Memories of working on APT

Dave Coxon

Trialling the Highspeed pantograph on APT-P

We in the R&DD had always maintained that the BR/Brecknell Willis pantograph was much better than the Faiveley derivative that was originally fitted to the APT-P, although this pantograph did have some plus points. It was fitted to the train when it attained 163 mile/h during tests on December 20th 1979 but later was to disgrace itself by striking a registration arm on the WCML near Blisworth due to excessive uplift and we saw the opportunity to fit our pantograph to an APT set for evaluation in the summer of 1980.

It meant Brecknell Willis designing and manufacturing a new base frame for the  APT-P mounting insulators but this was duly completed by our colleagues in Chard and we shipped the pan up to Glasgow in the summer of 1983.

APT-P BW highspeed

I travelled up to Glasgow by train with a technician from the workshop, who took his toolbox too. Imagine - travelling all the way by train then having to carry this big heavy toolbox between us from Pollokshields East station to Shields depot, about a mile. Today of course it would be thrown in a van and we’d drive up to Glasgow.

Once we arrived at the depot we encountered a problem in that one of the compressors on the power car had failed and this needed to be replaced. The problem was that it required access beneath the pantograph platform to enable the compressor to be removed. This was after we had struggled to persuade the shift manager to bring the train in the shop to fit our pan. To speed things up we assisted in removing and replacing the defective compressor following which we fitted our pantograph. Another long day I remember.

Whilst based on Glasgow Shields depot we stayed at the nearby Dalmeny Hotel whilst one of the Project team was rumoured to be camping out in Maxwell Park – I don’t know how true these tales were. The overriding memory from the Dalmeny was cold tomatoes for breakfast. We would later see the light and move around the corner to the Sherbrooke Castle hotel, a much more up market establishment with 5 course meals and a turret bedroom.

The Sherbrooke Castle was a magnificent baronial building crafted in rich red sandstone and set in beautifully landscaped gardens.

I have fond memories of Glasgow in the early 1980’s. Walking down to the local pub (the Four Feathers) and sometimes travelling into Glasgow on the ‘Clockwork Orange’ underground. Consuming curries in Queens Park, drinking Shipstone’s beer in the Bon Accord in North Street.

We were involved in quite a few tests with ‘our’ APT set and well remember having a ride up front in the cab footplate ride on the way back from Carlisle to Shields on one occasion. Our colleagues in the DM&EE Testing Section were conducting numerous tests on the train and I often found myself chatting to former work mates. I recollect walking through the train when various vehicles were suffering with tilt failure and having to leap through the corridor connection from one coach to the next which would be on the slant.

I remember stopping in a B&B in Carlisle when the train was stabled at Kingmoor depot and we had to rise at some unearthly hour with no breakfast – or sometimes cornflakes were left out for us. I remember we were stabled in the Up side loop opposite the depot but can’t recollect when or what tests were being undertaken.

We worked closely with our R&D colleagues from the Electrification Section and also the local CM&EE Electrical Engineer who had a fearsome reputation for flying off the handle. However, once you got to know him he was a decent chap.

We first undertook aerodynamic tests under the wire to ‘tune’ the pantograph to the roof of the APT with the train based at Polmadie depot in October 1983.

The BR/Brecknell Willis Highspeed pantograph was equipped with aerofoils, which were attached either side of the top frame in order to increase the uplift force in one direction. These could be adjusted to suit the type of traction unit on which the pantograph was operating.

The pantograph was raised in the normal manner but restrained below the contact wire by the use of two cables between each carbon carrier on the head of the pan and the base frame. Attached in-line with these cables were load cells, which allowed the uplift in each carrier to be measured. When the APT ran at high speed any increase in uplift force due to the aerodynamic effect could be measured. The aerofoil angle could then be adjusted as necessary to get the best performance from the pantograph.

By careful design of the individual items which made up the pantograph head and frame these effects could be countered or minimised. In the UK, excessive uplift force can lift the contact wire and in extreme cases the pantograph head can come into contact with the registration arms resulting in damage to both the pantograph and the OHLE and in a possible dewirement.

Tests of this nature were usually conducted off the wire but on these we used the same principle beneath live OHLE, with a second power car providing propulsion!

Runs to Carlisle or Beattock were usually undertaken to enable the pantograph to be tuned to the smooth aerodynamic profile of the power cars. It was found that the angle at which the aerofoils required to be set differently from that on used the class 86 and 87 locomotives, which was what we had anticipated.

Polmadie depot was a very interesting place in those days. Across the tracks in Rutherglen were some notorious flats whose occupants were frequently known to cross the tracks to get into Polmadie and strip out the catering cars in record time. They must also have ransacked the offices as we saw great steel bands across the drawers with large padlocks - presumably a necessity.

I also remember being in the workshop on top of the APT – to access the pantograph it was necessary to open a panel in the power car and climb through beneath the pantograph platform and clamber through onto the roof. We were up there one afternoon when a class 20 loco with ECS came through the depot at about 30 mile/h – quite a high speed for moving about in the shed!

High speed testing was undertaken in October 1983 with a shortened APT-P Set No: 370005 which had  the BR/BW Highspeed pantograph fitted to one of the two power cars.

We ran between Beattock and Quintinshill in conjunction with our colleagues from the R&DD Electrical Equipment Section who instrumented the OHLE at Murthat and conducted high speed filming on the neutral section. I think the tests were also monitored by the DM&EE Testing Section in view of the high speed running.

Based at Glasgow Shields depot the train ran to Beattock Summit at line speed then dashed down through Lockerbie to Quintinshill at speeds up to 150mile/h - the train would have been quite capable of higher speeds as the current collection was excellent but the Civil Engineer was concerned about running over certain underbridges hence limited the maximum speed.

APT-P attained a speed of over 150 mile/h with the BR/Brecknell Willis Highspeed pantograph over the week's test runs with exceptionally good levels of current collection.

Take a look at for more information and some photographs of the tests.

If you have any memories of working on the APT - Please let me know !

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Last Revised: 18.06.2022 8:28
by R G Latham
© 1998