Ton up Tornado

I think its entirely up to the loco owner, NR, and the operators as to if another loco gets a 90mph "ticket"

It would be a lot like a shaft rotating in an annular cavity surrounded by a thin film of oil, as opposed to a shaft rotating in an annular cavity surrounded by roller bearings lubricated by a thin film of oil. Either way, the layout of the bearings make little odds as to the practicalities of 90mph running. White metal has more than prooved its metal on that. Pun intended.

 

Turbine generator bearings in power stations are generally plain white metal bearings. As I understand it most of the wear is at very low speed during starting and stopping. I also remember reading somewhere that rollers are not used for this application because they would fail due to metal fatigue.

 

But is the oil pumped in a under pressure cooled by water.

 

Have you tried taking a try of six cups of tea down a corridor tender on the run at speed and the tank about half full you will see how much a eight wheel gresley tender goes side to side. FISH7373 81C NFP

 

If it's only got 4 wheels out of 8 it's no wonder it's going from side to side!!! lol.
Ray.

 

I got it wrong before i said three when it should be six wheel tender LOL

 

Yes that's correct. High pressure "jacking" oil is also pumped into the bearing during start up and shut down to lift the shaft in the journal, as it starts to turn, or comes to a halt.

 

One of the critical things about the 100mph run was to ensure the tender was as full as possible. Doing a full emergency brake test from 80mph then 90mph will put flats on an empty tender faster than you can blink! There was so much more going on that night than a *simple* bid for 100mph!

Foxy

 

Didn't they say it calmed down as the speed increased past 75mph though????

 

Relative to what any footplateman under the age of 70-odd is used to (i.e. 75mph), 100mph is 4/3 the speed, almost double the kinetic energy. So not surprising that the perception would be that it was lively - there is a lot of energy available to cause things to move about! Also conceivable that there was a degree of resonance going on at certain speeds, amplifying any movement. However, that is part of the point of doing tests, and having the loco wired up with accelerometers in the way that it was - lots of data analysis to do, but hopefully running up to 100mph will be sufficient to demonstrate that the overall movement of the vehicle is entirely acceptable at 90mph.

Does make you wonder what Mallard was like at 126 though - perhaps one of those occasions when ignorance was bliss about the dynamics of the vehicle ...

Tom

 

Not as lively as a Saint at 135 mph I bet.

 

Ah, but Swindon had perfected ultra-smooth track and had arcane knowledge about springs handed down to Churchward from an extra-galactic civilisation who made contact through the Mayan civilisation, plus we all know that locos with two big outside cylinders are inherently smoother running than those with three, so I'd imagine it ran as smooth as a sewing machine...

Tom

 

That's it...come to the light....

Can I top up your coolade?

 

Sarcasm overload.

It would be great to know how "within acceptable range" the lateral accelerations were.

There is a lot of moving around, but having stood in the vestibule of the HST from Edinburgh to Aberdeen, I suspect the window for lateral accelerations must be surprisingly wide.

 

I don't know why people are surprised: the original A1s were well known for - shall we say - interesting characteristics at speed.

Tornado showing similar characteristics is not surprising.

 

Double negative there...

 

I was going to say something similar. Peter Townend's book Top Shed pages 160 -167 is worth a read. Nothing can be inferred about the ride characteristics of an A4 at speed from those of an A1.

My take is that the requirement is for Tornado to be able to operate well into the 80s consistently over long distances, something which presumably A1s did every day in the 50s wherever the track was up to it. I did think that Steve Hanczar looked as if he might not want to do 100 again any time soon, but that is way in excess of what is required. The important things are (a) whether she has got the power, (b) whether she can stop the train, (c) how she rides at 85. The answers to (a) and (b) are clearly yes in the conditions of the test run.

 

Having gone to the trouble of adjusting the lateral springing on the bogie and changing the Cartazzi slide geometry to quosh that 'unsurprised' ? , pretty disappointed more like...

 

Why so? All the vast majority of us have seen is a couple of minutes of film. It has already been pointed out that, with a camera fixed to the loco giving a static frame of reference, the tender will appear to jump around all over the place - had the camera been fixed on the tender, it would look like the loco was bucking and bronking. Importantly, none of us know what "normal" looks like in that situation, and therefore whether the degree of movement was better, worse or about the same as predicted; or indeed acceptable or not to Network Rail (especially given than the 100mph test was to prove safety and capability for routine operation at up to 90mph - there is a big difference in energy input).

We also don't know to what, if any, degree the riding was dependent on the weight in the tender, given that that could vary by about 30 or more tons over the course of a day as coal and water is used up.

Taken all together, I don't think you can infer anything much from a couple of minutes of film - wait until the data that was collected has been properly analysed.

Tom