Building a GWR Iron Duke in 7mm broad gauge

[Florence Locomotive Works]

Hello all,

 

 

I’ve been planning this a for a while. In April of last year I began construction on my first scratchbuilt engine, a 2 inch gauge freelance 4-4-0, which was built basically with a hacksaw, blowtorch and a good set of files, with a lathe only being acquired after 7/8ths of the project was completed. I’ve now amassed a good collection of good quality tools, as I started work at around the same time in the watch/clockmaking industry, so I’ve decided it’s time build my second engine, a model of the GWR’s Iron Duke in Rover class guise, around 1883.

 

I’m a horologist by trade so the engine will be built in the style of a watch, meaning it will all be polished metal, no paint or plastic allowed! The wheels will be turned as solid brass disks and may get divided into sections for cutting out of the spokes with a jewelers saw. This is how the frames will be made from 13 gauge brass sheet. 
 

 

 

Current progress amounts to a load of research being done and the GA drawing of the chassis being done, along with a test leading wheel. 

 

As a point of interest, I also discovered that I have a copy of the original indicator readings from Great Britain in 1856, published in my 1892 copy of The Steam Engine by D.K. Clark. 
 

 

The main holdup right now in making the drawings is that I simply cannot find the boiler diameter. Anybody know? Without it it would be futile to do the cab and smokebox drawings. 
 

A few questions people may have.

 

1. Working motion? Maybe, I’m not sure.

2. Motorized? Possible, but only the tender.

3. Gauge? 48 mm.

 

Douglas

 

Edited July 11, 2022 by Florence Locomotive Works

[MPR]

Lots of useful information can be found here: http://www.finney7.co.uk/gwr-rover.html

[J. S. Bach]

Iron Duke? And here I thought that you were referring to this one:

[Florence Locomotive Works]

1 hour ago, J. S. Bach said:

Iron Duke? And here I thought that you were referring to this one:

No not quite, although I would like to build one of those one day.

[Florence Locomotive Works]

Just got done turning up two of the rough flanged and recessed blanks for the leading wheels from brass, only four more to do now.

 

 

The main driver will be more difficult though as currently there is no 2 inch diameter brass available in my city, I haven’t looked into the softer steel alloys yet though. So something needs finding and hopefully I won’t have to have it shipped here.

 

 

Douglas

[Florence Locomotive Works]

The first frame got cut today, roughly 3 hours work with my jewelers saw and 3 dozen #4 blades. It’s cut from steel plate using scribed lines transferred from the drawings I made using a compass made in the 1850s by P.S. Stubs of Warrington.

 

 

 

Now it’s time for finishing and then repeating the process on its twin. I will not be doing the double frames as there is little point in doing so in this scale, just the outside frames getting done.

 

Douglas
 

 

 

[daifly]

I confess to being confused as to the scale/gauge you are building to. You've mentioned 2" gauge (50.8mm), 7mm scale (gauge 49.2mm) but you're building to 48mm gauge. Do you also make watches with 59 or 61 minutes in an hour?!

Dave

 

[Florence Locomotive Works]

1 hour ago, daifly said:

I confess to being confused as to the scale/gauge you are building to. You've mentioned 2" gauge (50.8mm), 7mm scale (gauge 49.2mm) but you're building to 48mm gauge. Do you also make watches with 59 or 61 minutes in an hour?!

Dave

 

Im building to 49.2mm gauge, after some more research it seemed better than 48mm gauge which is also quoted as being feasible on the Finney drawings.

[Florence Locomotive Works]

Well a lot of progress has been made since the last update.

 

First I finished off all the leading and trailing wheels. These are made from C360 brass, and took ages to make as the tool I was using in the lathe was dull and I didn’t have a grinder to hand.

 

 

After the thankful conclusion of that I started on the driving wheels. These were turned from 2 inch Aluminum round bar, 1/4 inch wide. They were a lot easier but as anyone who’s ever turned aluminum in bulk on a lathe will know it makes a massive mess, seen below.

 

 

 

After those were done, I now had all the wheels finished, along with the axles, so it was time to start on the bearings. 
 

 

These are made from 3/8s inch round brass, (C360 alloy) and get turned flat and drilled in the lathe. The slots the enable them to run in the horn guides are cut with a jewelers saw (as I don’t have a milling machine, sadly).

 

 

 

After all those were turned, drilled, reemed and fitted to the frames it was time to fit all the wheels and axles and get them bedded in. Meaning I now had a rolling chassis!

 

 

(the bearings are an interference fit in the horn guides, holds then in pretty well)

 

 

So that brings us more or less up to date, except work has started on platework. I roughly cut out the footplate this morning and get it fitted up to see how much material needed filing off.

 

 

Douglas

Edited August 8, 2022 by Florence Locomotive Works

[J. S. Bach]

On 07/08/2022 at 17:17, Florence Locomotive Works said:

After all those were turned, drilled, reemed and fitted to the frames it was time to fit all the wheels and axles and get them bedded in. Meaning I now had a rolling chassis!

Douglas

How about a photo of the lamp in the backround.  I like older lamps and yours looks like a nice one.

[Florence Locomotive Works]

2 minutes ago, J. S. Bach said:

How about a photo of the lamp in the backround.  I like older lamps and yours looks like a nice one.

It’s actually not lamp, it’s a porcelain Japanese pagoda model thing which I thought would make a cool desk ornament. 

[J. S. Bach]

22 hours ago, Florence Locomotive Works said:

It’s actually not lamp, it’s a porcelain Japanese pagoda model thing which I thought would make a cool desk ornament. 

A photo if you please; it looks like a very nice piece.