Edward Thompson: Wartime C.M.E. Discussion

The noise thing is interesting as the assumption is that noise means these locos were unreliable.

The railway i work on has two locos that are nominally identical however they have different designs of crank pins and rod ends. The first features a crank pin where the couplings and con rod essentially run in separate grooves with a split brass held together with a wedge bolt. Second has a straight crank pin with a single piece marine style rod end. They are free to move side to side on the pin and are held on with a collar.

This second design develops a small amount of side play quite soon after overhaul resulting in a clonking sound as the rod slaps side to side, especially when coasting. The first design does not do this as the rod ends can't touch each other. They are separated by a groove. They both wear at the same rate radially and the rods are certainly not worn out when making this noise.

Now the reason for making this change is that one design is much much easier and cheaper to make.

So the point of all this rambling is that not making a noise is not the only design requirement, especially in times of austerity. The rods might clank but that could just be a feature of something designed to a price. There is no guarantee that the noise indicates the loco is worn out or unserviceable. It could just be a quirk of design. The sound of these engines clanking doesn't really tell us anything unless we know why it does it.

Tim

 

Great post Tim. Really good point.





These two loco classes have virtually the same valve gear arrangement, boilers (diagram 116 has a slightly bigger firebox), wheels, axleboxes, frames. The differences are found in the tanks, rear bogie and the wheel spacing of the rear driving wheels.

One has a great reputation, the other doesn't. Yet the overall designs remain similar.

Which class had better mileages and availability? Anyone?

 

This comes down to a mantra I often repeated at work. "Its the detail where you fail". The top trumps dimensions are surely quite irrelevant. Detailed design of components, lubrication, maintainability, detail design decisions like balancing, quality of manufacture and maintenance, these are the things that are going to make the difference. Big end problems on LNER locomotives weren't because there was something inherently wrong with powerful three cylinder locomotives, it was because they had p*** p**r big ends...

 

I don't think anyone has claimed that noise = unreliability.

 

WD 2-8-0s were noisy, but they were never unreliable. A great work horse.

 

I was just reading K J Cook's paper "The Steam Locomotive: A Machine of Precision". In it he states that by re-aligning frame, horns etc on the 2-8-0 WDs so bush clearances were in the 8-10 thou range, among other improvements small end bushes went from 10,000 mile life to 30,000 miles. One suspects that the WDs that Cook had had upgraded at Doncaster were a lot less noisy than when they were new.
Reading the paper again I hadn't previously realised that post war optical alignment kit, such as Cook introduced to the (L)NER, was not by Zeiss like the original GWR set, but was from a British manufacturer and worked on a slightly different principle.

 

I will need to stop quoting it as Zeiss then! What was the manufacturer out of interest Jim?

 

Didn't say I'm afraid.

 

I believe this kit was made by Reid & Sigrist Ltd, based, I think, in Leicester. Amongst other things they made aircraft instruments, and post war made the 35 mm Leica camera under the name of Reid. These were of a quality equal to the original German product. Got one of them myself.

 

They also built an aircraft. https://en.wikipedia.org/wiki/Reid_and_Sigrist_R.S.3_Desford

 

Thank you both, most helpful. That will change at least one sentence in my book, and hopefully a few others in future too.

 

http://kesr-mic.org.uk/resources/The+Steam+Locomotive-A+Machine+of+Precision.pdf
This is a copy of the paper. Its interesting.

 

Thank you for the link. What a fabulous resource are the other items that are also connected to the site.

http://kesr-mic.org.uk/index.html

 

That is going in the bibliography. Fascinating stuff. Thanks Jim for posting it.

 

But don't get me started on Leicestershire Council's intention to send it off for static display after having funded its restoration to flying order. Subject for another thread though.

 

I am a bit reluctant to enter into a discussion like this as there are clearly people here who understand the technical side of steam locos far better than I do. But surely the reason that the L1 had such an apparent "poor press" and the K1 did not is due to the nature of the work they were given to do. Put a K1 on outer suburban passenger work and I suspect that it would soon earn a worse reputation than the L1. Indeed you could wonder what work the K1 was good at. I remember asking the late Goeff Bird, former shed master at York, what he thought of them. He replied that apart from Officers Specials and heavy ballast trains there was little good use that he could make of them. He felt that they were too powerful for their own good and soon shook themselves to pieces. Clearly they were not his favourite class of loco. But a use was made of them on a variety of mundane non-passenger work, so unlike their L1 cousins they kept largely out of the public eye. I suspect that Simon is implying that the L1 "had better mileage and availability" than the K1, which would not surprise me one bit.

That said I have to admit that I am a great fan of 62005 and have had the privilage of firing it regularly on the West Highland line in recent years. On that route it is an ideal piece of kit, as its power can be put to good use at speeds which are well within its comfort zone - up to 40mph it is great but get it to 50 and it is a different matter altogether. But then no other railway is quite like the West Highland.

Peter

 

What is the problem at 50?

 

Rough riding

Peter

 

How would a K1 compare to an LMS Crab, or Stanier mogul then? Similar size locos with similar driving wheel diameter, designed for the same kind of work. Presumably the Southern N and U classes and GWR 4300s would also be comparable?