Steam speed records including City of Truro and Mallard

Even re-typing the two links I can't get them to work.

 

https://www.google.co.uk/books/edit...0NA0AQAAMAAJ?hl=en&gbpv=1&printsec=frontcover
https://archivecat.imeche.org/records/CAR

But in both cases, only the biographical details, not the actual paper(s) referenced - so you would need to find a reference library for those. Nonetheless, a useful lead for @S.A.C. Martin who, one assumes, should be able to access each via his university library service.

Tom

 

So... we seem to have a number of people on here desirous of proving that Mallard did NOT achieve even 125mph and so was beaten by the German 05 locomotive.

Well, to those I say: put your money where your mouth is and let's all see the documentary, verifiable proof that the 05 was faster. Y'know, real facts and records, dynamometer measurements, not a man with a stopwatch.

Otherwise that claim is as trustworthy as City of Truro's 102.3mph.

 

Yep, I have copies of both and they prompted my original investigation ahead of getting onto the PhD.

 

Here, here.

 

I’ve ordered the book on the 05 and will be interested to see the comparisons.

I am left with a lot of questions after reading Andrews’ points yesterday. Mostly how he has calculated these speeds for the quarter miles.

We still don’t have a copy of his data, and I find there’s a contradiction being made in the speed of the paper roll claims - but he has also questioned how the quarter mile marks are made.

I have reached out to the NRM team and am in the process of organising a meeting with an expert on the dynamometer car. I have put together some questions - if anyone else has any, please let me know and I will ask them and record the answers for you here later.

 

This is not the sore point.
The speed numbers published after 1938 run are physically impossible.
The publisher was either grossly incompetent or trying to fool the public.
If it was other peoples money publisher migth be behind bars.

 

You do talk some nonsense at times.

 

Can you therefore explain that in terms clear enough to convince a jury of lay persons beyond reasonable doubt (which would’ve been the standard of proof required to put that publisher in jail - leaving aside your assumption that prison’d be appropriate)?

 

I have also ordered a copy. My German isn’t the best so I will be relying on an element of google translate and a Germany dictionary to support me in my understanding!

Hermod, I respectfully disagree. I think what this whole thread has shown me is that there’s many ways of interpreting the same data and primary evidence.

My work, which is being peer reviewed, opens up its own can of worms. That’ll be covered in my limitations section of that part of the paper.

Mallards run is able to be studied more accurately than any other steam locomotive record. No other locomotive can be analysed to the degree Mallard has.

Whether she did 124, 125, 126mph - or faster - or slower - Mallards achievements are not found in the highest speeds section of the roll, but near the beginning of the run, in fact.

I think the LNER and then BR (E) teams worked in good faith and the publication of the 125mph run, later corrected to 126mph, is based on something real. But the interpretation of the data will differ from those reading it.

For my part, I disagree with Mr Andrews on a number of points but I respect the academic value of his thesis. He is allowed his views and some will agree with him. That is fine.

I don’t however subscribe to the view there is anything heinous that has been done by anyone here. To suggest so is provocative and unnecessary.

 

Some very quick ones:

1) What process did the NER (and later LNER) go through to calibrate the dynamometer car (for both distance and drawbar pull, though in the current discussion it is the distance that is interesting).

Hypothetically, if they ran trials over a carefully measured distance of > 1mile, then that was possibly perfectly adequate for their requirements, but wouldn't have shown the cyclical variation discussed by Andrews that is over a shorter period. Running calibration over a shorter distance would increase the error bars in their results. Worth bearing in mind that the primary value to the LNER of the dynamometer car was not to record peak speeds, but sustained efforts over a distance, so calibration over longer distances makes more sense even if it masks short-distance oscillations in calibration.

1a) Are the notes on the calibration for Mallard's run also preserved?

1b) How did the LNER adjust the results once they had run their calibration? For example, if they ran over a measured distance and found a 1% error, how did they adjust for that - could they do that in the mechanism, or did they apply a calibration factor in subsequent calculations?

2) Apart from Mallard's run, what was the fastest speed recorded by the dynamometer car? How frequently was it used above 100mph?

3) What was the precise drive mechanism between the ninth wheel and the paper roll?

3a) Could it be disconnected? (Presumably so, since I'd have thought you'd only want to record parts of any given run that was of interest).

3b) Was it connected by direct gearing, or some other mechanism?

4) What is the rolling surface of the ninth wheel like? Is there evidence that it had to be periodically turned? How did they allow for that in calibration?

(As a "for example": the circumference of the ninth wheel is said to be 12 feet, which is a nice convenient 440 revolutions per mile. But if you had to turn it down by 1/16", you take off 1/8" of diameter, about 0.4" of circumference. That introduces a distance error of about 0.3%, which will be on the positive side (i.e. reducing the wheel diameter makes the apparent speed faster than actual).

5) AIUI, the 1960s calculated speed trace shows very rapid variations of up to 2mph, and equally sudden decelerations, over the course of a few seconds. How does the NRM expert explain those variations?

I'm sure others will have other questions.

Tom

 

Thanks Tom - a number of these overlap with some of mine so I will merge them into the list. Many thanks for your swift response.

 

It took a little time to see what problem is.
A person who takes care of other peoples money(CFO?) is asked How is buisness?

He looks at numbers like this

Mallard by Hermod posted Dec 5, 2023 at 10:03 AM

chooses the best cherry number and says fine we are worlds best performing.
None of the numbers are true data.They have been distorted by unsuitable mechanical distance measurements and not so clever manual data selection.(5 seconds)
Luck has it that steam locomotive speed is not as important as insider trading for most people

 

What have you based this table off, out of interest?

 

These are largely the same questions I’ve been asking for a while. If I can add to Toms question 1, was a calibration check carried out afterwards (not necessarily on the same day or even week) and, importantly, were any adjustments found necessary? Still with calibration, was the chronometer checked?
Additionally;
2) How was the take up drum driven? Presumably by a friction drive from the distance wheel but could this drive drag the paper through the paper drive drums?
3). How were the quarter miles derived? It has been suggested they were derived from cams on the chart drive. If so, have these And the cam follower been checked for accuracy?

 

I will add these to the list Steve.

 

With all this questioning of the accuracy of the NER dynamometer car I'm left wondering how long it'll be before people then start questioning if Flying Scotsman ever achieved 100mph?

 

Your criminal charge is understood - but not your evidence. Perhaps you’d qualify as an expert witness but not as counsel for the prosecution

 

They won't be the first if they do.

 

Se 273 letter