What is perhaps less obvious, but arguably more serious, is the potential for warping and stress fractures in the trailer neck itself. Over time, this type of damage can require significant repairs and, gone unnoticed, could result in disastrous accidents.
The Don-Bur invention, "Leg-Safe" (Patent applied for), provides an elegant solution to this problem. When de-coupling, the system senses the position of the legs and warns the driver (visual and audible) that they have not been suitably lowered.
The system uses a minimum of just two sensors; one pressure sensor on the red emergency air line and one on the nearside landing leg, covered by a protective steel pressing. These sensors form the process logic. If the red airline has been disconnected, the system becomes 'live' and assesses the height of the landing leg. If the legs is not within 10mm of the ground surface, it triggers the alarms.
- Ensure legs are lowered before uncoupling
- Prevent trailer damage
- Prevent bay floor damage
- Enforce best practice and reduce heatlh & safety incidents
Additional sensors can be added to provide further benefit options:
- Ensure legs are lifted before transit
- Encourage correct coupling/uncoupling procedures