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Stations, Junctions, etc
Engine Sheds
Other
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Miscellaneous: Operating Equipment & Practices
Maintenance of the Permanent Way: misc_equip247
Photograph of a Hallade Recorder and an extract from a
London Midland and Scottish Railway handbook (dated 1934), which describes the
instrument and details how the Hallade Recorder was to be used.
The photograph shows at the bottom left, the clockwork
spring mechanism that powered a chain drive. Above this are two rolls, the
lower of which contains the chart paper and the other carbon paper. The
recording needles press on the carbon paper which leaves a trace on the chart
paper below. Three needles are attached to the pendulums on the right, each of
which can move in one direction allowing transverse, horizontal and vertical
movement to be recorded as separate lines. A fourth needle was operated
remotely by an air pressure switch and this was used by a spotter to add
location markers to the chart paper. On the Great Western Railway a fifth
needle recorded the operation of the Whitewash device. The Hallade Recorder was
protected in a robust case and positioned at the most sensitive location, which
was normally directly over a coach bogie.
Robert Ferris
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