Castle Aching

[Regularity]

The K was used, however, for cars that were fully side-corridor, as in TFK (for posh commuters from Tunbridge Wells, who used to form an orderly queue for each door, and effectively have ‘personal seats’) in the Hastings Units.

 

Which (as a later edit to your post) sort of backs up what I said: K for side corridor.

[Guy Rixon]

Regarding 6-wheelers into CA, has the geometry of thee approach curves been checked? The 6-wheeled beasties are absolute swine if there isn't enough side play and the flanges get rammed into the side of the railhead. They will come off if this isn't sorted and widening the gauge may be the easier way out.

[Compound2632]

Side corridor is what I was referring to, as reducing the seating capacity per foot length of carriage, though this generally went hand-in-hand with gangways. By the 1910s there were exceptions - I think the Great Eastern and Hull & Barnsley among others had non-corridor carriages with side corridor to give access to lavatories. Indeed, that idea goes at least as far back as the special Ladies' and Gentlemen's First Class Saloons Wolverton built for the Liverpool boat trains in the 1880s - 42' 8 wheeled radial carriages, of course; in that case about  half of each carriage was an open saloon - dining carriage style for the gentlemen, family carriage style complete with chaise longue for the ladies. The corridor not only gave access to the lavatory but also to smoking (gentlemen) and 'boudoir' (ladies) compartments. Of course there was no gangway between these carriages: segregation of the sexes was absolute. If you wanted the company of the opposite sex on those trains, it was second or third class for you.

 

EDIT: I don't think the LNER/BR codes could describe these saloons!

Edited February 12, 2018 by Compound2632

[Edwardian]

Regarding 6-wheelers into CA, has the geometry of thee approach curves been checked? The 6-wheeled beasties are absolute swine if there isn't enough side play and the flanges get rammed into the side of the railhead. They will come off if this isn't sorted and widening the gauge may be the easier way out.

 

3' minimum radius, there should be.

 

6-wheelers have to work.  Even if the WNR were to eschew the 6-wheeler, GE, GN and M&GN services will all be made up of 6-wheelers.

 

Given that, the WN should operate a mix of 4 and 6-wheelers.

 

I am not looking forward to producing multiple 6-wheel chassis.

[Compound2632]

The Midland were a bit of a special case.

 

I'll presume you mean that in a good way. 

[Guy Rixon]

3' minimum radius, there should be.

 

6-wheelers have to work.  Even if the WNR were to eschew the 6-wheeler, GE, GN and M&GN services will all be made up of 6-wheelers.

 

Given that, the WN should operate a mix of 4 and 6-wheelers.

 

I am not looking forward to producing multiple 6-wheel chassis.

 

 

The point about checking the geometry to see whether a sliding centre axle will do it or whether you need a Cleminson arrangement. There's been a winding discussion over on the S4 forum that has produce formulae for this.

[NCB]

For 6 wheel vehicles, some form of flexible chassis, such as the Cleminson truck, works wonders. I built a few Cambrian 6-wheelers from carved up Ratio 4-wheelers, and they were hopeless going round corners, even shallow ones. I modified one to use the Cleminson principle, and it would sail happily around a 12" radius test curve. Better than a 4-wheeler.

Edited February 12, 2018 by NCB

[Nearholmer]

Guy

 

There is no practical need of a formula, if you use a single radius arm from each outer axle cradle, as per the r-t-r ones that I showed in my thread. The result isn’t strictly in accord with Mr Cleminson’s patent, but it works a treat.

 

I’m sure the mathematical computations are interesting though.

 

Kevin

[Edwardian]

Guy

 

There is no practical need of a formula, if you use a single radius arm from each outer axle cradle, as per the r-t-r ones that I showed in my thread. The result isn’t strictly in accord with Mr Cleminson’s patent, but it works a treat.

 

I’m sure the mathematical computations are interesting though.

 

Kevin

 

Please explain, as if to a not particularly gifted child.

 

 

 

 There's been a winding discussion over on the S4 forum that has produce formulae for this.

[Nearholmer]

Sketch to follow when I get time.

 

K

[Edwardian]

Sketch to follow when I get time.

 

K

 

Bless'd are the sketch-makers

[Guy Rixon]

The more-subtle maths turned out to be to do with details of 4-wheeled vehicles. The formula needed for the 6-wheeled vehicle is more direct and brutal, the versine v = c²/8r, where c is the wheelbase and r is the radius of the curve. In this case, where the rigid wheelbase forms a chord across the outside rail of the curve, the versine is the distance by which the inner wheelset need to budge over to align with the rails. For a 3' curve and a 22.5ft wheelbase, the versine in 4mm scale is 0.88mm. If the coaches have this much side-play then they don't need swivelling suspensions. That amount of side-play is hard to get in P4 but should be easy in OO.

 

The thread also suggested that for  the curve, which works out to 3.5 chains equivalent, the full-size railway would use gauge widening that scales to about 0.25mm in 4mm scale. That's probably a good thing to do at CA.

[corneliuslundie]

You don't need a corridor for access to a lavatory. there are documented cases, though I can't remember which company, of carriages where there was a seat attached to the loo door, accessible from just one compartment. So if a lady was sitting on that seat and you needed to use the facilities you had to ask her permission - somewhat embarrassing anyway and worse if she had not realised that she was sitting outside the lavatory.

But let's travel in more style than that:

Interior of the restored Midland "Picnic Saloon" at Butterley - an 18 year job so far.

Jonathan

[Edwardian]

The more-subtle maths turned out to be to do with details of 4-wheeled vehicles. The formula needed for the 6-wheeled vehicle is more direct and brutal, the versine v = c²/8r, where c is the wheelbase and r is the radius of the curve. In this case, where the rigid wheelbase forms a chord across the outside rail of the curve, the versine is the distance by which the inner wheelset need to budge over to align with the rails. For a 3' curve and a 22.5ft wheelbase, the versine in 4mm scale is 0.88mm. If the coaches have this much side-play then they don't need swivelling suspensions. That amount of side-play is hard to get in P4 but should be easy in OO.

 

The thread also suggested that for  the curve, which works out to 3.5 chains equivalent, the full-size railway would use gauge widening that scales to about 0.25mm in 4mm scale. That's probably a good thing to do at CA.

 

Thanks, Guy.

 

I won't pretend to understand any of that.

 

The short version seems to me to be that, if the central axle can move side to side far enough, I don't need to worry about the outer axles. 

 

I will be unable, however, to:

 

(a) understand and apply the formula; or,

 

(b) widen the gauge on the curve because I am using proprietary flexi-track.

 

But, given the tolerances I tend to apply as a result of hamfistery, a mm either way would be pretty much unprecedented precision for me, so something that slops to and from by about a mm should be a piece of cake!

[Compound2632]

You don't need a corridor for access to a lavatory. there are documented cases, though I can't remember which company, of carriages where there was a seat attached to the loo door, accessible from just one compartment. So if a lady was sitting on that seat and you needed to use the facilities you had to ask her permission - somewhat embarrassing anyway and worse if she had not realised that she was sitting outside the lavatory.

 

Access to one lavatory from one compartment was the usual way of providing lavatory accommodation from the mid 1880s onwards, though the seat in front of the door was not usual. The normal arrangement was to have a pair of lavatories side by side, between two compartments each with access to one. The weak bladdered had to make sure they got into the right compartment!

[Edwardian]

Access to one lavatory from one compartment was the usual way of providing lavatory accommodation from the mid 1880s onwards, though the seat in front of the door was not usual. The normal arrangement was to have a pair of lavatories side by side, between two compartments each with access to one. The weak bladdered had to make sure they got into the right compartment!

 

Quite.  Take the GER 6-wheel 5-compartment Third.  It's just a 6-compatment Third with lav-compartments substituted, but you had to make sure you were in one of the 2 compartments that flanked them.  Chose one of the other three and it's Crossed-Legged to Cromer you go!

[Nearholmer]

IIRC, slop was good enough for HD and Wrenn. I don’t know about modern equivalents from Dapol etc, but I wouldn’t mind betting that they are sloppy too.

 

I’m still going to draw the sketch later, though ..... it might be useful to somebody.

Edited February 12, 2018 by Nearholmer

[ChrisN]

The Cambrian had a first class saloon with one toilet in the middle.  It was accessed from one compartment on one side but on the other side you had a door to the luggage compartment which had a door to the toilet.  I am not sure how you knew someone was already in there.  ('You have to be a good singer in our house.'  'Why's that?'  'There is no lock on the loo.')

 

Dart Castings do a set of W irons for 6 wheel wagons and produce a table of wheelbase and minimum curve.  I am in the process of building some 6 wheelers and once I get one to having four sides I will experiment with wheels.  Firstly, one end fixed, middle with side play and able to rotate, the last one with no side play and able to rotate.  If this fails then a clemenson type arrangement and if that fails, the flange on the middle axle will go.

 

The Cambrian did have some semi-corridors, SC as it put it, which was an internal corridor but no gangway to the next coach.

[Regularity]

Your curves are of reasonable radius, and you are working in 00 gauge, so you can if you wish fudge things a bit by building 4-wheelers using the outer axles, and for centre wheels, filing the pin points off and putting the axle in a tube, lightly sprung to keep it on the track but not carry any noticeable weight.

[Nearholmer]

This is a sketch what I have done.

 

All three axles ride in cradles, which carry the W-irons. The two outer cradles are pivoted in the centre and free to rotate, the centre one can slide freely from side to side, but not rotate.

 

The radius arms R transfer motion.

 

I have a feeling that this operates on a different principle from real Cleminson, in that the function of the radius arms is largely to prevent ‘oversteer’ and ‘crabbing’ of the outer cradles, which can otherwise be a serious issue (playmobil wagons have rotating cradles for the axles, and they will oversteer). In a real, and more complex, Cleminson, some actual steering occurs from the moment the leading wheelset encounters a curve ....... if everything is working super-freely.

 

The sketch looks ‘bent’ simply because of the way I had t9 grab a photo.

 

Makes sense?

[Regularity]

You need some form of guide for the central unit, to stop it twisting.

[Nearholmer]

Real thing as applied on Southwold Railway coach.

[Nearholmer]

Regularity.

 

Indeed, you do, otherwise it would float about in free space. The cradle slides laterally in a pair of channels or similar, not taking any of the load.

 

In the real thing, load comes down onto the centre cradle via a bearing pad, and crabbing is prevented by arms from each end of the cradle to the central linkage ...... as I say, the principles of operation are different.

Edited February 12, 2018 by Nearholmer

[robmcg]

as to all coaches looking the same to me, I'm totally gobsmaked that this was taken seriously and give up.

 

sigh

 

Progress on CA looks good.

[Andy Hayter]

Your curves are of reasonable radius, and you are working in 00 gauge, so you can if you wish fudge things a bit by building 4-wheelers using the outer axles, and for centre wheels, filing the pin points off and putting the axle in a tube, lightly sprung to keep it on the track but not carry any noticeable weight.

 

No need to file the points off.  Just don't use brass bearings on the centre axle - this will give sufficient side play for most non-set track curves.