Peckett's "Yorktown" class

[Ruston]

Ever since I first saw the last surviving Yorktown, at Cadeby Rectory, some 20 years ago now, I've wanted a model of one in 7mm. I took some basic measurements when the loco was still at Cadeby but I lost the notebook in which they were written.

 

Last year I heard that the loco, now named Teddy after the Rev. Teddy Boston, was at the NRM. So I emailed the NRM and recieved permission to photograph and measure the loco properly.

 

It's almost a year since my visit to the NRM and I've yet to do anything about making the model so I'm posting this in an effort to aqcuire more knowledge of these uncommon engines and to, hopefully, spark some discussion with the result that I'll get my finger out and start cutting some plasticard/brass/whatever...

 

The building of the model is going to pose a few problems, one being that no wheels of the size required (2ft. dia. on the prototype, so 14mm for the model) are available, as far as I know. If anyone knows different then please let me know.

 

Some pictures.

 

Since I saw the loco at Cadeby the cab appears to have been rebuilt. The sides were plain straight edged and now there is a nice curve to them. I guess this is the original style and the one at Cadeby was a "make do" thing.

 

The buffers are not original and look to be from a BR period wagon of some description. I'll use some Peckett pattern buffers from either Mercian or ABS.

 

[Nick Holliday]

It is impossible to tell from your photos how many spokes are required, but I wonder if you could do something with Alan Gibson's 4mm range.  He has slightly larger diameter 14.6mm wheels with between 8 and 12 spokes, the latter might be used by cutting out alternate spokes.  You will obviously need to provide longer axles, but steel bar of the required diameter is easily available.  I have to admit that to me the wheels look narrower than standard anyway, compared with the guards vam behind it.

[2mm Andy]

Dave,

 

I'm pretty sure that the cab as fitted at Cadeby was a bit of a make-do-and-mend job, as I recall being told that the scrapman had started cutting the loco up just before it was sold for preservation and the cab was the first bit to go!

 

There is a short film clip of Teddy driving the loco when it was based at Shackerstone (before it went to Cadeby) here;

 

 

There are also some Peckett drawings in the NRM's "Search Engine" library - with a catalogue on the website as well. Not sure if there is anything on the 'Yorktown' class though.

 

Andy

[Ruston]

Hi Nick,

 

I think the width of the wheels when compared to that brake van is an optical illusion. If they were much narrower it'd fall off the track. I'm sure.

 

Two spokes, three if you count the boss where that the crank pin sits in. What we have here is a narrow gauge loco that's eaten too many pies.

I could possibly have a go at making some wheels on the lathe but they would be solid and have no spokes and I'd need to make the axles out of something non-conductive.

 

Andy - thanks for the video link. :-)

[hartleymartin]

It does rather give the impression that Peckett built this locomotive borrowing from standard components from their narrow gauge range.

[avonside1563]

Gary Boyd-Hope, editor of Steam Railway, is the current custodian (Owner) of Teddy. I'm not sure if he has or knows of any drawings for the Yorktown class but I can ask him if required.

[Ruston]

Gary Boyd-Hope, editor of Steam Railway, is the current custodian (Owner) of Teddy. I'm not sure if he has or knows of any drawings for the Yorktown class but I can ask him if required.

If you would, please.

[Sir Hadyn]

Gary himself scratchbuilt a 4mm version many years ago, never got to see it sadly.

[90733]

I'd love a 4mm EM model of this loco, but there's the wheel problem again....

[Dava]

Lovely loco,

 

I built a model based on 'Marcia' (now on the K&ESR) which is the side-tank variant of the 'yorktown' saddle tank. See the Feb 2013 Gauge 0 Gazette for an article, or my gallery for some photos.

 

http://www.rmweb.co.uk/community/index.php?/gallery/image/42963-peckett-class-1287/

 

Martyn Bane's website has useful catalogue illustrations of both types. http://www.martynbane.co.uk/peckett/peckett-tanks-1938/index.html

 

Those wheels are a problem - after regauging a Hornby 0-4-0 chassis (suboptimal...!)  I found Slaters did a 16mm dia wheel for 21mm gauge (Irish ralicar driving wheel) which will go on an 1/8 axle for 32mm gauge. It is a solid wheel so no spokes. Marcia has 2'3" wheels, the yorktowns are even smaller at 2'.

 

I plan to build one some day...

[hartleymartin]

You might find someone who will turn down the 16mm diameter wheel to 14mm for you, machining 1mm off the tyre for you.

 

*edit*

 

In fact, Slaters do 2'0" driving wheels with a 6.5" crank throw. You will find these under 7mm narrow gauge, and they can be fitted to standard gauge axles.

[Ruston]

Thanks for the ideas regarding wheels. I've been giving this some thought and I reckon I can scratchbuild some.

 

If I make a plasticard pattern to 4x size I may be able to get centres profile milled in brass. I can then turn up some steel tyres to an interference fit and press the centres into them.

 

But what material to use for the axles? I guess I'd be looking at 1/8th in. axles.

 

 

Out of curiosity, does anyone know why Yorktown? I've looked on MS Autoroute and Google maps and can't find such a place in the British Isles. All references are to a place in the USofA and I can't imagine why Peckett's would name a loco after a location there.

[Ruston]

Thanks for that, Philip. The Altrincham loco was shown in a copy of Railway Bylines and I'm sure there's another one in another copy.

 

They are intended for fitting to steel split insulated axles.

 

I'm not sure how this is done but I'll take a guess.  If I were doing it I'd cut the axle in two, drill into the cut ends, face them off and then insert a rod of some kind of plastic, to hold the axle together, into each half and use an insulated washer to the diameter of the axle to keep them apart. I don't know what material to use though... Ordinary plastic rod, such as the type I use for buildings/pipes would be too soft to remain straight. What would you recommend?

 

I suppose doing it like this will allow the frames to be made with the sides insulated so that pickups are unneccessary?

[Katier]

3SMR do 14mm wheels, unfortunately I'm guessing their width would make them unsuitable.. but there may be something you can do.

[hartleymartin]

Thanks for that, Philip. The Altrincham loco was shown in a copy of Railway Bylines and I'm sure there's another one in another copy.

 

 

I'm not sure how this is done but I'll take a guess.  If I were doing it I'd cut the axle in two, drill into the cut ends, face them off and then insert a rod of some kind of plastic, to hold the axle together, into each half and use an insulated washer to the diameter of the axle to keep them apart. I don't know what material to use though... Ordinary plastic rod, such as the type I use for buildings/pipes would be too soft to remain straight. What would you recommend?

 

I suppose doing it like this will allow the frames to be made with the sides insulated so that pickups are unneccessary?

 

And you can use the graphite from a 6B or 9B pencil to lubricate the bearings. (Soft graphite is conductive).

[hartleymartin]

With wheels that small, I don't see why you wouldn't just use disc wheels and paint the supposed gaps between the spokes black just to give the impression of spokes being there. Half the wheel is counterweight and the gaps between the spokes would be tiny,

[Giles]

 

 

don't know what material to use though... Ordinary plastic rod, such as the type I use for buildings/pipes would be too soft to remain straight. What would you recommend?

 

I suppose doing it like this will allow the frames to be made with the sides insulated so that pickups are unneccessary?

Tufnol was the traditional material for this purpose, as it was designed as an insulating engineering material, and is available in round bars, even from places such as RS Components.

You won't be able to use a full wrap-around style motor mount with split axles done this way, of course.

 

If you have live frames, then you'll have to have insulated frame stretchers, and insulate your buffer beams and body.....

[peter220950]

Dave,

 

I would be interested in a copy of any drawings or dimensions you have, I have also got to build one in O gauge - I am building the Cadbury Bournville loco's and they had one for a while, though I believe it couldn't pull the skin off a rice pudding.

 

I have started scaling from elevation works photo's but it's all a bit of a guess at present. - perspective is likely to be distorting things a bit.

 

 

 

I think I will be cheating and using the Slaters 2'3" loco wheels but haven't decided yet so I will watch events with interest.

 

 

 

 

[5050]

This looks very like the locos used on the Lee Moor Tramway at 4'6" gauge.  Interesting that the Peckett 'signature' low front tank side handrails aren't fitted.

 

I make my own industrial loco wheels for split axles by turning brass discs, drilled for the axle slightly undersized and then taper reaming for a force fit on the axle. Coach (or wagon if really small) wheel tyres are then fitted, either by heating and shrinking as per prototype - or just brute force.  As they usually have large balance weights I drill out the spoke spaces and then file to shape with needle files.  In 7mm this should be easier to do.  Washers soldered to the face form the boss around the axle and the crank pin.  Crank throw is determined by a simple drilling jig or by offsetting the axle position in the lathe tailstock and drilling using a drill in a chuck in the headstock, preferably before marking out and drilling and filing the spokes.

 

My axles are turned from 1/8th silver steel, the trailing/non-powered axle(s) are the 'hole and spigot' style as above but where there is a gearbox then a 3-part axle is fabricated to avoid any possibilty of shorting.  In 7mm this should be easier than 4mm as there is more space.

 

I suppose it would be possible to get some 14mm tyres (from Gibson for example?) even if they're not specifically 7mm scale ones?

 

I use thick glass fibre double sided PCB for frame spacers, gapped and soldered to the side frames.

 

You could always come round and see how I've made mine.

[Ruston]

Dave,

 

I would be interested in a copy of any drawings or dimensions you have

I don't have any drawings. All I have are the measurements and some really rough sketches. I can give you some basic dimensions though.

 

Frame length (between buffer beams) = 173.5"

Frame height (from top level to bottom, not including the extensions of the horns) = 29"

Saddle tank length = 102"

Cylinders (over wrapper) 17 3/4"x11"

Slide bars L=33" Distance between bars = 6 1/4" depth of bar = 1 1/14"

Footplate to top of cab opening = 75"

Footplate to centre of cab roof = 78"

Front buffer beam H=18 1/2" W=83 1/4"

Top of front buffer beam to running plate = 4 3/4"

Distance from rear of frame to rear axle centre = 64"

Depth of rail under running plate = 2"

Wheelbase = 53"

Safety valve centre from cab front = 34"

Safety valve centre to chimney centre = 38 1/2"

Running plate to top of saddle tank = 50 1/4"

Driving rods = 2" deep

Springs L = 23"

Running plate to bottom of saddle tank = 17 3/4"

Cab steps H=28" W (top) = 12 1/2" W (bottom) 15"

Smokebox door = 32" dia.

Boiler dia. 29" (approx.)

Cab front plate W = 79.75"

Cab rear plate W = 70"

Cab windows 14" dia. over frame, 11 3/4" dia glass

Running plate W = 82"

Cab sides (lower section) L= 36 1/2"

Cab sides (upper section) Max length 36 1/2" curving to minimum of 20" and opening out to 27" by top.

Chimney H (overall) 23 1/2" section between base and cap = 11 1/2" Base max. width = 18"

 

This is the first time I've collected the dimensions together and I'm missing some. The buffer centres and the ride height being the most obvious. These things can be worked out as the build progresses so I'm not too worried.

 

PGH - Thanks for the info about Tufnol.

 

5050 - Thanks, I'll have to come around and look at how you do axles some time. The last time I came round to yours must be at least 20 years ago? 

 

I have cut the first parts from plasticard - the front buffer beam and a frame plate. The parts are 4x larger and will be used as patterns to get the real parts milled from brass plate.

[5050]

By 'eck, was it that long ago!!  Don't time fly, I were nobbut a lad then and tha' were just a bairn.

 

PM me if you want to arrange a visit.

[peter220950]

Dave,

 

Many thanks for the dimensions, I had a drawing prepared so I can now verify or alter as required, it's a great help and will give me a new impetus to get the box of bits out and start cutting metal. - I'll keep you informed of progress, best of luck with yours, look forward to seeing the results.

 

Once again thanks for the help.

 

peterL

[hartleymartin]

Buffers should be at 5'9" apart and 3'6" from the rail head. This often varies by an inch or so, but it is more-or-less the standard for all standard gauge British rolling stock.

[Ruston]

Dave,

 

Many thanks for the dimensions, I had a drawing prepared so I can now verify or alter as required, it's a great help and will give me a new impetus to get the box of bits out and start cutting metal. - I'll keep you informed of progress, best of luck with yours, look forward to seeing the results.

 

Once again thanks for the help.

 

peterL

 

I've just noticed that I'd typed 102" for the frame length. This should be 173 1/2" and I've amended my post accordingly.

 

How about starting a thread in parallel with this to show your progress? I'm always saying that we need more modelling in this section.

[peter220950]

Dave,

 

I've now had a chance to check my drawing which was, surprisingly, quite close, I was wrong on cab and chimney heights by a couple of inches, no doubt due to the angle the works photo was taken from. I am now update the drawing.

 

I think your dimension for the frame length between buffer beams has been transposed - (it's the same as the saddle tank length) - I recon it to be 165" ish? similarly the length from centre of safety valve to centre of chimney looks a bit short, if you add it to the c/l to cab it puts the chimney c/l nearly 30" back from the front of the saddle tank, my guess/scaling is that it should be about 56"? - I can't see an overall cab length, I think this is 52"?

 

Off to the drawing board.....................

 

 

Once again many thanks for the information, it's saved a lot of research.

 

peterL