Member postings for julian atkins

Hi Duncan,

This is quite an involved topic. It was vitally important for the box receiving a train to know what type of train this was on absolute block working with double track and refuse sidings and loops etc and also possibly relief lines.

A slow 'fly' goods might hinder an express service. Suggest you read the report on the Quintinshill disaster.

http://www.railwaysarchive.co.uk/docsummary.php?docID=158

When I worked on the railways in South Wales on The Valleys, the bell codes were still as per GWR despite no freight then being worked, but we had light engine movements when we worked LHCS, and ECHS workings, failures in section etc. Although no freight, we had track cleaning trains, and also engineers trains from NR.

Cheers,

Julian

Hi Jon,

I shall not waste too much time over this because you really ought to get more actively involved in your local club and get to drive a few miniature locos before you decide. And assist as best you can in unloading them and loading them in other members' cars etc.

LBSC's 'Speedy' 5"g design one could write a lot about. It is an old design hastily done with poor drawings and a defective valve gear. The valve gear has been corrected by Don Ashton.

I will trot out my usual advice for tyros not to build a loco with piston valves or a tapered barreled belpaire firebox boilered loco. The latter excludes 'Firefly', and the former also excludes other designs. 'Speedy' falls into both categories.

I agree that considering the long timescale of a build, cost should not be an issue especially if you plan ahead.

My own advice would be to build a 3.5"g LBSC 'Maisee' with the original boiler not the later combustion chamber boiler. Don Young's 3.5"g LMS 4F is also a good contender. My own first loco was Don Young's 5"g Railmotor which in my case was a modified Railmotor No.2 chassis with a No.1 boiler.

Don't try to lift any miniature loco on your own. I injured my back in 1995 doing this. With your disability, don't even consider assisting, and get others to do this for you.

Cheers,

Julian

Hi Malcolm,

Why not make your own water gauge? I am quite sure you will be able to make something far more satisfying than a standard commercial fitting, plus with your 7/32" x 40 TPI ME thread.

They are not difficult to make.

I have always made my own boiler fittings, and have never bought commercial products.

Cheers,

Julian

https://www.a1steam.com/2018/06/05/repair-progess/

Cheers,

Julian

Hi Jon,

Blackgates now market the Clarkson range, and included is the 5"g 2-10-0 WD Austerity loco. You can download the Clarkson catalogue on the Blackgates website.

Cheers,

Julian

Hi Clive,

There is some advantage to having a wheel on the end of the hardened shaft so you can turn it to prime the system and also give the cylinders a dope of oil before a steam up and run, though if your's is on a 5"g POW, then the oil will just collect on the steam chest cover.

The driving shaft must be hardened. By a few spare roller clutches. Carefully set the spring on the oil check valve to just above working pressure. This will reduce the system getting strained on a mechanical lubricator.

I prefer the Sight feed hydrostatic/displacement type for cylinder lubrication.

Cheers,

Julian

Hi 'Redsetter',

That last post of your's was out of order. Duncan is a highly respected miniature locomotive builder with considerable practical experience, as well as understanding the theory of what we make.

I have never made cardboard and pin templates for my valve gears, and I doubt they will give you any understanding of 'backset' for the expansion link connection to the expansion link, or any understanding of the 90 degree components via the (1) eccentric movement, and (2) the combination lever out of phase with the above by 90 degrees to provide the lap and lead component.

The computer simulators allow us to do this in a matter of minutes as Duncan states. The work of Don Ashton is invaluable in understanding 'whats what' and what makes a difference to good Walschaerts valve events.

Simon,

If you want a simplistic explanation just read LBSC's TICH construction book on the valve gear.

Cheers,

Julian

Hi All,

I can say without a shadow of doubt there is an error in the drawings for Gordon Smith's 'squat valve' PSV#2E from Polly. I had to go back to Gordon's original EIM articles to work out what the error was as the valve would not close till pressure dropped to 50 psi, working pressure being 90 psi. The answer was in Gordon's original articles and taking 10 thou off the bottom of the shroud resulted in perfect performance.

I have not seen the drawing that John has worked to, but in the light of the above the drawing I was making them to had an error.

The springs supplied by Polly were spot on and excellent in my case.

The parts do need to be made to a very high degree of accuracy, especially the body internal bore around the shroud retaining the ball, and the shroud itself.

Cheers,

Julian

Hi Simon,

Most if not all older miniature locomotives will have crown girder stays between inner firebox and outer firebox. These are secured in position by a few or more rivets on the inner firebox crown before silver soldering. These rivets are silver soldered in the course of the above, but sometimes they are missed or the silver solder does not penetrate properly.

Any repair attempt is determined by whether any of the adacent firebox stays are either comsoled and nutted threaded stays, or silver soldered.

Crown stay rod stays as opposed to girder stays are quite another matter.

A very careful examination of the inner firebox crown is required.

This requires the attention of an experienced club boiler inspector and his assessment and any repairs are going to be difficult.

Depending on the design of boiler and it's detailed construction (which you do not state or the design of loco or it's age, history and usage), and any inward bulging of the inner firebox crown on discovery of the leak, I would have serious doubts about an easy repair.

Usually such a leak would condemn the boiler.

Cheers,

Julian

Hi Chris,

I suggest you ditch the coaxial superheaters as they are not very efficient. The LBSC type is far better in copper pipe and spearhead return bends, but the return bends do need to be sifbronzed up to the copper pipe.

The coaxial type originated with Don Young's Mountaineer design in ME early 1970s at the suggestion of Alec Farmer.

A few years ago I became a convert of stainless radiant stainless superheaters extending into the firebox - that have to be TIG welded at the return ends, and is a job far beyond my capabilities. But friends with the requisite skills or contacts have provided the necessary.

I would never build a loco without superheaters in 3.5"g or 5"g. If you are a good attentive driver you notice the difference after the first half lap. The loco is more lively, uses less water and coal, and the valve gear can be notched up further so further using less steam. You also go through a tunnel and spectacle wearers like myself do not get their glasses 'steamed up' preventing seeing signals. The saving of coal and water is quite considerable in my experience.

Cheers,

Julian

Hi Kevin,

I would 3rd going down the Gordon Smith designs route.

Cheers,

Julian

Hi Gary,

The Blackgates Clarkson drawings and casting are the route to go by. The NRM have lots of drawings available, and there is a complete set of drawings for the LBSCR H2 Atlantic which devolved from the original Ivatt drawings, and which is being recreated in fullsize on the Bluebell Railway.

I have a GA from Doncaster of the Ivatt Atlantics as per Maisee, but LBSC took some liberties with his 3.5"g design.

I have not seen the Clarkson drawings but would imagine they are very accurate but not easy to interpret unless you have a lot of background knowledge.

W A (Bill) Carter built his 5"g Gold Medal winning example that won the top awards in 1967 and 1968 if you refer back to ME of this period. It was also a working miniature that proved itself on the track on the SMEE exhibition track for many years and at Beech Hurst.

I would also particularly recommend you acquire the RCTS LNER volume relevant to the large boilered GNR Atlantics and this will give you some appreciation as to the Richardson balanced slide valve version as to the later piston valve version.

Cheers,

Julian

Hi Chris,

You will not find the angles of advance for the eccentrics on the Torquay Manor drawings because Martin Evans did not know how to work this out.

With Stephensons valve gear there is an optimum setting of the eccentrics for best valve events.

You can these days work all this out accurately and quickly on a computer on a valve gear simulator such as Prof Bill Hall's. Or you work everything out mathematically using Don Ashton's book.

Or you can guess the angle of advance by laborious minor alterations at certain cut offs and noting the amount of lead at Front Dead Centre (FDC), and Back Dead Centre (BDC).

On a piston valve loco I would use the cylinder drain cocks to find out when the valve opens to steam, checking first that the drain cock holes are not obscured by the piston at the end of it's strokes.

The GWR Churchward Stephensons valve gear uses relatively short eccentric rods which causes lead to increase far more as the gear is notched up when compared with other arrangements.

Therefore your Manor should be set for the valves to provide negative lead in full gear cut off of say 79%. A good starting point would be negative lead of 10 thou in full gear. This will result in lead not being excessive when the gear is notched up.

Each time you alter one eccentric or both the valve will need centralising again to produce equal leads - which is rather time consuming on a piston valve loco.

FDC and BDC must be accurately established and not guessed at.

Cheers,

Julian

Hi Peter,

I would agree that Don's description is not clear except I have most of his construction notes for his many designs both in LLAS and ME, plus knew Don, and I think my interpretation is the correct one, even if there may be better (but far more complicated and time consuming methods). I haven't had any problems doing the axleboxes as per my interpretation of Don's description for your design, which is much clearer in his other construction descriptions.

Obviously you need to know your 4 jaw chuck well.

I think the other suggestions are serious overkill.

Cheers,

Julian

Hi Dean,

I have been watching progress with much interest.

Yes, 'Tugboat Annie' in your above pic with the special unique Holcroft valve gear. I am not so sure if 'Curly' considered it his 'magnum opus' - I think his 3.5"g 'Grosvenor' was his favourite. No published plans for either but Carl Jones has done an excellent job of re-creating 'Grosvenor' in 3.5"g.

'Grosvenor' was also Stroudley's favourite loco and arguably his masterpiece, so a working miniature example in 3.5"g would have had a special place with 'Curly'.

Holcroft was a regular visitor to LBSC's home in Purley. Holcroft was a valve gear expert as well as an ex GWR draughtsman who knew Churchward and was given the job of designing the GWR 43XX class. Later on with the SECR and SR he developed the 3 cylinder locos with conjugated valve gear under Maunsell.

Cheers,

Julian

Hi Peter,

I think you have misinterpreted Don's writings. Just do each axle box in turn in the 4 jaw slackening off the same 2 jaws and turning around the L-H axlebox when compared to it's corresponding R-H axlebox.

Cheers,

Julian

Hi Simon,

Not sure this is the best forum for your question. Have you come across NatPress?

Some poor sod in LNER and BR days was paid a pittance to shovel tons of coal into an A1 firebox getting backache and blister on his hands, scorched legs, and covered in coal dust. The same poor sod had to work the injectors and keep a watch on the water gauges on a draughty cab. He would have to get up at all hours of the day and night on shiftwork and was not paid enough to own a car so would walk or cycle to work in all weathers probably from a small terraced house or council house.

Some other poor sod had to shovel out a smokebox of ash, and empty the firebox of clinker, if the fireman was lucky not to have to do this also. No covered accommodation for this - the wind would blow everything all over you and if it was raining you got soaked.

The fireman would have to go down and couple up the coaches or goods vehicles to the loco/tender which was precarious and risky and also very dirty.

Long shifts at unsocial hours, and to no set pattern.

Then you get a poor loco long overdue for a shopping that shakes you to bits and gives a very rough ride and steams poorly and you spend your whole shift in discomfort and struggling to make steam.

You finish your shift filthy dirty and your home does not have a modern bathroom, neither do you have facilities at work to wash and change before going home.

(Suggest you read Harold Gasson's books)

Cheers,

Julian

Hi Brian,

Listen to the noise the clock makes when set up. I know this sounds elementary but a trained ear will be able to tell when the escapement is correct simply by listening to lots of other well set up clocks.

Cheers,

Julian

Hi Nigel,

As a rough rule of thumb I use about the same amount of silver solder in cost of the copper for the boiler. This would be for boilers with all silver soldered firebox stays. There are only a few grades of silver solder recommended for boiler work post the cadmium ban, that have the required ductility etc.

There are lots of reasons why people have problems silver soldering up miniature loco boilers, and one of these is meaness in applying the silver solder.

Cheers,

Julian

Hi James,

I have never made a screw down regulator. They were rather frowned upon when I started this lark because they gave poor regulation of the steam plus a non prototypical angle of opening for the regulator handle, plus if not eased off after a steam up would seize up on cooling down.

The Martin Evans shape of the screw down valve conical end is not optimal for graduated regulator opening.

I am surprised no one has yet mentioned the use of modern gas pipe valves. There would be ample room in a 7.5"g loco such as Holmside with a dome to fit one. They are quite common in miniature locos these days. Far too modern for me, but then I am a bit of a dinosaur!

Cheers,

Julian