LMW plus ride tests

Research Division Tests 1976 onwards

The author joined the Research Division of BR in 1974 working initially on derailment investigation.

Following internal changes, in 1976 I found myself working for the Dynamics Group looking at wheel/rail interface problems. This involved the deployment of one or more load measuring wheelsets (LMW).

The wheel set was very expensive as each spoked wheel was machined from a solid blank wheel and strain gauges were then attached to the spokes at pre-determined positions to measure vertical, lateral and longitudinal loads.

The output signals from the wheel passed through a set of slip rings mounted on each end of the axle. The signals from the vertical load circuit needed to be manipulated including part-inversion to give a steady output signal related to the wheel load. The other two aspects did not need such doctoring.

One test series I remember from October 1976, involved running on the Blaenau Ffestiniog branch line from Llandudno Junction through the beautiful Conway valley. The LMW's were fitted to the 4 wheeled test vehicle HSFV1 and the instrumentation was housed in Lab Coach 1. The ex-Ferry Van HSFV4 accompanied the tests and carried various spares and equipment, including hydraulic jacks for raising the wheel sets in order for them to have a 'no-load' calibration.

Here are some pictures of the tests undertaken.

Click on the picture for a bigger image - all photos are the author's unless otherwise credited

	In October 1976 the test train sits outside Llanwrst signal box behind 25255. The test engineers are attending to the calibration of the LMW's fitted to HSFV1 which is at the rear of the train beyond Lab Coach 1. The train will probably return to Llandudno Jcn. after the calibration results have been acquired.
	This is a Freightliner LMW during its construction, pictured on the calibration rig in the R&DD workshop. Note the wiring for the gauges (vertical, lateral and longitudinal) and the slip ring assembly glimpsed through the spokes. One can imagine that wheelsets such as this (machined from a solid wheel) can be very costly although R&DD made a small production line and the author spent a number of months attaching strain-gauges to these LMW's. BR Official
	One of the few remaining class 24 locos at the time poses in the sunshine at Llandudno Jcn in October 1976
I	A closer view of HSFV1 in the RTC yard - although not fitted here with LMW's. The suspension on this 4 wheeled vehicle was capable of 90 mile/h running and the vehicle's weight could be varied easily by the addition of rail packs - very useful when testing. D Bower

On another occasion in early 1977, the riding qualities of iron ore tippler wagons was investigated. This followed a number of derailments of these wagons on the line between Newcastle and Carlisle. The last vehicle of a loaded train was instrumented and monitored from a brake van on its journey from Redcar to Workington. Fortunately this one stayed on the rails.

	The view from the rear of the train at the Redcar sidings prior to departure
I	A wider view of the train shows the brake van which was specially marshalled to carry the test staff and instruments.
	Inside the brake van.
	The view from the brake whilst passing through Wylam station on the Newcastle to Carlisle line
	Accelerometers mounted on the end of the trailing tippler wagon.
	A view showing the test vehicle and brake van at the end of the train

More pictures will be added as time permits

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