Just How Fast will Bittern Go?

It may not have been possible in normal steam days on reasonable weight trains to have run that fast between Peterborough and Grantham because there used to be quite a slow restriction through Peterborough, (20 - 30 mph?).

I do recall some outstanding runs up Stoke by 60163 fairly recently , possibly on heavier trains but don't know the times or if they a had a clear road all the way. I'll check and come back on that.

But on ten cars such a time would be achievable by a number of classes of steam loco. And that would represent very good running for all of them.

It would help of course to know the exact time it did take. Still no sign of any detailed timing logs anywhere.

 

Can't easily find any pass to pass runs, most preservation era runs had strange stops etc!

But I found the 60163 run I was thinking of.

29.19 Peterborough- Grantham, start to stop. On 13 cars for 510 gross. Close to 70 over Stoke. In 2009. Equivalent to 24 minutes pass to pass, but with the 75mph limit applied. An outstanding performance on that load, albeit with an almost brand new loco, not one that would have every right to be enjoying a quiet and easy retirement now!

And from 1963 a 26.06 start to stop behind 60007 on 9 for 320 gross. 74 over Stoke. Equivalent to under 23 minutes pass to pass.

 

So, when will we find out the shocking truth about the top speed (and will it be debated in perpetuity as the 126 has been)?! I notice the voting options start at 93mph - suitably optimistic!

 

It was northbound heading towards Carlisle, Ralph.
I also remember that run out of Crewe with 46203 and on another occasion when the same loco came hurtling
down Boars Head bank and through Wigan NW at 90mph. Talk about hang on to your hat!

 

I have seen a log of a run with 60022 where speed had dropped on the northbound climb of Stoke but she then accelerated her train to the summit. The timer calculated that she'd put out more horsepower than when she broke the record. The problem is I'm damned if I can find the book in which I saw it.

 

As the stock is limited to 100mph I think they will go for 99.9mph down Stoke bank.

 

One can imagine the first aliens landing on Planet earth and the first question they would ask is, "we have been monitoring your country for decades now. But please tell us why the most debated subject is about an event that lasted just a few seconds xx years ago? Or didn't last that long according to many? Was the exact speed crucial to world food production? Or to controlling energy use? We can answer the question though, as we have been making recordings of every event on earth for many years now."

Now don't start that!

Not another "did she, didn't she" that will last into eternity, or until those aliens land.

 

60022, 415 tons full, checked to 20mph near Helpston crossing, 82mph at Little Bytham, dropped a little to 80mph at milepost 96, then hit 82 at Corby Glen. 78mph at Stoke Box.

60007 on the Coronation was a decent achievement too for the climb.

 

No one has mentioned the owner's wishes in all of this. 100mph represents 25% more kinetic energy relative to 90mph, and correspondingly higher forces being absorbed in the loco. In other words, the owner may well be happy to see a nominal 90mph (with a bit of leeway up to 92 or 93); but rather less keen on 100mph (witha bit of leeway up to 102 or 103).

And with regard the 10% rule (if such a thing exists). That is surely designed to allow a little bit of flexibility around the maximum speed to take account of the fact that locos tend to settle down to a certain rhytm where they are happy, and for the crew not to worry too much if that happy point is one or two mph over 90mph; nor to worry too much about a miscalibrated speed recorder. It is surely not carte blanche to say "90mph + 10% = 99mph, so 99mph is our target". In the same way that the police or a speed camera will allow you a little bit of leeway on a marked speed limit to allow for the fact that a speedo may not quite be perfectly calibrated, but 70mph still means 70mph: the fact that you probably won't get nicked up to 77mph isn't carte blanche to drive at 77mph - even though many people do just that.

Tom

 

Technically correct Tom, but when posting the following I did start to add such as the loco crew, support crew, owners etc, but it started to look like one of those Oscar acceptance speeches.

So for the first time in well over two thousand posts on Nat Pres I actually used two words to cover where I would normally have written two pages!

 

It's my belief that the '10% rule' is just an enthusiast's myth. The Railway Group Standard states:


2.3.2 Maximum permissible speeds
2.3.2.1 Railway undertakings shall restrict the maximum speed of steam locomotive movements to comply with the limits related to driving wheel diameter shown in Table A.
2.3.2.2 Railway undertakings shall, where a train is hauled by, or includes within its formation, more than one steam locomotive(s) with driving wheel diameters of different sizes, restrict maximum operating speed to that applicable to the locomotive with smaller driving wheels.

http://www.rgsonline.co.uk/Railway_...nt/Railway Group Standards/GORT3440 Iss 2.pdf

Neither is there any mention of a speed higher than 90mph in the Temporary Non-Compliance:
http://www.rgsonline.co.uk/Deviations/Temporary Non Compliance/13-039-TNC.pdf

 

I agree, I have not got the relevant document to hand but I am certain that speedos on railway vehicles have to be calibrated to a tighter specification than 10%, possibly 1%, and regularly checked.

 

Thanks for the link, interesting reading.

But no doubt a new version, or an addendum to the existing one could always be issued, (if only to keep this thread going! LOL).

You know the sort of thing. "Enormous public interest, two highly successful 90mph runs so far, (fingers crossed of course), no problems reported, crews happy, loco owners and all the various engineers etc etc see no problems. 100mph authorised specifically for one section, a to b".

Realistically I guess that is the only way 100mph could be attempted. Doing it without official sanction raises far too may issues, not only just currently but also for any future higher speed applications.

I wonder what the speedo was reading at 93 on the first run? Just past the 90mph mark may have been done to ensure 90mph was actually reached. Within the spirit but not the exact wording of the current authorisation I would say.

And I wonder if anyone on the footplate had time for a very quick photo of the speedo. Not the driver or fireman of course, but I imagine there was at least one other if not two others up there? But maybe they were concentrating very hard indeed on proceedings. I've never been on the footplate with a traction inspector as well as the crew, so I'm not up with what they do all the time. Very busy I am sure. Although in SA once a traction inspector riding with the crew took my cars keys at a water stop and drove my car for 25 miles or so , so I could have a footplate ride. I was on my own and that was the only way I could ride the loco. I even had a short "drive" of it. Full and 40 of course! Does that ever happen here in the UK?

Anyway. Have to wait and see if all does go exactly to plan with Bittern and if there is any further authorisation issued. If not, it should still be a continuing exhilarating experience for all on board, (loco and train), and those watching from the line side.

 

I believe the leeway is 2mph of actual speed. That's what we set the speedos to on the EMUs at work. No percentages involved.

 

Just checked and should be as you say,+-2mph, not near 10% at this speed.

 

Yes, but they've got to allow for some human error, though, surely?