P2 Locomotive Company and related matters

Is that a tender or a liberty ship on wheels...!
These may be of interest:
http://www.google.com/patents/US2518024
http://www.google.com/patents/US2210328
http://www.google.com/patents/US2158331

 

A bit of a liberty that one wasn't saved methinks......... Anyway, those patents are indeed very, very interesting, especially the Franklin one, do we have to add the name of Julius Kirchhof to the list of unsung steam heroes? It seems a great deal of time and effort was expended on poppet valve gear from the 1920's into the 1950's, a great pity that it wasn't developed to the point of mass application in the UK. Perhaps we could see a final realisation of the value of poppet valves with the building of 2007, I really can't wait to find out.

Thanks for sharing the patent info Mr Class 8Mikado, lots to keep me occupied for a while there.

Cheers

Alan

 

Alan,

We have already been in touch with our American friends re the T1 and various other locomotives, we are perusing as many avenues as possible.

I havn't had time to read all of todays posts in detail as I have only just got in from a day out but I will take a look when I can.

Andy

 

I believe those were small compared with the lone S1's tender!

 

With the closing of the Founders Club this month, the Dedicated Donations scheme has been floated for people who want to 'own' a bit of No. 2007.

'Be-spoke' covenants are being offered for the wheels!



Foxy

 

Ted Parker's video of the dedication weekend is up on the P2 YouTube channel:


Foxy

 

I hope you don't mind but I have included your excellent description of how Caprotti works in a video of the BR Class five
on my blog.

You can see it at http://steammemories.blogspot.co.uk/

 

Poppet valves were of course used in marine engines too in the UNIFLOW or often named UNAFLOW system. The advantage gained in the marine application was one of thermal efficiency as the steam always entered at hot ends of the cylinder and exhausted at the cooler centre. These engines were used very successfully in the American support carriers of WW2 and achieved some excellent speeds which a carrier needs when launching and retrieving aircraft. They were used I believe because of cheapness of manufacture over the conventional turbines and of course there ability to do the job.

I have included some video of the British Caprotti system on my blog which you can see at
http://steammemories.blogspot.co.uk/

 

Paget used rotary valves, which were the downfall of his uniflow loco. I presume the sheer number of cylinders precluded the use of poppet valves. (tbh I have no idea how his valves, with sleeves adjusting the cut-off, worked).

 

You're welcome, although if you want a slightly more authoritative source than some anonymous bloke from a forum, may I suggest http://www.71000trust.com/caprotti.html

The link also explains how the exhaust side works, which is the reverse of the inlet side (a roller sits on both cams, so if either exhaust cam is lifting then the exhaust valve is open).

 

I well remember when I was studying at Liverpool for my CEO's marine ticket a lecturer entered the room with the statement that Sulzer's had incorporated a rotating piston in their new medium speed diesel engine. Needless to say to a man we all said it would never work. But astoundingly it was a great success. Paget's Midland engine was a failure because he used rotary valves quite right. The marine engines produced in WW2 had poppet valves. The uniflow system was designed for high speed steam engines used for generating electricity and in particular DC electricity where rapid fractional changes of speed were needed for control of voltage in varying load conditions, particularly in ships working cargo where a Ward Leonard system was employed for the derricks and winches.

 

Found this short video of a (cambox?) from a caprotti valve gear equipped loco being demonstrated connected to an electric motor as a demo. Helped me understand better what goes on with this gear.



Hope others find this interesting!

Chris

 

Nice find. It's a pity they don't descibe the cut-offs they are going through, and you don't really get to see the valve events resulting, but it's a great view of the cams and scrolls etc. Might sound a bit sweeter with some more oil in there though! And you get some idea of the fragility of it all compared to the more usual valve gears.

 

Out of interest, when does a P2 cease to be a P2?

Looking at the recent CAD renderings that have been published- very little of the design appears to be original P2?

Frames, boiler, cartazzi truck, cylinders, valve gear and braking all appear to be 'not original design ' if I am reading this right- that seems like quite a lot more design work than remedying original faults.

Just seems a bit strange to me- its going to look like a P2, smell like a P2 but presumably will not perform like one.

Don't get me wrong, I am not criticizing, just interested to get my head around it all. Is the idea to recreate a P2 or to build something completely new- as it will be so far removed from the original?

Chris

 

As far as I understand it, simplistically speaking the idea is to recreate the original as near as possible, whilst eliminating its shortcomings and making it fit for the 21st century network, plus of course having as much commonality with the A1 as possible for economic and interchangeability reasons, without affecting the general P2 'look'. I'm sure all the answers are somewhere on the website ....... http://www.p2steam.com/

 

All 6 P2s were different in one way or another, so this is just a seventh member of the class that is continuing that tradition.

 

That is for sure - researching the building of a model of no.2003 Lord President at the moment, no one of the P2s even through rebuilding into streamlined formats for 2001 and 2002 produced identical locomotives out of the six. They only became more similar when modified into pacifics and even that isn't assured as they all had different boiler types, chimneys and other parts at differing times.

 

Combustion chambers, exhaust types, valve gear types, tender construction differences. Yes a bit of a mixed bag. The constraints of the modern day loading gauge mean that the original cylinder size cannot easily be accomodated, the driving wheel diameter is fixed so the only way to obtain the original T.E. is to increase the working pressure to compensate for the reduction in cylinder bore size. The P2 class were never fully developed so the new member of the class could be viewed as what theLNER would have built if a seventh member of the class had been deemed necessary at the time the originals were built. 2002 was a better locomotive than 2001, 2006 had a different boiler with combustion chamber which was felt to be an improvement, 2005 had a single chimney and was not viewed as a good steamer. As to the swing link pony truck, these work well at eliminating rolling on a straight track but are far, far less good at guiding locomotives through curves, so for other than the ECML this part of the design just had to be changed. All this has been covered before but I hope that it supports the case for 2007. We need the adhesion and tractive effort.
As to making 2007 look like 2001, it is the only aspect that I am unsure about. I much prefer modern piston vales, but I have stated this before too, but the video link might just help folk to understand why. Sheff's comment on fragility is worth noting.

 

It will be interesting to hear of progress at the annual convention on Saturday

 

Indeed, having missed the last two due to holidays as well - maybe bump into you there?