A Merchant Navy at 140mph + other speed record myths.

[coradiafan2000]

I was reading "The Modified Bulleid Pacifics" by Tim Hillier-Graves and came across a claim by a Southern Region fireman by the name of Jim Marsh that there was an article in Locomotive Express where an Exmouth Junction driver claimed he had covered 3.5 miles in 1.5 minutes, at an average speed of 140mph, in an unrebuilt Merchant Navy. I thought it was a typo at first, but Marsh then goes on to say that nobody contradicted the story and that another driver he knew said he knew the writer and that he wasn't prone to exaggeration. I can't help but raise an eyebrow at this.

Is there any truth to this claim at all? I know that the Merchant Navies were incredibly quick in their original forms, but would 140mph even be possible? Much less on a stretch of line that isn't Stoke Bank? There's no mention of what stretch of line this speed allegedly occurred on. I know there were several instances of 100mph by the rebuilt pacifics so I'm willing to believe even higher speeds were reached by the original engines but 140mph seems very far fetched to me.

Similarly, are there any other rumours of Mallard's 126mph being broken, or any other exceptionally high speeds achieved by steam? I've heard rumours that a GWR Saint reached 120mph light engine while on test, which I find a bit more believable. And are there any similar stories with diesel and electric traction?

 

[Gloster]

I was reading "The Modified Bulleid Pacifics" by Tim Hillier-Graves and came across a claim by a Southern Region fireman by the name of Jim Marsh that there was an article in Locomotive Express where an Exmouth Junction driver claimed he had covered 3.5 miles in 1.5 minutes, at an average speed of 140mph, in an unrebuilt Merchant Navy. I thought it was a typo at first, but Marsh then goes on to say that nobody contradicted the story and that another driver he knew said he knew the writer and that he wasn't prone to exaggeration. I can't help but raise an eyebrow at this.

Is there any truth to this claim at all? I know that the Merchant Navies were incredibly quick in their original forms, but would 140mph even be possible? Much less on a stretch of line that isn't Stoke Bank? There's no mention of what stretch of line this speed allegedly occurred on. I know there were several instances of 100mph by the rebuilt pacifics so I'm willing to believe even higher speeds were reached by the original engines but 140mph seems very far fetched to me.

Similarly, are there any other rumours of Mallard's 126mph being broken, or any other exceptionally high speeds achieved by steam? I've heard rumours that a GWR Saint reached 120mph light engine while on test, which I find a bit more believable. And are there any similar stories with diesel and electric traction?

I don’t believe that a Merchant Navy would ever get anywhere near 140, but this is is just the sort of thing that in a few years becomes a Wrong Fact, as discussed in another thread. Others will no doubt give more technical reasons for doubts.

Regarding the Saint, I think that when making a high-speed run it was always necessary to have a minimum of two or three coaches behind the loco. Otherwise the loco and, even more so, the tender would bounce all over the shop.

 

[Iskra]

City of Truro being the first steam locomotive to reach 100mph seems unlikely. *awaits wrath of the GWR faithful*

 

[coradiafan2000]

City of Truro being the first steam locomotive to reach 100mph seems unlikely. *awaits wrath of the GWR faithful*

To be fair I've read a couple of books stating 100mph was possible, mostly written by experts from a neutral standpoint. I think O.S. Nock made a case in one of his many books that while the claimed speed of 102.3mph was unlikely, it was very plausible that 100mph was reached.

 

[hexagon789]

City of Truro being the first steam locomotive to reach 100mph seems unlikely. *awaits wrath of the GWR faithful*

There have been a few articles in the RM Practice & Performance on this. The most recent from 2015, penned by John Heaton, President of the Railway Performance Society and with the aid of other members and modern computer modelling suggests a maximum of 99mph is most likely, not the quoted 102.3mph. O. S. Nock drew a not dissimilar conclusion some decades previously when penning an article on an anniversary of the original record run.

To be fair I've read a couple of books stating 100mph was possible, mostly written by experts from a neutral standpoint. I think O.S. Nock made a case in one of his many books that while the claimed speed of 102.3mph was unlikely, it was very plausible that 100mph was reached.

Yes, Nock claimed about 100mph in one of his P&P articles for the Railway Magazine and Heaton & others came up with 99mph in a 2015 revisit of the run.

I therefore think 99 can be claimed reasonably, 100 itself remains questionable.

 

[Iskra]

To be fair I've read a couple of books stating 100mph was possible, mostly written by experts from a neutral standpoint. I think O.S. Nock made a case in one of his many books that while the claimed speed of 102.3mph was unlikely, it was very plausible that 100mph was reached.

I believe it may have been theoretically possible, but I don't personally believe that there is enough evidence to confirm it.

 

[coradiafan2000]

I know Coronation's 114mph was also somewhat disputed. I believe Cecil J. Allen, O.S. Nock and two other recorders were all in agreement that the maximum was 112.5mph, but the speed recorder showed 114mph. I find it interesting that this was largely accepted while City of Truro's record wasn't, however I suppose it's almost certain that if the train didn't have to brake for Crewe 114mph would have undoubtedly been reached, probably higher.

 

[Taunton]

Regarding the Saint, I think that when making a high-speed run it was always necessary to have a minimum of two or three coaches behind the loco. Otherwise the loco and, even more so, the tender would bounce all over the shop.

It was normal for new GWR locos to be run light engine from Swindon to Stoke Gifford and back. Accounts are that, in his more junior days, Collett was on the footplate, and the regulator jammed open, they couldn't move the pole reverse with it open, and someone on the footplate was already prepared to take stopwatch timings, which later matched the times booked at signalboxes. Obviously 120mph is a pretty round figure, two minutes over a 4 mile distance.

One would have thought with a jammed open regulator first steps would be apply brakes and open cylinder cocks - which seemingly was not done.

 

[Harvester]

There is a well documented run by MN 35003 between Basingstoke and Woking on Monday 26/6/67, where 106mph was reached. The train was the 18:15 Weymouth-Waterloo, and the driver claimed he could have gone faster, but was concerned about a couple of speed restricted baggage vans on the train. This was probably the fastest run by steam on Southern Region metals, but with 6ft 2in driving wheels could ‘Royal Mail’ have gone much faster without seriously damaging the motion?

 

[Bevan Price]

There was also an undocumented claim, circa 1964/1965 that a Driver Porter had got a rebuilt Merchant Navy up to 107 mph somewhere near Winchester on a Waterloo - Bournemouth service; so far, I have yet to see a log that might confirm this, although I suspect it is quite feasible. As rebuilt, they were superb machines.

 

[507020]

I recently read somewhere that in 1899, the first of John Aspinall’s Class 7 Highflyer 4-4-2 Atlantics, the most powerful engines on the Lancashire and Yorkshire Railway, exceeded 100mph on a test run somewhere between Liverpool Exchange and Southport, where the present line speed is 60mph…

This was way before the 1923 grouping and even 3rd rail electrification in 1904, after which there would likely not have been the capacity for such speed record attempts. The LMS gave them the power classification 2P, compared to the 7P of William Stanier’s Princess Coronation, of course the most powerful steam engine ever used on British Railway, some 35+ years later, so I am very interested in this event in more detail as I definitely don’t know enough.

 

[hexagon789]

There was also an undocumented claim, circa 1964/1965 that a Driver Porter had got a rebuilt Merchant Navy up to 107 mph somewhere near Winchester on a Waterloo - Bournemouth service; so far, I have yet to see a log that might confirm this, although I suspect it is quite feasible. As rebuilt, they were superb machines.

Prone to slip, but very free-running once going and quite economical as well I understand.

I don't think they ever got quite the appreciation they deserved, compared to say Castles, A4s and Coronations etc. (And I say that as a dedicated LNER man by the way!)

 

[O L Leigh]

I seem to recall the GWR claimed that the broad gauge monster Hurricane (built 1838) with its 10 foot diameter driver was supposed to have exceeded 100mph somewhere near Twyford during September 1839, but only once the driver had received assurances from the directors that his wife and family would be provided for in the event of a mishap.

 

[hexagon789]

I seem to recall the GWR claimed that the broad gauge monster Hurricane (built 1838) with its 10 foot diameter driver was supposed to have exceeded 100mph somewhere near Twyford during September 1839, but only once the driver had received assurances from the directors that his wife and family would be provided for in the event of a mishap.

Anecdotal evidence, not official GWR claims, that it reached 100mph in September 1839 during a run where the first 22.5 miles from Paddington were supposedly covered in a quarter of an hour(!).

Given the lack of dynamic stability of the design, I'd be amazed if it could stay on the rails at anything approaching 100mph, to say nothing of the adhesion issues with so little weight on the sole pair of driving wheels.

Although Brunel was reputed to have approved of the design, Gooch found it to be a failure in practice, so had it withdrawn for parts.

I strongly suspect Gooch was right in that respect and the lump never did anything even close to 100mph.

 

[O L Leigh]

Given the lack of dynamic stability of the design, I'd be amazed if it could stay on the rails at anything approaching 100mph, to say nothing of the adhesion issues with so little weight on the sole pair of driving wheels.

Yes of course. I never suggested that I believed it, but I offered it solely in the spirit of the thread.

 

[hexagon789]

Yes of course. I never suggested that I believed it, but I offered it solely in the spirit of the thread.

No, I realised that - I didn't think you believed it!

I was trying to illustrate further why it was extremely unlikely if not effectively an impossibility.

 

[Harvester]

Similarly, are there any other rumours of Mallard's 126mph being broken, or any other exceptionally high speeds achieved by steam? I've heard rumours that a GWR Saint reached 120mph light engine while on test, which I find a bit more believable.

I believe the highest speed recorded on a normal revenue earning passenger train was 113mph achieved by A4 Silver Fox on an up Silver Jubilee run in 1936.

Bill Hoole could have gone faster down Stoke Bank with A4 60007 on the Stephenson Society Special in May 1959, having topped the summit at 75mph, retaining good boiler pressure in the process. However he was told to ease off after reaching 112mph by inspectors travelling in the cab.

Bill had been in trouble a few years earlier for speeding down Stoke Bank with 60007. He was covering for another driver and appeared unaware that some technicians were onboard with a Hallade machine doing routine tests. When the data was analysed a speed of 117mph was shown on the Hallade trace. He got away with a mere slap of a wrist, on the grounds that the data was considered unlikely to be very accurate.

 

[mike57]

Surely calculating horespower required to achieve 140mph, less assistance from gradients would give an approximate 'required' figure and one would have to say that in all likelyhood it would be way above what the Merchant Navy class could put out, even if everything else was perfect.

The best UK express steam locos seem to be capable of 110-120mph given optimum conditions.

After City of Truro when was the next GWR record made?

Its also worth remembering that wind resistance is a square law wrt to speed so small increases in speed needs a much bigger increase in power at higher speeds.

 

[Harvester]

Prone to slip, but very free-running once going and quite economical as well I understand.

I don't think they ever got quite the appreciation they deserved, compared to say Castles, A4s and Coronations etc. (And I say that as a dedicated LNER man by the way!)

I totally agree, and this is also coming from a dedicated LNER man.

Their tendency to slip was not quite on par with the light Pacifics, and the Bulleid boiler was a great asset. Towards the end, when in badly run down condition, and on minimum maintenance, they put in some brilliant performances with enthusiastic crews. It was not uncommon, once the Bournemouth line had been upgraded for 100mph running in 1967, for MNs to arrive at Waterloo 10 to 15 minutes early when running non stop from Southampton.

 

[coradiafan2000]

After City of Truro when was the next GWR record made?

I believe 4086 Builth Castle achieved 100mph down Honeybourne bank in 1939, which is what some considered to be the GWR's first 100mph record.

The fastest GWR speed I'm aware of is 108mph by 6015 King Richard III, which it achieved thanks to it's new double chimney and the other improvements made to the class by BR. I'd love to know if anything higher might have been reached.

 

[hexagon789]

I believe 4086 Builth Castle achieved 100mph down Honeybourne bank in 1939, which is what some considered to be the GWR's first 100mph record.

The fastest GWR speed I'm aware of is 108mph by 6015 King Richard III, which it achieved thanks to it's new double chimney and the other improvements made to the class by BR. I'd love to know if anything higher might have been reached.

The fastest authenticated is 108mph by multiple locomotives, though 109mph was claimed with 6001 King Edward VII.

they put in some brilliant performances with enthusiastic crews. It was not uncommon, once the Bournemouth line had been upgraded for 100mph running in 1967, for MNs to arrive at Waterloo 10 to 15 minutes early when running non stop from Southampton.

Well linespeed was officially 90 until the 442s arrived, but the track was certainly in very good condition when the Bournemouth line was upgraded during electrification. I am very aware that the limits, particularly linespeed, were treated much more laxly than today.

I've seen a couple of 105s, but nothing higher. 99-101mph seemed typical when drivers were "going for it", more than 101 was seemingly quite rare, perhaps simply the conditions for sustained high-speed running that would touch figures exceeding the ton were just not present - not enough straight track and favourable gradients?

 

[Taunton]

I believe 4086 Builth Castle achieved 100mph down Honeybourne bank in 1939, which is what some considered to be the GWR's first 100mph record.

The fastest GWR speed I'm aware of is 108mph by 6015 King Richard III, which it achieved thanks to it's new double chimney and the other improvements made to the class by BR. I'd love to know if anything higher might have been reached.

Honeybourne Bank was the GWR's favoured place for speed tests, When the 60th anniversary run commemorating City of Truro was done in 1964, the Castles being prepared for it were taken there and run flat out down the bank, a couple exceeding 100mph, to see that they were up to it.

Unfortunately one, on the day, subsequently proved that it wasn't.

 

[D6130]

Unfortunately one, on the day, subsequently proved that it wasn't.

Which one was that....and what happened?

 

[theageofthetra]

I'm sure I read a story about when testing the third rail for Eurostar high speed running a REP emu was radared at 115 around Paddock Wood during a nightime possession?

 

[Harvester]

Which one was that....and what happened?

4079 Pendennise Castle. It had to be removed at Westbury because of melted firebars. Hall 6999 replaced it as far as Taunton, where standby Castle 7025 took over for the run to Plymouth. Clun Castle (Plymouth-Bristol) and Earl of Ducie (Bristol-Paddington) failed to get the magic ton but came quite close.

 

[341o2]

Prone to slip, but very free-running once going and quite economical as well I understand.

I don't think they ever got quite the appreciation they deserved, compared to say Castles, A4s and Coronations etc. (And I say that as a dedicated LNER man by the way!)

Bullied originally proposed an eight coupled locomotive, but was defeated by the civil engineer and forced to accept a Pacific.
If only.....

 

[Taunton]

Hall 6999 replaced it as far as Taunton, where standby Castle 7025 took over for the run to Plymouth.

Taunton shed foreman's finest hour! 7025 had been polished to showroom standards as the trip's standby, and Taunton had been chosen as the halfway point of the trip to station it. Foreman and stationmaster on duty in their best suits and uniform. Plan had been it was to whistle vigorously as the train sped through. Was to be facing westwards for the morning run, then turned to face the other way for the return - but by then it had been used. To the disappointment of its Taunton standby crew, who thought their 15 minutes (2 hours actually) of fame had come to Plymouth, when the train arrived the full Old Oak crew, including two firemen and the WR's chief running inspector, all transferred over. The train was running to full WR Royal Train procedures, including being double blocked for signalling.

Alas, at a youthful time, I only learned afterwards about the train.

 

[hexagon789]

Bullied originally proposed an eight coupled locomotive, but was defeated by the civil engineer and forced to accept a Pacific.
If only.....

I appreciate that would've been much better on starting, but would an eight-coupled (are we talking Mikado wheel arrangement like an LNER P2?) have been faster than a Pacific?

Or was Bulleid more concerned with haulage capacity and acceleration than achievable speed?

 

[341o2]

I would say yes because the speed limit on the Southern was 85mph pre electric, and the biggest locomotives before the Pacifics were the Lord Nelson or King Arthur. Some trains had to be double headed because they were too heavy for the aforementioned classes.
When it was commented that the pacifics leaked oil. the reply was that having to resort to double heading would lead to the consumption of more oil.

Furthermore, the Bullied valve gear was designed to improve acceleration, on a visit to England after moving to Ireland, Bullied struck up a conversation with a driver, who not knowing who he was talking to, replied to Bulleid's comment "I hear they are modifying the Merchant Navy class", with "They might save a bit of coal and water, but don't pull half as well."

 

[Harvester]

The train was running to full WR Royal Train procedures, including being double blocked for signalling.

Didn’t that arrangement become unstuck on Wellington Bank on the return run? IIRC the sighting of an adverse ‘distant’ required a brake application when Clun Castle was in the upper nineties, probably preventing the magic ton. The 80mph speed restriction down the bank had been temporarily lifted that day to allow a fast decent.

The first preference Castle 5054 was used on the last leg, and 100mph was anticipated with a BBC crew joining the train at Bristol to record the event. However it was not to be, the highest speed Earl of Ducie achieved was 94mph at Little Somerford.