Locomotive Performance & Timing

Another ‘bugging’ question, this time on the value of Locomotive Timing Performance

Recently taking a fresh read of Winkworth on my pet subject of Bulleid Pacifics reminded me that many pages refer to locomotive timings taken in 1950s and 1960s. Locomotive timing is something that is still to be seen on steam rail-tours and is something I don’t mind admitting that I have ‘dabbled’ into in the distant path, if only for my own notes taken on the day.

I’ve always held a doubting view however as to what can be taken from such tables given that any two locomotives on any two outings will encounter an array of differing criteria that in my view, creates difficulties in comparing like with like.

For instance, weather conditions, leaf fall and sap, rail condition, differences in driver and fireman skills and techniques, quality of coal, condition of locomotive given time since last major overhaul, weight behind the drawbar for starters. On more modern rail tours, speed restriction and strict compliance to those restrictions along with a schedule allowing for passing service trains leaves me somewhat confused as to what such timings actually show?

Can we really say that one particular locomotive or type outperforms another on the same route given so many variables?

I’m not knocking those who are into recording timings, in fact I admire their eye for detail. What I am unclear of is what a table showing for instance how 34025 performed between Cannon Street and Tonbridge on a particular date, tells me about that locomotive and the skills of the crew compared with another? Did the schedule for that working really push the locomotive and crew?

I’m confident esteemed members of NP will point out the obvious omission in my thinking!

 

Another big issue is the fact that most of the timings involve a human element.

Manual timekeeping in Athletics and Horse Racing is recognised to have an element of human error in that on the whole performances tend to be made quicker than they actually are. The reason for this is that the timer is reckoned to be a fraction slow in starting the device at the beginning of a race and will tend to anticipate a finish and be a fraction quick to press the stop button.

The Wikipedia entry Athletic Abbreviations under times and marks gives a good summary of the concerns re manual timing and World Athletics detailed instructions re manual timekeeping includes the telling comments

'Differences in timekeeping are due to differences in individuals’ time to react at the starts as well as at the finishes.'

and

'Being a timekeeper means not following the events taking place in front of him as a spectator.'

If the Athletics world is concerned about accuracy when they have a timekeeper in a stable non moving position who can clearly see the start and finish over an accurately known distance in usually decent light then the concerns about such times on a moving train are considerably more.

https://en.wikipedia.org/wiki/Athletics_abbreviations

 

As noted the biggest variable is the human element as evidenced by the recent attempt to beat the Euston - Glasgow non-stop run time where the driver was keen but the signaller set a train in front IIRC at a critical point. If you recall other recent attempts it involved on-train staff keeping in contact with signalling staff to ensure clear paths to assist with the appropriate trial including the VT trial with the water coach to ensure a clear path to complete the calculated non-stop distance. Another recent example was in Japan where IIRC a driver was "carpeted" for being 8 seconds late on his bullet train and in the UK there are known drivers willing to speed trains to overcome delays whilst others stick to running times irrespective of the situations.

A (foreign) example I sampled in South Africa was the 2 Garratt-hauled freight trains were combined by the crews concerned because they were playing in a Rugby match in the afternoon and didn't want to be late back at base. "Dusty" Durrant was annoyed to miss such a rarity especially when both locos were facing the right way but accepted that being arranged on the day by local crews he had no chance of being aware beforehand.

 

Isn't it human nature to want to know how fast something or someone has gone? The Olympics, personal times for 10k runs. OK, steam trains are an esoteric interest but no different. What was the fastest steam ever from Settle Jct to Carlisle? See the RPS site, the answer might surprise you. What is the Blue Riband holder from Ormside to Ais Gill? See @iancawthorne website. How did 35018's best runs compare with the record? For a certain set of afficionados, there is interest in that. Obviously there is no performance interest in downhill runs with speeds limited to 60. But anyway.....

Timings show what the loco and crew did on that day, no more and no less. Didn't C J Allen run into trouble from time to time for describing various runs as disappointing or below par without knowledge of the circumstances on the footplate?

Winkworth is good though because he assembles data on hundreds of runs. So then, in principle, if you had proper data on the variables you mention, you could attempt some sort of mean/variance analysis to see if there was any systematic difference between rebuilt/unrebuilt or MN v WC, the time penalty for 400 tonnes v 300 etc.

 

I think I am likely to become the most unpopular railway author in the land, but...

Timekeepers and timekeeping is a niche that feeds into the specific aspect of very subjective opinions on locomotive design from line-siders and observers who were not involved in the day to day running of the railway.

If you want to know the value of a locomotive class, you look at its annual mileages, its availability to do work, the cost to design and/or build, and cost to maintain, and the value of the work done for the railway company. The bottom line is that the historical, primary evidence in the form of operational records for the locomotive class from the company concerned will indicate its true value.

Which is why, for aficionados of the LNER, for instance, the Use of Engine Power document at the National Archives has a much higher value to an objective discussion on locomotive performances than any timekeeper's logs, such as those recorded by Cecil J. Allen.

If I may hazard a comment: many of the timekeepers' books that were published in the 50s, 60s and thereafter, have muddied the waters significantly where locomotive performances are concerned. Obviously you know my specialist subject, but I doubt the locomotive designs of Edward Thompson are alone in having their reputations seemingly based on just performance logs and secondary evidence, as opposed primary evidence direct from the companies operating them.

 

Timings are very good for telling the story of one particular locomotive, on one particular journey, with one particular load, driven by one particular engine crew, on one particular day. Other than that….not much good for anything else!

 

When I saw the title of his thread my mind went immediately to all those 'Locomotive Practice and Performance' articles by O S Nock.

Unfortunately they were the pages I just thumbed through to get to the notices at the back that told us the sad news of which locos had been withdrawn from service that month, which had more immediate bearing to my life then.

 

I'll post something railway related in due course, but just to pick up this point: it is a misconception that F1 was once solely about the driver - it (and top-level motorsport in general) has always been as much about the machine as the driver. The origins of motorsport came from car companies wishing to demonstrate the abilities of their cars (whether in speed, reliability or both); the driver was simply a means to that end. Pit strategy has also always been an inherent part of racing.

An example to show the point - it comes from Indy rather than F1, which is an older series, but shows the point. On technology: the very first Indy 500, in 1911, was won by a single seater Marmon Wasp car (which, incidentally, still exists). At that time, most racing cars had a crew of two, the driver, and an observer whose primary job was to look behind and warn of upcoming traffic. The Marmon company fitted what was thought to be the world's first rear-view mirror; with that fitted, they dispensed with the riding mechanic, making the car smaller and lighter, and easier for the driver to concentrate. In the same race, the driver, Ray Harroun, had also discovered through testing that if he limited his speed to 75mph rather than the 80mph his car was capable of, he preserved his tyres, thereby needing fewer stops (at a time when a wheel change took several minutes). With that combination of better technology and better pit strategy, he won the race by just 1m43s, in a race lasting nearly seven hours.

That was well over a hundred years ago. So it is a misconception that somehow there was a golden age in which only the driver counted: that has never been the case.

Tom

 

thank you all so much so far - answers which I can all agree with. My Winkworth devotes nearly 100 pages solely to timings of Bulleid's which would have been very precious to those that recorded them yet for me, it's difficult to take anything tangible from them other than each table is a record of those specific runs on those specified occasions. On the other hand, had I been a regular commuter catching same train everyday hauled by same types of locomotive with a number of regular faces on the footplate, I could see how recording timings might have become addictive to some.

 

9F speed 90 mph.
It has been mentioned that a 9F could and did 90 mph every day.
Mr Steve who run steam on NYMR say that a WD 2-8-0/2-10-0 with no recprocicatory balance becomes uncomfortable at 25mph/2.5 rps .

9F reciprocicatory parts have more or less same mass as a WD and must have run 8.4 rps to go ninety.
Fore and aft forces go up with square of rps that is 11.2 times what Mr Steve find unacceptable with no reciprocicatory balance.
9F has 40% balance and the same level of uncomfort is thus coming at 3.3 rps or 37mph.

It interests me because I found by accident that boiler diameter ,grate area and pitch over rail is more or less identical for a 9F and a Chapelon 4-8-o.
A modified 4-8-0 9F doing say 40 as max speed is not really something but 75mph will be smart and a match going uphill.
Having a single 20 inch outside HP and an inside 30 inch LP it will use less steam for same job as a LMS or BR pacific,but will need some drastic balancing..

Chapelon 240P-overlay(4) by Hermod posted Apr 1, 2022 at 8:41 PM

4-8-0 Caproti. Nyeste by Hermod posted Jan 28, 2019 at 7:35 PM

 

For anyone who hasn't come across it and is interested, this is a very readable site.

https://locoperformance.tripod.com/performance-stm.htm

 

I can’t remember ever saying that the WD 2-10-0’s we’re uncomfortable at 25 mph. I’ve no complaints about them.

 

Was it only the WD 2-8-0 then?

LMS tried a Black Five at 20% and found it unacceptable;40% was OK plus 60% and that was nice.

All according to Cox

 

it certainly was not a regular occurrence .
92178 - or was it'58 ? caused a bit of a brouhaha when it was timed at 90 on the ECML. the result being a speed limit being placed on these engines

 

Provided you can keep the wheel rim in contact the rail and don't mind a lot of track renewal!

High reciprocating balance simply transfers the horizontal out of balance forces to the vertical plane.

 

Sure and makes it nicer on the footplate as the fore and aft movement is less than if there is noreprocicating balance as was the case with WD 2-8-0.
Mr Powell was allowed to modify a 2-8-0 and the crew did not believe it was same class of locomotive and mr Cox neither commented or promoted it after having been on the footplate.
In much of Europe two cylinder locomotives were allowed to run 5 revs per second and hammerblow 15% of the static load on wheel.
Going faster was only for three or fourcylinders.
9Fs were claimed to have run 8.4 revs or 90 mph and destructive forces and uncomfort goes up as a square law 0r 3.5 times the continental limit.
It can hardly have been pleasant on footplate and firing must have been difficult.
The thread here has timing as topic and I wonder how beliveable the 90 mph 9F claims are?

 

Yes, I rode a few Black Fives at speed in 1968. I don't know the percentage of reciprocating balance in each one but they were lively riders, although this was more to do with mechanical condition by that time.

The point I was making was that balancing is a two-way process with losses and gains. High balancing results in hammer blow and can lead to much worse. In 1939 the LMS did tests with three Black Fives balanced at 66.6%, 50% and 30% of the reciprocating masses respectively around 100mph on greased rails, so movement of the engine along the track was very small. At 66.6% there was little fore and aft oscillation; at 50% it was moderate; while at 30% it was stated as 'Excessive'. BUT - with the 30% balanced engine there was no lift of the wheels from the rail; at 50% the wheel would lift 0.4 inches each revolution; while at 66.6% balance the wheels lifted 2.4 inches clear of the rail.

Having been a fireman on the Severn Valley Railway, I'm all for crew comfort, but I have a pang of sympathy for the Pway gangs too!

 

Mr Cox states that the BR clas5 were 50% balanced,but what the normal LMS`s had is probably unobtainable today..
Claims of BR class five doing more than 100mph is claims.
Cox states that the 30% results were unacceptable and that is more than exessive I presume.
But it gives good numbers as I can find the mass of moving parts in Cox