LBSC Lewes,based project locos and stock.

[Oldddudders]

Hamilton Ellis has drawn her as one of his little vignettes in his LBSCR history - she had a square-top saddle tank. CHE shows her as having virtually no radius on the tank top-side edge. He quotes (from Burtt, I think - haven't found my copy yet) 15 x 22 cylinders, 5' drivers separately sprung. If I have inferred correctly, he says the bogie was equalised with bar frames.

[bertiedog]

Bradley describes this loco as having a square topped tank. 136 was one of four proposed 4-4-0 tanks of varying designs, but only two were built as such, the others appeared as 2-2-2 tanks. Photos of Craven locos, especially those that disappeared by 1874, are extremely rare, but there is one of one of the later pair, after a subsequent rebuild into a 2-4-0, which has what could be described as square topped which is probably the best indication one might get after 130 years.

 

That was the other option of course, still looking into it, may have a word with the NRM at York, and see if they have records. From the rebuild it looks like square is the most likely at the moment.

many thanks,

Stephen.

[bertiedog]

Hamilton Ellis has drawn her as one of his little vignettes in his LBSCR history - she had a square-top saddle tank. CHE shows her as having virtually no radius on the tank top-side edge. He quotes (from Burtt, I think - haven't found my copy yet) 15 x 22 cylinders, 5' drivers separately sprung. If I have inferred correctly, he says the bogie was equalised with bar frames.

 

That sorts it out then, square it is,,....... and it will actually have 4 foot 10 inch drivers, as the spare pair of brand new Alan Gibson drivers are 4 foot 10 inches!! with the allowance for the 00 flanges about right, spot on in fact.

The square tanks will be far easier to make as well,

many thanks,

Stephen.

[bertiedog]

in fact I should have looked harder at the drawing, the base of the dome is drawn flat, indicating a flat top tank.

Stephen.

[bertiedog]

And the Bradley references say No 136 was used on the Lewes line at the end of it's working life, before transfer to Portsmouth, so it does have excuse to be modelled, albeit a bit earlier than the Terrier.,

[bertiedog]

The parts and drawings in 4mm scale, the driving wheels are by Alan Gibson, 4 ft 10 inch diameter, 2 scale inches under O/A real size, but with the correct crankpin throw, crankpin position, and spoke count.. As the flanges are 00 size the O/a diameter is just right.

The leading bogie wheels are 12mm Hamblings, un-machined at the moment, in nickel silver tyred version. They re-profile easily to RP-25. Motor is FE five pole, the same as the Terrier, and a Gibson 38:1 gearbox is being considered..

Stephen.

[Brake Compo]

Have found my copy of Burtt - as one would expect the drawing reproduced by Bertiedog is Burtt's. I will repeat the entire entry for those not fortunate to possess a copy:

 

" In June 1859, an expoerimental engine was built at the company's works for the West End of London line, and was numbered 136. It was an outside cylinder tank, and was, we believe, the first tank engine combining in its design a leading bogie, four-coupled wheels and outside cylinders. It is illustrated by Fig. 39, from which it will be noticed that a striking peculiarity was the great inclination of the cylinders, which were 15-in. in diameter with a stoke of 22-in., the centres being 6-ft. 4-in. apart. The diameter of the bogie wheels was 3-ft., and of the driving and trailing 5ft. The total wheelbase wasd 16-ft. 9 1/2-in., the centre of the bogie to the driving centre was 8-ft. 0 1/2-in., and from the driving to trailing centres was 6-ft. 9-in. The bogie had bar framing with inside bearings. The external diameter of the boiler was 3-ft. 9-in., and its length 10-ft.; it contained 132 brass tubes of 2-in. diameter, and 10-ft. 5 1/2-in. in length. The length of the firebox was 4-ft. 3-in., its width 3-ft. 10-in., and the depth of the inside box 4-ft. 11 1/8-in. The tubes afforded 733 sq. ft. of heating surface, and the firebox 71.8 sq. ft., making a total of 804.8 sq. ft. The main frames were of iron, and were between the wheels, and the pumps were placed between the frames, the pump rams being worked by eccentrics on the driving axle. A compensating lever was employed for the bogie bearings, having one spring placed on each side of the bogie. The safety valves were placed over the firebox, and the regulator in the usual position on the boiler. The capacity of the tanks was 350 gallons, but a tank fixed under the footplate behind the trailing axle held 256 gallons, giving a total water capacity of 606 gallons. Unfortunately no record has been kept of the weight of this interesting old engin, which for a number of years worked the Uckfield line. It finished its days piloting at Portsmouth, and was broken up in the late seventies."

 

Hope that this is of some use.

[dajt]

The bronze gear is home produced, I could not find any commercial ones that ran concentrically enough, and the worm made in the lathe. The gears was gash cut and then hobbed in my gear hobber, which I have re-built recently.

 

I knew you were going to make the gears... it just took a while for you to realise it

 

I look forward to learning how to do that some day. It would make (modelling) life a lot easier.

 

Lovely work, as I expected your build would be.

 

Regards,

David.

[dajt]

The Semg website has re-prints of articles from Railway Magazine and this one on Lewes http://www.semgonline.com/RlyMag/LewesStationMystery-1.pdf has some very clear diagrams of the old and new stations which allow the view in the postcard to be located.

 

Thanks for posting that, I was looking for info on the Chard branch yesterday. Looks like a lot of good reads there.

[dajt]

And I will concede both drivers appear to have beards, and peaked caps.

 

It's a worry I was also looking at the facial hair in the photo to see what the beard/headgear situation was. Got to get the important things right...

 

Regards,

David.

[bertiedog]

I knew you were going to make the gears... it just took a while for you to realise it

 

I look forward to learning how to do that some day. It would make (modelling) life a lot easier.

 

Lovely work, as I expected your build would be.

 

Regards,

David.

 

Gears can be cut in several ways, the most satisfactory way for model railway is a gear hobber, where a blank gear slowly rotates against a cutter, which can be a single tooth, or a hobbing disk, with the teeth profile, or a multi toothed cutter which forms the natural contact shape to match pairs of involute shaped teeth.

 

Worms do not often have involute teeth on these small sizes and single point cutting tools with a straight face are often used.

 

The hobber consist of a frame with a geared motor, and a gearbox to the cutter shaft, as they have to stay in strict sync as the blank rotates. The secondary cutter shaft, whilst tightly geared can advance towards the gear blank, taking light cuts on each advance , till the gear is the right size. (pre determined from formulae or examination)

 

The concept is simple, but hobbers are complex as they can accept any ratio, or size work, but if it is purely to make one size or two, then you can make one yourself in a home workshop.

 

Several designs have been published in the model Engineer Magazine, and kits are available from Hemingway, and others, although most designs rely on using Myford lathe change gears to do the gearing, which it is assumed you have access to, but any make would do.

 

The other main way to cut the teeth is to do what watchmakers do and use a rotary table or index plate , which advances the blank manually one tooth at a time, and a high speed spinning cutter forms the tooth, with the shape ground on to the cutter.

 

This is a longer method, but easy to achieve with very basic lathe machinery. In theory the teeth may not be so smooth as a hobber, but when run in properly any problems vanish..

 

A combination method is often used, the teeth are gash cut on the second method, and finished on a hobber, but the teeth we use are so tiny it is barely worth while.

 

The worm is made as a simple screw cutting operation, with a ground tip for the shape, which should match the pressure angle. The Mechanics Handbook provides all the formulae and angles used, or most gear factors have details available, plus lots on the net.

 

To see hobbers working try You Tube, there are many, from simple to Gleeson CNC controlled ones for bevel gears, the most complex to make.

 

A small Sieg lathe with index plates could make say 40:1 gears without any trouble, it would need a forty toothed master gear or a plate. As Seig use gears you could pick a value from the standard set as master, and use that o index the cutting.

 

The tool post is removed and the blank and the master attached on a block, and the cutter is run between centres in a bar holder

Each tooth is cut by advancing the crosslide to form the tooth, and then indexing the blank around one tooth and then cutting the next.

Any small lathe could do the same, all you need is a master disk, any size, it merely is used as an index.

 

The simple method produces straight teeth, which in theory are wrong for the spiral of the worm, but in small sizes this does not matter.

You can cant over the blank to match the lead angle of the worm if you wish, but the cutter arc has to match the diameter of the worm, as in a hobbing machine..

 

Any milling machine can also make the gears by using index plates etc., in the same manor as the lathe can, and CNC machines can curt gears by replacing the indexing with a program control.

 

Hope this helps, the late TD Walshaw ("Tubal Cain" in the Model Engineer), taught me gear cutting, and published books on it for the Home Machinist, available from Specialist Model Engineer book suppliers (Several on the net, like TEE).

 

Stephen.

 

 

 

.

[Oldddudders]

Have found my copy of Burtt - as one would expect the drawing reproduced by Bertiedog is Burtt's. I will repeat the entire entry for those not fortunate to possess a copy:

 

[/i]Hope that this is of some use.

Well it avoids me making another trip upstairs to try and find mine, so thankyou!

[bertiedog]

It's not Hemingway that do the kit of castings, but College Engineering, to Mr Jacobs design published in the Model Engineer.

As you can see the set up could be done on a lathe, and amazingly can be done on a Unimat !, with a set of change gears.

It looks complex, but all it is a sync gear box keeping the cutter moving as the works moves as well. All the extras are to make the machine flexible, but a dedicated small gear cutter could be massively simplified.

Stephen

[dajt]

That's a beautiful machine on its own, but the method you described using a master and a blank on the cross-slide sounds more do-able for me. I have what I think are generically called a 9"x12" lathe which I am sure is more than enough to do it.

 

One thing I didn't understand though. You say a gear from the lathe could be used as a master, but they're all much bigger than any gear I'd want to make. How do you use an "oversize" master with a small blank?

 

Re Mechanics Handbook, last year I inherited my father's 18ed Machinery's Handbook, 1968. It kind of puts Tubal Cain's workshop companion into perspective! Having said that I've only used the TC book for BA drill sizes so I'm not exactly pushing the boundaries here.

 

Thanks for such a detailed explanation. I look forward to making my own gears and wheels some day

 

Regards,

David.

[bertiedog]

It does not matter what the master is or it's diameter within reason the larger the better, it is just used to index the blank to each position. Obviously you have to have a basic grasp of pitch, D/P, Mod, and teeth sizes before setting it up, read up on spur gears first. Spur are easier to make, but keep to accepted ratios, you can't run a 5 tooth against say 60, ( someone will say you can, but with involute teeth they undercut too far on the pinion. There are known accepted ratios than work with known tooth forms, the same applies to worm gears.

 

In a series of gears of the same number of teeth, all are stepped versions of each other in a constant ratio, so any gear can be copied to another despite the size.

 

Virtually any small lathe can be set up as a gear hobber, it is the gearbox and the universal jointed drive that are the extras to build. They have the universal sliding joint drive to allow the cutter to move and long pinions to be cut.etc.,etc..

 

Stephen.

[bertiedog]

After all the diversions, the Terrier is nearly completed, and the brass for the No 136 is being cut out this afternoon, on the bandsaw, with a very fine toothed blade, the best way to get smooth cuts and decent right angles, the parts come out only requiring a light edge sanding.

The big advantage of scratchbuilding is using far thicker material than etched kits, sturdy and easier to get the weight. Overlays are used for riveted areas.

The chassis will be solid brass, milled to profile, with a small block for the bogie. I don't think full springing is required, might just do the front axle.

The real thing had bar frames, very US style!, and no full footplate under the smokebox, just a plate in the middle. I am surprised this area is like that being a shunter etc., I would have expected more bracing with a full plate.

 

Stephen.

[burgundy]

Stephen

 

"That was the other option of course, still looking into it, may have a word with the NRM at York, and see if they have records."

 

Slightly oddly, this loco is one of the relatively few that does not appear to feature on the NRM list.

 

"The real thing had bar frames, very US style!, and no full footplate under the smokebox, just a plate in the middle. I am surprised this area is like that being a shunter etc., I would have expected more bracing with a full plate."

 

Please! This is no shunting engine; it is one of Mr Craven's various attempts at a suburban tank engine. I agree that the front end looks pretty flimsy, but I wonder how much of its time was spent running bunker first?

 

Eric

[bertiedog]

Well it was reduced to station pilot at the end, I did not mean designed as such. It did run about the Uckfield to Lewes area, so there is justification for it's use.

Most Parts are cut out to blank form, assembly over the weekend I hope.

Stephen.

[bertiedog]

The drawing more clearly shows the brake gear of the brake vans on the LBSCR, Craven type.

It appear that the W irons are connected with a beam on which the brake shoes slide, being forced outwards by the levers and connecting rods pivoted behind the beam.

The base of the W irons hornways are connected with a round truss rod, secured with nuts, to provide further bracing.

It looks like etchings or castings could be made combining the beam with the W irons as a unit, or at least a set of expandable parts to cope with length variations.

Modified drawing from Ian White original,,

Have I interpreted the operation correctly?, the colours separate the parts better on the drawing much more clearly..

Stephen.

[bertiedog]

Is it right, gathered from reading about the Lantern stock, that a train had to run two, one at the front and one at the back, sounds logical, one brake coach and one passenger brake van, with the un-braked carriages in between?

I assume two brake coaches could act as ends for a train, or two passenger brakes, or any combination or way round?

They must have been glad when through braking was introduced to the LBSCR.

Stephen.

[burgundy]

The drawing more clearly shows the brake gear of the brake vans on the LBSCR, Craven type.

It appear that the W irons are connected with a beam on which the brake shoes slide, being forced outwards by the levers and connecting rods pivoted behind the beam.

The base of the W irons hornways are connected with a round truss rod, secured with nuts, to provide further bracing.

It looks like etchings or castings could be made combining the beam with the W irons as a unit, or at least a set of expandable parts to cope with length variations.

Have I interpreted the operation correctly?, the colours separate the parts better on the drawing much more clearly..

Stephen.

 

Stephen

Colouring certainly makes the detail clearer. My only suggestion would be that the solebars should be wood and the same colour as the body, which would have vermillion ends.

Eric

[bertiedog]

The colouring was not meant to be exact, just to sort out the brake gear operation and arrangement, which looks a bit vague on some kits and drawings.

Stephen.

[bertiedog]

 

 

Am I right in assuming that the second view is the reverse of the first, it shows the Scotch block, on the siding with the horse box parked up.

It appears to show the other side of the junction with the Brighton / Hastings platform in the background.

The over bridge is shown, with the buildings around it, but cannot see the signal box.

The train is being drawn by a Craven open cab loco and it a very mixed bag, with brake coaches and break van and two more horse boxes, which seem most common and well worth modeling.

Perhaps it clearly shows why the lanterns where dropped as normal sized stock like the horse boxes completly obscured the view from the lantern!

Stephen.

[bertiedog]

Does any body know of a vintage shot that shows the bridge as in the coloured postcard, with Roman style X palings on what looks like an open sided bridge with access to the road, but no station building I can make out, so assume a single storey ticket office behind the overbridge?

Stephen.

[3 link]

Hi Stephen,

 

Yes you are correct with reference to the second picture, as you can see the old chalk quarry in the back ground which was sited to the east of Lewes. The chalk quarry actually had a private rail connection which joined the Lewes to Newhaven line just outside Lewes.

 

ATB, Martyn.