POP train
This test train originally consisted of
two skeletal cars (PC3 - RDB975634 and PC4 - RDB975635) each having one mock
up power bogie (P) and connected with an un-powered articulated trailer bogie
(O) in between hence the nickname 'P-O-P'.
It was used from September 1971 as a test bed to prove the APT-E suspension, tilting and braking systems. The 'Power pumps' were only mock-ups, although similar externally to PC1 and PC2 in the APT-E unit minus cabs, and the whole set had to be hauled by a locomotive. Later the P-O-P train was modified with an APT-P vehicle (Laboratory 8 - 'PILOT' RDB975636) being built and formed between the original two vehicles, which were re-mounted on revised articulated bogies and given body cladding. The three vehicle set then performed bogie and ride research work, mainly on the West Coast Main Line. Following the abandonment of the APT project, all three vehicles were scrapped in 1985. The set was eventually formed as follows:
A great deal of testing was carried out at the test track in connection with the APT development programme using POP train. On 10th January 1973 a test train heading north on the test track 'ran out of road' whilst carrying out a high speed test with the 'POP' train and finished up 'on the floor'. Rumour had it that the brakes on the 'Peak' were incorrectly adjusted and the decision to apply the brakes was left until the last second and the arrester bed was devoid of polystyrene having been widely distributed during a planned test with a well wagon previously. |
For more information and pictures look here
Pictures courtesy of Kit Spackman except where otherwise credited
Main line runs