Rivermead Central

[John R Smith]

It perhaps says a lot about the works at Northampton, or the volume of models being made, that a part needed for every locomotive built (albeit with variations depending on the particular type) was being scratch built for each model.

I find it interesting that amongst all the printed material I have which documents the Bassett-Lowke company, I have never seen a photograph of or reference to the part of the works (at Winteringhams?) which made and assembled the clockwork motors, both four and six coupled. A bit surprising, when literally thousands of the four coupled ones at least must have been made. Perhaps you have seen somehing about this, Martin?

I think poor control of assembly tolerances and lack of QC may well account for the surprising variations in performance I have found between the clockwork engines. I have noticed the same variations with Hornby, too.

John

 

[40057]

I find it interesting that amongst all the printed material I have which documents the Bassett-Lowke company, I have never seen a photograph of or reference to the part of the works (at Winteringhams?) which made and assembled the clockwork motors, both four and six coupled. A bit surprising, when literally thousands of the four coupled ones at least must have been made. Perhaps you have seen somehing about this, Martin?

I think poor control of assembly tolerances and lack of QC may well account for the surprising variations in performance I have found between the clockwork engines. I have noticed the same variations with Hornby, too.

John

Hi John

No, unfortunately, I have no documents or other material that give any information about the manufacturing of clockwork motors. Tens of thousands (at least) of the four coupled version must have been made.

Variations in the haulage capacity of motors could be due to:
1. Inaccuracies in construction leading to friction losses;
2. Variation in the inherent strength of the spring. I have motors with ‘thicker’ and ‘thinner’ springs.
3. A tired spring that has been heavily used or left wound up for a lengthy period. Springs wear out.

Martin

 

[John R Smith]

3. A tired spring that has been heavily used or left wound up for a lengthy period. Springs wear out.

This interests me. I know that all the recommendations from B-L are to wind down the clockwork motor before storage, but the only scientific study I know of says the opposite. One of my obsessions is film photography with vintage Hasselblad cameras. The lenses on these, and the bodies, are all spring-driven. You cannot mount the lenses onto the body (or remove them) unless the bodies are wound and the shutters are cocked in the lenses, hence the guidance is to keep and store all the parts of the system full wound. Hasselblad issued guidance in a service bulletin which says the following -

"Hasselblad engineers have never found any evidence to show that the life of a spring is shortened if the spring is kept tensioned, even after extended periods of non-use. Hasselblad suggests that cameras and lenses be stored in the wound position. This eliminates the possibility of a camera jam caused by attaching an uncocked lens to a wound body, or vice versa." (information from David Odess, factory trained Hasselblad technician)

Counter-intuitive, I know. But as you say, springs do wear out. Coil springs and torsion bars on cars do sag after many years of use, but I have a feeling that this is due more to thousands of cycles of expansion and contraction rather than storage in a tensioned position. So perhaps it is lots of use which wears springs out and compresses their elastic limit.

John

 

[40057]

This interests me. I know that all the recommendations from B-L are to wind down the clockwork motor before storage, but the only scientific study I know of says the opposite. One of my obsessions is film photography with vintage Hasselblad cameras. The lenses on these, and the bodies, are all spring-driven. You cannot mount the lenses onto the body (or remove them) unless the bodies are wound and the shutters are cocked in the lenses, hence the guidance is to keep and store all the parts of the system full wound. Hasselblad issued guidance in a service bulletin which says the following -

"Hasselblad engineers have never found any evidence to show that the life of a spring is shortened if the spring is kept tensioned, even after extended periods of non-use. Hasselblad suggests that cameras and lenses be stored in the wound position. This eliminates the possibility of a camera jam caused by attaching an uncocked lens to a wound body, or vice versa." (information from David Odess, factory trained Hasselblad technician)

Counter-intuitive, I know. But as you say, springs do wear out. Coil springs and torsion bars on cars do sag after many years of use, but I have a feeling that this is due more to thousands of cycles of expansion and contraction rather than storage in a tensioned position. So perhaps it is lots of use which wears springs out and compresses their elastic limit.

John

Hi John

I haven’t any scientific data on spring durability and care.

Advice from Bassett-Lowke (Model Railway Handbook etc.) was always not to leave a loco wound up for long periods.

The clockmaker who replaced a spring for me said the same.

I believe on Crewchester and similar layouts, spring replacement was routine to keep locos in good working condition. Jack Ray was certainly instrumental in getting replacement springs manufactured after quality clockwork locomotive mechanisms were no longer being made.

Ultimately, I have taken the received advice on trust as being correct. I have no evidence of my own.

Martin

 

[John R Smith]

The clockmaker who replaced a spring for me said the same.

I think that clocks and watches are always wound up, if they are working, that is. So that is somewhat strange advice . . .

However, I am sure that being cautious as you are cannot possibly do any harm!

John

 

[40057]

I think that clocks and watches are always wound up, if they are working, that is. So that is somewhat strange advice . . .

However, I am sure that being cautious as you are cannot possibly do any harm!

John

Hi John

You are right, of course. A watch that is being used will (almost) never be fully run down. I suppose, on average, it will be half wound. Of course, lots of clocks and watches are brought into the Antiques Roadshow, for instance, that have sat in a cupboard for years. These though ought always to have been run down during storage as there is no ‘brake’ to stop them unwinding. It’s only a locomotive (or similar) that you can leave fully wound for years.

I’ll stick with received wisdom and Bassett-Lowke’s advice meantime. But, it is something to perhaps look into. Just because everybody has been saying something for years, doesn’t mean it’s true. The Earth, it turns out, isn’t flat or the centre of the universe.

Martin

 

[simond]

Springs are smooth hardened steel. The coils do rub on one another as it is wound and unwound, and I expect that leaves some kind of polishing marks. I expect also that you oil the springs to minimise friction between coils as they are wound and unwind, so it seems to me that there will be some, but very little wear.

I am struggling to see that the chemical/crystalline structure of the steel changes much over time, certainly at "room temperature" or thereabouts.

Fatigue is a further element to the "wearing out" question. It seems that clock springs do lose their temper (otherwise Jack Ray et al would not have needed to arrange spares), and the stress when wound is clearly higher than when fully unwound. I can imagine the stress being raised further if there is a significant change in temperature whilst stored, fully wound. And of course, the spring can't lose its "fully wound" tension if it's not fully wound, and losses in the unwound tension are likely to be less.

That said, how often does a loco get used? Clocks and watches would perhaps get "365" cycles per year and might be expected to last tens of years, or more, I don't really know how this might compare with model use.

Might be worth digging on clock makers' websites?

Simon

 

[John R Smith]

That said, how often does a loco get used? Clocks and watches would perhaps get "365" cycles per year and might be expected to last tens of years, or more, I don't really know how this might compare with model use.

I was thinking specifically of automatic spring-drive wrist watches, which while they are on your wrist are always more or less fully wound. Of course at night they do run down, but never completely. It is very, very rare for a high quality wristwatch (Omega, Rolex, Patek Philippe etc) to suffer a broken mainspring.

I am going to have to be very careful here, otherwise I am tempting fate and inviting disaster, but at the Club 60 years ago we had a whole raft of clockwork engines, Bassett-Lowke and Hornby, but I do not remember ever experiencing a broken spring. And they used to get hammered (by me!) with long heavy trains up steep gradients and were almost always fully wound. (Coming down grade at high speed with the train pushing the loco beyond its normal over-run was probably the most dangerous time). As I understand it, the most common point for breakage on clockwork railway engines is at the centre of the spring, where it attaches to the winding arbor. This makes sense, because it will be the point at which the spring is most highly stressed.

I expect also that you oil the springs to minimise friction between coils as they are wound and unwind, so it seems to me that there will be some, but very little wear.

W J Bassett-Lowke always did advise owners to lubricate the coils of the spring as part of regular servicing. With most of the mechanisms, it is quite difficult to access all the coils, though.

John

 

[Phil O]

In the good old days of steam ships, the safety valve springs especially and other sprung components were tested and where necessary re-hardened and tempered during refits. Refit frequency was not more than 10 years. Small springs were usually replaced.

 

[40057]

There must be proper scientific data on the performance of springs as used to drive timepieces and clockwork models.

Unfortunately, I don’t know where to look for it. I very likely wouldn’t understand the science anyway.

Anecdotally, then.

Springs get tired if used intensively or for long periods. True or false? A restorer of old clocks (I mean properly old, antique) would probably be the best person to definitively answer this question. Can a spring be regularly wound up for decades (or longer) and still power the clock? If performance does decline, how long before the spring ceases to store sufficient power for the clock to work? Do all springs behave similarly in this regard? Or do better quality springs last longer?

The only time I have asked a clock restorer for comment on the issue, he did say springs eventually became ‘tired’.

As for springs in model locomotives, I make the following observations.

1. Between the wars, Bassett-Lowke offered a repair service. My recollection is that replacing drive springs was specifically mentioned as a repair that could be undertaken. Meccano (Hornby) offered a repair service too, but I haven’t any information about what sorts of repairs their service would do.
2. It is rare, but I have seen locomotives that appear to have suffered a spring explosion. Most of the broken clockwork motors I have been able to examine had failed winding ratchets, rather than broken drive springs. Of the very few motors I have seen with broken springs, most of them were examples of the late 1920s Bing 6-coupled mechanism. I have never, for example, seen one of the large Bassett-Lowke 6-coupled mechs with a broken spring.
3. The vast majority of 100+ year old clockwork model locomotives show no signs of having ever had their drive spring replaced. They still work, often very well.
4. Over the years, I have had three locomotives (Bing, Hornby, Bassett-Lowke respectively) that had apparently sound motors which turned over freely and easily, yet they could hardly move themselves let alone pull a train. Tired springs was my assumption. But possibly defective springs, of faulty manufacture. These locos (motors) might have always been uselessly weak, hence no signs of use or wear.
5. Larger springs (longer, broader) can store more energy so locomotives with bigger springs are more powerful and/or travel further on one winding. (The balance between haulage capacity and length of run will be determined by gearing and driving wheel diameter). There is I am sure also an effect of how ‘hard’ the spring is; how much force is needed to bend the metal, so how much energy is stored. The late 1920s Bing 6-coupled mechanism I think would be widely acknowledged as the most powerful clockwork motor made for 0 gauge. It is seen in action here:

Note the loco slipping on starting, almost unheard of with clockwork. But with hardness may come brittleness. As mentioned above, based on a very small sample, anecdotally, I have seen relatively more broken springs in these powerful Bing motors. The similar-sized large Bassett-Lowke motors are not as powerful, but I have never seen one with a broken spring.
6. What load can a clockwork locomotive be expected to pull? That will depend of course on multiple variables including radius of curves, how free running the rolling stock is, etc. In terms of the present discussion, and whether or how quickly springs wear out, the question is: Did vintage clockwork locomotives pull more when new than they do today? Again, I can only report anecdotal information. When the large Bassett-Lowke 6-coupled mechanism was introduced, the company claimed it would, fully wound, run 120’ on reasonably straight track with a load of five coaches. A few years ago, I tested a locomotive powered by one of these mechanisms on a large circuit including 3’ radius curves. The locomotive pulled a load of five heavy Exley coaches around the circuit. The locomotive was built in 1930, the motor and, as far as I know, the spring have never been replaced. The locomotive was run frequently on a garden railway from c.1930–c.1960. The original owner said on the garden line, the usual load was 7 Exleys. Not much if any deterioration despite regular use. I am not knowledgeable about Hornby trains and don’t have copies of catalogues etc to refer to. However, my recollection from seeing 1930s Hornby boxed sets is that passenger sets with a 4-4-0 locomotive contained either two coaches — if clockwork — or three coaches if the loco was electric. Suggesting two coaches was the limit even when the clockwork mechanism was new.

I am not sure what conclusions can be drawn from the limited personal observations above. If anyone can add additional relevant information, that might help build a picture and allow some reliable generalisations.

Martin

 

[Fitzroy]

How "tired" a spring gets will depend on it's temper and the working stress level and it's yield stress in comparison to it's working stress.
100-150 years ago quenching and tempering of springs was done by eye comparing the colour to a colour chart. Since the mid-20th century it would be done with a thermocouple-controlled furnace, so older springs were highly variable in quality due to fatigue properties varying considerably as a result. Basic spring steel quality has greatly improved in recent years, but the quality of spring fabrication (i.e attention to very high grade ground and polished surface finishes on features like slit edges having imperfections) has got worse in recent years, so modern replacement springs are not necessarily very good at all.
Generally "power" springs are quite different to clock springs in terms of their temper and working stress levels, so I would definitely follow the original Bassett-Lowke advice.
Pieter

 

[John R Smith]

However, my recollection from seeing 1930s Hornby boxed sets is that passenger sets with a 4-4-0 locomotive contained either two coaches — if clockwork — or three coaches if the loco was electric. Suggesting two coaches was the limit even when the clockwork mechanism was new.

Just to add my past experience - if we are talking about the Hornby No 2 Special 4-4-0 locos (like the GW 'County' or the LMS Compound) then they could certainly pull a lot more than two coaches in the clockwork version. Back at our model railway club which I am always banging on about, the Hornby County was my favourite engine and could pull just as many heavy old tinplate coaches as the B-L Compounds and the DOY. I have one now, as well as a No 2 Special tank, and they are both very nice runners but of course I cannot test their haulage capacity on my present tiny layout.

I agree that ratchet failure is actually more common than broken mainsprings (and more difficult to fix). A reason for this is that the ratchet on the four-coupled motors is hidden away and difficult to lubricate, so it gets neglected.

John

 

[40057]

How "tired" a spring gets will depend on it's temper and the working stress level and it's yield stress in comparison to it's working stress.
100-150 years ago quenching and tempering of springs was done by eye comparing the colour to a colour chart. Since the mid-20th century it would be done with a thermocouple-controlled furnace, so older springs were highly variable in quality due to fatigue properties varying considerably as a result. Basic spring steel quality has greatly improved in recent years, but the quality of spring fabrication (i.e attention to very high grade ground and polished surface finishes on features like slit edges having imperfections) has got worse in recent years, so modern replacement springs are not necessarily very good at all.
Generally "power" springs are quite different to clock springs in terms of their temper and working stress levels, so I would definitely follow the original Bassett-Lowke advice.
Pieter

Thanks, Pieter. I knew someone would know! What you say makes perfect sense and explains a lot (all?) of the empirical observations. The apparently contradictory findings are explained if the springs were different, highly variable, as manufactured. Some strong, some weak. Some giving many years of service without noticeable deterioration, others become very tired.

So an old locomotive with a (still) ‘good’ spring probably really does have a good spring. One that happened to have been very well made. The performance differences between individual springs of the same type are probably greater now than they were when the springs were only a few years old.

Martin

 

[40057]

Just to add my past experience - if we are talking about the Hornby No 2 Special 4-4-0 locos (like the GW 'County' or the LMS Compound) then they could certainly pull a lot more than two coaches in the clockwork version. Back at our model railway club which I am always banging on about, the Hornby County was my favourite engine and could pull just as many heavy old tinplate coaches as the B-L Compounds and the DOY. I have one now, as well as a No 2 Special tank, and they are both very nice runners but of course I cannot test their haulage capacity on my present tiny layout.

I agree that ratchet failure is actually more common than broken mainsprings (and more difficult to fix). A reason for this is that the ratchet on the four-coupled motors is hidden away and difficult to lubricate, so it gets neglected.

John

Hi John

I obviously know nothing about your Club layout, but if it was built using Permanent Way type track with 3’ or larger radius curves, the same Hornby engine is going to pull a lot more than on Hornby 2’-radius round-headed rails.

The track, rolling stock etc obviously makes a huge difference. Bassett-Lowke were careful to set out the conditions under which their 6-coupled mech would pull 5 coaches for 120’. Permanent Way and ‘reasonably straight’.

I think the key point here is Pieter’s. Variability between springs. Sure, there will be, under specified conditions, an ‘average’ haulage capacity for a Hornby no.2 Special mech. But a mech with a ‘good’ spring might be 50% or more better than average. The sets Hornby was selling would need to still work well with a loco with a ‘below average’ spring. Otherwise they would have been doing a lot of work under guarantee. Perhaps two coaches, on Hornby 2’ radius track, was the load that even the poorer springs could be relied upon to manage. That way, the sets as sold should all have ‘worked’ as implied by the contents.

It is very tempting to try to generalise and compare the performance of different types of motor. I have done exactly that in recent posts. Meaningful comparisons require standard, or certainly specified, conditions. Reasonably straight Permanent Way track, or whatever. Because everybody’s layout and rolling stock are different, reported variations in the performance of similar locos are unsurprising and attributing cause impossible. Genuine, significant, differences due to the drive springs will be buried amongst differences due to rolling resistance of coaches etc. Pieter’s comments above suggest I at least may have underestimated the proportion of the observed variation due to the characteristics of individual drive springs.

Martin

 

[John R Smith]

I obviously know nothing about your Club layout, but if it was built using Permanent Way type track with 3’ or larger radius curves, the same Hornby engine is going to pull a lot more than on Hornby 2’-radius round-headed rails.

The track, rolling stock etc obviously makes a huge difference. Bassett-Lowke were careful to set out the conditions under which their 6-coupled mech would pull 5 coaches for 120’. Permanent Way and ‘reasonably straight’.

Martin

Your points are well taken. Just as a basis for comparison, our Club layouts, both indoor and outdoor, were built using B-L or Milbro brass rail in slide-on cast metal chairs, on wooden sleepers laid on wooden battens. Our points were mostly B-L Scale Permanent Way. The same specification that I am using now on Kingswell Street, in fact. We were lucky to have a large indoor hay loft and a big Vicarage garden, so all our curves were at least 3 feet radius or larger. Most of our PW and rolling stock was pre-war, and at the time (say 1962 -65) I remember that we were beginning to have difficulties getting supplies of chairs, sleepers and battens. In the winter, a lot of our time was spent building track for next season's outdoor expansion plans!

Sadly, as far as I am aware, one can no longer purchase a new clockwork O Gauge engine. Or a new clockwork motor. And very few people seem to have any real interest in spring drive - it seems almost as if you and I are the only members of this Forum to be working seriously in this area. And yet there is plenty of competition for vintage coarse-scale engines and rolling stock on the auction sites, as we know. Do all these things end up in display cases, and never get run?

John

 

[40057]

Martin

Your points are well taken. Just as a basis for comparison, our Club layouts, both indoor and outdoor, were built using B-L or Milbro brass rail in slide-on cast metal chairs, on wooden sleepers laid on wooden battens. Our points were mostly B-L Scale Permanent Way. The same specification that I am using now on Kingswell Street, in fact. We were lucky to have a large indoor hay loft and a big Vicarage garden, so all our curves were at least 3 feet radius or larger. Most of our PW and rolling stock was pre-war, and at the time (say 1962 -65) I remember that we were beginning to have difficulties getting supplies of chairs, sleepers and battens. In the winter, a lot of our time was spent building track for next season's outdoor expansion plans!

Sadly, as far as I am aware, one can no longer purchase a new clockwork O Gauge engine. Or a new clockwork motor. And very few people seem to have any real interest in spring drive - it seems almost as if you and I are the only members of this Forum to be working seriously in this area. And yet there is plenty of competition for vintage coarse-scale engines and rolling stock on the auction sites, as we know. Do all these things end up in display cases, and never get run?

John

Hi John

A quick response on two separate issues.

Performance of different motors. At the extreme ends, a large Bassett-Lowke 6-coupled motor versus the motor for a Hornby 0-4-0, it’s easy to generalise. The one type is more powerful than the other. Where the difference between two types is less, people tend to hold views derived from personal experience (A is better than B, or vice versa) and often based on small numbers of mechanisms. I’ll express performance here as ‘coach units’. The number the mech can pull of a specified type of coach on a specified type of track. For the sake of argument, the true average for a Hornby No.2 Special mech is, say, 2.8. For the standard Bassett-Lowke 4-coupled mech it is, say, 3.2. But due to variations in the manufacture and performance of drive springs, the range in haulage capacity between different examples of both mechs is 2, 3 or 4 coaches. Due to random chance, if someone has two locos containing each type of mech, the two Hornby engines might easily be the two stronger locos. That person will maintain that the Hornby motor is the better motor. That’s not actually true as per the invented ‘averages’ above, but no-one has done the proper testing, with large samples under controlled conditions, to accurately measure relative performance. Arguably, the ‘average performance’ of each type of mech is not terribly relevant anyway. It is not going to be a very good predictor of the performance of a particular loco given the proportionately large variation between individual motors’ haulage capacity.

Competition for locos in auctions etc. There are at least two groups buying vintage trains. I’m a railway person. My interest is trains and, by extension, models of trains. And amongst the many kinds of model trains I like, I particularly like vintage 0 gauge — hence Rivermead Central. But I am also interested in other trains. Vintage model railways are also bought by toy collectors. Nothing wrong with being interested in toys, to study and/or collect. But the toy collector is not necessarily a railway enthusiast. Their wider interest may be other toys. Indeed, I am quite often surprised how little some train collectors know about full-size railways or how to operate a layout realistically. They are not, primarily, railway people; they are toy collectors. Which, as I say, is a perfectly legitimate field of study. But not the same as being a railway enthusiast.

Martin

PS There is a discussion to be had about about new models in the tinplate tradition and specifically clockwork, but another time.

 

[John R Smith]

I’ll express performance here as ‘coach units’. The number the mech can pull of a specified type of coach on a specified type of track. For the sake of argument, the true average for a Hornby No.2 Special mech is, say, 2.8. For the standard Bassett-Lowke 4-coupled mech it is, say, 3.2. But due to variations in the manufacture and performance of drive springs, the range in haulage capacity between different examples of both mechs is 2, 3 or 4 coaches.

Martin

To reply, at the risk of boring all our other valued contributors for which I apologise, but here I go anyway. I understand that the figures you give above are only hypothetical, however back in the day if we had any clockwork tender engine only able to pull three coaches we would not have bothered getting it out on the track. Even a B-L 0-6-0 tank should easily manage that.

Jack Ray's "A Lifetime with O Gauge" book has lots of photos of the old clockwork Crewchester layout, and you can see in there a B-L Compound hauling four coaches (p6), a Scotsman hauling five (p26), a Scot hauling six (p31), a Compound hauling six (p32), and a Duchess on six (p58). In his articles in MRN (December 1956 p306, for example), Jack makes it clear that these are normal loadings which he would expect his locos to take.

Fully loaded, I would expect to sometimes have to give the engine just the slightest nudge with a finger to overcome stiction from standstill, admittedly. But these figures above are much more in line with my own experience with a big stud of clockwork engines sixty-odd years ago.

When we got bored and we wanted to run a really long train, we would just bung another engine on the front and double-head!

John

 

[40057]

Martin

To reply, at the risk of boring all our other valued contributors for which I apologise, but here I go anyway. I understand that the figures you give above are only hypothetical, however back in the day if we had any clockwork tender engine only able to pull three coaches we would not have bothered getting it out on the track. Even a B-L 0-6-0 tank should easily manage that.

Jack Ray's "A Lifetime with O Gauge" book has lots of photos of the old clockwork Crewchester layout, and you can see in there a B-L Compound hauling four coaches (p6), a Scotsman hauling five (p26), a Scot hauling six (p31), a Compound hauling six (p32), and a Duchess on six (p58). In his articles in MRN (December 1956 p306, for example), Jack makes it clear that these are normal loadings which he would expect his locos to take.

Fully loaded, I would expect to sometimes have to give the engine just the slightest nudge with a finger to overcome stiction from standstill, admittedly. But these figures above are much more in line with my own experience with a big stud of clockwork engines sixty-odd years ago.

When we got bored and we wanted to run a really long train, we would just bung another engine on the front and double-head!

John

Hi John

I have Jack Ray’s book. This though does come back to the other factors that massively influence haulage capacity. Particularly, in regard to Crewchester, curves of large radii and bearings on rolling stock. A good clockwork loco, on straight or gently curving track, hauling modern coaches/wagons with pinpoint bearings, should be able to haul a really long train. But, historically, tinplate track, heavy coaches, 2’ radius curves etc will have severely limited train length. If Hornby (Meccano) had expected their clockwork 4-4-0s, on their track hauling their rolling stock, to pull a train of three coaches, why did the clockwork boxed sets only have two coaches instead of the three in the electric sets? Two coaches must have been the appropriate load. I believe three coaches was the length of most rakes of stock on the Sherwood Railway. That might have been due to length of platforms, loops etc as much as loco limitation. Though in one of his accounts I do recall Norman Eagles explaining one loco (a Claughton?) was particularly used on a certain overnight train because it could pull the 5-coach set used. Based, inevitably, on experience with relatively few different individual motors, I would say the ‘5 coaches on reasonably straight Permanent Way track’ Bassett-Lowke claimed for their large 6-coupled motor was a fair and accurate claim. That’s about right, though some motors are better than others, and large, heavy, locos with lots of wheels use quite a lot of effort to move themselves around even 3’ radius curves. The smaller Bassett-Lowke motor (4- or 6- coupled — it’s the same motor) should take three bogie coaches, though it depends so much on the stock and the track. I have had one of these smaller motors happily pulling five heavy coaches, but on a garden line where even the curves were ‘reasonably straight’.

It would be interesting to know if, generally, clockwork locos have become a little less powerful over time. The evidence is I think inconclusive. Largely because, without knowing the circumstances, haulage capacity in terms of “pulled X coaches” is virtually meaningless. Which coaches (weight, bearings, alloy or cast iron wheels?) on what track (tinplate, Permanent Way?) of what radius? Track type and curvature make so much difference. On my Cavendish Goods branch, up trains slow down at each 90 degree curve (3’ 2 1/4” radius) though the curves are dead level. Once back on straight track, on a rising gradient of 1 in 66, trains accelerate. The drag of the flanges on the curves takes more energy to overcome it than climbing the gradient.

What I would say is that clockwork locos don’t have lots of surplus power relative to the loads they might reasonably be asked to pull on a good sized railway. I don’t have space for 14-coach trains, or even 7-coach trains. But I would want to run four or five coach trains. To do that, I need to give the locos as much help as possible. Nothing less than 3’ 6” radius curves on the main line, and mostly larger radii. Cast iron wheels on coaches. Good lubrication of bearings. Look after the motors. I think I will be able to run the railway I want and have space for using clockwork.

Martin

 

[Ian@StEnochs]

This thread is interesting from a historical perspective but I am afraid the locomotives & trains do nothing for me. Having said that I have had some experience with repairing clockwork locomotives. A couple of colleagues at work were into tinplate and because I was recognised as somebody who did model railways, and had some technical skill, they persuaded me to help in the repair and restoration of clockwork mechanisms. Particularly in turning bushes for worn rods or axle bearings, making replacements where lost and sorting broken springs.

In view of the recent comments about springs let me outline my experience. I was often asked to repair a spring that had broken. This was almost always near the end so to fix required the end to be softened to permit the end to be reshaped or drilled and then re hardened and tempered. The spring was obviously shorter and this would reduce the length of run but replacement springs were hard to come by.

The heat treatment was tricky to do and relied on watching oxide colours change before quenching in oil. Not very scientific but from a practical point of view, worked. My friends were happy with what was achieved and kept me busy frequently coming back.

Ian.

 

[John R Smith]

Hello Martin

How is the rebuild of the Royal Scot coming along? I would guess that you have all the wheels and motion stripped out of the electric motor by now. I suppose that it would be prudent to test the clockwork motor with just the wheels and coupling rods fitted up, before restoring it in the body and assembling the connecting rods and valve gear.

John