Roundhouse Fowler

The first thing to be aware off is that there are now FOUR types of smokebox fitting:


1. Early type.

Here the smoke-box casting is riveted to the front footplate and the exhausts and superheater pass through a hole in the bottom of the casting. This means that even if you drill out the rivets (to replace them thith screws) you cant remove the smoke-box. David Turner's account on the Argyll page, tells how he got round this, but the more straightforward option is to remove the boiler to access the exhausts. This type will have short exhaust stubs which may require you to lengthen the chuffer connecting pipe or order a special longer one. 


You can check if yours is this type by looking at the back of the smoke-box saddle to see

if there is a gap. If you can't see then investigate with a bit of bent wire. If there is no

gap - then it is the early type.


2. Mid type.

Here the difference is that the superheater and exhausts pass through an open backed

 slot in the base of the smoke-box casting. You can look or probe for this as above. If it is

there, it means that drilling out the rivets will allow you to remove it as Chris Haley

 describes in the Argyll section. Again the exhausts are likely to be cut short. If you can't access the rivets, then proceed as for the early type.


3. Late type

Here the slot is there as in the mid type, but the smoke-box casting is screwed on and

can be removed -  if you can get at the screws. If you can't access the screws, proceed as for the early type.


4. New Type

These have been produced from Autumn 2011 with the intention of making them more "Chuffer Friendly"! The smokebox can be removed by taking out four screws - though it does require some skill and nerve! See the bottom of the page.....



1. Fitting Notes - Early Type

It is worth reading how David Turner dealt with his early type Argyll - but below is how I tackled the boiler-off method


My notes: (see bottom of the page for photos of this process on a late type loco where we couldn't reach the screws)

In the notes provided by Roger Loxley, he said that to get inside the smoke-box on the Fowler, you need to remove the boiler. When I came to tackle the job – I looked for shortcuts in the way that David and Chris had done for Argyll – but then I decided to tacke it as Roger suggested and it was a lot easier than I expected. I have since checked with Roger and he has confirmed that all Fowlers are built the same way – the boiler is fitted after the smoke-box – so the principle applies to all, though details may differ a little on later models. Please note that this is still a quite complex task so please take advice if you are in any doubt about your skills. Oh yes - and have small containers handy for the parts and a safe plce to put the big stuff.



1)  The dummy pipework and sanding lever look very complex, but are, in fact, very easy to remove. First remove the two screws holding the sanding lever to the sandboxes. These were self-tappers on mine. The sanding lever can then be removed.

2)  Unscrew the large screws in the top of the sandboxes and lift them clear, together with their dummy pipes. (note that on later Fowlers, the tops of the sandboxes unscrew to remove). Put them somewhere very safe!

3)  You will now see that the rest of the dummy pipes can be lifted off as a unit. Do this and put the whole lot in a safe place. Also remove the water filler dome.

4)  Now remove the cab roof by undoing the four screws holding it to the pillars. When these screws are out, the roof will be held in place by the gas pipe union. Carefully undo this union using the correct sized spanner – not pliers! The roof can now be removed. Next unbolt the cab front sheet from the side sheets and put this and the roof somewhere safe.

5)  Now, if you have a digital camera handy – take a few photos of the plumbing in the cab – just in case. They might be handy if the re-assembly is a couple of days later.

6)  Undo the screw holding the jet into the burner and remove the jet and gas pipe.

7)  Now undo the steam pipe unions at the regulator and at the superheater pipe. Use two spanners for the latter to protect the superheater from twisting. Remove the lubricator and pipework.

8)  Next, carefully undo the two screws holding the burner into the boiler and withdraw the burner.

9)  Underneath the boiler flue – you will now see one screw holding the boiler in place. Remove this and the boiler can be freed from the smoke-box and withdrawn backwards – lifting it up to clear the cab back-sheet and sliding it over the superheater pipe. (Note that on a newer Fowler, I needed to ease the bend in the end of the superheater pipe so that it would pass down the flue. I did this very carefully with a tight fitting spanner on the nut and then twisted the spanner with a pair of pliers. On re-assembly, you need to be just as careful to bend it back to meet the steam pipe union.

10) Now you can see the inside of the smoke-box. But before you continue – replace the screw that held the boiler to secure the cab to the frame. This will avoid damage while you are dealing with the smoke-box.


The Chuffer

Now there are three possible scenarios when you look into the smoke-box.


You might see two 1/8” exhausts running up into the chimney – crimped at the top and cross drilled. If this is the case you need to measure down 72mm from the top of the chimney and, after protecting everything with cloth or cardboard, cut them with a cutting disc (remember the essential eye protection). The ends will need to be cleaned up with a file and then the Chuffer pushed on.


You might see a 1/4” tube – either open or crimped at the top – pushed over the exhausts. This needs to be removed and you will be left with two 1/8” exhaust stubbs.  Now on mine these were too short for the Chuffer to be in the chimney. The copper tube on the Chuffer needs to be extended to bring the top of the chuffer to 5mm below the top of the chimney. This can be done by sleeving in a section of 5/32” brass tubing – but it is better to contact us and we will swap your Chuffer for a longer one.


Or you might just see the stubs as the 1/4” tube had a habit of dropping off if the loco is inverted. If this is the case – proceed as above.


Please note that if you look down the chimney before you start – you should be able to see which exhaust you have.


2. Fitting Notes - Mid Type (also see the Argyll notes)

 Here the smoke-box is removable, but it is rivetted on so it is necessary to drill out the two rivets holding the smoke box to the footplate - if these are accessible (a big if!). If they are not accessible, then see the notes for the late type or contact a Chuffer Fitter who will sort it at reasonable cost.


First remove the sand domes and dummy pipework (see 2 above) and it then just needs a light touch with the drill (about 1/8") and the top of the pop rivet comes off. The smoke box can then be removed. You will then need to either tap the existing holes (after punching out the remains of the rivet) to take bolts or drill and tap new holes.


If you have screws hidden by the pipes, John Battersby reports that by loosening the steam pipe unions, he managed to just get a screw driver to them.


3. Fitting Notes - Late Type (also see the Argyll notes)

If you are lucky, the screws holding the smoke-box casting from underneath will be accessible and easy to remove. The smoke-box then just lifts off. If they are difficult to get at then John Battersby reports that on his model, loosening the pipe unions gave him access. If that fails then

Richard Bailey reports on his fitting experience below - please note that Richiard is not recommending this method - and neither are we! If in doubt contact a Chuffer Fitter who will sort it for you.


UPDATE - I have now fitted a late type Fowler where the screws were inaccessible. I followed the instructions for the early type above but then when I got to the smoke-box, the pipes were too difficult to access. I detached the front footplate by removing the coupling and the single screw behind. Then I waggled the whole thing to access the two screws. With the smoke-box right off it was much easier to cut the pipes.


Richard writes: "I have fitted the chuffer pipe to my Fowler!!! Quite a task. I did it on Monday Bank holiday and spent most of the day on it. At that time I had not read your latest website instructions so went straight in to remove the smoke box.


My fowler is the very latest design (now superceded - see below) being made only last July so the first thing (in hindsight) is that I cannot see how to remove the two top domes and pipes as no screws or removable caps are present on mine? (the tops of the sand-boxes unscrew - CB)


However, I managed it by the following method.


1- Removed front buffer beam

2- Disconnected piston shaft from connecting rod and also removed screw to valve rod.

3- Removed allen screws securing cylinders to frames.

4- Removed cab roof to gain access to disconnect super heater steam pipe at connection from lubricator.

5- at this stage the cylinders and steam pipes can be wiggled around to gain access to the screw heads thro the top of the side frames just behind the top of the cylinders on each side. These screws hold the top 1/4 sq frame cross member to which the plate under the smoke box is screwed by one central screw from above and not removeable without removing the boiler first.

6- The smoke box is now released with the bottom plate attached and can be wiggled around and this together by wiggling the cylinders allows the two verticall screws that secure the bottom plate to the smoke box to be removed. These screws are obscured by the steam pipes when everything is held down .This allows the smoke box to be separated from the bottom plate and the smoke box pulled off the front providing one of the dummy steam pipes that plugs into a hole in the smoke box is sprung/Bent up? a bit.

7- The steam pipes are then exposed just as they are in Katie and can easily be cut and the chuffer fitted.

8- Put it back together!!!!  


I am pleased I managed it without any damage other than a couple of dabs of black required to the slotted screw heads.


The result GREAT."



4. Fitting Notes - New Type

From the Autumn of 2011, the Fowler smokebox is secured by four screws, two behind the smokebox screwed down into a frame spacer and two through new tabs, folded outside te frames, just behibd the dfront buffer beam. After removing these four screws and putting them somewhere safe, it is also worth removing the two holding the front buffer beam. The smokebox is now just being held in place by the dummy pipes and the exhausts up the chimney. Now I normally recommend that the sandbox tops are unscrewed, together with the dummy operating lever, to allow it all to be removed, but on the one I tackled, the sandbox tops were firmly painted on. I therefore eased the pipes away from the smokebox and used a wooden wedge for the one that goes through a hole. The wedge used against the boiler reduced the bending. It was then possible to ease the smokebox forward, and by tilting it at the same time, I could clear the exhausts.


I protected everything with cloth and used acutting wheel on a Dremmel type drill to cut the pipes. Once the pipes were cleaned up with a file, the chupper was pushed on and tapped home. I then tilted it forward (this took a little effort as the exhausts were stiff in threads) and it was then easy to get the smokebox back into place. I just had to bend the dummy blower pipe slightly to get it to seat back in its hole in the smokebox.