Was the 'WOLF' the most powerful passenger steam loco in Britain

[melmerby]

IIRC

If you took a Coronation Class and fitted it with 6' 2" wheels, it would have more TE than 2007 as it has more ( need to check) cylinder volume.

Likewise if you fitted 6' 9" wheels to 2007 (not possible BTW) it would end up with less TE than the Coronation

Nuf said.

 

Had another look at this

A quick Guestimate (can't be bothered with the maths in this heat) would put it's TE with larger wheels around that of the W1 which has smaller cylinders but higher boiler pressure i.e about 41000 lbsTE

 

Edited July 19 by melmerby

[Compound2632]

43 minutes ago, Bucoops said:

 

I suppose it relies on three things -

 

Accuracy of the timepiece - these days we could calibrate against an atomic clock, not sure what they would be able to use then?

Accuracy of the milepost distances - I don't suppose they were prone to moving much, but were they accurately placed? Probably limited difference if a couple of feet out of course.

Accuracy of the timepiece operator - there is the reliance on the user taking the time at the same relative location of their seat to the milepost at each point. The distance of the post from the running line can alter when the post becomes visible for example.

 

Just my thoughts - I have no knowledge on the accuracy of the timepiece used, etc.

 

 

All true - but these point lead not to proof or disproof but to a refinement of the uncertainty estimate. But to give an idea of their significance, a 1% error - 1 mph error at 100 mph - would require:

• for the stopwatch, an error of 0.1 s over 9 s, which is anyway about the same as the timing resolution of stopwatch. How one would obtain traceability for time interval measurements at that time I don't know. We're familiar with how railway time was disseminated - by telegraph, or by the guard's watch - the latter would have been checked and adjusted periodically - but that's for periods of minutes and hours, rather than a few seconds. Interesting question.
• for the mileposts, a position error of 4.4 yards. 
• for the observer, the same 4.4 yards. This depends on the skill of the operator, of course. 

If taking successive quarter-miles with alternate stopwatches, which is what I understand people such as Rous Marten, C.J. Allen, and Nock did, a misplaced milepost or a mis-timed reading would show up as a blip in the data, with unfeasible variations of speed. There was, so I've read, a notorious badly mis-located milepost on the Grand Junction that led to spurious claims of a quarter-mile covered at 60 mph soon after the line opened - the next quarter mile would have given an erroneously low speed - if genuine, the acceleration and deceleration would have been very obvious to all concerned!

 

All these sources of error are halved if one switches to timing over half-miles rather than quarter-miles, which is what Nock says he did at over 80 mph - 90 mph.

 

All piquing the interest of a former time and frequency metrologist and atomic clocksmith!

Edited July 19 by Compound2632

[DenysW]

4 hours ago, Compound2632 said:

Apologies for continuing a digression, but how would you prove or disprove Charles Rous Marten's milepost timing data? 

I don't think it's possible at this distance in time. I've seen comments on Mallard's run by people who want to disbelieve/discount it citing the big-end failure and the assertion of burning coals on station platforms, and similar nit-picking against both German and US alternatives.

 

There's also the fact that actual record attempts were very rare indeed, so Rous-Marten's notes are not only using Best Available Technology, but mostly on scheduled services that would only be encouraged to go for speed when conveying royalty (one instance) or recovering time when late.

 

Plus there wasn't a specification. On the flat? Both flat and straight? Pulling a design load of coaches? Pulling 4 coaches? No mechanical failures? City-to-city in-service? I suspect the Guinness Book of Records would sneer at attempts to introduce a new category of 'Fastest reciprocating Steam Engine' or 'Most powerful Reciprocating Steam Engine (UK sub-category)' without this type of detail unified.

 

And as a digression back to the OP, there is a picture of an LMS Garratt pulling coaches on an (unsucessful) trial. Does that and the fitting for vacuum braking make some of them passenger locomotives?

[34theletterbetweenB&D]

On 10/07/2024 at 16:04, LMS2968 said:

...You cannot calculate the power output...

And of practising steam loco engineers, you had to be Andre Chapelon to make a reliable estimate: which ability was then validated by testing.

 

On paper, the 50 sq ft grate area of the respective boilers should generate much the same heat output, with the Coronation's larger superheater area transferring more energy to the steam, and the P2's Kylchap exhaust system extracting more power from any given mass of steam throughput.

 

Where the P2 should possess an operational advantage is a much higher factor of adhesion, which should deliver the ability to put more power down, especially in poor rail conditions.

[Compound2632]

33 minutes ago, DenysW said:

Plus there wasn't a specification. On the flat? Both flat and straight? Pulling a design load of coaches? Pulling 4 coaches? No mechanical failures? City-to-city in-service? I suspect the Guinness Book of Records would sneer at attempts to introduce a new category of 'Fastest reciprocating Steam Engine' or 'Most powerful Reciprocating Steam Engine (UK sub-category)' without this type of detail unified.

 

Indeed. At the risk of upsetting the Gresleyites, Wagner's 05-002 Baltic's 200 kph - 124 mph - was, as I understand it, maintained over several kilometres on level or slightly falling grade; unfortunately I don't have a note of the load - there used to be an interesting website on this by a train timing enthusiast but it disappeared some years ago. Anyway, a contrast to Mallard's momentary 125 mph. Both were attained under test conditions, though those of the DR engine rather more rigorous!

Edited July 19 by Compound2632

[sulzer27jd]

On 11/07/2024 at 05:42, Combe Martin said:

Surely the P2s were only ever designed to be passenger locos, and the reason for the 6ft 2in drivers was the difficult 'road' they were designed to operate on.  Was there space in the frames for an 8 coupled 6ft 6in wheel set ?

 

Has anyone ever seen a photo of a P2 on a non passenger working ?  

No photograph but they regularly worked the Aberdeen fish trains. According to my late father-in-law those were the hardest days work ever. Firing a passenger timed train but without the station stops.

[H2O]

On 11/07/2024 at 17:25, Combe Martin said:

 snip:

When the Pines Express was diverted away from the Somerset & Dorset line to run via Basingstoke and Oxford, Bournemouth shed continued to allocate a West Country to the job but using a Bournemouth crew now rather than still using a Branksome crew (who would regularly handle the Pines 12 coaches over the hilly S&D line with a WC).  The Bournemouth men struggled to manage it with a WC over the much easier new route and demanded a Merchant Navy be allocated to the job !

 

   

IIRC the pines was piloted on the hilliest bit when it had a WC, i e. over the Mendips. I'm not taking anything away from the S&D crews. Read Peter Smith's books for what they regularly did with what they were given. A 9f was ok to take trains unassisted.

(MN were not permitted on the S&D as they were too heavy for the line.)

Edited July 19 by H2O

[rodent279]

Reading all the above about CoT's "was it/wasn't it", it strikes me that the big problem with "proof" is that we only have the word of one timekeeper.  Either way, if it wasn't 100mph it's clear that it was pretty darn close.

[Compound2632]

1 minute ago, rodent279 said:

Reading all the above about CoT's "was it/wasn't it", it strikes me that the big problem with "proof" is that we only have the word of one timekeeper.  

 

But equally, Mallard's record is based on the output of one machine. 

[rodent279]

And I believe SNG did not claim any more than 125mph? As with CoT if it wasn't 126 it was pretty close, and at this distance in time, with all the major players and companies long since gone, in an age where 100mph has been commonplace for over half a century, does it matter? A4s, Cities, DR 01s 05s etc were clearly well designed engines for their time and no one can take that away.

Edited July 20 by rodent279

[Compound2632]

9 minutes ago, rodent279 said:

And I believe SNG did not claim any more than 125mph? As with CoT if it wasn't 126 it was pretty close, and at this distance in time, with all the major players and companies long since gone, in an age where 100mph has been commonplace for over half a century, does it matter? A4s, Cities, DR 01s 05s etc were clearly well designed engines for their time and no one can take that away.

 

Indeed, and 100 mph is a rather arbitrary speed to get excited about, since the actual number depends on your choice of units. Richard Wagner and his team were aiming for 200 kph running.  The world record speed with a steam locomotive stands at 56 m/s.

 

But for me, the City of Truro event of 9 April 1904 remains fascinating as a study in measurement analysis. As locomotive performance goes, I find that day's sequel more impressive. At Pylle Hill Junction, Truro came off, along with the van with the northern mails, the 4-2-2 Duke of Connaught came on and took the remaining 120-ton train the 118 miles to Paddington in 99 m 46 s - an average speed of 71 mph. The 70 miles from Shrivenham to Westbourne Park was covered at an average speed of 80 mph (try doing that on the M4) without the maximum speed exceeding 83 mph. (All from Charles Rous Marten's stopwatch; the guard's journal gave 100 min start to stop.) Of course it's downhill much of the way, but very gently so - certainly not Whiteball or Stoke Bank! 

[LMS2968]

It pains me to say this as I have no interest in speed records just for the sake of them, but it does matter since that extra mph is the result of a higher power output. The required power needed rises roughly with the square of velocity, so doubling the speed requires four times the power. The power graph is exponential and rises ever more steeply as speed rises. The difference in power needed between 25 and 26 mph is hardly worth talking about, but between 125 and 126 mph it is considerably higher.

[Compound2632]

6 minutes ago, LMS2968 said:

It pains me to say this as I have no interest in speed records just for the sake of them, but it does matter since that extra mph is the result of a higher power output. The required power needed rises roughly with the square of velocity, so doubling the speed requires four times the power. The power graph is exponential and rises ever more steeply as speed rises. The difference in power needed between 25 and 26 mph is hardly worth talking about, but between 125 and 126 mph it is considerably higher.

 

Absolutely. And this is why Rous Marten's 8.8 s is doubly dubious - the other timings give a curve approaching an asymptotic limit a bit above 100 mph, at which the power of the engine - pretty well constant over this timescale - aided by gravity on the descending gradient (constant), would balance the rolling resistance of the train (also increasing with speed), i.e. acceleration would cease. But the additional acceleration to get that 8.8 s quarter-mile would require a sudden increase in power output of a magnitude well beyond the engine's capabilities (and in any case there's no indication the driver was making any adjustment in those few seconds, rather, his next action was to ease up considerably).

 

F.W. Webb understood all this very well. He published a graph showing how engine power increased with average train speed and weight, demonstrating why he needed to scrape for every extra bit of efficiency he could to keep the cost of his express passenger engines within bounds his Directors were used to. The little Newtons and Samsons of the 1870s could happily manage 40 mph expresses of non-corridor stock, but for the 50 mph 2pm 'Corridor' (with much reduced seating capacity per ton thanks to the dining saloons and side corridor), one needed a Teutonic.

[kevinlms]

23 hours ago, rodent279 said:

And I believe SNG did not claim any more than 125mph? As with CoT if it wasn't 126 it was pretty close, and at this distance in time, with all the major players and companies long since gone, in an age where 100mph has been commonplace for over half a century, does it matter? A4s, Cities, DR 01s 05s etc were clearly well designed engines for their time and no one can take that away.

Did any of it matter to the average person sitting in an ordinary seat - not one bit. They might have noticed a particularly good run, but did they notice as much as Rous Marten? Almost certainly not, as most passenger were interested in a right time departure and a right time arrival!

These record breaking speeds, did nothing to help those speeds become standard every journey.

[Combe Martin]

Surely it was about generating publicity for the company, by emphasising their level of technology at that time, (the LNER and LMS were in a race to be the fastest to Scotland).  Just like the Le mans 24 hours race, 'win on Sunday sell cars on Monday'.

[Miss Prism]

The GWR was very concerned about the news of CoT's antics getting into the public domain, for fear of worrying passengers, and it wasn't until nearly 20 years later that details of the CoT run became available via one of the railway mags (which were generally read only by enthusiasts).

 

[LMS2968]

26 minutes ago, Combe Martin said:

Surely it was about generating publicity for the company, by emphasising their level of technology at that time, (the LNER and LMS were in a race to be the fastest to Scotland).  Just like the Le mans 24 hours race, 'win on Sunday sell cars on Monday'.

Do they really? I worked in the motor trade for twenty five years. I cannot recall a queue at the showroom doors the day following an F1 race or the Monte Carlo rally. Similarly, a news report of a new world record for the 100 metre sprint didn't result in many people running to work the next day.

Edited July 21 by LMS2968

[Compound2632]

1 hour ago, kevinlms said:

These record breaking speeds, did nothing to help those speeds become standard every journey.

 

The 1888 and 1895 races resulted in a long-term acceleration of Anglo-Scottish expresses, from 10 hours for London to Edinburgh (and Glasgow by the West Coast) to 8 hours. 

[Combe Martin]

1 hour ago, LMS2968 said:

Do they really? I worked in the motor trade for twenty five years. I cannot recall a queue at the showroom doors the day following an F1 race or the Monte Carlo rally. Similarly, a news report of a new world record for the 100 metre sprint didn't result in many people running to work the next day.

 

This was a quote that specifically referred to the Le Mans 24 Hour race, probably in the 60's because sports car racing is all about the manufacturers whereas F1 was just about the drivers.  I don't know when it started, possibly by Ford when they started to challenge Ferrari there.

 

Just checked, apparently it started in the 50's in the USA (where else) and referred to NASCAR racing.  However it was certainly quoted in Britain later than the mid 60's (I didn't notice things like that before I was about 20) and specifically about Le Mans, and it has certainly seemed to have worked for manufacturers like Porsche and Audi (the winning, not necessarily the slogan).

Edited July 21 by Combe Martin
Added the last paragraph.

[Bucoops]

3 hours ago, LMS2968 said:

Do they really? I worked in the motor trade for twenty five years. I cannot recall a queue at the showroom doors the day following an F1 race or the Monte Carlo rally. Similarly, a news report of a new world record for the 100 metre sprint didn't result in many people running to work the next day.

 

Saab capitalised on it in the late 70s - after a run of rally wins they "borrowed" Donnington and gave passenger rides in the new Turbos. For a small manufacturer, they sold quite a few.

[kevinlms]

3 hours ago, Compound2632 said:

 

The 1888 and 1895 races resulted in a long-term acceleration of Anglo-Scottish expresses, from 10 hours for London to Edinburgh (and Glasgow by the West Coast) to 8 hours. 

It actually led to later starts, for places like Aberdeen. As you know, the west coast companies at one stage in 1895, arrived at 4.30am, which I'm sure the arriving passengers (other than those with stopwatches, who went straight back to Euston!) were thrilled with the greeting they received at that hour.

 

I thought that the timings for Glasgow/Edinburgh in 1888, were deliberately kept at those timings by agreement - relating no doubt, to the old days where they used to stop at the refreshment rooms.

[Compound2632]

2 hours ago, kevinlms said:

I thought that the timings for Glasgow/Edinburgh in 1888, were deliberately kept at those timings by agreement - relating no doubt, to the old days where they used to stop at the refreshment rooms.

 

Yes, but the 1888 races led to a revision of the agreement, from 10 hours to 8 hours. 

 

I dare say that while publicity departments - such as they were - were delighted, there was much unhappiness from timetable planners, locomotive engineers, and shareholders. A victory for the travelling public over corporate interest.

[DenysW]

On 19/07/2024 at 17:38, 34theletterbetweenB&D said:

Where the P2 should possess an operational advantage is a much higher factor of adhesion, which should deliver the ability to put more power down, especially in poor rail conditions.

True, but mostly important at start-up and on greasy rails (the state between dry and wet). Both probably factors more important on Scottish services, which seems to have had most stations in the bottom of the valley, followed by rising gradients in either direction. A good  choice by Gresley.

 

On 20/07/2024 at 08:41, LMS2968 said:

The required power needed rises roughly with the square of velocity, so doubling the speed requires four times the power.

Not actually true across the board. Lifting the weight of the train up a gradient is linear with velocity- the same weight is lifted by the same height, in a time set by the speed. Same with the power benefit of going down-hill. Frictional losses (air resistance and rolling resistance from the wheels) are probably square-law. Losses from wheel-bearings depend on the design, and range from negligible (roller bearings) to having an inertial effect on start-up, followed by a gradual increase with speed. There was no consensus on the rolling resistance vs speed relationship at the time, with each company having its own opinion, which could also change over time.

 

9 hours ago, kevinlms said:

Did any of it matter to the average person sitting in an ordinary seat - not one bit. They might have noticed a particularly good run, but did they notice as much as Rous Marten? Almost certainly not, as most passenger were interested in a right time departure and a right time arrival!

These record breaking speeds, did nothing to help those speeds become standard every journey.

Completely true, although Rous-Marten (and later C.J. Allen when he took over the role for the 'Railway Magazine') did have a lot of correspondents reporting timings. And mostly ignoring the fact the the drivers were only expected to go faster than expected when making up time.

 

There was, of course, a lot of disappointment from the trainiacs post WW1 when timings did not immediately revert to pre-War levels.

[DenysW]

On 20/07/2024 at 09:00, Compound2632 said:

But the additional acceleration to get that 8.8 s quarter-mile would require a sudden increase in power output of a magnitude well beyond the engine's capabilities (and in any case there's no indication the driver was making any adjustment in those few seconds, rather, his next action was to ease up considerably).

This valid point has also been used to challenge the blip in the Mallard trace used to squeeze the 1-2 extra MPH required to beat the dastardly foreigners' impertinent attempt to seize the record from our gallant boys.

 

But, as noted above, if the target was to reduce safe, reliable inter-city journey times, then the 'records' don't really matter, although the attempts may reveal the flaws of limitations in the designs tested.

[LMS2968]

18 minutes ago, DenysW said:

Not actually true across the board. Lifting the weight of the train up a gradient is linear with velocity- the same weight is lifted by the same height, in a time set by the speed. Same with the power benefit of going down-hill. Frictional losses (air resistance and rolling resistance from the wheels) are probably square-law. Losses from wheel-bearings depend on the design, and range from negligible (roller bearings) to having an inertial effect on start-up, followed by a gradual increase with speed. There was no consensus on the rolling resistance vs speed relationship at the time, with each company having its own opinion, which could also change over time.

Resistance comes in three forms: rolling friction  (mostly bearings); gradient (which can be  negative resistance going downhill); and aerodynamic. With the first two, velocity is not a component: the rolling resistance is exactly the same at zero mph and 100 mph. Mass (weight) is a factor in both of these. Mass is not a factor in aerodynamic resistance, but velocity (squared) very definitely is. This is why I said the required power rises roughly with the square of velocity, because that rolling resistance is still in there but becoming of less and less significance as the speed rises.