What does TPWS stand for?
TPWS (Train Protection and Warning System) and AWS (Automatic Warning System).
What is the difference between AWS and TPWS?
TPWS comprises of OSS (Overspeed Sensor System) and TSS (Train Stop System). AWS gives train drivers an audible and visual indication of the status of the signal ahead. If the driver does not acknowledge the indication of a caution signal the AWS system automatically applies the vehicles emergency brakes.
What is AWS in railway?
The Automatic Warning System (AWS) was introduced in the 1950s in the United Kingdom to provide a train driver with an audible warning and visual reminder that they were approaching a distant signal at caution.
What does SPAD stand for train?
passed at danger
A signal is passed at danger (SPAD) when a train passes a stop signal when not allowed to do so. SPADs are one of the potential precursors to railway accidents. Since the train protection and warning system (TPWS) was introduced serious SPAD incidents and the risk arising from SPADs have been greatly reduced.
Where is TPWS used?
The Train Protection & Warning System (TPWS) is a train protection system used throughout the UK passenger main-line railway network, and in Victoria, Australia.
Is TPWS Fail Safe?
Equipment Failure TPWS equipment cannot therefore be considered as ‘failsafe’. The absence of a light indicates that there is a fault either with the TPWS equipment or with the indicator itself. The driver will advise the signalman of the fault.
What is an AWS magnet?
A permanent magnet, used to test the operation of a train’s AWS equipment, may be provided at the exit of certain maintenance depots. Portable magnet. Portable AWS magnets are provided to give a warning to the driver, on the approach to temporary and emergency speed restrictions.
What happens if a train runs a red light?
If the red lights are flashing at a railroad crossing all vehicles are required to stop even if a train is not in sight. After stopping, drivers should not proceed across the railroad tracks until it’s safe to do so. Trains very often are moving faster than they appear to be.
How does a TPWS work?
When the train’s TPWS receiver passes over the first loop a timer begins to count down. If the second loop is passed before the timer has reached zero, the TPWS will activate. These are end to end, and thus will initiate a brake application on a train about to pass a signal at danger regardless of speed.
What speed do you pass a yellow aspect?
70-80
The next aspect will always be yellow unless it changes as more of the train’s route is clear. An unofficial advised speed past this signal is 70-80.