Holding Devices

The retarders were designed to slow down or hold a train preventing run back, derailments, when uncoupled from the locomotive. When the locomotive is uncoupled from the coaches there is a major safety risk of the train creeping in the direction of the gradient which gains momentum and normally ends up in a fatality like the Ravos rail recently and an incident at RBCT Richards Bay.

The retarders are strategically positioned in areas typically at shunting yards, tipplers and where the operation is reliant on external equipment like charges typically at tippler areas where the loco is disconnected from the line of trucks that would need to be unloaded at a tipping operation. Once the Loco is removed the train trucks need to be held in place for the tipping motion to take place this is where the retarders are activated securing the train from possible run back and forward movement. The securing of the trucks also prevents the misalignment of the trains entering the tippler areas and the truck is tipped and secured with one motion in a controlled manner.

  • The retarders have to be designed to hold trucks once uncoupled from the loco
  • The retarders have the ability to slow down trucks entering in a controlled area
  • The retarders are environmentally friendly NO oil activated retarders will be placed in operation where the possibility of contamination can take place    
  • The retarders are activated by air pressure only
  • They are activated by air and spring returned
  • The sealing arrangements can withstand condensation and temperatures up to 60 degrees  
  • The sealing arrangement will be of silicon fibre design
  • The installation must be done by trained technicians
  • The air supply to the retarder pots must be supplied by a reciprocating compressor @ 14 bar
  • The air supply must be passed through a Dryer and refrigerator supplying a 14 bar pressure with ambient temp at 25deg,relative humidity @ 100% and compressor discharge @35%
  • Pipe work including pilot lines and couplers are all supplied stainless steel
  • All operating air control manifolds are of aluminium construction
  • Retarders are encased in stainless steel boxes to protect and prevent contamination.