Brassmasters Duchess test build

Jim smith-wright

Western Thunderer
Hi All

I am currently embarked on building a test build of the forthcoming Brassmasters Coronation or Duchess kit. Way before I got distracted with Brettell Road I always thought that if Brassmasters ever did a Duchess i would have a go at building one as 46235 'City of Birmingham'. Well now they are and so I am!

Of course its a personal opinion thing but I never really liked streamlined steam locos. While the Duchesses were a little more thoughtfully designed than the god awful GWR efforts I always thought they looked a bit like an upturned bath tub and have to admit the A4's did look a fair bit better. However with the streamlining taken off the Duchesses were 'it'. The steam locomotive version of the Concorde moment. To my eyes, at least, the pinnacle of steam loco perfection.

Anyway enough hero worship and on to the model. Starting with...


The main sub-frames. The loco frames come in 3 sub sections related to the wheels. A driving wheel section, a pony truck section and a bogie section.


The chassis upside down, test fitting the main coupling rods.


The main frame with the brass overlays fitted.


The front or bogie area sub-frame.

More to follow.

Jim smith-wright

Western Thunderer
So progress continues on my Coronation build.


The front frame is as far as I can go for the moment. (I don't have the cast bits for the loco yet. If you are wondering about the cylinders they are a separate sub assembly.


No problems with the pony truck so far. The kit provides for both the earlier and later types. This is the later one.


The bogie is compensated. As the bogie is the only part of the loco that traps the wheels in place I have used some old/rejected wagon wheels for the moment. I ideally only want to put wheels onto the axle once if I can.


Without the wheels in the way.


I couldn't resist a temporary mock up to see get a better feel for the loco. I've used a High Level Road runner + gearbox. The main drivers don't have their springs in place yet so its sitting a little off at the moment.



Western Thunderer
Looks the part Jim, even in 4mm scale.

What is the purpose of the slanting parts behind the rear driving wheels?

If you need any detail photos of CoB, let me know as I took pot loads when I was building my 7 mm Gladiator Duchess.



Western Thunderer
Looks the part Jim, even in 4mm scale.

What is the purpose of the slanting parts behind the rear driving wheels?

If you need any detail photos of CoB, let me know as I took pot loads when I was building my 7 mm Gladiator Duchess.


i also have a bunch of photos of 46235 taken earlier this year. My Finney7 build is stalled at the moment but has been a great experience.

Looking good, Paul


Western Thunderer
What is the purpose of the slanting parts behind the rear driving wheels?

Footplate brackets alongside the throatplate.



The LH one also doubles as the speedometer bracket in BR days.

What is interesting about this kit is that it is a direct (for the most part) scaled down version of the Finney7 Princess Coronation, both came from the Martin Finney range.


Western Thunderer
You're welcome, although they're exposed now and at risk of damage, that seems to be exaggerated once they are folded up.

If they fold up the same way as the 7mm version then the joint between the sloped flange at the top and the frame side is very weak, you can see I've over soldered mine from above to try and strengthen it. If that joint fractures then the bracket has a tendency to fold back and break the main joint with the frames.
If you take too much cusp of that slanted flange inner joint then the bracket bends to far forward and thus hangs low under the footplate, too little and it sits high and kicks up the footplate; all that messing around getting it right also reduces the strength of the main joint.

The bracket has to be 90° with the frames, if not it impacts the footplate height or hangs low and leaves a gap.

These brackets are part of the frame overlays, with hindsight they might have been better as stand alone brackets with a slot and tab arrangement twixt bracket and frames.

Jim smith-wright

Western Thunderer
I've moved away from the loco for a while as the next stage of the build is the cylinders and I don't have the castings i will need for them just yet. So attention has shifted to the tender.


The first stage is the outside sub frames - a simple box really. The kit allows for springing or internal compensation. I've opted for springing.


Underside of the tender showing the sub frame, brake gear and water scoop gear. A little fiddly but its been fun to build so far.

Jim smith-wright

Western Thunderer

Progress on my tender build continues. This is the front end with some of the detail started.


And the rear end.


Inside showing the fire iron tunnel and and the coal pusher which is a 3d print.
Below are the some images of the tender in its nearly complete state. There's still a few bits I need such as the ladder etc but focus will now shift back to the loco.




Jim smith-wright

Western Thunderer
After a longer gap than would have liked attention had returned to my Duchess build.


Starting with the lower firebox and damper operating rod.


Next up the brakes. As can be seen clearance is kind of on the minimal side. Theres no springs fitted yet either so the chassis sill sit a little higher than is seen here.


The motion brackets. Again theres not a lot of clearance between the bracket and the leading driving wheel.


The chassis so far.


Moving on the next stage is the footplate, seen here in its assembly jig.