Steam: Class 9 Locos / The P2

[alexl92]

A few random questions along a vaguely linked line of thought here...

Under BR, steam locomotives were categorised as classes 1-8 (passenger) and 1-9 (freight).

My question is, hypothetically, what would constitute a Class 9 passenger loco and why was one never attempted? Was there just no need?

Also, the new-build P2 is being advertised as Britain's most powerful steam locomotive. Is that an accurate claim (bearing in mind machines like 6233 DoS, 71000, and the 9Fs), and what would the P2 have been classified under BR?

 

[CarltonA]

http://www.steamtraingalleries.co.uk/pic_brc_003.html
Poor ol Janice needs a bit of attention but she would be very powerful in working order.

 

[alexl92]

I was specifically thinking locos built for use in Britain - I imagine that the chinese loco in the NRM would be more powerful than many of ours!

 

[TheEdge]

A few random questions along a vaguely linked line of thought here...

Under BR, steam locomotives were categorised as classes 1-8 (passenger) and 1-9 (freight).

My question is, hypothetically, what would constitute a Class 9 passenger loco and why was one never attempted? Was there just no need?

Also, the new-build P2 is being advertised as Britain's most powerful steam locomotive. Is that an accurate claim (bearing in mind machines like 6233 DoS, 71000, and the 9Fs), and what would the P2 have been classified under BR?

I doubt there really was ever a need for a 9P. I think the Coronations were the most powerful passenger class and it was an 8P. Although saying that it looks like the Coronations had a higher t/e than the 9Fs, go figure.

Looking quickly at the data online it does look like the P2s were more powerful than the Coronations (40,000 lbf vs 43,462 lbf) but again, my quick google seems to imply that there was more to it that just the raw tractive effort, appears other factors were included like brake force and superheating but I can't find the exact manner it was done.

 

[CarltonA]

I was specifically thinking locos built for use in Britain

http://en.wikipedia.org/wiki/LNER_Class_U1

Heres another biggun for consideration.

 

[TheEdge]

http://en.wikipedia.org/wiki/LNER_Class_U1

Heres another biggun for consideration.

http://en.wikipedia.org/wiki/MR_0-10-0_Lickey_Banker

And Big Bertha.

And another, rebuilt W1.

http://en.wikipedia.org/wiki/LNER_Class_W1

 

[E&W Lucas]

I doubt there really was ever a need for a 9P. I think the Coronations were the most powerful passenger class and it was an 8P. Although saying that it looks like the Coronations had a higher t/e than the 9Fs, go figure.

Looking quickly at the data online it does look like the P2s were more powerful than the Coronations (40,000 lbf vs 43,462 lbf) but again, my quick google seems to imply that there was more to it that just the raw tractive effort, appears other factors were included like brake force and superheating but I can't find the exact manner it was done.

Ability to boil water is the absolute key to a steam loco. It's all very well having the mechanics in place, but the thing has to be able to generate enough steam to feed them. (Put in the most simple terms).

 

[Bevan Price]

Stanier had a proposal to build an enlarged 4-6-4 version of a Duchess - got stopped by WW2, etc.

A major problem might have been the fireman's ability to put enough coal in the firebox - it would probably have needed mechanical firing (or oil firing) to produce enough steam to function for long periods at "9P" rating.

The UK loading guage was also a limiting factor in the size of steam locos that could be built.

 

[alexl92]

Fair enough! Thanks all.

Does anyone know how the P2 would have been classified under BR?

 

[Bevan Price]

Fair enough! Thanks all.

Does anyone know how the P2 would have been classified under BR?

Track straightener ? The wheelbase was too long for some curves on the routes they were mainly built for (Edinburgh - Aberdeen).

 

[alexl92]

Track straightener ? The wheelbase was too long for some curves on the routes they were mainly built for (Edinburgh - Aberdeen).

Hahahaha!