C T Gifford
Note the grille over the windscreen of the loco and the ex-LMS Dynamometer car (now known as Test Car 3) and a couple of Mk1 coaches in the train
Authors collection
Authors collection
High speed testing on WCML in the 70's
|
In late 1970 and early 1971, a series of high speed tests was undertaken using the first Class 86 locomotive to be fitted with 'Flexicoil' suspension. The trials took place at Cheddington on the WCML and the loco, affectionately known as 'Zebedee' after a spring-mounted puppet in the popular 'Magic Roundabout' children's programme of the time, was tested with and without a glass-fibre nose cone during the series to assess its aerodynamic affect. The tests were also used to check turbulence caused by trains passing at 125 mile/h and to assess the high speed riding qualities of the then new 'DOC2' bogie fitted to a Mk2 coach No:E5625. This was the forerunner of the BT10 Mk3 bogie. Our train was hauled by E3173 'Zebedee' with Test Car 4 and E5625 and was confined to the Down line. The train would start its test run just to the south of Linslade Tunnel and the southbound train would start from Leighton Buzzard. At a pre-arranged and synchronised signal both trains would start off and run at controlled speeds to ensure as far as practicable that the trains passed just to the North of Cheddington station. As far as I remember, the other train was hauled by a Deltic class locomotive with another short formation. There was a specially installed 'dipped joint' in the Up fast line just north of the station where vertical track force measurements were recorded as the Deltic passed at high speed. Aerodynamic probes were also installed on the trains and alongside the track to measure the effects of turbulence inside and outside the trains. Total possession of the Up and Down Fast lines was taken on three consecutive Sunday mornings between Leighton Buzzard and Tring for the purpose of the testing to allow the trains concerned to set back 'wrong road' to the starting positions after each run. I remember that we were based at Bletchley depot and had to leave there at around 05.30 on the Sunday morning. We had breakfast on the Test Car but at lunchtime the trains would stop and set back to Cheddington where food was especially provided and served in the Down platform waiting room. It was during these tests that Test Car 4 (a GWR Hawksworth coach with GW bogies and plain bearings) was hauled at 130 mile/h! |
Click on the picture for a bigger image - photos are the author's unless otherwise indicated
|
|
E3173 is pictured near Tring in
an earlier test series in October 1970, when it was fitted with the
streamlined nose cone.
C T Gifford |
|
|
One of the test
trains stabled at Bletchley depot with E3173 - this is probably from early
1971. The author was not involved with these particular tests.
Note the grille over the windscreen of the loco and the ex-LMS Dynamometer car (now known as Test Car 3) and a couple of Mk1 coaches in the train Authors collection |
|
|
The instrumented
Faiveley pantograph on E3173 viewed from inside the depot at Bletchley on an
early test in 1971 - how this monstrous pantograph behaved at 125 mile/h is
lost in the mists of time! Authors collection |
|
|
In this very poor quality picture (Boots slide film) the Mk2 coach E5625 fitted with the prototype Mk3 bogies is shown in the Down Fast platform at Cheddington. Note the wasp stripe rear door cover with air horn on the top and the viewing window all of which were fitted to facilitate propelling during the tests. |
|
|
This shot looking back from the test train on the Down Fast shows Cheddington station with all lines occupied. Normal traffic is confined to the Slow lines and the other test train is still in the Up Fast platform. |