Another Gresley Thread, middle big end

I've heard much about Gresley's middle big end giving problems, and the (frankly) poor steps taken under his regime to not so much rectify the problems as to let it be known that they had occurred, So can anyone tell:

1) What the cause of the overheating was?

2) What the actual essence used in the 'Stink Bomb' was?

3) Which classes suffered most?

4) Did Thompson/Peppercorn locomotives also suffer? If so....

5) Did Thompson/Peppercorn use a different design?

6) When did an improved design come into use?

7) Did Bulleid use a similar design, and if so did it give problems with His locomotives?

Finally I've got no agenda here It's just (morbid) curiosity.

 

Whip in the 2:1 gear caused by slack/wear in the pins, allowing the middle cylinder to do "more work" by overrunning.

Aniseed I believe.

Depends on the source, however it is accepted that classes doing over 60mph regularly (i.e. mixed traffic and express passenger classes) suffered the most.

No, they didn't.

Yes, three sets of walschaerts valve gear instead, divided drive.

Depends on what you mean by "improved" but variations were introduced until the early 50s when a mixture of better alignment during overhaul (Cook, Zeiss Optical gear), and a beefed up middle big end with a different arrangement for lubrication came into use.

He did not use it, he used a chain driven valve gear. That's a whole other debate!

No problem, asking questions is what the forum's here for I think.

 

Some Great Questions seem to recall the Bill (?) Hardy book goes into detail about one beefed up big end design., a later one was taken to BR derby by Harison for 71000's middle big end
(which seems to have proved stronger than the actual Rod)
Fairly sure the Bulleid Middle big end would be different being from the Eastleigh or Brighton drawing office.

 

I've also seen mention of garlic.

 

Me too.

 

Do you mean Richard Hardy? Also another source might have been Peter Townend.

 

I've always thought this an odd way of looking at it. Instead of hand wringing about what a terrible thing the "more work" of the middle rod was, wouldn't the correct solution have been to design a big end that could cope with the actual loads it was going to experience. After all whatever extra power the middle cylinder was pushing out it surely wasn't going to exceed that delivered by the cylinders on the largest 2 cylinder classes? OK a solid big end for outside cylinders was an easier proposition, but was designing a decent big end bearing for the 18.5 x 26 inside cylinder on an A4 really so much trickier a proposition than the 20 x 28 inside cylinders on a B12? Cook's theory was that it was mainly down to lubrication. It certainly seems reasonable that it wouldn't matter how solid the bearing and how large the surface area if a significant part of it wasn't seeing enough oil.

It's something that one comes up time and again in all sorts of industries, an acceptance that a certain level of trouble is inevitable and the job the best that can be done, and there's no point in spending too much effort trying to resolve it. I've found it very hard in IT to persuade management that a level of trouble is worth devoting time and attention to when they'd much rather the effort went on another new high profile project to look good on the CV.

 

Not *Zeiss* optical gear. Apart from everything else they were the wrong side of the iron curtain!

Cook talks about this in his 1955 paper to the ILE "The Steam Locomotive: a Machine of Precision". In 1952 he came across a British company exhibiting some optical equipment at a trade show in the UK and realised that it could be adapted for the job of setting up locomotives, and indeed be an improvement on the Zeiss gear. My understanding is that it was this, rather then Zeiss gear, that was brought into the LNER works. Certainly the photographs of it in use in the paper look to me very like LNER locomotives.

 

A typical problem with Government IT problems and - presumably - the IT world in general. Whenever a problem arises the option is to provide a solution that solves the immediate problem (e.g. replace the faulty bearing(s)) or find the solution that solves the problem altogether (e.g. redesign the lubrication problem and bearing alignment). This is a common problem in any industry when the choice is between the immediate quick fix or spend time finding the long term solution - and the willingness of the company to accept the time and effort to fix problems as they arise or spend more time and effort to find the solution that eliminates the problem altogether.

 

Oh yes indeed. I used to characterise a related attitude as "I'm much too busy to go and do the training that would enable me to do the job in half the time."

 

Sorry I am getting befuddled; could be in the . Bill Harvey's 60 years in steam. book but may well have been in Dick Hardys Steam in the Blood... both worth a read.
Wasnt aware that Mr Townend had done a book, just a few articles...

 

I think you mean Bill Harvey

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The composition of the white metal may also have been changed as a result of the E S Cox report

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https://www.steamindex.com/jile/jile45.htm

With respect Jim, I am doing my best with the resources I have.

 

The LNER were working on an improved version of the middle big end for around a decade before Thompson finally canned development and went for two sets or three sets of walschaerts for everything. The late 40s/50s development of the middle big end was something that was born of the failures during the exchange trials. The steam index I have given above suggests that the redesign was Churchward inspired.

 

Its part of why steam lasted as long as it did, and why we still have diesels.

But, more prosaically, it’s also about whether it’s worth making changes, with the associated costs, or tolerating a level of inefficiency until a step change is worthwhile.


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I can name three: Top Shed, East Coast Pacifics At Work (reading this at the moment), The LNER Pacifics...

 

I believe this equipment was made by Reid & Sigrist Ltd of Leicester. As an aside, in the early 1950s they made very good exact copies of the Leica camera.

 

Chain driven valve gear, but his locos still had an inside big end!

Tom

 

Weren't Zeiss split between East and West? Rather as Auto Union DKW (which became Audi in the West.)
I have a pair of Zeiss field glasses (ex-Bundeswehr) that my father obtained during his time in BAOR in the '80s. Marked 'Carl Zeiss Jena'. I once met a Norwegian while on a ship at Svalbard who was ex-NATO and had an identical pair.
Pat