Castle Aching

[Caley Jim]

I have a feeling that this operates on a different principle from real Cleminson, .......

On a proper Cleminson the pivot point is midway between the outer and centre axles, resulting in all three axles always being radial to the curve and the outer axles moving in by the same amount as the centre axle moves out.  I'll try and find time tomorrow to take a photo of the underside of one of my 6-wheeled coaches.

 

Jim

[Regularity]

There’s always Brassmasters. They work well.

http://www.brassmasters.co.uk/cleminson_underframe.htm

[Metropolitan H]

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.

We had one of the H-D ex LMS design 6 wheel "Stove" van models - when they were new and only 13/- (£0-65p). A very nice looking model, but the centre axle arrangement was rather floppy - to say the least - and there were occasional problems with derailments.

 

Regards

Chris H

[Nearholmer]

Jim

 

That would be interesting, because although I’ve got a copy of the Cleminson patent drawing in a book somewhere, I can’t remember which book, or where it is!

 

If you notice, the Southwold version appears to have fixed pivot points on the outer cradles, and I’m not sure the patent was like that.

 

Kevin

[corneliuslundie]

Beware that proprietary flexitrack can sometimes go a bit under gauge on curves. It depends which type. This can make the six wheel carriage problem more severe..

I'll photograph a Brassmasters Cleminson chassis tomorrow for you. I have some for some unfinished Rhymney 6-wheelers in various stages of undress.

Jonathan

[Donw]

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.

 

The curves are pretty gentle 3 to 4 ft and through the turnouts. Besides 00 track has so much clearance it could be regarded as permanently gauge widened. We did try to go for nice flowing track so I hope the six wheelers will be happy.

 

When young nearly all the coaches on the Paddington trains were corridor coaches so I rather assumed they were the norm although the Southern electrics didn't have corridors I think (I was quite young when I travelled on them although I have later memories of escorting a young lady back to Wokingham at night but my attention was not on the coach!

The DMU that started to appear on the trains from Paddington seemed revolutionary with their open seating. 

 

The connections between coaches I knew as Corridor Connections. Gangway sounds more like the Isle of Wight Ferry 

Don

[Donw]

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.

 

If Edwardian was using 00SF I would agree with the gauge widening  but since most things will pass through the 16.2 mm 00SF turnouts normal 00 at 16.5 effectively has 0.3mm clearance more than the gauge widening you suggest. Which is helpful seeing as the turnouts are built and the plain track will probably be 00 flexi track.

 

Don

 

edit I would suggest the best thing would be to build a 6 wheel chassis rigid but with a modicum of side play and run it through the curves to see how it goes. It might save faffing about with Clemenson or it may show it is necessary. Obviously the 6 wheel test chassis should have the longest wheelbase you are likely to need. The 6 wheel tank wagon should have little problem compared to the longer coaches.

You can see the side play needed by placing a ruler across the track to check the offset at the centre of the wheelbase then checking the sideplay on the coach. As guy says it is about 0.88mm 

Edited February 12, 2018 by Donw

[Shadow]

If you look at page111 of this copy of "The Engineer" it has a drawing and description of the Cleminson method. Feb 15th issue, 1878.

 

 

[Nearholmer]

So, it does have fixed pivot points.

 

K

[Northroader]

Way back, I had one of these, which performed very well, although a bit klunky in appearance, and you could pick up one of these quite cheap to act as a guinea pig:

[Compound2632]

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.

 

Don't. Just remember you're dealing here with obsessives such as myself who can identify the style of beading at a hundred paces and have patience with our weaknesses.

 

But do mind what you say about wagons...

Edited February 13, 2018 by Compound2632

[Edwardian]

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

 

 

 

It's for your own good.

 

One day you'll thank us. 

 

It must be confessed, I have a bit of a 'thing' for coaches.  I tend now to think about what coaches I need for a supposed or real service, and then think about what locomotives might be suitable.

 

I think I can explain how this obsession arose. Are you sitting comfortably ...?

 

For me, it was always the steam-age railway, and I came to it in part through the obsession of modellers and preservationalists for the Great Western between the wars.  Blame annual pilgrimages to the Dart Valley and the Torbay & Dartmouth. Even the model railway at Paignton station (you really didn't want to leave the station and see Paignton itself) was classic 1930s Great Western.  I never made it, have never made it, to Didcot, but I once was taken to the Severn Valley, and magazines and books were full of Pendon and countless other GW layouts.  BBC Children's telly even had a series based on the Severn Valley.  Everything conspired to influence me in but one direction ...

 

So, a bigger, better model railway was planned, but, before it was completed, I began to perceive the limitations even of the superior Airfix and Mainline equipment of the day.  Why were the only coaches Thirds and Composites?  Why were the only decent corridor coaches Centenaries (the Hornby Colletts of the day were absolutely rank, a situation only properly remedied 2-3 years ago)?  Where was I going to get 70' Coaches for my West of England expresses? 

 

The problem?  Well, with a few well-worn exceptions (mainly Bulldogs), the South Devon mainline in the mid-Thirties showed the Churchward Revolution Triumphant and Complete. Standardisation meant that, yes, all the locomotives did look the same! 

 

I loved them/love them dearly, but where the Great Western excelled in variety was in its coaching stock, a fact emphasised by its absolute determination to include as many different styles and periods of coaches in each train it marshalled.  While the Southern faffed about with 'sets', the Great Western formed its trains entirely for the satisfaction of the carriage historian.

 

In order to understand what you were seeing, you had to achieve a basic mastery of the history of GW coach design. 

 

Who could not be stirred by the elegance and dignity of a Dean Clerestory, or thrill to the sheer size and powerful lines of the Dreadnoughts, or warm to the Concertinas for adding a touch of whimsy?  By the Thirties, a West of England Express might have a Dreadnought, Concertina, panelled Toplight, steel Toplight, steel South Wales, each noticeably different from the other, having only a length of approximately 70' in common.

 

So, I approach any given railway or company with an eagle eye for its coaching stock.

 

Some understanding these matters is fascinating, but also helps you to choose the appropriate period and type of coach and the coach formation for your layout, even where you have no information or photographs to help you.  It also helps in determining what to create as fictitious stock for a freelance railway.

 

For instance, the West Norfolk has a long and prestigious enough run to its principal coastal resort via the major population centre (the Birchoverhams) to warrant 6-wheel coaches.  These need to accommodate 3 classes, because the line has not abolished Second Class by 1905.  The distances involved are not such as to justify the provision of lavatories, however, and on-board catering was the exception, not the rule, in those days.

 

A through service from the Great Eastern will also use 6-wheel coaches in the main, though it will be confined to two classes, as Second was abolished in 1893.  This train will have taken a longer run, perhaps from London, via King's Lynn, so its coaches are likely to need lavatories and perhaps additional luggage compartments. 

 

So, immediately, there will be differences between a prototype train designed for one purpose and a freelance train designed for another.   

 

Have we persuaded you of the virtues of Caring About Coaches yet?

 

Say "yes", or we'll just keep going.

Way back, I had one of these, which performed very well, although a bit klunky in appearance, and you could pick up one of these quite cheap to act as a guinea pig:2B691032-33CB-4063-B2AB-5E772C2DFC74.jpeg

 

A good idea, thanks.

[Edwardian]

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?

 

That has the brilliant simplicity of genius.

 

I will try it.

[Guy Rixon]

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.

 

Another way to do the same thing is to mount the centre wheels on a 2mm length of tube, then arrange the tube to slide on a 1mm fixed axle. Bill Bedford suggested this and it's quite easy to arrange.

 

However the central axle is arranged, it needs something to stop the flanges climbing over the rail head. It's OK if the axle normally carries negligible weight, but it needs to gain significant weight to push it back down before the wheelset can rise one flange depth. Basically, it needs some kind of bump stop so that if it rises more than ~75% of the flange depth it starts to the lift the coach and weight is then transferred and the wheelset goes back down onto the rail. This is how rigid-suspension toys* stay on iffy track with insane curves and speeds.

 

If there's no weight transfer, and the centre wheels just rattle around in a sloppy hole, then they will work sometimes and jump off at others. Basically, if the frictional, sideways force in the bearings happens to exceed some fraction of the weight of the wheelset (around 50%, given by the Nadal formula, which is a real concern in full-size railways) then the wheels will climb off. This is a practical matter. I've seen trains of beautiful 6-wheelers that fell off plain line whenever somebody farted three stands away.

 

* I refer to systems like Hornby Dublo which can get round tramway curves at a scale ton because it has huge flanges and weight transfer always happens when a wheel start to climb. I'm not implying that all models with rigid suspensions are toys.

[Nearholmer]

Bang on.

 

It’s OK, desirable even, for the centre cradle or axle to drop low when the vehicle is lifted, but it mustn’t be allowed to rise high.

 

In the sketch showing the cradle sliding in channels, the top of the cradle should be a gnat’s quaver (= less than wheel flange depth) clear of the top flange of the channel when standing on a sheet of glass, and should be able to move up and down and side-to-side freely.

 

Some people put bits of lead on the centre cradle, but metal wheelsets are quite heavy, so probably not really necessary.

[corneliuslundie]

As promised here are some photos of a couple of Cleminson chassis, one under a Rhymney 6-wheeler and the other awaiting installation. Note that the carriage awaits its J hangers.

 

 

The views of the chassis alone show the centre axle at its maximum sideways travel.

These chassis are easy to assemble - they must be if I can make them successfully. The wheelbase can be adjusted to suit the prototype.

 

Back on philosophy, I followed much the same route as Edwardian without the advantage of visits st preserved railways. My first layout was a 1930s West Country branch, though with SR interloping for a bit of extra interest - the result I suppose of having grandparents living in Exeter.

But the big influence was having my tonsils out. While I was recovering I moved from the front bedroom I shared with my brother to my sister's back bedroom (I don't remember where she went!). It had a view across to the Rhymney Railway main line. At that stage it was mostly 56xx with rakes of maroon suburban carriages, but still some coal. However, it opened my eyes to the fact that there were railways other than the GWR. And that passengers were really just a nuisance, getting in the way of the coal etc. it took a long time to gell that this was really a promising area to explore rather than staying in the territory of GWR Stone nos 1, 2 and 3..

Hence rather than carriages, by interest turned to wagons, which is why i have some 20 books on PO wagons alone and most of the other books published on wagons. You know things have got beyond recovery when you start quoting wagon diagrams, or, worse, you can explain how Dean-Churchward brake gear works. I fear I am beyond rescue.

Jonathan

[wagonman]

 

 

I loved them/love them dearly, but where the Great Western excelled in variety was in its coaching stock, a fact emphasised by its absolute determination to include as many different styles and periods of coaches in each train it marshalled.  While the Southern faffed about with 'sets', the Great Western formed its trains entirely for the satisfaction of the carriage historian.

 

 

 

 

 

I always thought the GWR marshalled its passenger trains blindfolded...

[Edwardian]

I do have to factor-in cost. 

 

Just the extra axle for each coach is pushing up the price. I like the idea of the Brassmasters Cleminson.  It is the £9 per coach that adds, rather than the complexity, that concerns me.  I do not say £9 is an unreasonable price, but I have to compare that with the cost of 3 bog-standard W Iron sets and a bit of wire.

 

Once the track is laid and the thing works, I will need to get cracking on stock.  Locos mainly use proprietary chassis, so that is some time and effort saved.  I have a modest stack of goods wagon kits to start upon.  Few of these are of any complexity.  4-Wheel coaches are just big wagons wot need lining.  

 

I do need to have something like a production line for 6-wheelers.

 

The layout intends to rely heavily on 6-wheelers, as I believe that this is appropriate for a line of this nature at this period.

 

If I set out the possible stock that I envisage, you can see the balance between 4, 6 and 8-wheelers.  This is a somewhat optimistic plan (which, of course is subject to change/abandonment):

 

- WNR Mainline: 'Modern' (1890s) 6-wheel set (5 coaches)

 

- WNR Mainline: 1880s 6-wheel coaches (again, est. 5 coaches) 

 

- WNR Mainline: 1880s-1890s long 4-wheel general service stock (4-6 coaches)

 

- WNR Achingham branch set - short 1870s 4-wheel stock (4 coaches)

 

- WNR Wolfringham branch set - short 1860s-70s stock (3-4 coaches)  

 

- GER Service No.1:  Holden 6-Wheel Type 5 & 7A 6-wheel stock (6 coaches)

 

- GER Service No.2:  Holden 6-Wheel Type 5 & 7A 6-wheel stock and bogie Composite (4 coaches)

 

- GNR Service: GNR 6-wheel stock (5 coaches)

 

- Midland Service: Clayton bogie Clerestories (4 coaches)

 

- M&GN Service: ex-MR Clayton 6-wheers (2), ex-GNR 6-wheeler (1) E&M 6-wheeler (1), E&M 4-wheeler (1)

 

Admittedly, that's a lot, and it breaks down as follows:

 

- 8-wheel (bogie) coaches = 5 

- 6-wheel coaches = 28

- 4-wheel coaches = 12-15

 

In addition, of course, there will need to be a number of NPCs, mainly 4-wheel.

 

My intention would be to work at these one train at a time, thus, I would be working on batches of 4-6 vehicles.  I only need one train and a handful of wagons to run the layout, so it really does not hugely matter the rate at, or extent to, which I work through this programme.

Edited February 13, 2018 by Edwardian

[Regularity]

I always thought the GWR marshalled its passenger trains blindfolded...

According to Jenkinson, the LMS wasn’t any better.

[Nearholmer]

Carriage building plan: ambitious.

[Edwardian]

I always thought the GWR marshalled its passenger trains blindfolded...

 

According to Jenkinson, the LMS wasn’t any better.

 

As long as you can tell a RH Van Third from a LH one, and arrange the brake ends leading a trailing blindfolded, then, yes, you can marshal a GW train that way!

 

 

Carriage building plan: ambitious.

 

Keeps me off the street

[Guy Rixon]

I think it's excellent to have a stock-building plan and good to have trains to progress to after the first. I would hate to feel that I had to build a new layout to justify different stock. Also, nice to have planned trains that might absorb some forthcoming kits.

[sem34090]

Isn't that how the old Hornby palethorpes sausage/LMS/GWR Insulated milk van worked? I have one and it seems rather similar...

Just noticed Northreader's post...

[Compound2632]

According to Jenkinson, the LMS wasn’t any better.

 

... inherited from the LNWR. At least by the time LMS standard stock was dominant, the profile was uniform and carriage length mostly 57' or 60'. In late LNWR days, a typical express could include arc, cove and full elliptical-roofed carriages, the latter in two panelling styles, widths 8', 8'6" or 9' - not counting any dining carriages, in their own style of panelling and either clerestory or elliptical roofs and 8'6" or 9' wide. 

[Edwardian]

I think it's excellent to have a stock-building plan and good to have trains to progress to after the first. I would hate to feel that I had to build a new layout to justify different stock. Also, nice to have planned trains that might absorb some forthcoming kits.

 

I have been in touch with David Eveleigh, and it may be that he can help with some 4mil stuff. 

 

The other side to this ambitious programme is that the GE coaches, and the trinity of GE locos and the GE wagons for CA would be a nice fit for a future Wolferton layout, and I daresay that the Midland, GN and M&GN could find other uses, too. 

 

The GER services could each be hauled by any of the No.1 Class 2-4-0, T26 Intermediate 2-4-0, or passenger fitted Y14 0-6-0

 

The Midland, Great Northern, and M&GN services could all be hauled by a M&GN A Class Beyer Peacock 4-4-0 or Johnson C Class 4-4-0.  However, Midland and Great Northern locos might work past Lynn, allowing a Johnson 2-4-0 or a GN single or bogie single to take turns.

 

It is, then, worth trying to build up a number of foreign trains, as well as the WNR's own stock. Quite a variety of locomotive liveries and types become possible as a result.