The Patiala State Monorail Trainways

[Stubby47]

The Patiala State Monorail Trainways

 

The PSMT was a unique rail-guided, partially road-borne railway system running in Patiala (British India) from 1907 to 1927.

It was the only operational locomotive-hauled railway system built using the Ewing System in the world.

 

https://en.wikipedia.org/wiki/Patiala_State_Monorail_Trainways

 

This project will consist of :

• The building of the loco and coach
• The technical requirements to make the loco operational
• The layout construction and scenery

The Ewing System

 

 

The Ewing System is a balancing monorail system developed in the late 19th century by British inventor W. J. Ewing .

 

In the Ewing System the main wheels of the train run on a single steel rail. The system had been proposed in 1868 by William Thorold, a civil engineer from Norwich, Norfolk.

 

The major benefit of trains is that they run on steel tracks. Steel rail can carry more load with less rolling friction than any other mode of ground transport. However there are several disadvantages of laying conventional railway tracks consisting of two rails: Both rails have to rise and fall and bank together. Laying two rails requires a lot of space and maintenance. The turning radius of the train is restricted by the difference in length or distance traveled between the inside and outside rails due to curve resistance. Curve resistance means that the wheels on the inside rail travel a shorter distance than the wheels on the outside rail to get the vehicle around a curve. The trains can only turn to the limit where its outer wheels can cope with the additional required speed. If the outer wheels fail to maintain or reach the required speed, the train may derail.

 

W.J. Ewing implemented a monorail system, with only one rail and double flanged rail wheels, that had been proposed by William Thorold in a lecture to the British Association in 1868. This system avoided all those problems, since it was laid out along the side of a road, it took up very little land. Further, the road or balance wheel's main purpose was to balance the train and to keep it upright. The balancing wheel on the road carried only 4% or 5% of the load, it did not subtract much from the steel wheel-steel rail efficiency. As the track was on side of the road, it was no obstacle to vehicles crossing it. Further, since it was a monorail with a supporting wheel on the ground, the issue of curve resistance did not arise in Ewing System, since the wheels were placed on a single track only.

 

https://en.wikipedia.org/wiki/Ewing_System

 

 

The Loco and Coach

The loco will be scratch built, possibly using a brass chassis and plasticard body. The motor will be mounted to drive one of the double flanged wheels. Power will come from the single rail and will be 12v dc.

 

The coach will be scratch built using wood strip where ever possible.

 

The track & road bed

The track will be a single Code 100, possibly from set track curves and straights. The track will be sectioned, each being powered via SPDT reed switches embedded along side, each switch feeding the next rather the adjacent section. A strip of magnets in the loco will reach to cover two reed switches at the same time.

 

The road bed will be a line of paving slabs, or a representation of a solid road surface. The bridge over the small water course will be as open as possible, hopefully just the single rail and metal girder for the road wheel.

 

The track will form a single circle, with no points, running either on an embankment or in a cutting. There will be no hidden section, but the scenery will help disguise the simple shape.

 

The layout

The board will be about 6ft x 4ft, depending on the minimum curves required. The base may well be a hollow internal door, with the track raised on formers and/or polystyrene blocks.

 

Scenery will be representative of an Indian semi-mountainous region, with hopefully room for a couple of traditional Indian-style low buildings a low bridge over a stream and lush, green vegetation.

 

This layout is scheduled to appear at the Captain's SWAG party in April 2016.

 

The loco build will entered into the 2105 2015 Loco Build challenge. http://www.rmweb.co.uk/community/index.php?/topic/103277-scratchbuild-loco-challenge-psmt-no-4/

 

I will be entered in to the nearest sanatorium fairly soon...

Edited October 18, 2015 by Stubby47

[ed7]

An interesting project.  I have seen this system at the Delhi railway museum - but it has not been operating during my visits.   How are you going to get an electrical contact via the road surface to complete the DC circuit?  The road slabs could be made of brass but will need to be painted / coloured in some sort of conductive paint.    Another option could be battery power with radio control.   Or is there another solution?

Edited September 14, 2015 by ed7

[Stubby47]

Yep, sectional track with reed switches & magnets.

 

I thought about radio control with batteries and using the road, but the planned solution is, I think, easier...

 

[peter220950]

Loving this one, the ultimate narrow gauge. - Any thought on scale?

 

Presumably if you went for 7mm/ft on a track gauge of zero it would be O0 gauge

 

Awaiting the next installment with interest, presumably all sections of track will need to be exactly the same length, and that will be limited by the loco/coach length divided by 3ish ?

 

Peter

 

Edit

 

P.S. Might Hall sensors be a better way to go than reed switches?

Edited September 14, 2015 by peter220950

[Stubby47]

It will be 7mm - any smaller will be harder to make work mechanically, any larger would need a bigger layout.

 

I'm not sure what Hall sensors are.

[peter220950]

I'm not sure what Hall sensors are.

 

Nor me really! - but I believe them to be solid state 'reed switches' which would possibly be more reliable than traditional glass ones, having no moving parts, and being a bit more up to date, it would need someone with a bit more brain and knowledge to confirm my belief that they might be a better bet.

 

I'm guessing that the technicalities of what you propose need to be spot on, and these devices might be more suited, let's see if anyone else has an opinion, my previous experiences with reed switches have been a bit mixed, but that's probably down to me rather than the switches.

 

Never having seen this monorail system before I am intrigued and look forward to seeing it progress, there being quite a lot of technical issues to overcome, there's a lot for us to learn from your pioneering work. - at least there shouldn't be a lot of bickering about gauge standards.

 

 

Peter

[Stubby47]

Peter,

A good point about glass reed switches- I do need to buy a few varieties and experiment.

 

I'm hoping a strip of fridge door magnet will work, but the distance between magnet & switch will be critical.

 

Yes, all experimental, but should be fun.

 

Stu

[trisonic]

One of my colleagues visited it at the museum and they fired it up for him (“Come back here in two hours!”) as it runs on a simple loop you could model that........

 

This was several years ago - they might not be as accommodating nowadays.

 

Best, Pete.

[Snofi]

This sounds fascinating!

Edited September 14, 2015 by Snofi

[JDW]

It does indeed sound fascinating, I read about the system not that long ago (possibly from a link elsewhere on here?) and was intrigued. 

 

I can only imagine that it must be a much more complicated build than he is letting on, though, if the loco is being "entered in the 2105 Loco Build challenge" - 90 years to construct a loco, that's some commitment!

 

Seriously, though, I look forward to seeing this progress, Stu.

[raymw]

A year or two back I posted a link - someone showed a photo of some building work encroaching on the railway track, iirc almost over one rail, - and I suggested they needed to use one of these mono rail locos. Some other post more recently got me trying to find a reference to it, but I failed to find said link.

 

Without trying it, i think the reed relay system will not give slow running - you will need short isolating sections between each length, else the wheels will short out between the adjacent sections, and running fast could be nice and sparky with no isolated bits. However, if you used lengths of track about half inch long sections, you could use it instead of a motor commutator. - a different type of linear motor, if you like.  Something like a stepper motor driver would do the trick, with a small stepper motor in the loco. But on board battery would be the way to go, imnsho.

[raymw]

Hi Stubby,

 

I've thought of a few ways, perhaps the best beginning, assume you can have sections say 6inch long, have a half inch isolated length between each section. Lets suggest you apply dc, +,-,+,-,+,- around the track. No reed relays. On board have a bridge rectifier and a capacitor (to get you across the short isolated sections). That'll get you going in one direction, assuming you do not start with the pick-ups on the isolated sections. Then, I reckon you could do something with dcc or similar to control speed and direction. If you just wanted speed, then a simple rheostat controller would do it. If you don't want dcc type of control, and you still want direction changing then you will need to use a sort of three phase pulse system and wire the track as a,b,c,a,b,c etc. 3 ph Model motors (as used in electric drones/cars/helicopters are 3 phase motors, and you can get the bits for driving them quite cheaply, but the speed can be high. Or use four sections, a,b,c,d,a,b,c,d, etc, and use stepper motor and driver. Your basic problem is that the track is digital in sequence, and normal motors are analogue. Or use a couple of  solenoid point motors driving a crank on the driving wheel, and a decent flywheel, that could be nice and clanky, in keeping with the whole ethos of the system, instead of the stepper motor.   may need to give it a shove to get it going. With a lot of these suggestions, you will not need any extra expenditure on a smoke generator.

[Nick Holliday]

Rather than all that electrical trickery, I would consider a reverse Minic Motorway pick up system. That had a central pick up wheel, with insulation in the middle, running in a narrow groove with conductors on either side. Could you fabricate a rail section with metal on either side, with a central insulator? Perhaps a suitable plastic section, (inverted T?) with metal square section glued on each side to give a Vignoles' type section?

[Stubby47]

Guys,

Thanks for all your thoughts and suggestions, very much appreciated.

Prior to starting the thread I have been considering many different ways to supply power along a single rail, including the minic system and permanently supplied positive and negative sections.

However, I think the proposed idea I have will work.

As each section of track ahead of each wheel will be correctly polarised before the wheel reaches it, there should be no sparks. The critcal distance is that between the two pickups - as long as the track sections are shorter than this it should all work.

So first task is to set up a simple circle of track, a ring of reed switches and a long magnet on a wagon with a bulb.

Edited September 15, 2015 by Stubby47

[Mallard60022]

Good grief Stubbs, where the he** did that idea come from?

I'm totally intrigued now.

Phil

[peter220950]

I too thought there would be issues with arcing on the rear pick-up, but that's really down to thr schematic drawing, which shows a wheelbase = two sections.

 

After too much thinking about it yesterday I concluded that if wheelbase = 2 sections + a bit, the  contact wheels are always on correctly energised track, it''s a brilliant concept, however, due to the precision required to get section spacings sorted I would use Templot for the design

 

Peter

[Stubby47]

Good grief Stubbs, where the he** did that idea come from?

I'm totally intrigued now.

Phil

It's one of those ideas that's been nagging at me for many years.

 

When I was at school we built a robot that could follow a single white line on the floor. This railway seems to be in the similar vein, a very simple idea but fascinating at the same time.

 

I also feel I now have the modellng skills to do it justice, not just the buildings and scenery, but the loco and rolling stock too.

 

Time will tell....

Edited September 15, 2015 by Stubby47

[Northroader]

Shouldn't it be possible to make the road surface with a dull, rough finish that is still conductive? Then you could still have a return through the balance wheel. I seem to remember that oxen could be used as well as steamers?

[Stubby47]

One of my colleagues visited it at the museum and they fired it up for him (“Come back here in two hours!”) as it runs on a simple loop you could model that........

 

This was several years ago - they might not be as accommodating nowadays.

 

Best, Pete.

 

 

An interesting project.  I have seen this system at the Delhi railway museum - but it has not been operating during my visits.   How are you going to get an electrical contact via the road surface to complete the DC circuit?  The road slabs could be made of brass but will need to be painted / coloured in some sort of conductive paint.    Another option could be battery power with radio control.   Or is there another solution?

 

Hi Ed7 - do you have any photos of the loco or coach from your visit ? I would be very grateful for any and all information which is not available on line.

 

Pete - same question to you - does your colleague have anything he'd be happy to share ?

 

Cheers

 

Stu

[Stubby47]

Shouldn't it be possible to make the road surface with a dull, rough finish that is still conductive? Then you could still have a return through the balance wheel. I seem to remember that oxen could be used as well as steamers?

 

Very possibly, but using only one wheel might result in poor contact and thus stalling.

 

I'm going to try my idea, but I'm quite willing to admit defeat and resort to another of the excellent suggestions posted so far.

[dhjgreen]

Are these any use?

 

[Stubby47]

YES !!

Thanks

[Talltim]

When I first read about the Faller road system, I wondered if it would be possibly to power them using the 'two rail' principle, using graphite impregnated rubber for the road surfaces and tires, with an insulation strip down the centre of the lane. Not sure if it would actually conduct enough to work, and I would imagine it would be an industrial process to make it.

[Indomitable026]

I went to Delhi Railway Museum years ago when I worked out there.

 

I've got photo's somewhere including a shot of a mono rail loco working - I'm sure

[St Enodoc]

YES !!

Thanks

Stu, here are some photos I took in February 2012:

 

 

 

 

There was no loco to be seen anywhere and the coach looked as though it would fall apart if anyone tried to move it

 

Good luck!