Interlocking

Still key to high-tech systems

In and around traincare depots, where a momentary lapse of concentration or small error of judgement can have dire consequences, properly engineered solutions can play a major part in protecting personnel and equipment. Engineers at zonegreen have applied the concept of interlocking, long familiar in the rail industry, to create increasingly sophisticated systems with the potential to prevent personal injury or costly damage. These systems can prevent unauthorised train movements or other actions initiated by personnel who have not followed the stipulated safety procedures or precautions.

One important example of interlocking deployed within a traincare depot is the zonegreen system that physically prevents access to high-level working platforms while overhead line equipment remains live. The gate to the platforms may only be opened with a key that cannot be withdrawn from a control panel until the OLE has been safely isolated and earthed. The zonegreen system includes provision for the safe installation and removal of manual earthing clips on OLE and can deal with risks associated with bridging of sectional isolators by trains employing two pantographs or multiple third-rail pick-up shoes.