Rivermead Central

[40057]

Hello Martin

Just an update on my progress at Kingswell Street. Sadly, I have made no advance with the problem Bassett-Lowke SR 2-6-0 Mogul, which still refuses to run properly in forward gear (but runs fine in reverse). Nothing daunted, I have jumped in at the deep end again, this time with rather happier results.

Another B-L engine caught my eye in a Vectis auction. Not this time the giddy heights of a B17, but a fairly commonplace LMS 4-4-0 Compound, but in this instance a rather uncommonplace example of one. This is the final iteration of the LMS liveried Compound, numbered 1082, produced for a short period in the late 1940s before the change to the black BR version. (On the internet I have found an original sales receipt for one of these from 1952, so they were being sold as late as this).

View attachment 265299

What caught my attention was the fact that the engine was clockwork, and also its splendid condition. I could also see that a previous owner had made some tasteful modifications - sprung buffers, three-link couplings, and larger diameter bogie wheels. I also spotted that the driving wheels were not the expected 14 spoke Mazak variety, but 18 spoke. They turned out to be cast-iron, like the electric drive version, but pressed-on rather than centre-nutted. When the loco arrived, it did not disappoint.

View attachment 265300

The new bogie wheels are cast-iron, and the tender wheels have been changed too, so there is no Mazak on this engine. As you can see, the buffer and coupling changes have been done very neatly (and I would think it was a professional job). Of course, these changes mean the Compound is no longer really collectible, which was to my advantage in the auction.

View attachment 265305

As you can see, the engine does not seem to have had much use - there is very little wear on the mechanism, and hardly any dust on the finish, let alone dirt. It almost makes me wonder whether it has been stored in a display case (it did not come with a box).

View attachment 265309

The larger bogie wheels really do improve the appearance of the front end, but I would think there is no chance that it would negotiate 2 foot radius curves with this setup. The very good news is that 1082 is a splendid runner - I just gave the mech a service and lube, and she goes like a new engine. Quiet, smooth, and with excellent controls.

View attachment 265310

So here is the latest addition to our MPD, seen on a running-in turn at the head of a local train to Gloucester. These Compounds were a Bassett-Lowke classic, in this tinprinted and tabbed form lasting from introduction in the 1928 catalogue as number 1190 right through to the end of Bassett-Lowke in 1965 in its BR livery.

John

Hi again John

By way of a PS.

Check the tender wheels on your compound. The tender appears to be riding far too low. I wonder if someone has fitted BL cast iron wagon wheels — 21 mm in diameter — rather than tender wheels which should be c.28 mm diameter. 3.5 mm would bring the platform at the front of the tender up to the level of the loco footplate.

Martin

 

[John R Smith]

Check the tender wheels on your compound. The tender appears to be riding far too low.

Yes Martin, well spotted. The tender wheels seem to be too small enough! So now I have another hard to find item on my list . . . .

John

 

[40057]

Yes Martin, well spotted. The tender wheels seem to be too small enough! So now I have another hard to find item on my list . . . .

John

Hi John

I think your options for replacement tender wheels are:
1. Find a set of alloy B/L tender wheels and put back what was there originally.
2. Get new wheel-sets made by Walsall Model Industries, or if you have the facilities, buy their castings and turn them yourself. Walsall will have a casting very close in appearance to B/L 28 mm tender wheels.

You cannot, unfortunately, use original B/L cast iron tender wheels. Not easily, anyway. A standard B/L item as used on the Stanier tenders for the Duchess and Royal Scot. However, the frames on the Stanier tender are much closer together than on the tab-and-slot tenders, so the axles on B/L cast iron tender wheel sets are not long enough to use in a Compound tender.

I don’t think you will find it too difficult to obtain original alloy tender wheel sets. Walsall will turn their castings to B/L standards if that’s what you specify. My experience is they are quick and reliable.

Martin

 

[Fitzroy]

Hi John

I think your options for replacement tender wheels are:
1. Find a set of alloy B/L tender wheels and put back what was there originally.
2. Get new wheel-sets made by Walsall Model Industries, or if you have the facilities, buy their castings and turn them yourself. Walsall will have a casting very close in appearance to B/L 28 mm tender wheels.

You cannot, unfortunately, use original B/L cast iron tender wheels. Not easily, anyway. A standard B/L item as used on the Stanier tenders for the Duchess and Royal Scot. However, the frames on the Stanier tender are much closer together than on the tab-and-slot tenders, so the axles on B/L cast iron tender wheel sets are not long enough to use in a Compound tender.

I don’t think you will find it too difficult to obtain original alloy tender wheel sets. Walsall will turn their castings to B/L standards if that’s what you specify. My experience is they are quick and reliable.

Martin

John and Martin, there is a third option. When I did the A1/A3s, I commissioned die tooling and had a run done of the pressure diecast B-L style alloy tender wheels. Martin, if you look at the wheels on Firduassi you will see what I mean.

Cheers

Pieter

 

[40057]

John and Martin, there is a third option. When I did the A1/A3s, I commissioned die tooling and had a run done of the pressure diecast B-L style alloy tender wheels. Martin, if you look at the wheels on Firduassi you will see what I mean.

Cheers

Pieter

Hi Pieter

Thank you, yes indeed, I had noticed those. Perfect copies. And Mazac, so durable, not white metal.

Can you supply spares or did you just get the number you needed?

Martin

 

[Fitzroy]

When I had the dies made I had enough shots done to lay on a copious supply. I also had a repro done of the Hornby 8 spoke diecast wagon wheel in the same die set. So if anyone is interested in either type they can PM me.

Cheers

Pieter

 

[40057]

Just a little modelling progress in between efforts at weed control.

I have started making the length of sleeper-built fence to go immediately south of the wall shown most recently in post #978:



A foot long, so far. I’m aiming at 18–20”. I had two part boxes of Bassett-Lowke sleepers and the first of these is now used up. The last of the sleepers from that first box are the eleven in the centre above. The sleepers from the second box are the distinctly blue-ish ones at either end. They really are that colour, and a different much yellower wood. I will have to paint this length of fence more thoroughly, rather than just a light spray of matt black.

The (unlikely) starting point for a locomotive:



Purchased on a well-known internet auction site for a few pounds, it arrived in the post today. This is — or, rather, was, since I have now dismantled it — a complete dial with all the ‘works’:



The bits I was after are these, the dial regulator:



In model railway terms, this is a ‘Teleguv’. Fitted to a clockwork locomotive mechanism in place of the traditional rotary governor, the clockwork motor will pull more, make less noise, run more slowly and travel further.

I bought three Teleguvs about twenty years ago from a small business supplying parts to telephone collectors. The last of these three went into Caledonian Railway no. 828. This time, I couldn’t find a supplier for just the dial regulator parts, hence the purchase of the complete dial assembly.

Now I have the necessary Teleguv, serious thought can be given to the rest of the locomotive and what will be needed to build it.

Martin

 

[Fitzroy]

Interesting! I have a couple of dials in the shed and I've just thought of another cunning use for the skewed gear set. The physical engineering that went into 20th century telecoms equipment is just breathtaking, and underpinned by a vast array of standards and practices. Some of that kind of expertise is being resurrected on a much smaller scale in medical equipment, but in a completely ad-hoc and non-standardised way, so a lot of the benefit of the engineering knowledge needed is sadly just dissipated.
As a matter of interest, do the bobs ever splay out enough to rub inside the cup- i.e. is that just a retainer for extreme travel, or does rubbing form part of the governing function, like a knee in the torque curve?
Edit:- By the way, if anyone hasn't been there, the phone box museum at Avoncroft definitely warrants a visit- as well as the lovely phone boxes, they have a working mechanical mobile telephone exchange connecting them all up. A friend and fellow B-L Soc member is heavily involved in keeping it all going. Fun fact, small children react well when they are at the Police box and someone rings from the exchange and when they pick up said someone says "Where is the Doctor????" with a Dalek voice. Don't ask me how I know.

 

[simond]

In model railway terms, this is a ‘Teleguv’. Fitted to a clockwork locomotive mechanism in place of the traditional rotary governor, the clockwork motor will pull more, make less noise, run more slowly and travel further.

I understand that this is a speed governor and working by the bob weights swinging out and rubbing inside the drum to provide friction braking. I can imagine that it’s well made, effective and quiet.

I have no knowledge of “traditional rotary governors” but I don’t understand how a friction device can improve haulage or length of run. Is it that the traditional devices were yet more wasteful?

Puzzled of Sandgate.

 

[John R Smith]

I have never understood just how a Teleguv is fitted into a standard B-L or Hornby clockwork mechanism. Surely one would have to firstly disengage the drive from the final pinion to the standard governer, and then transfer this drive to the Teleguv. So how is the Teleguv mounted (without increasing the overall height of the mech), and how is it driven from the original clockwork?

John

 

[40057]

Is it that the traditional devices were yet more wasteful?

Yes, that’s it.

After about 1895, good quality clockwork locomotive mechanisms always included a governor. In service, of course, there are effectively two governors, the other being the train. The very earliest — 1890s — Marklin 0 gauge locos do not contain a governor. The train regulates the speed. The instructions are clear that the locomotive will stay on the track if it is run with the train supplied. All of it. I know someone who has one of these. It runs at prodigious speed around 1’ radius curves, but it does stay on the track as the manufacturer stated.

Anyway, later mechanisms do have governors. The exact arrangement varies, but in essence there are small weights attached to a shaft by springs inside a circular casing. As the motor (shaft) speeds up, centrifugal force brings the spinning weights into contact with the casing. Hence the loud rattling sound typical of traditional clockwork. The friction caused by the weights hitting the casing slows the motor, momentarily. But immediately the weights are no longer hitting the casing that contains them, the motor speeds up again. This cycle is repeated until the speed of the motor drops and is too slow to extend the attaching springs sufficiently for the weights to hit the casing. Typically due to the spring running down or because the train is climbing a gradient or running round a curve. Whilst there is rapid fluctuation in the speed of the governor, the train progresses smoothly. But a lot of energy is wasted in the speed regulation. Less, of course, if the locomotive is pulling a heavier train and that is acting as the governor.

I don’t have an engineering background, and may not correctly understand how the Teleguv works. However, I think the two bobs in the circular brass housing are continuously in contact with the housing when the motor is running. The motor speeds up until the friction of the bobs prevents it going any faster. My surmise is the motor is then in a true equilibrium position, as opposed to the speed oscillation that is inherent in the traditional governor. As the spring runs down, or the train slows around a curve due to increased rolling resistance, the Teleguv compensates with reduced friction.

What is undoubtedly true is that clockwork locos fitted with a Teleguv run almost silently. No rattle. They do go further. With a traditional governor, a loco might go once round a circuit with three coaches before stopping. Take off one coach, it will do another lap. Then pick the loco up, and the wheels will spin furiously: the spring isn’t exhausted, but it won’t pull a train. The Teleguv fitted loco will do three laps with three coaches. Pick the loco up and the wheels might go round slowly two or three times only: there is nothing left. The energy stored in the spring has almost all been used for useful work. The Teleguv fitted loco will also run at a much slower, more realistic, speed.

For a new, scratch build, clockwork loco, I would always want a Teleguv fitted mechanism, certainly if using any of the four-coupled mechs from the major manufacturers. It’s different with speed control mechanisms where the friction introduced by the governor can be varied by the operator. Fit a Teleguv, and the speed control facility would be lost.

Martin

 

[simond]

Thanks Martin.

I'm still a bit puzzled.

Presumably the "traditional" governor does not touch the brake drum at all if the train is sufficient to restrain the motor - and this must surely be the optimum in terms of getting useful energy out of the spring - the biggest train for the longest distance (ton-miles if you like!) as no energy is wasted in friction on the brake drum. Does this form of governor work at wheel speed? And from what you say, it is rather on-off in operation, which may be more wasteful than something more progressive.

If the teleguv is touching/rubbing continuously then I surmise that there is friction and there is energy being wasted, maybe not very much if the speed is such that it is not working hard to restrain the spring, but some waste nonetheless. I can see that if it is in constant contact, the operation will be more linear (actually, I think it will be a square law, have to go and think about that) and thus progressive, rather than the hit and miss affair I assume the traditional device to be. Do you oil these governors?

I guess the gearing of the teleguv is important - the worm will be rotating 18 times faster than the input gear wheel, so the friction torque can be quite small - the braking effect will be amplified by the gear ratio, and also by the friction in the wheel and worm interface itself. Still, energy is lost.

An interesting rabbit hole, thanks
Simon

 

[John R Smith]

Do you oil these governors?

I have asked this question before, Simon, but never found an answer in any of the literature. All of these governers - clockwork railway engine, telephone dial, and wind-up gramophone - use friction to impose a load on the spring drive. By definition this must waste energy, as you say, the friction being converted to heat energy which will be dissipated by conduction. So speed control is achieved, but in a wasteful way.

The only governers which work correctly are those which regulate the road speed on a steam traction engine or diesel tractor, where the governer controls the throttle setting on the engine. I have very fond memories of hay-making back in the 1970s, and taking a Fordson Major and trailer load up a steep lane. For a given hand throttle setting you could just sit back and enjoy the bark of the engine getting louder as the tractor hit the grade, the speed staying constant as the governer kicked in.

John

 

[40057]

Thanks Martin.

I'm still a bit puzzled.

Presumably the "traditional" governor does not touch the brake drum at all if the train is sufficient to restrain the motor - and this must surely be the optimum in terms of getting useful energy out of the spring - the biggest train for the longest distance (ton-miles if you like!) as no energy is wasted in friction on the brake drum. Does this form of governor work at wheel speed? And from what you say, it is rather on-off in operation, which may be more wasteful than something more progressive.

If the teleguv is touching/rubbing continuously then I surmise that there is friction and there is energy being wasted, maybe not very much if the speed is such that it is not working hard to restrain the spring, but some waste nonetheless. I can see that if it is in constant contact, the operation will be more linear (actually, I think it will be a square law, have to go and think about that) and thus progressive, rather than the hit and miss affair I assume the traditional device to be. Do you oil these governors?

I guess the gearing of the teleguv is important - the worm will be rotating 18 times faster than the input gear wheel, so the friction torque can be quite small - the braking effect will be amplified by the gear ratio, and also by the friction in the wheel and worm interface itself. Still, energy is lost.

An interesting rabbit hole, thanks
Simon

Hi Simon

I’m afraid my lack of engineering knowledge/understanding is letting me down at this point.

No, the Teleguv doesn’t get oiled (or the traditional governor). They both rely on friction to regulate speed, so I guess oiling would be counter-productive.

The bobs in the Teleguv will have a tiny area of contact with the housing. I think the key is the point you make about gearing. A piece of paper can be used as a sprag in the arms of the Teleguv and it will stop the motor — prevent a large and powerful spring from unwinding. So a tiny friction loss in the Teleguv is all that’s needed.

Martin

 

[40057]

I have never understood just how a Teleguv is fitted into a standard B-L or Hornby clockwork mechanism. Surely one would have to firstly disengage the drive from the final pinion to the standard governer, and then transfer this drive to the Teleguv. So how is the Teleguv mounted (without increasing the overall height of the mech), and how is it driven from the original clockwork?

John

Hi John

The original governor is redundant and removed. The Teleguv replaces it, but not necessarily in the same position.

To date, I have had three motors modified to replace the original governor with a Teleguv. The work was done by a clockmaker. He’s retired, so that option is no longer available. But in each case, the Teleguv was only one element of the alterations required.

Each of the three motors (one Hornby, one B/L, one Bing) was rebuilt to go into a specific model, and a pre-grouping prototype in each case. For all three locos, in consultation with the builder, it was decided to turn the motor and power the rear axle. The principal gain of this arrangement being unimpeded ‘daylight’ under the front part of the boiler. However, for the motors to fit, the overhang beyond the powered axle had to be shortened. Especially so for 828 since the CR 0-6-0 classes all have their rear axle very close to the back of the loco. So as important as the improved performance, the purpose of replacing the governor in each case was to reduce the size of the motor.

This is 828’s motor, rebuilt by the clockmaker, but after further alterations by Tom Mallard:



The Teleguv has been positioned nearly upright in what had been a void within the motor. The original governor was at the end of the motor nearest the camera, with the brake. The part of the frames that had enclosed those parts has been cut off so there is now very little overhang beyond the powered axle. Hence the motor would fit in 828. If left as originally manufactured, the motor in 828 would have had to power the middle axle. The space under the boiler ahead of the middle axle would have been mostly occupied by the motor: no ‘daylight’. The keyhole would have been very visible. The reverse could not have been operated by the scale reversing lever as it would be on the wrong side. The track performance would be far less good.

Finding the right motor for the model, and modifying it as necessary, I always see as key to a good clockwork model.

Or finding the right prototype for the motor. With the Q1 currently being built by Tom Mallard, my starting point was I needed a powerful and controllable shunter I could operate at arm’s length. Which led to the conclusion I would have to use a mechanism from a van Riemsdyk 0-6-0T. The task then was to find a suitable prototype which would need to have small wheels, a sufficiently high-pitched boiler to accommodate the spring and side tanks to hide the motor. The Q1 is ideal for the mechanism, so the loco will be a great looking accurate model that will do the job it is being built for perfectly.

Martin

 

[John R Smith]

I think the key is the point you make about gearing. A piece of paper can be used as a sprag in the arms of the Teleguv and it will stop the motor — prevent a large and powerful spring from unwinding. So a tiny friction loss in the Teleguv is all that’s needed.

Perhaps we are reaching the nub of the matter. If we examine the arrangement in a standard B-L four coupled clockwork mech, you can see that the pinion driving the governer is rotating at the highest speed of the entire gear train. So a small amount of resistive force applied here over a large spinning movement will result in a large amount of braking force transferred back as a small movement along the gear train to the output shaft (driven axle). Interestingly, these governers - which all work the same, whether they be Bing, Bassett-Lowke or Hornby - do no not in fact work very well. They tame a locomotive's wildest excesses, but do not produce reliable slow speed running.

Which leaves the question of why the Teleguv produces a superior result. We need not doubt that it is superior, as Martin has direct experience and Jack Ray was a keen exponent. Perhaps it is because the Teleguv is even more highly geared than the standard item?

John

 

[40057]

Perhaps we are reaching the nub of the matter. If we examine the arrangement in a standard B-L four coupled clockwork mech, you can see that the pinion driving the governer is rotating at the highest speed of the entire gear train. So a small amount of resistive force applied here over a large spinning movement will result in a large amount of braking force transferred back as a small movement along the gear train to the output shaft (driven axle). Interestingly, these governers - which all work the same, whether they be Bing, Bassett-Lowke or Hornby - do no not in fact work very well. They tame a locomotive's wildest excesses, but do not produce reliable slow speed running.

Which leaves the question of why the Teleguv produces a superior result. We need not doubt that it is superior, as Martin has direct experience and Jack Ray was a keen exponent. Perhaps it is because the Teleguv is even more highly geared than the standard item?

John

Hi John

Higher gearing may be part of it. I think probably so. But continuous rubbing of a small surface area (as with the bobs on a Teleguv or in a van Riemsdyk motor) may be more efficient than the on/off hunting — intermittent contact — of the traditional governor. Less energy used for the same effect?

Martin