Mallard. Well, did it?

Bit of a question, this one. Did Mallard ever really do the business? There is no denying it went really fast. But...Was it 126mph? The reason I pose this, is because of the dyno car. How do you calibrate it? Do you match it against another equally calibrated machine (not easy, when you only have one), or is there another way?

Point to point is quite straightforward. Start here........Stop there. As long as the measured distance is known, then you are ok.

Also, I read somwhere that the technicians on board the run said that Mallard achieved 125mph. When the driver heard this, his comment was that Mallard had done 126, and this speed stands. Now, if one man can alter a world record, by word alone, then how accurate is the recording device?

Please, no throwing the baby out of the pram.......

Nothing wrong with an A4.... It starts in London, finishes in Bristol...... Via Reading, Marlborough & Bath.....

Ian

 

of course it did 126...don't make me come round there....:faint2:

 

126 was later verified. The video (worth watching either way) clarifies how it was all verified.

Part 1
http://www.britishrailways.tv/british-railways?task=viewvideo&video_id=1389

11 minutes in has the details.

Part 2

http://www.britishrailways.tv/component/hwdvideoshare/?task=viewvideo&video_id=1387

Regards

Duncan

 

Wrong there mate. Best thing about the A4 is stretch that takes you FROM Bristol TO London from where you can go to the southern end of the ECML - the home of thoroughbreds.

 

Calibrating the dynamometer car was fairly straight-forward. The distance was measured by a 'ninth wheel' which served no load-bearing purpose but which rested on the rail and rotated with the movement of the coach. This wheel was of known circumference, so you know how far you've gone. Time-measurement is quite simple with a good clock checked against some standard time piece. Hence you can calculate the speed.

But all measurements have a degree of inaccuracy - the error - and therefore the record had to be further analysed for the errors and the 'best-fit' line drawn through the points to get the average. (This is the extra analysis refered to in the video clip.)

Regarding the driver commenting on the speed - you have to remember that he was not speaking at the time of the speed attempt but at some time afterwards, by which time he'd been told what the actual speeds were at the various points from the detailed analysis that had been done by then.

Hope this makes things a bit clearer,

Regards,
John Webb

 

I was told, many years ago, by the Late John Bellwood that he believed 'Mallard' may actually exceeded 126 MPH. As the Dynamometer car was not designed to reach such speeds the one factor that was never calculated for was the increasing drag of both the paper over the rollers and the ink on the paper as speed increases. He believed that perhaps another 1.5-2 MPH could be added to allow for this.

 

I can see the logic in that line of thinking. I wonder what the author of that article in SR a couple of months ago would make of it?

 

That's quite an interesting point...

 

The idea of the ninth wheel slipping is just the sort of thing I was thinking about. I'm (hopefully) not suggesting that Mallard didn't do it, more a case of accurately recording the speed. If it did actually go faster, then thats fine. If it went slower, thats OK as well, after all its only 73-odd years ago.....

Ian

 

I remember reading somewhere that Mallard wasn't the best example of the A4 to try for the record, the factor in the choice was that she was the first fitted with a double kylchap. Apparently, the likes of Guillemot were supposed to be much better engines. More record attempts were planned for late 1939, but as history tells us, these attempts were never made.

Interestingly the rebuilt W1 was apparently intended to be the testbed for further enhancements to eventually develop the rumoured 'Super A4'. Does anyone know if there ever were such plans or developments that actually took place?

Mallard is still my favourite loco, will never forget the first time I set eyes on her.

 

Not denigrating Mallard. City of Truro, Sir Nigel Gresley etc but I find many of the speed records a bit hollow as they all relied on the assistance of gravity on a reasonable train weight to achieve the reported speeds.

I would much prefer such speed records to be based on running on the flat rather rather than being influenced by which line had the steepest, longest hill. I do not know if it has ever been calibrated but are there any indications of what speeds would have been recorded on the various record breaking runs if they had been run on the flat. I would be quite interested in knowing the differential i.e. what speed was down to the loco alone and what was gained from the assistance of the downhill run

 

True, but not many countries can boast an adequately flat stretch of track over a substantial enough distance. Railway record-making is by its very nature an imperfect science affected by gravity/wind direction at some point on a given run. Even if a test-train encounters a flat stretch of track after a descent, it would still be under the influence of momemtum for a fair way before a true reading can be taken, and by that time, it is probably time to climb again.

 

According to the Pennyslvania Railroad the true fastest steam locomotive was this one.. in 1907..



So for those not in the know, the PARR claim is that this locomotive on June 12th 1905, ran at over 127mph thus surpassing that of 4468 Mallard.
Considering by the time of the worlds fair in 1939 (at the time of the US tour by LMS 6229 Duchess of Hamilton as 6220 Coronation) the real 7002 had been scrapped, and the historical significance of this locomotive not only missed.. but forgotten and not noticed by the railway press following Mallards feats in 1938..
This locomotive is actually 8063 and was renumbered 7002 specifically for the world fair of 1939 and retained it since.

 

Most of the older rail records would abjectly fail any kind of reasonable evaluation. Who had the best hill seems to be a large part of it - and who was prepared to "break their bloody necks" was of course another part. Ideally records would be taken of the average in both directions like any other speed record, but there are very few places where it can be done. But by any reasonable evaluation the DRG locomotive which reached 200kph on substantially flat track two years earlier was a faster locomotive.

 

126?127? who cares? my car is faster than that.
Thing is it isn't a Legend and Mallard is...(stupid name though..shame it wasn't called Doncaster Castle or some other proper name)

 

Great videos. Thanks for posting the links. Was the commentator on the Silver Link footage in part 1 having a bad day? He says a very bad word just after 4 minutes 30 seconds ".............******* ancestors." I thought I was hearing things but can't work out what else he is trying to say.

 

It's not as though there wasn't any Swindon tat named after a bird or other daft animal or even plants is it? Oh hang on a minute, 3352 Camel, 3741 Pelican, 3742 Penguin, 4110 Petunia etc. So looks like the Swindon boys did choose some stupid names after all. 125 or 126, 4468 was still miles faster than those glorified dock shunters that Swindon cobbled together.

 

Meow !!, wassup was there no spam in the can this morning ?

 

Just enjoying a bit of Swindon bashing and baiting.

 

as I am too...