Fowler A7 Traction Engine

Fowler A7 Traction Engine

2" Scale Fowler A7 Traction Engine as it was in the early part of this centaury.
2″ scale Fowler A7 Traction Engine using MJ Engineering castings as it was in the early part of this centaury.

Fowler A7 Traction Engine – Update 30th December 2021


Fowler A7 Traction engine is a very long term project (I’m ashamed to say, circa 2000).  The wonderful addition of 4 grandchildren in the mean time meant a different focus was needed. So the two major projects put on the back burner were the Fowler traction engine (MJ Engineering version) and a pair of Edgar T Westbury Seal engines (castings supplied by Hemingways kits).  

The Fowler traction engine won the bid to be first project for 2022. Since all the smoke and steam would be more ‘exciting’ to the grandchildren (and Granddad) than the pair of Seals.

State of play for the Fowler A7 Traction Engine

Much has been completed so far.  The boiler, horn plates, wheels, spud pan, axle shafts, smoke box, chimney, fire door, various oilers, gears, brake drum, steering and more ‘little’ items were done during the intervening years.

Nevertheless there is still quite a bit to do. One of the biggest items left to do is the tender itself.  That is what will be tackled now with gusto and during 2022.

Tender construction.

At the present time the drawings have/are being studied alongside the manual as supplied by MJ Engineering. One possible frustration could have been the dimensions for the 3” version only in the manual.  Fortunately the drawings are available for both 2” and 3” scale, with a full set already bought.

The first consideration was to either convert all dimensions to metric or stay with imperial?  In the end, whilst a little rusty, and all the previous work completed it’s back to imperial. It’s a good job all the earlier tooling still exists.  Well you don’t throw away tooling… you! 

If starting again however it would definitely be in metric!

3D printer as a tool for the building of the tender

The recent addition of a modern 3D printer, and the recent adoption of Fusion 360 CAD/CAM software, started me thinking if it could be used to help marking out or indeed cut using CNC? 

With the tender’s construction the width of the tender is critical.  Would printed spacers help? Would they be accurate enough? Or was it a case of ‘playing’ with the newest addition to the workshop?  The answer to all three were yes!

The first trial pieces printed were a hole cover plate, door profile and tender width spacers [see photo’s below]. All were quickly drawn up in Fusion and printed out. 

The first two examples will aid marking out for certain.  The spacers will also help when it comes to needing a third pair of hands assembling the tender sides and back.  Additionally any adjustment with size is easily adjusted.

These would both hold the two sides apart and give an approximate width, were soon produced. The accuracy achieved is impressive, and will be a great help I am sure.

[photo hole cover plate and the profile for the door cut out.]

Two 3D printed pattens.
The circular pattern is for one of the tender covers to be cut out of brass whilst the second is a profile for the door to be cut from the tender sides itself.


Fowler A7 Tender build in 2" scale
3D Printer spacers act as a third hand for working on the tender for the A7 2″ scale traction engine

More updates will be added in the coming weeks so, come back for more progress reports.

Thanks for visiting and as always, I welcome any emails




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4 thoughts on “Fowler A7 Traction Engine

  1. Hi Mike, I have recently acquired a ‘started’ A7 from the steamworkshop, strangely this was begun in 2000 and a lot of nice work done so far. I have tried in vain to contact MJ to get a copy of the
    construction manual (I do have a full set of drawings) . Have you any idea what the position is ?

    1. High Roger I’ll try MJ myself although its been a while since I contacted them.

      I have a fairly clean copy so if you can’t find one let me know and I copy it for you if MJ no longer are trading. So ill let you know how I get on before we decide to photocopy a fairly large document.

      Also be aware that MJ Engineering only produced a manual for 3” scale so you’ll have to convert where necessary. Since you have a full set of drawings that should’ve be a problem. Let me know what you want to do.

      Good luck with your model.


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