975634

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Your comments

• Ben Williams

  23 November 2004, 08:33:36

  This test train originally consisted of two mock Power cars (PC3 - RDB975634 and PC4 - RDB975635) with nothing (0) in between hence the nickname 'POP', it was used from September 1971 as a test bed proving the suspension, tilting and braking systems.

  Later the P-O-P train was modified with an APT-P vehicle (Laboratory 8 - 'PILOT' RDB975636) being built and formed between the original P-O-P vehicles, which were re-mounted on revised bogies and given body cladding.

  The three vehicle set then performed bogie and ride research work, mainly on the West Coast Main Line.

  Thanks to info from http://www.apt-p.com

• Kit Spackman

  9 July 2007, 16:20:35

  In its first gestation POP train was not skinned, being just a collection of steel tubes with ballast weights fitted to simulate the positions of the gas turbines etc in the APT-E structure. There was a small cabin in each vehicle to house the tilt and brake packs and some intrepid staff to look after them, usually me as well as anyone else I could con into doing it!

  As Ben points out, PC3 and PC4 were run back to back, originally with the RTC Unimog as traction power (!) and then with the last Class 17 Clayton. At first POP was fitted with Swinging Arm bogies in all three positions, later replaced by E1Ts, and later, as seen above, by two H4Xs and BT11 (I think...) articulated bogies.

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