Wright writes.....

[St Enodoc]

Just out of some possible interest, though no group is considering building a new DUKE OF ROTHESAY, the P2 Group is effectively building a loco named after the same individual.

Indeed, and given where the P2s ran originally I cannot understand why the new loco won't be called by this name or (my preference) Lord of the Isles.

[Michael Edge]

In layman's terms, Darlington works decided to ignore the drawings. They decided to pipe up the manifold in such a manner that if any of the auxiliary equipment was operated the boiler pressure was seriously compromised. If boiler pressure was maintained then the auxiliary equipment would fail. The auxiliary manufacturers had an inkling about what the problem was but seemed reluctant to inform the LNER big wigs of what was a rather embarrassing schoolboy error on their part. In the meantime, the running department continued hit various bits of equipment with hammers and the manufacturers continued to replace them.

 

Many experiments were carried out to make the locomotive steam, mainly with drafting and blastpipe experiments. By the time that a red-faced LNER finally worked out that the manifold was strangling the locomotive, time had moved on. The locomotive as a test bed comparison with class A1 was now redundant, he super pacific's and then the A4's had far surpassed the original locomotives. The corrected locomotive was finally given the opportunity to fulfill something like its full potential with the test runs with the dynamometer car on the Leeds Hull runs. The results were very impressive and suggested that the locomotive could have reached just under 4000 IHP at 90% cut off. Sadly, just as the engine was at a last in a condition that was something like 'fit for purpose' the decision was being tacken to rebuild the locomotive. 

Are you seriously suggesting that so much steam pressure was lost through the blower and injector feeds? That's about all the "auxiliary equipment" (a term I've never heard applied to a steam loco) that would be in use while running.

[grob1234]

Sorry folks, back to the A4/W1 chassis...

 

Tony, inspired by your pictures I started assembling the motion for my SEF W1 chassis which I believe is essentially the same (as far as the moving bits are concerned) as the A4.

 

Using your experience with the mismatch of the connecting rod throw (I had exactly the same issue) I decided the best way to solve the problem was to move the cylinder blocks forward about 2mm. This has enabled me to keep the big end hole round, and evens up the throw of the cross head slipper. So far so good!

 

However my problem came when I attached the cross head slipper to the small end. When I presented the cylinder and slipper assembly along with the connecting rod to the frame, the connecting rod doesn't clear the front wheel crankpin and washer. In fact the connecting rod bends round the crankpin which even I know won't work! I find this odd as I haven't doubled the thickness of the connecting rod as per the instructions. The only thing I have done is slightly splay the wheels to finescale standards but we are only talking a fraction of extra width and not enough to cause the lack of clearance I'm experiencing.

 

The solution I'm leaning towards is to pack out the cylinder blocks a couple of MM which seems to cure the problem. I'm wondering is this an issue that others have had or am I missing something? I dare not file the crankpin washer down any more. Also when I tested the cylinder blocks with the extra backing everything seemed more in alignment and just looked right. In order to fit the body over the widened cylinder blocks I'll just remove a corresponding amount of material from the outside.

 

Also, what size BA nuts and bolts are used on the slipper, I'm going to need replacements?

 

I'll post a couple of pictures later.

 

Many thanks in advance.

Edited December 29, 2016 by grob1234

[Headstock]

Are you seriously suggesting that so much steam pressure was lost through the blower and injector feeds? That's about all the "auxiliary equipment" (a term I've never heard applied to a steam loco) that would be in use while running.

 

Steam pressure was lost because of the intermittent failure of the injectors due to the inadequate supply of auxiliary steam. The phrase auxiliary equipment, referring to anything running off the manifold is a term freely used in correspondence between HN Gresley and JN Gresham producers of the HP injector. After a three-page report was prepared by Gresham's, Gresley finally ordered the fitting of an independent steam supply for the HP injector. I would recommend William Brown's excellent book Hush-Hush the story of LNER 10000. It is based on the original documentation that has remained hidden in the archives of the National Railway Museum for around seventy years.

 

It would seem that due to the work of the P2 group, particular as regard to the inadequacy of the crank axle, that the relevant chapter in the green book regarding that class of locomotive will also need a rewrite.

[ecgtheow]

Regarding the Hudson wheel arrangement, the question is surely whether or not 6 drivers could lay down the power?

 

Over on the West Side of America the 4-8-4 arrangement suggests that this was the way to go. Two famous heritage locos remain in regular service, the UP 3985 and the SP 4449. I have had the pleasure of riding behind 3985 with at least 17 on at 62 mph with one cylinder coasting due to a "problem" that was solved overnight by an oilfield welding company in Houston. Videos of the GS4 4449 running excursions at similar speeds are available on line, just search. When in service the GS4s pulled the Daylight from San Francisco to Los Angeles in less than 12 hours including some heavy (assisted) gradients.

 

The Northerns were, in many ways, the ultimate North American steam locomotive. But you also have to admire the NYC Hudsons for what they could do day after day.

 

Incidentally, one 20th Century Limited left Chicago with only four passengers, proving that the statistical gaussian distribution curve really does exist.

 

Edit at 3 am. The UP Northern is, of course 844, 3985 being the Challenger. A senile moment perhaos when a long way from my library. The Challenger 4-6-6-4 could put down even more piwer and go fast enough to pull passenger trains across hilly terrains.

 

The Dreyfuss Hudsons were, as others have pointed out or implied, built for sustained high speeds on the Waterlevel Route i.e. more or less flat track with few gradients & needed a booster to get them going from a standing start. The 4-6-4 arrangement allows for a much bigger firebox supported by the trailing truck than on a pacific for sufficient steam production at high speed. Also these Hudsons originally ran with 275 lb/in2 boiler pressure, but at that pressure they bent their rods, so it was reduced to 265lb/in2. Though the "streamlining" almost certainly didn't improve their performance, it looks dramatic to me. It was a 4-8-4 "Northern" loco that superseded the Hudsons on the NYC, but only for a short time, as the diesels took over in the late 1940's.

[Headstock]

I had to put the modeling aside before Christmass but normal service has resumed. Forgive me if I side step the great valve gear debate, too many cooks and all that. I have managed some modeling over the holidays, the GWR compo (from up the thread) is now in the paint shop with just the ends to paint and gangways to fit. The door handles are yet to be fitted, and it still requires transfers and curtains to put into the windows. Being a bit of a dumb ass I forgot to paint the droplights before glazing, oh well out with the little brush.

 

Also on the go are a couple of LNER fish vans. The venerable Parkside 12' wb version, an old D&S  9' wb van and a Bachmann 10' wb type. The latter has been modified to represent a van fitted with a plywood door. Three down, only another twenty-seven to go.

[CF MRC]

Good evening Tony. I was inspired by Tom's video of your Little Bytham layout....

 

At the end of the edited clip I've faded to the original to show the difference. I took the background from a google streetview image of Little Bytham, although I may not have the orientation right. You may not be able to tell but the clouds drift a bit (I was quite chuffed at getting this to work without losing the telegraph pole). I added more foliage in on the right hand side as it was quite difficult to mask the model trees, easier to take them out and add them back in, so to speak.

 

Edit: I should probably add there are a few rough bits on it where the masking isn't great, but overall I hope it's ok.

Super video. It just needs some birdsong to add to the ambient sound when the trains have gone.

We had some fun with cloud effects on Copenhagen Fields a few years ago. All shot with an iPad (we have one that looks through the backscene down the NLR for operating at exhibitions).

 

https://www.youtube.com/watch?v=RpBmCkwLr-A&sns=em.

 

I have another view that shows a hand holding the sky!

 

Tim

[peach james]

Regarding the Hudson wheel arrangement, the question is surely whether or not 6 drivers could lay down the power?

 

Over on the West Side of America the 4-8-4 arrangement suggests that this was the way to go. Two famous heritage locos remain in regular service, the UP 3985 and the SP 4449. I have had the pleasure of riding behind 3985 with at least 17 on at 62 mph with one cylinder coasting due to a "problem" that was solved overnight by an oilfield welding company in Houston. Videos of the GS4 4449 running excursions at similar speeds are available on line, just search. When in service the GS4s pulled the Daylight from San Francisco to Los Angeles in less than 12 hours including some heavy (assisted) gradients.

 

The Northerns were, in many ways, the ultimate North American steam locomotive. But you also have to admire the NYC Hudsons for what they could do day after day.

 

Incidentally, one 20th Century Limited left Chicago with only four passengers, proving that the statistical gaussian distribution curve really does exist.

 

Edit at 3 am. The UP Northern is, of course 844, 3985 being the Challenger. A senile moment perhaos when a long way from my library. The Challenger 4-6-6-4 could put down even more piwer and go fast enough to pull passenger trains across hilly terrains.

Don't forget about up here- where CN thought the 4-8-4 was the cats meow, and ended up with something like 1/2 of their new build engines being them.  Contrast that to CP, who made engines for this, and engines for that.  (mind, the F1 Jubilee could probably give an A4 a run on it's money- they made it to 112.5mph with a dyno car, a record that stood as the fastest train in Canada until 1977).  I think that the difference between east and west (and particularly, the NYC) has a lot to do with grades.  The NYC was called "the water level route" for a reason, in comparison to most it was very flat by North American standards.  Out here, there are miles on miles of 1:100 or worse (1:33...) grades, which would have caused caos in the UK, over here, they just got on with it...If you think I'm biased:

 

 

That's me with our J2.  The only complaint that I have about it was it was rather heavy for me at one end @ 11-12 years old.

 

 

James

 

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

[jamie92208]

The Dreyfuss Hudsons were, as others have pointed out or implied, built for sustained high speeds on the Waterlevel Route i.e. more or less flat track with few gradients & needed a booster to get them going from a standing start. The 4-6-4 arrangement allows for a much bigger firebox supported by the trailing truck than on a pacific for sufficient steam production at high speed. Also these Hudsons originally ran with 275 lb/in2 boiler pressure, but at that pressure they bent their rods, so it was reduced to 265lb/in2. Though the "streamlining" almost certainly didn't improve their performance, it looks dramatic to me. It was a 4-8-4 "Northern" loco that superseded the Hudsons on the NYC, but only for a short time, as the diesels took over in the late 1940's.

 

The problem with the bent coupling rods was solved on 844 by having tandem rods between the 2nd and 3rd drivers to spread the load from the con rod.  They worked at 300psi.  I once visited the roundhouse at Cheyenne and had a tour of 844 and it's parts donor 838.  On the crank pin where the con rod drives onto the tandem rods the rod boss is IIRC 23" in diameter. The engines only held together by using cast steel engine beds instead of frames with I think the cylinders, brake hangers and spring hangers and axle pedestals all cast into the one piece engine bed.  However there is a video taken with a camera attached to the slide bar of 844 and when it is under heavy load the whole frame appears to wobble a bit with each piston stroke.  I hope that Tony won't mind me putting this link in as I was fortunate enough to see 844 leaving Cheyenne going west In 2012 with 17 on, plus 3 diesels, which were only at idle.   The ground was shaking as she went past.

https://www.youtube.com/watch?v=RVL_R4xpvl0

 

As an aside the genius behind the design of  UP's superpower, Otto Jableman is buried in London where he died of a heart attack during the war.

 

Jamie

[Focalplane]

Just for fun, a photo of the rear engine of 4-6-6-4 Union Pacific 3985's drive train, being lubricated and repaired between two weekend excursions from Houston. Prior to this, the first run had been clocked at 62 mph with 17 cars while entering Northern Houston south of Spring, TX. Despite the valve gear on this cylinder havibg been temporarily placed in "neutral". I should add that this was the explanation given by one of the UP crew and I did not venture to ask for more details as they were tired, needed to do the repair ready for a 7am departure the next day.

 

The photo demonstrates the size of the rods and valve gear on a loco that generated 97,000 lbs of tractive effort.

 

[CoViAnna]

I look at that and all I can think is K.I.S.S. 

[Michael Edge]

Steam pressure was lost because of the intermittent failure of the injectors due to the inadequate supply of auxiliary steam. The phrase auxiliary equipment, referring to anything running off the manifold is a term freely used in correspondence between HN Gresley and JN Gresham producers of the HP injector. After a three-page report was prepared by Gresham's, Gresley finally ordered the fitting of an independent steam supply for the HP injector. I would recommend William Brown's excellent book Hush-Hush the story of LNER 10000. It is based on the original documentation that has remained hidden in the archives of the National Railway Museum for around seventy years.

 

It would seem that due to the work of the P2 group, particular as regard to the inadequacy of the crank axle, that the relevant chapter in the green book regarding that class of locomotive will also need a rewrite.

Insufficient steam may well have compromised the injectors but that wouldn't reduce the power output of the loco in the short term. The water level would be dropping but not the steam pressure.

[APOLLO]

My favourite Yank loco was also New York Central - The Niagara class 4-8-4, built 1945/6 just as Diesels were becoming main stream. It is said that in comparison tests the Niagaras nearly matched the efficiency of (the early) Diesels, upsetting the Diesel sales reps..

 

Info & comparison tables etc here

 

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

 

This interesting bit from above.

 

The six days per week running schedule of these locomotives meant that all of the maintenance work normally done over the course of that week would have to be done on one day. This meant a specialized system was developed, where men in "hot suits" (asbestos heat-resistant coveralls) entered the firebox while the locomotive was still in steam and cleared all of the tubes, repaired the brick arch, etc. As the temperature inside the firebox itself would have been well over 100 degrees Celsius (212 F), and the working area these maintenance workers would have been standing on was the still-hot firebars of the grate, all references describe these workers as 'heroic' (reference: pages 172 ~ 173 The Great Book of Trains, Brian Hollingsworth and Arthur Cook (Bedford Editions, Salamander Books, 1987) )

This type of intensive maintenance was studied by steam locomotive designers such as Andre Chapelon, Livio Dante Porta, and David Wardale. These designers based their modern steam locomotives on the experience gained in these Niagara-class locomotives: reliability; and a close attention to details leading to a reduction in maintenance costs.

 

 

 

Fantastic looking locos (A Yank "Britannia ?") They all had very short lives - all gone by 1957 & none preserved.

 

Brit15

Edited December 29, 2016 by APOLLO

[Headstock]

Insufficient steam may well have compromised the injectors but that wouldn't reduce the power output of the loco in the short term. The water level would be dropping but not the steam pressure.

 

So the boiler pressure was allowed to drop until the injectors re-engaged. Injectors on, water into the boiler, pressure rises, injectors pack up again and repeat. That was the true story of the Hush Hush, nobody put two and two together. The injectors were returned to the manufacturer again and again with a terse 'they don't work'. The fact that the injectors had usually been reduced to scrap by the use of a lump hammer didn't help diagnose the problem. I'm not clear what is meant by short term, especially with a high-pressure compound locomotive with a water tube boiler. I think that we would both agree, that the chain of events beyond the short term would lead to catastrophe unless measures were taken to stop the water boiling away.

[New Haven Neil]

90% cut off?  No way.  Wouldn't run at speed, it couldn't clear the exhaust steam.  Most Gresley locos had cut off limited due to conjugated gear limitations, OK not an issue on 10000, but 75% max is usual on all locomotives. 

[Headstock]

90% cut off?  No way.  Wouldn't run at speed, it couldn't clear the exhaust steam.  Most Gresley locos had cut off limited due to conjugated gear limitations, OK not an issue on 10000, but 75% max is usual on all locomotives. 

That was a theoretical figure based on solid data received from the Dynometer car tests, see the earlier post. If you can't get to York to see the original file I would recommend the Brown book, it is really very good.

[Tony Wright]

I am sorry to be picking nits again but isn't the valve gear on that otherwise lovely A4 suffering from a backwards facing expansion link?

 

It is easily done. I have done it myself in the final assembly, by mixing the LH and RH components. It was one of those "Oh flipping heck" (feel free to insert other phrases) moments when I spotted it.

 

Tony,

 

Nit-pick away, please, but isn't this right? With the convex curve to the rear? 

[Tony Wright]

 

 

Two more close-ups of the A4 expansion link, both sides. I think what tricks the eye is the presence of the motion-support bracket. 

 

 

Now, can anybody out there please help with this one? Yesterday, five dear (old) mates came and ran the railway. There was a derailment caused by two wagons buffer-locking when being reversed!!!!! Other than that, apart from my operating hopelessness, a 'perfect session'. Thanks chaps. One of the mates brought this along and gave it to me (thanks Keith). His cat had decided to 'play' with it; hence the missing buffer and a few dings. 

 

The question is, what is it? Obviously a brake van, but what sort? He acquired it from a swap-meet some time ago, but knows nothing of its provenance. It has a white metal body and etched-brass frames. It's compensated, and that's all I can say. 

 

Many thanks in anticipation. 

[Tony Wright]

Sorry folks, back to the A4/W1 chassis...

 

Tony, inspired by your pictures I started assembling the motion for my SEF W1 chassis which I believe is essentially the same (as far as the moving bits are concerned) as the A4.

 

Using your experience with the mismatch of the connecting rod throw (I had exactly the same issue) I decided the best way to solve the problem was to move the cylinder blocks forward about 2mm. This has enabled me to keep the big end hole round, and evens up the throw of the cross head slipper. So far so good!

 

However my problem came when I attached the cross head slipper to the small end. When I presented the cylinder and slipper assembly along with the connecting rod to the frame, the connecting rod doesn't clear the front wheel crankpin and washer. In fact the connecting rod bends round the crankpin which even I know won't work! I find this odd as I haven't doubled the thickness of the connecting rod as per the instructions. The only thing I have done is slightly splay the wheels to finescale standards but we are only talking a fraction of extra width and not enough to cause the lack of clearance I'm experiencing.

 

The solution I'm leaning towards is to pack out the cylinder blocks a couple of MM which seems to cure the problem. I'm wondering is this an issue that others have had or am I missing something? I dare not file the crankpin washer down any more. Also when I tested the cylinder blocks with the extra backing everything seemed more in alignment and just looked right. In order to fit the body over the widened cylinder blocks I'll just remove a corresponding amount of material from the outside.

 

Also, what size BA nuts and bolts are used on the slipper, I'm going to need replacements?

 

I'll post a couple of pictures later.

 

Many thanks in advance.

Tom,

 

I didn't have a problem with the connecting rod catching on the leading crank pin. Like you, I thinned the latter right down, both sides. On the driven crank, I always put a fibre washer, then a crank pin washer between the coupling rod and the connecting rod, which pushes the latter out, clearing the leading pin, usually. I then put a further fibre washer, then another crank pin washer between the big end of the connecting rod and the return crank.

 

The tiny fibre washers are excellent for giving clearances and also for preventing solder from getting where it shouldn't. If you look at the pictures in my previous post, you can see where I've put them between the expansion link, radius rod and the 12BA nut which holds it all together. 

 

I used 14BA nuts and bolts to join the crosshead to the little end. 

 

I hope all this helps. 

 

Regards,

 

Tony. 

[queensquare]

SE Finecast A4 12.jpg

 

SE Finecast A4 13.jpg

 

Two more close-ups of the A4 expansion link, both sides. I think what tricks the eye is the presence of the motion-support bracket. 

 

NE brake van.jpg

 

Now, can anybody out there please help with this one? Yesterday, five dear (old) mates came and ran the railway. There was a derailment caused by two wagons buffer-locking when being reversed!!!!! Other than that, apart from my operating hopelessness, a 'perfect session'. Thanks chaps. One of the mates brought this along and gave it to me (thanks Keith). His cat had decided to 'play' with it; hence the missing buffer and a few dings. 

 

The question is, what is it? Obviously a brake van, but what sort? He acquired it from a swap-meet some time ago, but knows nothing of its provenance. It has a white metal body and etched-brass frames. It's compensated, and that's all I can say. 

 

Many thanks in anticipation.

 

Can't help with the origins of the kit I'm afraid but that looks like a Great Western outside framed toad to me.

 

Jerry

[TrevorP1]

SE Finecast A4 12.jpg

 

SE Finecast A4 13.jpg

 

Two more close-ups of the A4 expansion link, both sides. I think what tricks the eye is the presence of the motion-support bracket. 

 

That looks fine to me Tony and far better than my fumbling fingers could produce.

[jwealleans]

If that brake van is LNER/NER, it's like nothing I've ever seen. O/F Toad looks a better bet to me.

[Barry Ten]

Looks quite similar to these models of an AA16 toad:

 

http://www.rmweb.co.uk/community/index.php?/blog/1004/entry-12798-2mm-scale-gwr-diagram-aa16-brake-van/

 

http://www.windyurtnowski.com/DaveDay/railways/brake4.htm

 

Alastair (Barry Ten)

[nerron]

Can't help with the origins of the kit I'm afraid but that looks like a Great Western outside framed toad to me.

 

Jerry

I agree and possibly from a D&S kit.

[Tony Wright]

Looks quite similar to these models of an AA16 toad:

 

http://www.rmweb.co.uk/community/index.php?/blog/1004/entry-12798-2mm-scale-gwr-diagram-aa16-brake-van/

 

http://www.windyurtnowski.com/DaveDay/railways/brake4.htm

 

Alastair (Barry Ten)

Thanks Alastair (and others). 

 

Definitely GWR (which I rather suspected). It'll have to live on another railway.