With full regulator: locomotive performance then and now

Don Benn looks at the work of Gresley’s A4 pacific No. 60007 Sir Nigel Gresley, reaching 90mph in Scotland in 1965, high speed on the West Coast Main line in 1967, a very fine run with a heavy load on the Great Western main line to Bristol in 2008, and returning from Kingswear on the Berks & Hants line in 2014.

A4 class Pacific No. 60007 Sir Nigel Gresley has returned from extended overhaul, so I thought it an opportune time to look at some of the work of this very fine locomotive over the years that I have been acquainted with it.

Although I first saw it at King’s Cross in 1961 when it was allocated to King’s Cross shed, I didn’t have a run behind it until it had been transferred to Aberdeen Ferryhill shed in 1963, primarily to work the lightweight three-hour trains to and from Glasgow, sharing the work with seven other class A4 Pacifics exiled from the East Coast main line by the Deltic diesels.

I had 368 miles behind it in Scotland prior to its withdrawal in February 1966. Although a general 75mph speed limit applied throughout Scotland at that time, the A4 Pacific drivers in particular paid scant attention to this on the three-hour trains and 80mph on the 07.10 Aberdeen to Glasgow service was commonplace, especially on the 32.5 mile Forfar to Perth segment, timed in 32 minutes, which I believe by 1965 was the last remaining 60mph start-to-stop average steam schedule in the UK, Southern’s Atlantic Coast Express having finished in September 1964.

It was a matter of honour among Ferryhill drivers such as John Thompson to cover this section in under half an hour, which required a fast start and upper 70s to 80mph running across the largely level Strathmore section prior to the dip over the River Tay near Cargill, where the maximum speed was usually reached.

On one of my first trips to Scotland in October 1964, No. 60009 Union of South Africa, with John Thompson driving, covered this stretch in 29 minutes 38 seconds, with 84mph over the Tay Bridge. The 07.10 to Aberdeen usually had a good path to the Perth stop and would arrive a couple of minutes early, giving more time for the Perth South crew to water the engine.

My chosen run in Table One though gave me my only 90mph speed with an A4, in this case with No. 60007 Sir Nigel Gresley. I had travelled north as usual on the 19.30 ‘Aberdonian’ from King’s Cross behind Deltic D9016 to Edinburgh and EE Type 4 D361 from there, allowing time in the Granite City for a brief breakfast before boarding the six-coach 07.10 to Glasgow, which I used as far as Stirling.

The tare weight of 219½ tons suggested BR Mk.1 Commonwealth bogie stock, the gross weight being 235 tons. It was a very cold and snowy day early on and the A4 struggled with much slipping to get the train going up the initial steep climb to Cove Bay, culminating in more than a mile of 1-in-102. But once over the top at milepost 234, we dashed away to reach 80mph before the Stonehaven stop, having dropped over a minute on the schedule. Once again from the restart the engine struggled on the climb to Carmont but then ran well, with 80mph either side of Laurencekirk and a minimum of 56mph on Farnell Road bank.

Easier running saw us into Forfar just half a minute late in a shade over even time for the 41.15 miles from Stonehaven. From Forfar, leaving nearly two minutes late, there was more slipping before the engine got into its stride and we ran the 8.65 miles from Coupar Angus to Stanley Junction at an average of 82mph, with an exhilarating 90 over the River Tay Bridge at the foot of the 1-in-160 down from Cargill.

After a minimum of 78mph at Stanley Junction and 82mph at Strathord, brakes steadied the train on the final decent into Perth as it was now snowing heavily. The time of 29 minutes three seconds from Forfar was my fastest, but certainly not a record. The new Perth South crew took us on to Stirling in 35 minutes one second (against the 36 minute schedule) and I then returned to Stirling on the 09.15 Glasgow to Dundee West behind BR Caprotti Class 5 No. 73152 on eight coaches for 310 tons, according to my records standing in for a failed diesel loco.

This produced a very fine performance, with lots of total thrash up the 1-in-100/78/88 climb to Kinbuck that started at 54½mph at Cornton and finished at 40mph after an absolute minimum of 36mph. After the Gleneagles stop, speed reached 83mph at Dunning before a series of signal and temporary speed restriction checks ruined our chances of an on-time arrival in Perth. There I saw Edinburgh St. Margarets allocated V2 No. 60816 on an 11.00 relief train to Edinburgh and I will forever regret not changing my plans and catching this train. Instead, I travelled back to Stonehaven on the 11.34 – 10.00 from Glasgow – behind EE Type 4 Diesel No. D1631 on eight coaches.

On what was now a beautiful and sunny but cold day, the ride across Strathmore to Forfar with the snow covered Grampian hills to the north was a superb experience, enhanced by the performance of the Brush as we gained time from a 12-minute late start with some very fast intermediate start-to-stop times, including 11 minutes 27 seconds for the 11.9 miles from Alyth Junction to Forfar, 92mph maximum! We were early as soon as Bridge of Dun and got to Stonehaven five early.

Next journey

Moving on to October 28, 1967, No. 60007, running as LNER No. 4498, worked RCTS ‘The Border Limited’ 08.28 Nottingham Midland, taking over the train at 10.59 from Crewe. The load was a modest one of 11 coaches for 385 tons full, and the enthusiastic crew was driver Stewart and fireman Cadman. Tables Two and Three show the running between Crewe and Warrington and then Preston to Carlisle. As these runs took place before the end of steam on BR; normal speed limits applied and driver Stewart took full advantage of the A4’s potential for speed, though not reaching the dizzying heights of the postwar record of 112mph reached by Sir Nigel Gresley down Stoke Bank on May 23, 1959.

Alan Rawlings was on ‘The Border Limited’ and he tells the story: “‘The Border Limited’ in October 1967 was an enthusiast’s day out. The trip originated at Nottingham, with steam from Crewe. There was also some rare track around Carlisle and up to Longtown, including a lay-over at Kingmoor depot. The train then returned to Crewe and Nottingham via the Settle and Carlisle, Skipton to Colne (now lifted), and Blackburn.

“But the main reason for travelling was because No. 4498 Sir Nigel Gresley was to take us over Shap and Ais Gill; and it was in garter blue.

“No. 4498 took off from Crewe like a scalded cat. Despite the locomotive effectively starting from ‘cold’, we were inside even time after 12 miles and touched 95mph in the Hartford area before easing slightly.

“The Warrington stop was reached well inside even time. The journey was picked up again on the leg from Preston to Upperby Bridge Junction, where the train turned off for the freight lines around Carlisle.

“Once again, speed rose quickly, with 83mph at Garstang before the first of two permanent way restrictions approaching Lancaster.

“The pace quickened again north of Carnforth and Sir Nigel swept its 385 tons over Grayrigg at an impressive 53mph. Shap was also despatched at pace with a speed of 74 just before Tebay and an impressive 47 over the summit.

“Further extended restrictions in the Shap station area were followed by a final flourish of speed up to 88mph after the Penrith check before coming to a stand at Carlisle No.13, where a Stanier Class 5 was to take us forward to Longtown.

“Based on what trains of typical weight and motive power achieve nowadays, this 89-mile leg was covered in no more than 87 minutes net. Either way, it was a sparkling performance by the Stewart and Cadman combination up front.’’

Ray Churchill with 60007

Moving on to the preservation era, No. 60007 worked a Waterloo to Bristol special on Wednesday, December 3, 2008, and I was fortunate to be on it.

The load was a heavy one of 13 coaches, 470 tons full, and Ray Churchill took over from Pete Roberts at Reading. Ray’s fireman was Les Perry.

Table Four shows the detail of this top-class performance, confirming that the A4s weren’t just speed machines – some of the acceleration from stops was quite phenomenal. For instance, from the Challow start 12 minutes late, the first 11.16 miles were covered in just 12 minutes one second, with 76mph reached in just over nine minutes.

Then came the first of two very fast stops caused by the AWS automatically applying the brakes. Ray told me that the warning signal was very soft on No. 7 as it was the old type which worked on the vacuum at that time, but it was still annoying to have such rapid progress interrupted. Nothing daunted, off we went again with a wonderful loud A4 roar, recovering rapidly past Swindon, and we were soon back to cruising in the mid to upper 70s, having to brake at Dauntsey to keep speed down.

The minimum of 73½ after Corsham was a prelude to another dash through Box Tunnel with the brakes on, only to be stopped again by the AWS just short of Bath. We had covered the 30.32 miles from the previous stop at an average of 65.87mph and what’s more had run the 42.56 miles from Challow to the stop inside even time; so two even time runs on the same section, which is somewhat unusual.

We were just over five minutes late arriving in Bath but overtime made us eight late away and even though we ran up to 76 ½mph at Keynsham, we only just kept the tight 16 minutes booking on to Bristol, producing a 55.5mph time over just 11.49 miles, and that with 470 tons – an altogether exhilarating performance.

I asked Ray for his recollections of this run. He said: ‘’This is how I imagine things would have gone on that trip. On leaving Challow loop, the regulator would have been gradually opened to about three quarters and cut off gradually, brought back to about 35% and left there for a while to see how she responded to that load on the slight up grade. As she got going I would have brought her back very gradually at a notch at a time, but I wouldn’t have thought it came under 30% until we got over the top at Swindon with that load on.

“Unfortunately, before we got to Swindon I failed to hear the AWS warning horn in time, which was a little on the quiet side; you only have 2.5 seconds to cancel it and so that beggared up the good work done and we came to a stand. We got away again and once through Swindon the gradient turned in our favour on through Wootton Bassett and down the 1-in-100 of Dauntsey Bank at full tilt, after which the gradient eases for about four miles, then turns up grade by about the same grade for roughly seven miles through Chippenham and on to Corsham. At that change of gradient, the regulator was opened to about three quarters with only about 15% but a wary eye on the speedo saw it gradually dropped to 20%, after then of course very little steam is required to Bristol.’’

Ray also told me that on the return run via the Berks & Hants line, he had a pilotman on board as he didn’t know the road. They were doing very well, with an average speed of 66.7mph uphill between mileposts 90 and 71 and a minimum of 65mph over Savernake, when Ray was shocked to be told that the water level was very low, so he asked the pilotman how far it was to the Theale water stop, which was about five miles. They just made it with the tender empty and water just showing in the gauge glass!

Finally and also on the Berks & Hants line is another log from Alan Rawlings showing in Table Five a competent performance, with No. 7 driven by Bill Warriner and fired by Craig Stinchcombe. On this trip also, water had to be conserved as the A4 ran for more than three-and-a-half hours from Kingswear to the Taunton water stop.

With grateful thanks to all my correspondents for their contributions.

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