Steam speed records including City of Truro and Mallard

I have no evidence but 4 length measurement on a 24 inch piece of paper from 1938 in NRM can show if mr Andrews and I are nuts.

 

It is a pleasure to read the Gottwaldt book.
The 05 run was organized and measured by state people with latest equipment.
Their daily job was to find not fullfilled specified contractual values on the expensive junk private locomotive manufactures used to rob the common moneybox with.
A british CME built and tested own creations.
05 had 2m per second following wind during test.
Any comparison with a train going down a 1:200 grade is meaningless.
The number of revs per second not going haywire is the real important number
Mallard 8.82 05002 7.78 A2 spinning was +11 from acustical analysis and caused human harm.

 

I would suggest that either "revised" or "amended" would have been a better choice of words than "corrected" as that implies that 126mph has been proved. I know it's a minor thing, but appearances count, and I'm sure you don't want to have your research called into question by any possibility of bias towards one particular outcome or another. Obviously, if in due course you are able to prove 126 mph, this becomes an irrelevance.

 

Noted, but just for the record, I was writing in a hurry earlier.

I’ll be sure to “correct” that for the publication!

 

With their very large drivers, long frames and long boilers, the 05s were heavy machines at 129t. They were paired with large 10-wheel tenders of laden weight 85t, carrying 10t coal and 8100 imp gals (37 cu. m.) water. Mallard's tender was significantly lighter at 64t, although still heavy compared with a GWR King's 47t tender.

The Germans might have benefitted if they had tenders designed by Mr Bulleid. He somehow contrived to build MN-class tenders that squeezed 6000 inp gals of water into a 6-wheel vehicle with a laden weight of only 52t.

The large German tenders were presumably designed to be adequate for the 286 km (178 mile) route from Hamburg to Berlin, without needing to refill or change engines half-way. That is a similar distance to the routes from London to Exeter, Manchester and York.

The reference above to John Ramsbottom and water troughs is perhaps a timely reminder of an important factor that is easily overlooked in comparisons between different railways. When first invented in 1860, water troughs must have seemed something of a gimmick. For some decades, only the LNWR employed them, joined from 1887 by the LYR. They spread more widely to other British companies from around 1900, as the arrival of corridor stock and restaurant cars removed the need for refreshment stops on long journeys.

Overseas take-up of water troughs appears to have been limited to the French Western Rly and to some railroads in the NE of the USA (including New York Central and Pennsylvania). Given the maintenance and operating overheads of water troughs, it was possibly something that would appeal only where a railway was in competition and an offer of improved speed would help to attract custom from a rival.

Reference the 1895 "Races to the North". Without the LNWR's troughs, Mr Webb's engine "Hardwicke" would not have been able to achieve its phenomenal 67 mph dash over the hilly 141 miles from Crewe to Carlisle (with a reported 84 mph max on the descent from Shap Summit - fast, although some way short of the 102 mph attributed to "City of Truro" only a few years later). Without troughs, an engine change (at Lancaster?) would have been needed. Without troughs, would the West Coast companies have still emerged victorious in that race?

 

The extra wheel set must be a sizable chunk. Then one suspects the lack of water pick up apparatus and associated ducting etc would be part of the differential, and is your LNER figure for a corridor tender? Would Bulleid's wheels have been lighter too?

 

John Ramsbottom and the LNWR held patents on water troughs, and engineers and railways hated paying royalties on anything. It's likely that they simply didn't install troughs until there became a real unarguable reason for them.

I believe the GWR got around the royalties by allowing the LNWR free use of the crosshead driven vacuum pump so it was a simple exchange deal.

 

Possible irregularities in the movements of the chart paper are of some interest, but not as critical as the distance markers. So please add a question;
What was the exact drive mechanism between the ninth wheel and the pen that recorded the distance markers?

 

Toms questions cover that I think but I’ll put this down on the list.

 

Just a thought that occurred to me which is spoken more out of curiosity than to make a point - was the paper on the roll actually a continuous piece, or was it made of several pieces joined together? If there were joints would that affect the recording as the joints went through the mechanism? Joints might not show up on a photo very clearly.

Steve B

 

Just an observation.

We are getting into the minutiae of how the dynamometer car works to an nth degree. Which I don’t mind tbh as I think it’ll show us that it’s a very accurate mechanism, well looked after, but likely working at the limits or beyond its original design limits on this specific run.

Yet whenever I look back at the discussions we’ve had on other speed records, which ultimately come down to a man looking outside with a stop watch at mile posts in the ground, the level of interrogation is very different and the level of acceptance for the limitations of that approach are very very different.

CoT did not achieve 100mph, in my view, based on the scant evidence we have available. I think the argument against it mounts up when we consider the locomotives own limitations, aerodynamics, and more.

In Mallard's case I am supremely confident that it’s not “black magic” that is required to hit 126mph for a short period and I think there are some obvious facts that push us in the direction of a higher speed, not a lower one.

But it is fascinating to see the arbitrary positions being taken up, regardless!

 

Whilst it is good to examine detail, there is a terrific amount of "yeah, BUT..." going on here where Mallard is concerned.

 

As always there are good points here, but even as a GWR man I'm agnostic about what CoT may or may not have done, other than (like Mallard, or Coronation in 1937) run quite quickly down a hill. I think any reference to CoT is irrelevant at this stage of the conversation here, partly because I don't think anyone has really mentioned CoT in the last few pages, but mainly because of the plurality of sources that there are relating to the 1938 run, not least the presence of the dynamometer car, as opposed (as you note) to 1904. I'm not also convinced that anyone is taking arbitrary positions on Mallard's run, although I'm sure there are some people who believe on side or the other, and would no doubt like it to be proved to their satisfaction. The only person who seems to have taken a well-defined, informed, and argued position on what happened is David Andrews, and while that's a position which you appear to disagree with, it's certainly not arbitrary. Again, for the benefit of doubt, I have no idea myself -it's way beyond my pay grade.

 

I just want to make it clear, I do not consider Mr Andrews work arbitrary.

I am referring to other statements made.

 

What primary information exists for the German run?

 

Reportedly, not much.



http://www.germansteam.co.uk/FastestLoco/fastestloco.html

On a side note - have we all done this dance before? And is Mr Andrews name on this forum “Courier” per chance?

https://national-preservation.com/threads/saint-class-135-ish-mph.923959/page-22

I’m posting this for interest as I thought some of the things being said sounded familiar and have gone back and re read many of the posts made.

I didn’t have access to Mallards roll in 2017 so we were all discussing what appears to be Mr Andrews interpretation of it then.

I now have access to it and I am, to put it mildly, amused at some of the things that were being said in 2017.

One thing I would like to address - there is a claim in that thread from the user Courier which states 125mph was not to be found on Mallards roll.

I don’t know where this comes from but it most certainly is found on the roll, it’s calculated over a five second interval and is physically written on the dynamometer roll. This speed happens just ahead of milepost 90.

I have done my own examination of that section of the graph and it undoubtedly shows 125mph was achieved by Mallard. Both by examination of the LNER teams calcs, my own quarter mile calcs, and examining Mr Andrews approach.

Putting the question of 126mph to one side, there’s absolutely no doubt of 125mph being recorded on the dynamometer roll.

 

According to his profile

https://national-preservation.com/members/courier.10874/

Courier is

Full Name:
Andrew Gamarra

 

The plot thickens!

 

No idea why his profile shows a different name but if you have a look at all 7 posts by @Courier in the following thread, you’ll see he clearly identifies himself as the author (David Andrews) of the August 2018 Back Track magazine article about his examination of the dynamometer roll.

https://www.national-preservation.com/threads/mallards-maximum-speed.1191983/

 

Will it be a breach of your copyrigth obligations to measure distance between the relevant quartermile marks on your secret and very expensive high class photocopy?
Could save a lot of noise here.