Saint Class 135 ish mph

I'll just pick up on the word "criticism" in relation to the above posts because I don't think that they are. What I believe @Courier has done, (and others, including yourself!), is an excellent job to analyse the information to hand, and to identify that within the speed measuring processes there may be inconsistencies that, whilst very small, will affect the total accuracy of the final readings. The higher the speed goes the greater the impact of any inconsistencies and I believe we are still talking about +/- variations, so depending on which side of the fence you wish to make a stand on, the opposite could also be deduced from the same findings.....or you could just sit on the fence and say that the result is somewhere in the middle and we are all none the wiser!

I don't think that like for like, anyone will assert that a man with a stopwatch is going to be more accurate than a properly calibrated dynocar. (I'm still hoping to hear if anyone knows how we can be sure of the calibration!). Calling the stopwatch used into question is a little far fetched I think - a timepiece, (and I know nothing of such things), that perhaps looses a few seconds or even a minute over say, a 24 hour period will have such a minute bearing on the outcome as to not warrant consideration. Clearly the reflexes of the man holding the watch deserves the greatest scrutiny as well as the accuracy of the milepost placements!

 

Whilst I agree with the crux of your point, my point in a roundabout way is that the comparisons being made and investigations into the two records do not appear to have the same level of scrutiny or questioning.

Hence the timepiece question; which you can take seriously or not as you please, but it remains a factor.

 

So with doubts concerning the accuracy of both the 100mph records of COT and FS, Papyrus which definitely achieved 100+mph was scrapped...

 

Oh honestly. You can hardly say that Rous-Martens timings have been under-scrutinised (or under-questioned) over the decades. Very hard to bring anything new to that table.

 

From where I'm sitting, Courier's aim seems to be to disprove Mallard's claim to be the fastest steam locomotive in the world. I feel therefore that his analysis is not dispassionate.
I await his thorough probing of the German claim with interest.

 

Both Silver Link and Silver Fox attained speeds well in excess of 100 and they've been scrapped. There will be others of course.

 

True, but I was alluding to the fact that Papyrus may have been the first to really achieve 100mph, and unfortunately is no longer with us.

 

I'm rather bemused that people here are still finding anything to argue about. CoT certainly did somewhere about 100 mph. Probably slightly over, but possibly not quite. In the absence of a time machine anything more definite than that will never be known. Mallard certainly did about 125 mph and so did the German loco. Given the various sources of measurement errors it's impossible to be certain which went slightly faster, but Mallard's claim has been generally accepted for 80 years and nothing said by anyone on here is likely to change that.

The most valuable contributions here have been the various analyses of the sources of error and the interesting comparison of the two independent sets of marks on the dynamometer roll.

 

My aim is to be objective. I went to York thinking I might find evidence confirming 125 or 126, and was quite surprised to find that wasn't the case. If anyone doubts my findings it wouldn't be difficult to see the roll and form your own opinions, all you need is a free day and an unhealthy obsession about collecting and processing data.

I have already given my opinion on 05 002 earlier in this same thread:

That concerns me also - comparing a modern interpretation of Mallard's speed against the historic one of 05 002 is not apples to apples. The original roll of the German run is not preserved as far as I know. It is known that the method was very similar. In some ways it appears less accurate (the paper speed was much less, 150mm per km I think, about 10"/mile), in other ways more accurate (it appears that the 200.4 kph claim is based on an average over 5 km) - but without seeing the original roll who knows how accurate their messwagen was at such high speeds. I suspect that the most you can say is that the two locomotives achieved speeds too similar to be distinguished using the measuring methods of the time.

I don't think there is anything more to say on this topic. To sum up...

• A speed claim based on a one second timing is not robust.
• The paper roll was travelling at 24"/mile - but the speed varied causing artificial speed peaks at 0.1 miles (for instance at 90.1 and 91.1 miles from KX) and dips at 0.6 miles every mile. This can be seen by comparing point speeds with the average over the mile over 15 miles of roll.
• The scale used by the LNER to measure speeds off the time trace gave readings slightly high. This can be seen by calculating the distance travelled from the LNER speeds and comparing them with the distance actually travelled.

On that note I will bow out.

 

All fair enough. Just to round it off with the OP you could add that Lady of Lyons was not timed in any meaningful way, but was most likely running at well in excess of 100mph, but any mention of 135 has no measured basis at all and serves only to confuse the issue.

 

I think I may well do that. It has certainly piqued my interest (and from my side, I hope you know my debate is not a personal thing - robust debate is healthy and I have enjoyed the back and forth. It has been educational).

I am unsure that it was a one second timing but I agree with the crux of your jibe.

How do you know that this was definitely the mechanism and not the locomotive?

The centre cylinder on the Gresley LNER Pacifics (not the Peppercorn or Thompson ones) does more work than the outside two and it was apparent during testing for the Gresley A1s and A3s that at higher speeds the centre cylinder overran and produced higher power than the outside cylinders.

This is due to the conjugated valve gear mechanism and is a well known characteristic of these locomotives.

I would be curious to know what statistic you have used for "the distance actually travelled?" As in what source are you working from?

It is also curious that you claim the speed was definitely not 126, nor 125, but won't given an indication as to what you believe it is.

 

I did mean specifically within the confines of this thread Jim. My apologies for not being clear. You are quite right however that his timings have been well scrutinised previously.

 

If you have a regular cyclic variation over the course of a significantly long distance (@Courier says each cycle is a mile) it is highly likely to be an artefact of the dynamometer mechanism. Any variation on account of the valve gear would be over a cycle of roughly 21 feet (i.e. one revolution of the wheels) and would cause essentially imperceptible speed variations because the huge inertia of the train would smooth out any variation.

Tom

 

hardly matters really, 125 or 126...my Focus will do that. (won't do 135 though)

 

I am led to understand that when BR was breaking records with HST's they had a man with a stop watch to log it all, I believe they had a 'preferred' (not staff) train timer for this

 

Fair points all - thank you Tom.

 

I've devised a simple system to resolve the controversy:
To any measured or claimed speed, you add or subtract the following:
1. For being built at Swindon, +5mph
2. For every member of the Nazi party on board the train -1mph
3. For being the most beautiful class of express loco ever built +3mph
4. For nice blue livery +2mph
Then you divide by the amount of time we've all wasted discussing it, and multiply by the BR running number (or DRG number, or book number of Thomas the Tank Engine appearance).
Hey presto!

 

So, in spite of their less than Swindon pedigree, the Caley 'Cardeans' really were superb after all?

 

You mock, but I have enjoyed the debate and learning more in the process.

 

No time wasted here - we didn't touch on livery once!

P.S. I think the Internet was pretty much invented for time wasting anyway.....