P2 Locomotive Company and related matters

The best example (and where I'll leave the Thompson discussion for now) is that of the story of Thompsons funeral. The Gresley Observer stated nobody being at his funeral as being an example of his popularity. In fact Thompson asked for nobody to be present, and for a simple service in accordance with the rites of the established church.

But never let the facts get in the way of a good conspiracy story, eh?

 

To be fair Keith that job has already been taken, but even so im sure SACM will be as well read up as its possible to be on 2007.

Its in everyones nature to talk about what they know/ have read and that is how threads drift. I have learned an incredible amount (some of it useful) from thread drift...

 

Somewhat churlish isn't it? I find the concept of being interested in heritage railways without that interest having their history as one of its foundations somewhat counter-intuitive!

Tom

 

Simon and I have spoken by PM on previous occasions and i glad he is creating history by being part of the P2 project but the thread is about the p2 and i think there is already a thread for ET.

 

An entirely fair response. Perhaps it is best to relocate the Thompson posts to the ET thread.

However in my defence: I'm an LNER man through and through. That means supporting Gresley, Thompson and Peppercorn. You can't talk about a locomotive like the P2 without overlapping I'm afraid.

What the new P2 will do more than anything is prove the basic idea was sound, but what was needed was development. Gresley didn't provide that. Why is anyone's guess.

The fact remains that Britains most powerful express steam locomotive was never developed beyond six different prototypes.

We now have effectively a seventh - and perhaps this time, it'll be the locomotive the P2 class should always have been.

 

I do agree Tom. However I am aware I can bore the proverbial hind legs off a donkey about Edward Thompson...!

 

I hate to be pedantic, but the highest Nominal Tractive Effort is not the same as the highest power output. That claim belongs on the other side of the Pennines!

 

Touché!

But we will see which side it ends up on when 2007 is running.

#challengeaccepted

 

Oooh, might have to fit a Mechanical Stoker to 6233, just to be on the safe side !

 

8 wheels beat 6. Its a no brainer who wins that competition.

There isn't a machine on these islands that can compete with the P2 once she is finished. Maybe a 9F, but that's a big maybe and they are off network anyway.

Also, does Tornado not run like absolute clockwork? The recent clips of her hauling *** out of Pad and making up a huge deficit through Slough and Reading were impressive to all.

With everything the Darlington crew will have learned building and running the A1, my money says the P2 will be utterly untouchable.

 

Nope, it doesn't work that way. You could also say that 6' 9" wheels beat 6' 2" wheels. Speed is a very relevant factor in Power Output / requirement. Power = Torque (ACTUAL Tractive Effort being produced at the time) x Velocity (Speed). The coupled eight wheels provide adhesion; they don't increase power output.

 

Happily there are enough different ways to calculate the, shall we say capability, of a steam locomotive that almost everyone can make a case that their line is best. And even more happily almost all those calculations are entirely theoretical with only a passing resemblance to what might happen in the real world, so the potential for enthusiasts to argue happily on the topic is almost unlimited...

 

I just find it rather wonderful that we might have an answer to the age old dispute of Gresley vs Stanier with arguably their greatest creations getting a run out on the British main line in the modern age. It would be nice to think the P2 and the Duchess will be able to be in steam together so we can compare the two. I rather think a big engine gala at the GCR would be nice one day. Just think of the locomotive types we could have...

 

The Coronation has 88% of the cylinder volume of the P2 as built. Even if we fit 19" liners to the P2, it still has 92% of the volume of the Coronation.

That's just for starters. The P2 has smaller feet and 2 more of them, so is much better able to use the force those cans will be kicking out, per cylinder as below.

Coronation = 53456 LBF
P2 21" = 86590 LBF
P2 19" = 70882 LBF

Its a cake walk for the P2. That doesn't detract a thing from the Coronation however.

 

We'll see. As I said, Power is speed dependent. The P2 has a big advantage when starting and steep climbing at medium speeds, but at 75 mph it could be a different matter, and quoting dimensions and static piston thrusts doesn't come into it. By that argument, Gresley's Garratt is the obvious contender, but there was no recorded use of it on the pre-war Coronation high-speed train!

The fact is that the maximum UK power output was set by Stanier pacific 6234 on 26th February 1939 at 3,348 i.h.p., about 250 i.h.p. more than an A4 is credited. In preservation, sister 6229 is thought to have exceeded 3,500 i.h.p., although this is based entirely on resistance formulae, so more open to error. Not, I would imagine, by an excess of 500 i.h.p., or nearly 15%.

I reality, it will be difficult in preservation to establish a new record as the means of measuring drawbar horsepower aren't available, unless the Horwich dynamometer car is fully refurbished, calibrated, and allowed to run on the main line, which seems unlikely. A shame, because many locos have raised the stakes during the preservation era, and it would be good to see by how far.

Let me say that there is no intention here to denigrate the P2, but their design was based on the need for brute strength at medium speed on a difficult and twisty road, rather than very high speed on a less arduous one.

 

Indeed. An 08 shunter has a maximum tractive effort of 35,000lbf, about equivalent to a Gresley A4. Rather less likely to be bowling along the ECML at 100mph though!

Tom

 

Yes I'm using a very basic analysis to make the point, but the point still stands. Force = pressure x area. Without getting in to crank diameters, effective torque, Mean Effective Pressure etc etc this will suffice to make that point. Dimensions and forces absolutely come in to it, as that's where power begins.

The Edinburgh - Aberdeen line is tricky, however it does have sections of fast running. I think you will find the P2 has got to have some legs as well as power to keep to time. The difference in wheel diameter is only 8%. Even 9Fs were known to run at 90 when given a chance.

Likewise, I'm not trying to denigrate the Coronation. They are fine machines. But they wont be able to match this.

 

I think we might have to agree to disagree - amicably - on this one! But the main ingredient of power with a steam locomotive was the boiler, not the cylinders or wheels.

 

Imho this is slightly beside the point, it is not about the cylinder forces. That is good only for the strength calculations. This is about effective use of these forces and there the Tractive Effort calculation comes into play. With some human effort this can be extended over
the whole range of speeds and loads, certainly in this day and age of computers where one's grey mass is only needed for proper formulation of the problem and interpretation some seconds later.
Kind regards
Jos Koopmans

 

By golly you're right! I could go and put this in to Excel! But no, I think I'l leave it. As LMS2968 said, probably for the best to agree to disagree.