TPWS testing

Initial trials with the Train Protection and Warning System (TPWS) took place at the Old Dalby test track utilising the single car test vehicle Iris 1.

Later trials were undertaken using the dual voltage class 319 units as the two selected installations were on AC and DC lines on the route between Bedford and Brighton - later known as 'Thameslink'.

The AC test site was between Luton and Harpenden and the DC site was at Three Bridges. Several trials were carried out south of Luton on the Up Slow lines running at red signals. The test train was made available from Bedford. The 'Tomorrow's World' team also visited the trails which usually took place on a Sunday morning under a total track possession.

The TPWS and further AWS trials took place on the route and also on the Sutton Loop line and the train was based at Selhurst depot. I remember finishing the tests about 3 am and sleeping in the train in the depot sidings until the first service train on the Sunday morning.

Old Dalby Iris 1 pictured at Grimston on the Old Dalby test track. The TPWS tests were undertaken in the Widmerpool station area
RTC The class 319 was used for a the first trials for the TPWS system.

Author's collection

During 2002 numerous on-track testing of the newly introduced system was undertaken mainly to verify the use of the TPWS equipment on the numerous different types of traction in UK.

The testing was done overnight in a T(iii) possession and at the selected site temporary loops were installed in the track (this was before the final design of the GRP grid). A short test programme using the specific type of traction was undertaken including stop signal and speed trap tests. The experimental loops were capable of being configured as train warning or train stop. 

Work was mostly undertaken at Brentwood (on the Liverpool Street to Shenfield route) and Knockholt (on Boat Train Route1) but we also went to Micheldever (between Basingstoke and Winchester) and Biggleswade (On the ECML)

Tests were carried out on the stock in the pictures:

Click on the picture for a bigger image - photos are the author's unless otherwise credited

The Class 91 was tested at Biggleswade DVT The Mk4 DVT was also tested at Biggleswade
321 The class 321 was tested at Knockholt in the summer 365 The class 365 was tested at Knockholt in the summer

Author's collection

Class 411 was tested at Knockholt in the summer 442 The Class 442 was tested at Micheldever in January and it was freezing!

Further high speed tests (TPWS-plus) were carried out on a Class 91 and IC225 set at Doncaster

More info will be added.

If you would like to know more about train protection systems on the British railway system have a look here


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