High speed 4 wheel vehicle suspension developments
|In the mid-1960's fundamental research was being
undertaken by R&DD at the RTC into the action of wheel on rail and the role of
The suspension fitted to the majority of the four-wheel goods wagons of the period dated back to Victorian times and whilst it was acceptable for the rough and tumble of the steam railway and the slow speed trains which were the norm, with the advent of diesel and electric traction the limitation in speed of this primitive suspension was all to obvious.
Although there had been some new designs based on UIC standards in Europe i.e. friction link, double link and long link, these all relied on leaf springs for their vertical control and the friction in the links for lateral control. When the links were new and unworn their friction had a damping effect on lateral oscillation, but as the links wore so the damping effect decreased. Oiling or greasing the links would similarly reduce the friction and hence increase the tendency towards lateral oscillation.
All photos are the Author's unless otherwise indicated
|Conventional leaf spring suspension - CCT|
|UIC double link suspension - COV-AB|
There were numerous derailments of these vehicles mostly due to bad riding characteristics, in particular the Palvans were notorious (and 100 of them were fitted with UIC long-link suspension in 1966) as were the Cemflo cement wagons (see below) and the Blue Spot fish vans, but the mechanism of instability leading to derailment was not really understood.
|The result of a Palvan
derailment near Rugby Central in 1961
With the completion of the RTC at Derby in 1964, various engineers were brought together and began to address these problems in a scientific way. The instability of the vehicles brought about by the higher running speeds was investigated and a one-fifth scale model of a four-wheeled vehicle with a novel suspension was built and tested on a similar-sized roller rig. The suspension allowed lateral and yaw flexibility between the wheelset and the frame for the first time and incorporated lateral hydraulic damping.
Following these successful experiments, a full-sized
version of the roller rig was constructed and in 1966 the
four-wheel High Speed Freight Vehicle (HSFV1) was completed. This proved to be stable at up to
140 mile/h when tested on the roller rig.
This concept was the fore-runner of the railbus chassis, but more importantly results from various tests with HSFV1 allowed the wheel/rail interface to be better understood and this played a major role in the development of high speed operations leading to the design and build of the experimental Advanced Passenger Train (APT-E).
|Inside the Advanced Projects
Laboratory showing an APT-E bogie on a roller rig
|HSFV1 in the yard at the RTC in
the 1980's in its original rail blue livery
|An earlier view of the Advanced
Projects Lab and the roller rigs in the pit. It was on these rigs that the
HSFV1 was tested
|HSFV1 in the yard at the RTC in March 2005|
|Still retaining its original owner's name||A close up of the revolutionary suspension|
|The Leyland Experimental Vehicle used a similar suspension - pictured on the NNR on 11th July 2009|
|Cemflo fitted with HSFV3
suspension in the yard at RTC around 1970
|A close up of the suspension
All photos are British Rail unless otherwise indicated
|HSFV4 at the Old Dalby test track in the mid-1970's. Note the handrail for the roof access ladder projecting from the roof.||HSFV4 on a test train at
Llanwrst on the Conway valley line - HSFV1 is on the rear - October 1976
|HSFV4 at the Old Dalby test track used as an auxiliary test vehicle for static OHLE testing pictured on an overnight test c1977.||HSFV4 in the company of the
Drewry Car at the top of the Widmerpool straight at the Old Dalby test track
in the summer of 1980. Note the logo 'Auxiliary Testing Vehicle (HSFV4)'
|A view of HSFV1 and Lab One taken from the roof of HSFV4 at the Old Dalby test track in the mid-1970's||At the RTC in its later Research
livery in February 1983. Note the corner of HSFV1 on the left and the
maximum speed of 90 mph!
|HSFV4 at the Eden Valley Railway
on 25th February 2006 looking a bit worse for wear. From its livery it would
appear to have spent some time with the S&T's 'Satlink' fleet. For more
info on its present state and its post-R&DD history look
HSFV4 was still extant at the Eden Valley Railway in February 2006 where it is to be restored to its former glory.
* Modern Railways -September 1976, 'Taperlite: a new suspension for air-braked freight wagons', pages 342, 343.
Other developments in 4-wheel wagon suspensions
|BSC pedestal suspension
P Garland collection
Gloucester Floating Axle suspension
More will be added as time permits
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