High Speed Current Collection Project
The High Speed Current Collection Project trials, from which the now widely-used BR/Brecknell, Willis High Speed pantograph was developed, were conducted at the test track between 1973 and 1982. The principle of the trials was to validate, by experiment, the predictions of a computer program, which modelled the overhead and pantograph as a complete system of masses, springs, struts and ties etc. |
OHLE The overhead line at Old Dalby was originally constructed in 1973 with five tension lengths, two of which were devoted to 'scaled' equipment, having half the normal mast spacing and twice the usual contact wire mass. The contact and catenary wires consisted, in fact, of wire rope approx. 20mm diameter. The dynamics were such that running over this equipment represented normal running at twice the train's speed over conventional equipment. The remainder of the system replicated the equipment in use on BR at the time i.e. Mk3B with a complete neutral section installed at Widmerpool. This was used for high speed, close-up filming of various types of pantographs at speed, in order to determine the pantograph's behaviour whilst traversing the NS, which was effectively a 'hard spot' on the system. Various designs of NS were also trialled in this way. Although the OHLE was erected primarily for the Electrification Section of the R&DD for trials with a servo-assisted pantograph and development of high speed neutral sections, section insulators etc, by the late 1970's the Dynamics Section were casting glances towards this facility. The potential offered by the BR/Brecknell Willis pantograph in the furtherance of studies into modelling the interaction between pantograph and OHLE meant that the Electrification boys took second place at the test track. |
Pantographs Static and dynamic tests were carried out over a number of years at the test track, during which time various experimental pantographs were constructed, modified and discarded. As with all projects there was a great deal of preliminary work carried out before the final developments. This project commenced by utilising the existing pantographs which were in use on BR at the time. Examples of both the Faiveley AMBR and the AEI Cross Arm pantographs were acquired and subsequently modified with an additional top frame etc. but found eventually to be unsuitable. However with the assistance of Brecknell, Willis and Company the final pantograph, which was developed as a result, proved to be a world-beater and can be seen in places as diverse as the USA, Taipei and Bletchley Depot. A potted history of its development and its ups and downs is included on the Brecknell Willis highspeed pantograph page on my train testing web site. A variation is now fitted to the Pendolino. Here are some pictures of the various works undertaken on this Project - click on the picture for a bigger image. |
Static Tests
Dynamic Tests
Later testing
With the completion of the HSCC Project the overhead
equipment part of the test track was used for aerodynamic testing as well as
some development work by the Electrification Section with servo-assisted
pantographs and high speed neutral sections. In connection with this a class 87 loco was utilised and rumour had it that the pantograph was not successfully lowered at the end of the test run resulting in it striking an over bridge. However I cannot vouch for this story! |
87005 'City of London' with the BR/Brecknell Willis highspeed pantograph. It is rumoured that a test with another Class 87 resulted in its pan striking an overbridge |
Re-building and Maintenance
Over the latter years of the HSCCP test programme from 1978-83 the scaled overhead equipment was re-built several times to represent different types of equipment, i.e. trolley wire (a single contact wire only), stitched equipment (as used extensively on the high speed lines in France) and Mk4 equipment (with higher tension in the cables). Representative bridge and level crossing wire gradients were also included in the 'scaled' equipment. To accomplish this a Drewry Car self-propelled overhead line maintenance vehicle was acquired from the Eastern Region in 1977/78. It had been one of a small class of vehicles used extensively on the former Manchester, Sheffield, Wath DC lines and also on the GE and was restored and modified in the workshop at the RTC for use at Old Dalby. Two Drewry Cars were acquired by R & D - one was used as spares. Equipment consisted of an hydraulic access tower which could be raised and lowered as required. This was original equipment onto which was mounted a new solid timber platform which was capable of extending either side in order to access the fittings on the masts. The hydraulically operated tower had an access ladder attached which rose and fell accordingly. This was adjacent to the steps at the rear of the vehicle and could be dangerous if one didn't watch where ones feet were as the ladder descended. Luckily we never had any accidents of this sort when I was involved Creature comforts included a small gas cooker mounted on one end of the workbench and a couple of gas heaters mounted on the wall sides within the vehicle. Opposite the workbench was a bench type seat. When we needed 240v/110v for power tools I think we brought along a petrol generator and placed it on the rear platform A wooden extending ladder was mounted on supports on the outside of the vehicle for independent access to masts and contact wire. I well remember climbing the ladder to fit accelerometers to the centre of the spans - very disconcerting when you're up in the air 16 feet off the ground with nothing surrounding the ladder! |
Although two Drewry Cars were acquired by R & D and numbered RDB998900 and RDB998901 only one was modified for its new role. It was utilised for a number of years, and was even painted in the new colours of red & beige. However together with its mate it was eventually sold off to the EM2 Society as no longer being required. Today it has been restored to its Research Division livery and fitted with seating. |
A nice picture of both Drewry cars at Old Dalby on
5th November 1978 - note that RDB99800 which was not used still retains its BR
Green livery at this stage RCTS |
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The second Drewry Car RDB99800 which was acquired
for spares survived and in 1997 was sold along with its operational sister unit
to the EM2 Society. It is seen here on 1st August 1997 round the back at Old
Dalby showing not a little rust Note the novel single buffer on the buffer beam Ian Dobson |
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The operational Drewry Car RDB998901 is seen here on
1st August 1997 round the back of the compound and wearing the later R&DD livery
of beige and red. It had probably not been used for many a year when this photo
was taken Ian Dobson |
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DB988901 in BR green as running on the Middleton Railway in 2000. It was restored by the EM2 Society. Their site gives more details of its restoration with numerous photos David Annable |
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The Drewry car back in the red and blue of the R&DD. The vehicle is now nicknamed 'Oliv', (Overhead Line Inspection Vehicle). For more information about the vehicle today click here Ian Dobson |