Cleminson 8 wheel flexible wheelbase for coaches

[ianmaccormac]

Hi

I have found details of the 6 wheel cleminson flexible wheelbase trucks for a carriage underframe as per the picture in here

 

http://www.bio-nica....ceanicCanal.pdf

 

Does anyone have similar or knowledge of how the system worked for 8 wheel vehicles. I am looking particularly at the early LB&SCR Stroudley 7 compartment first class coach. I have an HMRS drawing showing the rebuiding back to bogies in 1893 but have no details of the original set up.

Can anyone help please?

Cheers

Ian in Blackpool

[kevinlms]

Well someone didn't like his system.

 

http://trove.nla.gov.au/ndp/del/article/8969362

 

Kevin Martin

[Penlan]

The LNWR had radial 8 wheel coaches, when I get home again I will see if I can find an underframe drawing - is this just for 1:1 interest or are you then moving onto modelling Radial stock?

 

I think the two inner axles where fixed laterally and the outer axles moved within a radial framework, the outer springs were definatly different. But will check the drawings. Modelling wise I've used a bogie with the pivot point offset towards the coach end.

[Phil Traxson]

Having spent some time researching the Cleminson 6 wheel chassis and then turning it into a production version for modelling I am intrigued by the idea of an 8 wheel version.

To my mind, the centre trucks would have to slide laterally and pivot about the centre of the axle to take up the correct position. Very complicated to engineer so that they also take some of the weight of the coach as well. I can see why the system was abandoned for 8 wheel coaches!

 

Attached should be a photo of the result of my research.

[relaxinghobby]

Hi all

 

Brassmaster Models do a 4mm version of the Cleminson 6 wheel system that works very well around my small radius curves. You can construct it as inside or outside verson

 

I have also made a very crude variation using DJH inside wagon bearings, it all sits invisibly behind the spring and axle box mouldings and foot boards, and when on the track you can't tell what's there whilst merrily pushing a train of them around the bend.

 

For an 8 wheel system I would think that a pair of inside bearing bogies will do the trick. I doubt if an exact scale versions will work on anything except the slightest of curves.

[Poor Old Bruce]

The LNWR had radial 8 wheel coaches, when I get home again I will see if I can find an underframe drawing - is this just for 1:1 interest or are you then moving onto modelling Radial stock?

 

I think the two inner axles where fixed laterally and the outer axles moved within a radial framework, the outer springs were definatly different. But will check the drawings. Modelling wise I've used a bogie with the pivot point offset towards the coach end.

Surely any pivot on a bogie arrangement should be offset towards the centre of the coach, not the end. Either would affect weight distribution and propensity to derail though. Some of those coaches were ultimately fitted with bogies anyway.

[ianmaccormac]

Yes, this for modelling the 1879 LBSCR 7 compartmant first. 6 built by Cravens with bogies and 6 built with 8 wheel cleminson flexible wheelbase! I doubted this but have just received a drawing from the HMRS which shows the conversion of the coaches to standard bogies in 1893, so they were in use for 14 years

I have used the Roxey system for 6 wheelers, my version with varying wheelbases shown here, for the various saloons etc that I am about to produce, only test etches so far, and have made this sprung as well as I prefer that to compenstation for the smoothness of ride.

I would be very interested to see other railways versions of this. I know from the NZ or Aussie newspapers that have been digitised recently that there was quite some use made of this on the LC&DR and am trying to follow that up at present.

Any other info anyone?

I must say the 3D print matches the drawings to a T. Very impressive! What scale are these in please?

I am working in, mainly 4mm but have dabbled in 7mm occassionally.

Thanks

Ian

[Phil Traxson]

I must say the 3D print matches the drawings to a T. Very impressive! What scale are these in please?

I am working in, mainly 4mm but have dabbled in 7mm occassionally.

Thanks

Ian

Ian,

It's not a 3D print it's cast resin. It is part of a pair of resin kits for 7mm scale narrow gauge (0-16.5 or 0-14) North Wales Narrow Gauge cleminson 6 wheeled coaches which I have just released.

 

If you find a drawing for the 8 wheel version I would appreciate sight of it.

 

Regards

Phil T.

Port Wynnstay models

[ianmaccormac]

Hi Phil

I think this will be a case of not holding your breath!

Nice resin!

Cheers

Ian

[34theletterbetweenB&D]

For an eight wheeler, surely the centre axle bearer of a six wheeler carries a pair of axles

Well someone didn't like his system.

 

http://trove.nla.gov...article/8969362

Thos. Midelton, we never knew you. A man after my own heart, that's a magnificent denunciation on a point of principle, and he gets the verdict of history: Bogies vs Cleminson Radial system , Bogies by KO.

[Phil Traxson]

For an eight wheeler, surely the centre axle bearer of a six wheeler carries a pair of axles

 

Thos. Midelton, we never knew you. A man after my own heart, that's a magnificent denunciation on a point of principle, and he gets the verdict of history: Bogies vs Cleminson Radial system , Bogies by KO.

 

The whole point of the cleminson system is that the axles were kept as near as possible to 90 degrees to the track at all times to reduce wear and friction, therefore a centre truck with two axles would not fill the bill.

It was a good theory but didn't work out so well in practice. I would think it's biggest down side would be the amount of daily maintenance needed in comparison with a bogie vehicle.

It would also have a very finite minimum working radius, limited by the amount of sliding movement of the centre axle. For shorter vehicles it was almost unnecessary, the "psuedo " cleminson wagon on the Festiniog Railway was tested after rebuilding and moved less than 1" on the tightest curves in Boston Lodge works!

 

As you can see, because I made a model of it doesn't mean I agree with it, on the contrary it only confirmed what I thought about it in operation.

 

Phil T.

[Penlan]

Surely any pivot on a bogie arrangement should be offset towards the centre of the coach, not the end. .......

First the LNWR's Radial axle can be seen to have a radius of 6' 9.5" on the drawing below and as you say thus offset to the centre wheels of a 1:1 scale coach, but also note just how tight a radius that is, and as the inner wheels (16' wb) are fixed there will in fact be very little side swing on the radial axle.

 

On my (and other peoples) models of 8 wheel Radial stock where we have used discrete bogies to replicate the prototypes actions (and keep life simple) we have found it helps if you offset the bogie pivot point towards the end of the coach - don't forget we are also trying to give the impression the inner axles don't move!!!!!!

 

I can push these radial coaches with ordinary 42' and 50' conventional bogie stock + 6 wheelers into a siding without buffer locking - The 6 wheelers have a sprung downwards otherwise free to move sideways centre axle - I'm not complicating things with Clemisons etc., oh and a 3'6" min radius too.

 

In the late 1960's when we tried the pivot point towards the centre of the coach (like the 1:1) they buffer locked. I don't know why... These etched underframes are from the long ago 'Red Rose Models' range.

 

PS - Yes there is bits of lead there around the underframe to get the weight up, and I see a passenger too, must have missed their stop - I feel a familiar song coming on........ 'Oh Mr Po.....'

[Grovenor]

Those coaches look very nice.

In the late 1960's when we tried the pivot point towards the centre of the coach (like the 1:1) they buffer locked. I don't know why...

simply, the further the bogie pivot from the end of the coach the greater the side throw on the buffers.

So this is one of the compromises you need for sharper than scale curves.

Keith

[Penlan]

Reading the OP again, Clemison 8 wheel system - we have dealt with the 6 wheel, but nothing yet as a drawing of the 8 wheel (I think) from Cleminson, though one wonders if the Crewe/Wolverton system was similar, but got round the patents......

I seem to recall there was a 6 wheeled coach with a radial axle at one end only, the centre and other end being fixed.

[Grovenor]

Its the first time I have ever heard of a Cleminson 8 wheel system, was there such a thing?

The Cleminson idea was to make 6 wheelers suitable for sharp curves without going to the expense of an extra axle, with 4 axles the bogie was well established for this purpose.

Regards

Keith

[Snow White]

Neither have I ever heard of a Cleminson 8 wheel chassis. Even for 6-wheeled stock, I read somewhere that the Cleminson system was far from universal. In theory it was great, but in practice did not work too well. I do not think it was used widely in the UK - except perhaps in model form.

[Phil Traxson]

Neither have I ever heard of a Cleminson 8 wheel chassis. Even for 6-wheeled stock, I read somewhere that the Cleminson system was far from universal. In theory it was great, but in practice did not work too well. I do not think it was used widely in the UK - except perhaps in model form.

Used on some of the Irish 3ft railways and by the Manx Northern on the Isle Of Man and also on the Southwold Railway, again a 3ft Gauge line, and of course on the three coaches for the 2ft gauge North Wales Narrow Gauge Railway. The latter is where my interest lay.

 

Phil T.

[Guest notascoobie]

Good evening,

The GNR also had some rigid 8- wheeled carriages, courtesy of Mr Howlden, who had also designed the 6-wheelers.  The key difference was that the 8-wheelers had the axles at the ends, whereas the 6-wheelers had a centre axle.  As such, my choice would be to go for the sliding axle arrangement on the inner axles.  I claim no originality but I have used the method on 6 and 8 wheel vehicles.

Take a length of 2mmOD/1mmID brass tube the same length as the face-to-face measurement on your wheelset.  Carefully remove the wheels and mount on the brass tube.  Place the brass tube over an Exactoscale 1mm dia pinpoint axle and place into pinpoint bearings in the axleguards.  The brass axle is free to move laterally over the fixed steel axle, allowing cornering. The method works fine in EM although those without flanges might struggle.

I hope that helps.

Regards,

Vernon

[ianmaccormac]

Thanks to all for thoughts and replies. I have been playing about with card mock ups to see if anything actually worked. From this, for anything to work on this Cleminson type system, there needs to be an odd number of trucks. The other thing noticed is that the solebars always are further apart on the carrianges using this system and this shows up well in photos of the six wheelers and this 8 wheeler also has wide solebars.

I think there must have been something at the ends of the coach that moved sideways as this is the area that the HMRS drawings shows as being rebuilt by adding bracing for central buffing and a cross member for the bogie pivot. There was also a torsion bar fitted from each side in line with the pivot, on the outer face of the solebar to a central queenpost. Presumably, there must have been some support being given to the body by the Cleminson system.

The centre truck having 4 wheels would sort of work and I may make up a demo to see if this has any benefits or look like the very poor, oblique angled photos that I have of this type of coach.

Again, many thanks

Ian

[AMJ]

There were also some Cleminson 6 wheelers on the DHR. Comments in Iron Sherpa indicate that the sharp radius curves were not liked by the system and caused a few derailments.

 

Some time ago I built a trial 6 wheel LWB chassis where I had one outer axle rigid and the centre and other axle were a bogie but with a pivot point above the outer axle. Just like this modellers could lash up trial ideas for 8 wheel stock and test without having the expense that 1:1 have.