AWS (Automatic Warning System) is provided primarily to aid drivers in observing the fixed signals, particularly under adverse weather conditions, and is supplementary to the fixed signals, which the driver must observe. Although supplementary, its correct operation is of the highest importance since any confliction between the fixed signal and the AWS indications will confuse drivers.
The equipment in the track consists of a protective ramp preceding a Permanent Inductor (AWS3) and an Electro Inductor (AWS1). The Permanent Inductor has its North Pole uppermost and this magnetic field by itself gives a “caution” indication to the driver. The Electro Inductor (AWS1), when energised, has its South Pole uppermost and this South Pole following the North Pole of the permanent inductor gives a “Clear” indication to the driver.
On bi-directional lines, special permanent inductors called Suppressor Inductors (AWS2) may be used to prevent a train receiving A.W.S. indications at a signal for the opposite direction to which the train is travelling. These inductors have a permanent inductor and, in addition, a suppressing coil which, when energised, diverts the magnetic flux, suppressing any indication to the train.
- Low profile design suitable for installation on Slab Track or Sleepers
- High strength enclosure machined from solid aluminium block
- 100% compatible with imported units – same footprint and
- internal specification
- Replaceable vibration mounts
- UV stable cable sheath
- Watertight – internals encapsulated in 3M re-enterable gel
- Water-proof sealant
- Powder coated
- Corrosion protected
- No ballast removal required
- No post-production modifications required
- Low maintenance costs