The reversing rod on North Star 4-4-2

[knobhead]

Gentlemen!

 

Was North Star equipped with lever or screw when delivered? Have been unable to find a picture on the web or in the publications I have.

 

Many thanks!

 

Stefan

[Miss Prism]

All 4-cylinder GWR locos were screw reverse.

[knobhead]

Excellent! Much appreciated, Miss Prism.

 

Regards,

 

Stefan

[HowardGWR]

But do your wheels have the crank pin in line with a spoke?  I discovered recently that a 4mm wheel supplier only has Castle wheels on offer that have the pin between the spokes.

 

If you can overlook such things then of course clearly this is not a problem.

 

BTW, Miss Prism knows this, but I wonder if you are modelling the inside valve gear?  If so, North Star has scissors gear whereas the rest had two sets of Walschaerts.   

 

Also the pitch of the boiler is different.  IIRC the footplating is different too.  

[knobhead]

Hi HowardGWR,

 

I just checked the crank pin position and it's between the spokes and the boiler pitch is probably wrong. I did raise the footplate a bit.

 

I appreciate all input regarding my models. However, the only thing left to do is paint on the loco body and I don' feel like throwing it all in the bin and start over. It is what it is.

 

Regards,

 

Stefan

[Weaselfish]

Tantalising to hear that North Star is so close to completion. Are you going to post some photos when she's done Stefan? Your Victorian and Edwardian builds are really impressive.

[knobhead]

Thanks Weaselfish!

 

The 2-2-2 will be finished tomorrow and North Star will follow shortly after. There will be plenty of pictures of both loco's.

 

Regards,

 

Stefan

[Il Grifone]

But do your wheels have the crank pin in line with a spoke?  I discovered recently that a 4mm wheel supplier only has Castle wheels on offer that have the pin between the spokes.

 

If you can overlook such things then of course clearly this is not a problem.

 

BTW, Miss Prism knows this, but I wonder if you are modelling the inside valve gear?  If so, North Star has scissors gear whereas the rest had two sets of Walschaerts.   

 

Also the pitch of the boiler is different.  IIRC the footplating is different too.  

 

 

I gather there was some dispute with the Midland Railway over North Star's valve gear regarding patent rights, to which GJC is reputed to have said, "Deeley can go to Hell!" (or words to that effect). Whether it was due to this or to the scissors gear being a PITA, the subsequent locomotives had two sets of M. Walschaerts' gear with rocking shafts

 

 

 

EDIT addition of "with rocking shafts", which I forgot.

[The Stationmaster]

I gather there was some dispute with the Midland Railway over North Star's valve gear regarding patent rights, to which GJC is reputed to have said, "Deeley can go to Hell!" (or words to that effect). Whether it was due to this or to the scissors gear being a PITA, the subsequent locomotives had two sets of M. Walschaerts' gear.

In later years the scissors gear was hated by Enginemen when it came to oiling. Apparently very difficult to get around in between the frames and regarded as dangerous.  I would think it likely that the problems were appreciated very quickly once the loco entered service and the design change reflected that.

[Miss Prism]

I gather there was some dispute with the Midland Railway over North Star's valve gear regarding patent rights, to which GJC is reputed to have said, "Deeley can go to Hell!" (or words to that effect). Whether it was due to this or to the scissors gear being a PITA, the subsequent locomotives had two sets of M. Walschaerts' gear.

 

W H Pearce built the original scissors gear at Swindon in June 1905. Deeley applied for the patent on his gear on 11 August, which was granted in June 1906, but No 40 was already built and operational by that time.

[Il Grifone]

W H Pearce built the original scissors gear at Swindon in June 1905. Deeley applied for the patent on his gear on 11 August, which was granted in June 1906, but No 40 was already built and operational by that time.

 

It would suggest the possibility of expensive litigation was a factor in the decision to change the gear, probably combined with the complication of the gear.

[Miss Prism]

It would suggest the possibility of expensive litigation was a factor in the decision to change the gear, probably combined with the complication of the gear.

 

I think intellectual eminence carried far more clout than ungentlemanly litigation in those days. The principle of using 'cross-cylinder' gear was alive among locomotive and marine engineers at the time, and in anycase, Swindon could prove it made the gear before Deeley applied to patent it. The real reason for the abandonment of the scissors gear was therefore not because of any indignancy on Deeley's part, but because a fault in one cylinder in the scissors gear arrangement would render the other cylinder non-operative, and hence such a loco could not limp home in the way a conventionally-geared loco could. I think Churchward was only too happy to have moved on to a more conventional long-travel Walschaerts arrangement before Deeley had time to gather sour grapes.

[buffalo]

I think intellectual eminence carried far more clout than ungentlemanly litigation in those days. The principle of using 'cross-cylinder' gear was alive among locomotive and marine engineers at the time, and in anycase, Swindon could prove it made the gear before Deeley applied to patent it. The real reason for the abandonment of the scissors gear was therefore not because of any indignancy on Deeley's part, but because a fault in one cylinder in the scissors gear arrangement would render the other cylinder non-operative, and hence such a loco could not limp home in the way a conventionally-geared loco could. I think Churchward was only too happy to have moved on to a more conventional long-travel Walschaerts arrangement before Deeley had time to gather sour grapes.

 

That's pretty much how Holcroft described the situation, including the potential disadvantage. Apparently, Deeley had come up with a scissors design years earlier when working under Johnson. The latter rejected the idea and it had to wait until Deeley was in charge before anything further was done. Apart from Deeley's design, Holcroft also mentions earlier Belgian (Stevart) and American (Lewis and Young) examples of cross-connected gear.

 

Nick

[MarkAustin]

John Gibson in Great Western locomotive design: a critical appreciation, who worked first for the MSWJR and then for the GWR post-amalgamation in the Locomotive Shop said that the reason for the change was that the scissor gear could only be adjusted by fitting it, trying it and if it was wrong taking it off again and changing the lengths of the gear. This took a whole day. Acceptable for a single engine, but not for a largeish class. So, a change had to be made in a hurry, it had to be invisible, as Churchward's position was not totally secure, with some Directors concerned about the cost of the locomotive programme, so, inside Walschaerts. Otside would perhaps have been better, but it would have made the original problem too obvious.

 

Mark

[buffalo]

I'm inclined to take Gibson's comments with a pinch of salt. His Swindon experience relates to many years after the great period of experimentation in Churchward's early days as CME and probably reflects the contemporary twenties view of the one-off valve gear on No 40 as a maintenance and replacement headache. No 40 was not built as part of a large class, it only became that later. It was part of a series of experiments much of which involved taking ideas from the French Atlantics and adapting them to Swindon practice. When production of 4001-10 began the following year, the use of inside Walschaerts gear was hardly a quick fix. Instead, it was in part a reversion to the tried and tested gear used on the 'Frenchmen', but with the addition of the compensated rocking arms to drive the outside valves as used on No 40. The latter was, of course, to become a standard component of GWR 4 cylinder design.

 

As to Churchward's position, there was conflict with some of the directors and with the press throughout this period, though I doubt his job would have been on the line over a mere matter of valve gear.

 

Nick

 

ps. as to being 'invisible', the change from 4-4-2 to 4-6-0 was probably visible to Churchward's dumbest detractors

[The Stationmaster]

John Gibson in Great Western locomotive design: a critical appreciation, who worked first for the MSWJR and then for the GWR post-amalgamation in the Locomotive Shop said that the reason for the change was that the scissor gear could only be adjusted by fitting it, trying it and if it was wrong taking it off again and changing the lengths of the gear. This took a whole day. Acceptable for a single engine, but not for a largeish class. So, a change had to be made in a hurry, it had to be invisible, as Churchward's position was not totally secure, with some Directors concerned about the cost of the locomotive programme, so, inside Walschaerts. Otside would perhaps have been better, but it would have made the original problem too obvious.

 

Mark

Churchward opted for inside valvegear for very practical reasons as it allowed fro much larger bearing size in a number of places in comparison with outside valvegear (and of course there was a far greater and cheaper availability of labour in those days as well.  Swindon valvegear was always known for its robustness and its ability - in post WWII years - to endure considerable abuse in terms of slapdash preparation and oiling with little or no apparent ill effects.

[HowardGWR]

Well, well, such knowledge.  I suspect Knobhead will be satisfied just to get the right shade of green on the boiler and the correct logos on the tender for his modelling period (not always achieved by either preservationists or modellers :-) ).  Look forward to seeing the result KH.

[Castle]

Hi All,

 

Like the scissors valve gear topic that has risen from this Stefan's question, this is a very interesting point about colour and logos or insignia raised here by HowardGWR. A few things need to be considered when talking about steam era colour schemes. These are just some of the issues that you have to contend with as a preservationist.

 

What is the right shade of green when the paint was hand mixed by individuals and made of pigments that were far less colour fast than they are today? While the paint mixer would have been as careful as possible, it doesn't take much to put in a tiny bit too much or a tiny bit too little pigment and pigments are strong stuff. Add to this a covering of soot, dirt, and so on, then buffed off with a paraffin oil mix then having another layer of dirt applied followed by another clean and so on... Any sample of paint on a card will be different to the colour on the actual locomotive due to the slight yellowing effect of the varnish and indeed the varnish getting more yellow as time goes on.

 

One great example is the modern paint on No. 4144. During its previous overhaul, this was painted in the shade closest to the given evidence at the time. For some reason, that particular batch faded strangely and the colour when it was stripped for overhaul was half way to LNER green! Sliding the cab shutters back revealed the original shade and the difference was quite dramatic.

 

The photographic technology available to the general public (who took the vast majority of colour railway images) of the era also wasn't up to modern standards and the emulsions don't always stand the test of time. The samples of surviving paint we have are all slightly different to how they were at the time due to reactions in the chemicals of the paint, UV degradation and so on. It just isn't that exact a science unfortunately. Preservationists take a great deal of time getting the details like this as right as possible but unfortunately the techniques and materials of the past - until the end of the steam era - just weren't up to that level of scrutiny at this distance of time.

 

Logos and insignia are another minefield of course - just because a livery was introduced in, say, 1928, it doesn't mean that all locomotives and rolling stock were repainted within the month. There were old liveries that hung around for a long time. The thing that people fail to remember is that this was a commercial concern or a government department that had to run a railway and not ensure that all their rolling stock was the same shade of green, red or grey... There also may not be a photograph of 'your' engine at the date you wish to portray so you have to take the overhaul records and see when it was worked on to see if it was likely that it got that scheme. There are also a number of modifications that any steam locomotive would have undergone in service and to be 100% accurate it would be necessary to undo all those modifications. Should original steam era material be removed in these circumstances to satisfy the demands of a few enthusiasts or should the original material be preserved and a few minor discrepancies lived with? The debate goes on... The painting of No. 5322 in khaki was a great example (outside steam pipes and all) - if you don't let the loco wear the livery then it closes the access to the loco's history to a lot of people. Not everybody reads all the little panels at a museum but if they read ROD 5322 on the tender then they ask a question and a whole facet of WW1 history is revealed to them. Some people said it looked horrible but the aesthetic qualities of the scheme really wasn't the point.

 

In short, the evidence for the actual colour is often minimal and relies on records of formulas of chemicals no longer used to produce paint or original samples or photos which have degraded so you have to take the best evidence and go with that. There was never a completely standard GWR green across all the locomotives painted due to the methods and technologies employed at the time and the toll that the harsh environment that these vehicles operated in took on the paint.

 

I hope this gives a little insight into the trials and tribulations that are gone through when you look at the loco you have just overhauled, sometimes over decades and then you sit down with the colour charts, experts and records and pick a colour. You can never please everyone. I agree that there are cases when individual owners have applied their version of the livery to their locomotive (No. 4079 is a prime example!) but at the end of the day it is THIER locomotive.

 

All the best,

 

Castle

 

PS: I agree - Stefan's model will be superb when it is finished - they always are!

[6892 Oakhill Grange]

Nice one castle

[HowardGWR]

Good post Castle.  There is a difference of course between full size 'reverse engineering' and modelling.  There is no excuse for a modeller using a G badge W logo on a tender that is supposed to be trundling around in 1935.  There is an excuse for a GREAT space WESTERN logo on the side of a pannier tank in 1935, indeed later - but fading to the point of 'almost invisible' would be a nifty choice (see photos).  I think R G Williams' advice was (as always) impeccable.  He recommended trying always to model a photograph of a specific engine.  I've been looking through 57xx engine photos recently, and it is amazing to discover the variations, even from the same batch, over the years.

[Castle]

Hi Howard,

 

If the layout is claimed to be a specific representation of a very specific time period that is used for a specific educational or reference purpose then perhaps but otherwise I refer you to Rule 1...

 

But at the end of the day the paint keeps the oxides off the real thing and prevents you seeing what a model is made of. I have a great time enjoying trains of all types and colours in 1:1 scale and smaller!

 

All the best,

 

Castle

 

Sorry Stefan, back to North Star...

[tomparryharry]

Mr Gibsons book is very good, but some passages are (or, should be) taken with a pinch of salt.

 

Most industry, railways or otherwise, were driving towards ever greater quality, and ease of manufacture, and it's unreasonable to expect Swindon, or anywhere else, to get it 'right first time', especially when dealing with unknown service parameters.

 

Harold Holcroft's books are much more realistic and honest. Churchward was a visionary, but the likes of Holcroft translated that vision into the finished product.

 

Ian

[MarkAustin]

It has become fashionable to claim that Gibson in his writings is unreliable.

 

I do not believe this is tenable.

 

Let us look at the facts.

 

He worked at Swindon Works, admittedly 20 or so years after the design of the Stars. However 20 years is not sufficicient to remove all people with first hand experience, and the evidence is overwhelming that he was both knowledgable and curious about GWR locomotive practice. It beggars belief that he could have worked on the valve setting gang---as he did---without speaking to "old hands" who remembered the "old days". Indeed he quotes the chargeman as saying that it took ten days to a fortnight to set the gear of North Star, as opposed to a day or so for the others. I agree with him that this was acceptable for a single engine, requiring attention every two years or so, but not acceptable for a substantial class.

 

He also quotes the evidence of his father---who knew Charles Mortime, one of the GWR's Directors---who when hearing Churchward's locomotives praised, responded "Unnecessarily big and heavy, causing us to spend too much money on track and bridges", and added "and too expensive to build". This might have been a minority opinion on the Board, but I do not believe it would have been expressed if not widely held.

 

So, Churchward bungled with the Scissors gear--and I believe it is a reluctance to admit this that causes Gibson to be downrated---his designs had opponents at the highest level. He needed to do something that would not be an admission of failure, if only in this one small area. Hence, inside Waelscharts valve gear, with the flimsy excuse that  the two sides could be disconnected to allow an engine to work home on one side only.

 

Mark A

 

Edited to correct spelling

[buffalo]

It has become fashionable to claim that Gibson in his writings is unreliable...

It's nothing to do with fashion or reliability, Mark, simply critical appraisal that should be applied to any source and to any views purporting to be derived from those sources.

 

...He worked at Swindon Works, admittedly 20 or so years after the design of the Stars. However 20 years is not sufficicient to remove all people with first hand experience, and the evidence is overwhelming that he was both knowledgable and curious about GWR locomotive practice. It beggars belief that he could have worked on the valve setting gang---as he did---without speaking to "old hands" who remembered the "old days". Indeed he quotes the chargeman as saying that it took ten days to a fortnight to set the gear of North Star, as opposed to a day or so for the others. I agree with him that this was acceptable for a single engine, requiring attention every two years or so, but not acceptable for a substantial class...

No one denies that he worked with and spoke with old hands nor that the valve gear on North Star was difficult to maintain. Perhaps the only surprise is that it was not rebuilt with conventional gear earlier. As you say, maybe acceptable on a single engine, but it never was applied to an entire class, only to a one-off experimental engine. The simple fact is that, for whatever reason, Churchward did not continue to use this gear when the Stars were built. Churchward, like Dean before him, made great use of experimental prototypes, and it is the nature of experiments that some features will be retained and others abandoned if and when production ensues.

 

...He also quotes the evidence of his father---who knew Charles Mortime, one of the GWR's Directors---who when hearing Churchward's locomotives praised, responded "Unnecessarily big and heavy, causing us to spend too much money on track and bridges", and added "and too expensive to build". This might have been a minority opinion on the Board, but I do not believe it would have been expressed if not widely held...

An unusual association of "minority view" and "widely held". Of course it was a minority view and there's no reason for surprise that there were minority views on the Board, 'twas ever thus. Fortunately, it did not prevail. Can you imagine what a mediocre railway the GWR would have become without Churchward's larger designs? Think Midland small-engine policy.

 

...So, Churchward bungled with the Scissors gear--and I believe it is a reluctance to admit this that causes Gibson to be downrated---his designs had opponents at the highest level. He needed to do something that would not be an admission of failure, if only in this one small area. Hence, inside Waelscharts valve gear, with the flimsy excuse that  the two sides could be disconnected to allow an engine to work home on one side only...

 

"bungled", "flimsy excuse" and "admission of failure" are ridiculously emotive terms for a rejected experiment. Remember that the method of driving the valves by rocking shafts was retained and became the standard on subsequent GWR four cylinder designs. A critical reading of Holcroft, himself a not entirely uncritical admirer of Churchward, suggests that the decision was primarily to avoid paying fees or potential litigation from Derby, though it is debatable whether Deeley's patent would have stood up in court given the prior art dating back to the mid-1860s and specific differences between Deeley's design and Churchward's implementation. Had Churchward been particularly keen on the scissors gear, it's not unreasonable to suggest that he could have come up with an implementation that was sufficiently different from Deeley's design. As to the "flimsy excuse", Holcroft appears to present this as a minor beneficial side-effect of the modified Walschaet's implementation, not the primary reason for the change. An engine with the scissors gear would not be able to move at all under it's own steam in the event of certain failures. The Walschaert's gear was modified so that the reversing system on the failed side could be pinned in mid gear. That said, is there any record of the scissors gear failing?

 

Gibson's views are interesting in many ways, not least because they give a wider voice to some of Churchward's detractors. They should be read and respected for what they are, not distorted in an attempt to undermine others.

 

Nick

[HowardGWR]

More interesting to modellers is why no RTR manufacturer has not implemented Guy Williams' moving rocking shafts implementation, or something like it, as that would be a real sales item, would it not?