Preservation Loco 'Exchange' Comparisons

No axle box is sprung. It is a dead weight carried on the axle, which is in unsprung contact with the rails. It is the frames and rest of the loco which is sprung.

 

Not to mention the track! Of course, you're perfectly correct, so far as those factors go. Nonetheless, all such considerations aside, methinks the original question remains valid.

 

Of course!

 

Are cannon boxes significantly heavier than plain bearing axleboxes?
This might make a difference.

 

See #35

 

First and foremost can I say I’m not an engineman, but from an article in the Beano a few years ago regarding operating 92203 at the North Norfolk, there was something in there mentioning this, I’ll try and dig it out.

 

I've heard Clive Groome's remark about roller bearing Std 5s too.
I've occasionally wondered what the difference was. It is most likely unsprung weight. The cannon boxes are rather large.
I don't know about plain bearings being 'malleable' though. Although white metal is malleable, if you get to that stage then you are hammering the bearing material out the sides of the box. Elasticity would have more bearing. (see what I did there?)
All 4-6-0s bash your feet through the cab floor to an extent. As Steve says a worn engine can be quite harsh.
847 on its previous period on running at the Bluebell was rough at the end. A good sudden slip like you might get in the tunnel gave a pronounced vertical motion to the cab.
As for ride quality generally the 0-4-4 seem to be good. H class in particular, even the M7 was decent from what I remember. Probably the nicest thing I can say about it.

 

Another good comparison is when you get visiting engines, as they will be new to you, and of course you might have to fire or drive them differently to your home fleet loco's, I can remember back to when, at the MHR, we had SNG visit, , and I must say, I was presently surprised with how she performed, But the real fun was when 257 Squadron visited, she was completely different to Swanage, who , you had to have a thick fire on, to make it go, yet 257, only needed the grate covered and away she went, the steam reverser also was a lot faster on 257, Goes to show you even 2 engines of the same class can be different,
Some engines are clearly marmite engines, you either love them, or hate them, the S160 being one, Then you had the ones that clearly were not right, and really should have not been steamed, A castle in good nick is a very good bit of kit, but not when its busy trying to put its own fire out it isn't,

 

There’s been a few comments on here in the past about 7029’s condition when it went to Hampshire in the mid 1990’s, it’d be interesting to see how it’s rated now.

 

Thanks that is interesting to learn.

Was your mum a jockey?

Did you get to have a go on Maude when she visited?

Saying about Furness 20 and the discussion of older locos got me wondering if anyone here has driven or fired any of the older engines that were steamed in the 80s such as Hardwicke, the Midland compound or Stirling Single and what they are like to work on.

Prince on the Ffestiniog is only a year later than Furness 20, although obviously much rebuilt, I guess we will have to wait for the new build Mountaineer for the 1863 experience. One for @meeee and other FR people is how does coal firing compare to oil firing and has it made a difference to any of the locos?

 

Its much easier to get coal on the shovel.

 

Thanks, no mum wasn't a jockey though there are quite a few racing stables and four tracks in Sussex.
She knew quite a few people with horses which need to be exercised by somebody if not the owner. So she and a friend would go out a couple of times each week on a fully prepared horse and someone would dispose afterwards.
I have fired Maude on its home turf, the Bluebell and Bo'ness have strong links and have worked together over the years.
One group would visit for a week in the summer and cook killer breakfasts for crews.
I don't remember anything unusual or odd about Maude, fairly typical for its time I imagine. I do remember firing with Monkton Hall coal which came in pieces the size of a kitchen table, very brittle and smokey. Oh and the snow blowing in one side of the cab and out the other.
I've just recalled an oddity on the NLR tank, the reverser was a pole converted to a screw, so the indicator goes the wrong way. A trap for the unwary.
The modern class 2 tanks which seem highly regarded here, were known as 'Mickey Mouse' tanks round our way. It was not a term of affection. I bet the the Brighton radials were as good or better at most things other than going fast. There were 75 E4s which is a lot for a small railway.
Any one had thoughts on different lubricators? The Ashford ones are fiddly to fill. The bought in ones, Detroit, and so on are generally nicer to use.

 

2968 does that too. It's because the reverser was inherited from the Horwich Crabs, where the lifting link was turned through 180 degrees before reaching the radius rod, while all Stanier engines had a direct link to it behind the expansion link. We always emphasise this point when she visits other railways, but it still catches drivers out now and then, even on the Severn Valley.

Those Brighton Radials must have been brilliant in their time, then! I often fired the tender version, 6443, and it was a cracking little engine. You could fire it with a teaspoon and it would still steam, and do anything the driver asked of it.

 

I think on a hilly preserved railway like the Bluebell, there is a lot to be said for an unsaturated class 2 - you have plenty of oomph at low speed, they will keep going if the pressure goes off a bit, and you also remove all the maintenance headache of the extra complication of a superheater. By contrast, while I am sure an Ivatt class 2 was a fine loco in BR service, because of the limited speed you probably aren't using it in the performance area where it excels, i.e. using the capability and efficiency at higher speed. the duty cycle is lots of stopping and starting, slogging up big hills and lots of time stationary when you want to keep things quiet and everything cools down - not the best means of operation to get the best out of a small superheated loco.

Tom

 

Haven't you learnt yet Tom, if it's in use on the IoW then it is plainly infallible and that superheater and associated inefficiency will be necessary, we just await a justification...

 

Those two factors oppose one another though; one would expect more elastic deformation with the point-loadings (OK, technically line) of roller bearings, but less in them because of the steel. I'm still somewhat amazed that the minor variation in deformation between roller and plain can result in a rough ride; maybe there's some interaction with the springing (e.g. some sort of resonance) that causes it?

I'm a bit surprised that in the later ages of steam, which were quite technically sophisticated, someone didn't look into this to work out exactly what was going on. Also, ISTR a lot of new-builds seem to have gone with roller bearings (anyone know why?); I wonder if their designers had taken the ride issues into account?

Thanks to all who replied; I'm still a bit mystified by the phenomena, though (I couldn't pick up a 'generally held' explanation).

Noel

 

My understanding (based purely on remembering things I've heard elsewhere) is that a roller bearing loco, in steam days at least, could go longer between shopping, so perhaps it's just that they will deteriorate less per given mileage, reducing costs of upkeep?

 

Palmerston or Welsh Pony are probably better comparisons being saturated. It's probably not a fair match though as the England engines are allowed to do more than 15mph and pull a decent train.

The boiler pressures are higher than they were orignally and in my experience this makes a big difference. Certainly on small locos working hard anyway. If you drop 10 pounds or even 5 pounds off the redline on a 160psi loco like Linda or Blanche it can be really hard to get it to recover. You'll really struggle to get water in. It's made worse of course because you are then sacrificing water level to get the pressure back up where it should be. On Lyd which has a 200psi boiler you could have it 20 psi down and you don't really notice much difference in steaming or performance. That margin seems so much bigger the higher the pressure and the hotter you run the engine.

Tim

 

I'm with Mr Bonsor. I cannot imagine any deformation in plain bearings, otherwise extremely bad things would be happening. In any case AIUI there shouldn't be any metal to metal contact, both sorts of bearing ought to be running on a lubricant film.

 

I think that you have to consider that there is some flexibility in the track. If you watch a train roll by, the rails are depressed when the wheels pass over, then recover as they pass by. My guess is that the deterioration in ride is due to the interaction with the greater unsprung weight of the roller bearings and the flexibility of the track. This throws greater movement up through the springs into the locomotive.