Author's Collection
Author's Collection
Author's Collection
Derailment Detection Device
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At the end of 1974 the line was used to demonstrate a 'derailment detection device'. This was thought necessary since a large number of 4-wheeled vacuum braked wagons were still in use on BR and derailments were not uncommon. If after derailment the brake pipe remained complete, the derailed wagons could run for miles damaging the track and often the loco crew didn't even know they had a derailed wagon, the power of the modern diesels was unaffected by the extra drag. The device was connected to the braking system and consisted of one ceramic pipe above the vehicle's leaf springs and one attached to the axlebox. When the vehicle de-railed the gap above the spring was closed thereby breaking the element and venting the brake pipe, alternatively the one on the axlebox would come into contact with the rail head. Although successfully tested by deliberately de-railing a van the system was not really a practical proposition and was never developed any further. |
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The devices are shown attached
to the suspension of a 10ft wheelbase 'Vanfit'. The white parts are the
frangible elements, one between the spring buckle and the solebar and the
other placed so as to break when it came into contact with the rail. All a
bit unbelievable after 40 years
Author's Collection |
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The switch was designed such
that when a bar fixed to the leading wagon came into contact with the
lever it would open thereby derailing the trailing wheelset. It worked!
Author's Collection |
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The aftermath: The van derailed
and the brake pipe vented. All filmed from the train and from the
trackside.
Author's Collection |
