71000

Thank you for a very detailed and compressive reply .It would seem from your reply you are closely connected with the engine and as this is your first post welcome to the forum ,

 

Just to add to BR8P's post, the small ejector would need to be on at all times when any vacuum braked loco is moving.
The reason it started just before departure of the train was to keep the noise down in the cab during the water stop.
When it is open it gives ( the best way to describe it) the sound of a 'hiss' of steam. Not loud, but enough to be annoying!
Fred Lewis, the driver, would have turned it off when he came to a stand.
If the train had been a vacuum braked one the driver would have had to wait for all the brakes on all the vehicles to release before departing, which takes a little time. This being an air braked one the brakes on all the coaches would probably be off, thus only the loco's vacuum brake system would need to be charged. Much quicker. The moto being 'only have a noisey cab when it needs to be noisey!'.

 

Thank you all for your replies, they have provided me with some interesting reading!

 

Except for GWR of course: the western used an air pump which was more efficient, especially at their higher vacuum.

 

Few others agreed, and those that did fit vacuum pumps soon did away with them.

 

I might be wrong as never been on 44871 but when hauling trains on Network Rail you would still need the air compressor running and the air system charged as the AWS and TPWS only work with the air braking system.

Jamie

 

You're not wrong. 44871 requires air for TPWS/AWS purposes, as does 45407.

 

How does this work with vacuum braked locos that don't have compressors but use TPWS?

Dave

 

Hi, as has already been stated you are not wrong. For mainline working this is true in the case of a air braked loco fitted with TPWS/AWS as the EP (electro-pneumatic) valve needs to vent air from the control pipe of the brake application unit to effect a TPWS or AWS brake application. I had overlooked this on my initial explanation so apologies. For preserved railway working with vacuum braked stock then the compressor can be shut down and the DV2 isolated but this only works with a split system as I have previously explained which was the point I was making.

Then the EP valve would just destroy the train pipe vacuum rather then vent the air brake pipe pressure via the brake application unit. A brake application is still gained this way.

 

A valid point. There was still an ejector and the pumps were later removed on some engines.

 

Your most welcome, glad to make it clear to you and thanks to the others for a warm welcome.

 

Another query regarding DofG please folks; this loco was not designed to be unique but instead the first of a class.
It's in a book that five more Clans were planned for exclusive use on the S&D and it even listed their proposed names, Wildfire, Firebrand etc.
If 71001- 71050(or however large the class would have been) had been built, were any names decided on please?

 

Where did you get this information about the Duke Class of locomotives.? As far as most people are aware, the demise of 46202 at Harrow led to Riddles authorising the design and building of a 1 off loco to replace it. The loco incorporated some novel features to see whether they would be suitable for future designs. You are not getting confused by the fact that 71000 was the first loco of order 486 (Lot 234) to be built at Crewe. The other locos on this order were Brits 70045-54.

 

Thanks for that Std Tank; I was once told it was the first of a class, but due to the Duke's poor steaming, construction was initially put on hold until the problem was solved. Then dieselisation increased and there wasn't a need for extra locos hence the Duke being unique.

 

Further info re 71000; according to ES Cox [ Locomotive Panorama Vol 2 pp24 pub Ian Allan] there was no intent to provide a Class 8 in the Standard range as the individual regions had sufficient Class 8 locos for their needs but when the recently rebuilt 46202 was destroyed in the Harrow smash Riddles was authorized to provide a replacement in the Standard series - hence the creation of 71000. It was initially considered as a modified "Duchess" but being allocated to the LMR it was never accepted as equating to the much loved "Duchesses" hence the lack of enthusiasm to fine tune the gas-air-steam cycle which had already been noted from tests at the Stationary Plant Tests undertaken at Swindon.

 

RC BOND Advocated another trial between the Duchess (Ivatts final version) and the Peppercorn A1 to see whether or not either of these designs could be perpetuated. I think the Duke may have just been an act of vanity on the part of Riddles et al. Done under the guise of - 'if we need some more class 8's we'd better have a standard design'. As such the Duke was intended to be first of a class - if the demand ever arose... Dont think it ever got as far as names. There was a lot of messing about with the Britannia names and Potentially there we're lots of Brit names never used.... i like to think that they would all have been Dukes

Interesting that Bond, Cox et al all said that they knew that the Potential of the Duke had not yet been unlocked....

 

Some time ago, I placed an article on the LMS Forum and it has since been published in the 8F Society's magazine, Black Eight. The link is as below, although you might need to be a member of the Forum to access it.

http://lmsforum.forumup.co.uk/viewtopic.php?t=64&start=0&mforum=lmsforum

Basically, I suggeat that Robin Riddles wished to build a Class 8P locomotive, but none was needed by the various Regions (in truth, the LMR could have done with some) so he could not abtain authority to build it. At Harrow though, two 8P pacifics received heavy damage, and if one of these were to be withdrawn, the LMR would be below 8P strength so could not refuse the new loco. 6202 was chosen as the victim since she was still unique, while 6242 was one of a class of 38 engines. But 6202 was not withdrawn but remain dismantled at Crewe works until until May 1954, 19 months after the accident and only days apart from 71000's completion. It is possible that the remains were ratained in the hope that the LMR would accept 71000 in its own right, but when this didn't happen, the sacrifice was made. Retrospective authorisation for 71000 was then applied for and granted. Rather than 71000 being built to replace a badly damaged 6202, as so often stated, 6202 was withdrawn to make a space for 71000.

As I state in the article, supporting evidence for this conspiracy theory doesn't exist: Riddles was far too inteligent to allow it and the destruction of paperwork at the end of steam will surely have elliminated anything which got through. But dig below the surface and there is a fair bit of circumstantial evidence, a bit too much to ignore.

 

Given the fact that the boiler was repaired and paired, firstly with 46212 from 1954 to 1958, then 46208 from 1960 to withdrawal of the loco in 1962, you could well be right.

 

Who was Robin Riddles?