Detailing the boiler - Above the footplate

For me, detailing is ‘everything beyond the basic construction’. So all the fittings, pipes, handrails, etc. For the most part, detailing can be done in a relatively random order because many parts have no logical connection to each other. That is why the order in which I discuss these details on this page is also relatively random.

Exhaust

Detailing starts with the exhaust. The casting that I have is a NS 3700 exhaust from Philotrain. It is 1.2 mm too tall for the LTM 51.

The form of a exhaust is irregular and vulnerable so simply sticking it in the chuck of the lathe is out of the question. The only reliable straight surface is the inside hole of the exhaust but a look inside revealed that wasn't up to par either.

So I stuck it in the chuck of the lathe protected by a thin sheet of aluminium (from a soda can). I carefully drilled and centered the hole to an acceptable geometry.

I then parted the exhaust base at the lower rim. I filed the exhaust base flush with this rim.

I measured its height and calculated how much material I still had to remove from the upper part of the exhaust. Just a few tenths of millimeters and these were quickly disposed of on the lathe.

I stuck a M1.6 bolt through the exhaust and its base and secured them with a nut.

Then I soldered them together avoiding contamination of the bolt by smearing a bit of grease on the thread. So after soldering I could remove bolt and nut again.

The safety valves

I filed down the safety valves I bought from Philotrain (left) to make them look more like those on the LTM 51.

It wasn't difficult, but it is a small part, so holding it is a challenge.

The base required a little more thought. Safety valves were placed on top of the fireboxes. In the Netherlands, these were usually Belpaire fireboxes, which were flat on top. This flat top is reflected in the equally flat base of the safety valves. So I had to remove some material to make it fit the round firebox of the LTM 51.

I took an older version of the boiler out of my scrap bin. That boiler was scrapped because it was slightly too small. Too small, but with a layer of 360 sandpaper, it was just right. I put a little oil on the sandpaper to prevent the grain from clogging.

With some careful sanding, I achieved a sufficiently good fit. The small gap on the right will be filled with solder.

Steam dome

The dome received a similar treatment

Steam turret

The steam turret on the LTM 51

The steam turret on an Australian AD60

The drawing of the controls in the cab, with the rear of the steam turret cover in the frame.

Now attention turns to the cover over the steam turret directly in front of the cab.

The steam turret requires some explanation. Normally, each device has a boiler connection with a shut-off valve. If there are many devices, it can be advantageous to group them in the steam turret. This

• reduces the number of boiler connections, each of which weakens the boiler construction,
• and reduces the number of shut-off valves; the entire steam turret requires only one shut-off valve. This reduces the initial costs and maintenance costs.

A steam turret is an unusual device for a Dutch steam locomotive, but based on the drawing of the rear wall of the boiler (left), I know that it is present. The close grouping of all the controls betrays its presence. The steam turret on the LTM 51 is probably covered for aesthetic reasons and to make cleaning easier.

The parts provided for in the Kaffa etches consisted of

• a top and sides sheet which should be bent twice over de the pre-etched recesses
• a front sheet

Assembly seemed easy enough: bend and solder. I wanted to solder with 240C solder. Later it must be soldered to the boiler and that will require a lot of heat so I took this higher melting point to prevent the cover from falling apart again.

That didn't end well.

I burned a hole in the top and side plates with my small burner. I was pretty annoyed. After I took the two apart again, in my anger I sanded too hard with a piece of sandpaper while cleaning the front plate. Both were now scrap.

I accepted my loss, sawed and filed a strip of brass, and copied the front plate onto another new sheet of brass.

At the end of a difficult evening, I had a shiny cover on the boiler. I was contendly looking at it when I realised with horror that it was too wide. So I grabbed the callipers and started comparing.

*) Measured in the centre, i.e. on the top of the boiler.

The conclusion was inevitable: my first impression was correct. The slight excess height of 0.7 mm could be corrected with a little filing, but an excess width of almost 2 mm could not be ignored. But was Kaffa so wrong?

No, that was not the case. I made a mistake in both attempts. I assumed that the top and side parts had to be wrapped around the front plate (left diagram), but it turned out that the front plate had to be placed in front of the top and side parts (right diagram). As the drawing shows, this arrangement results in different dimensions.

These sizes are still not entirely correct, so on the third attempt I will transfer the correct measurements onto the brass plate.

Three generations: 1. Scrap 2. Too big 3. At last.

In the photo, the cover lies not quite right yet, but I made a few corrections before soldering. I am satisfied with the dimensions, despite the 0.2 mm excess width.

Soldered in place.

Due to the bulk of the surrounding brass, I did not attempt to solder this with a regular soldering iron. The gas burner was applied very carefully with 140 °C solder. It worked perfectly.

Why am I paying so much attention to this cover? First of all: you are a model builder or you are not. But more importantly, this cover is unique to this locomotive and has a huge impact on its appearance. So if the locomotive is to look good, it has to be done properly.

Project grinds to a halt for a while

What I described above all happened sometime in 2021. After that, the project essentially stalled. There are many reasons for this. The momentum had somewhat dissipated. The transition from the structural work to the detailing proved difficult. Detailing was a lot of work and initially confusing. What's more, I wanted to do everything perfectly. To be honest, that paralysed me.

During that period, I was also involved in other model-building activities (BR 52, BR 99, GMAM, BR 45, J-Class) and each time I allowed myself to be distracted from the LTM 51. After completing such a job, I tried to start again and found myself stuck in my urge to oversee everything and do everything perfectly. Sigh. Now that I am updating my website, I realise that I have let almost four years slip through my fingers.

It was not until 2025 that I finally got around to actually installing all the boiler equipment.

Shut-off valves drive untis

One of the things I was definitely not looking forward to was making the drive unit shut-off valves, which also served as snifter valves. The purpose of the shut-off valves was to be able to shut off the fresh steam supply to a drive unit in the event of damage or malfunction. The locomotive could then limp “home” on the drive unit that was still functioning properly. Whether this function was used much in practice remains shrouded in mystery. To the best of my knowledge, this was the only Garratt that had such a provision.

The snifter valves, the right-angled pipe at the rear, served to prevent the cylinders from creating a vacuum when coasting with the regulator closed, for example when going down a slope or approaching a station.

These valves are quite complex parts to make and they are also very small. But in the past few years I have done crazier things with the lathe and the milling machine, so I ‘went’ for it.

Shut-off and snifter valves in the right hand side.

A drawing on which I have jotted down the dimensions.

The party began with turning down the tapered head and drilling a 0.5 mm hole for the handwheel to be fitted.

I used 2x2 mm brass rod. Strictly speaking, I don't think it's entirely correct because the body of the valve is also slightly tapered, but that's where I drew the line. The whole thing is only 8 mm long, after all!

The hand wheels were supplied by Weinert.

How do you hold such a hand wheel?

To turn the stem down to the desired 0.5 mm, I devised this method to hold the part in place: gluing it into a concentrically drilled hole. After turning down the stem, the glue was heated and the handwheel fell out.

The hand wheel fits, but has not yet been glued. There is still a lot to be done, so to protect the hand wheel, it has been temporarily stored in a box.

For the record: I always made both parts at the same time. I had to mind that they were handed, as left and a right part.

The front view drawing shows that the steam supply pipe to the drive unit runs away at an angle that is tangent to the smoke box. I was able to deduce this angle from the drawing.

I copied that angle onto a thick piece of styrene, which I then used as a template to bend the steam pipe.

A drilled piece of brass rod served as a makeshift tool.

And of course, the first time went wrong. The second and third times, I annealed the brass a little to make it softer. Then it all went well.

Good enough. I have also drilled a hole for the snifter valve. I didn't take a photo of it, but that's not very exciting anyway.

When making the snifter valve, I soon realised that brass rod simply cannot be bent acute enough to achieve the shape shown in the drawing. So I filed it with a square file to create an angle that was slightly greater than 90 degrees.

Then you can fold it closed at a acute angle.

For comparison.

The top one was made using the file-and-fold method.

The bottom one is the best result I could achieve with straightforward bending of brass rod.

The snifter valves were soldered into the body of the shut-off valve, and a piece of M1.0 thread was soldered onto the boiler side. Once again, my thumb serves as an indicator of how small the valve actually is.

Completed shut-off valve.

Both shut-off valves.

Mounting the fittings on top of the boiler

Previously I have already described how the safety valve, steam dome and exhaust were made. Now it is time to attach them to the boiler. This is tricky work, because any deviation from the centre line of the boiler is immediately visible.

Two components have not yet been discussed.

The one on the far left is a hand wheel that needs to be placed on the front of the steam distribution box (most likely the steam turret shut-off valve).

The second from the left is topfeed for fresh water from the water tanks. This is an extremely complex component. I didn't feel up to fabricating it in the same way as the drive unit shut-off valves. I found a friend willing to print it in 3D and in brass.

Everyting in place!

I was apprehensive about soldering these parts with a gas flame, like the steam turret cover. So I decided to glue them. According to many sources on the internet, JB Weld could serve very well as both epoxy glue and filler. That would be great, because JB Weld is much easier to work with than Milliput, for example. So my first attempt at gluing these parts was with JB Weld. It soon became apparent that JB Weld is strong but not shock-resistant. So after the parts came loose a few times (see also below), I gave up and removed all the parts and glued them with standard 5-minute epoxy from Bison. I later filled any gaps with JB Weld and smoothed them out.

Note that I pre-drilled the holes for the handrails and various pipes.

Steam bell at the front of the boiler

There isn't really much to say about it. It is, of course, another nasty little thing that you can't hold on to. That's problem number one. Problem number two is that the bell is not in the centre of the boiler but slightly to the left in the sloping curve of the boiler on a small tapered base.

I solved problem number one by drilling a hole in the bottom of the bell and soldering a piece of brass wire into it (just visible in the left-hand photo). That also served as the spigot that would attach the bell to the kettle.

I solved problem number two by drilling a hole exactly vertically through the boiler at the desired location using a 1.0 mm milling bit. A drill bit would not work here, as it would slip on the sloping surface. The bell was then glued in place, taking care to ensure that it was vertical in all directions. The epoxy, supplemented with JB Weld if necessary, then provides the platform on which the bell sits.

Wash-out plugs

The washout plugs were supplied with the Kaffa etches, as separate etched discs. My problem was however how to position them accurately on the boiler. I turned five discs of 0.2 mm thick and a stem 1.0 mm wide.

And I drilled the five corresponding holes. Incidentally, the setup clearly shows that drilling the boiler at this stage is anything but easy.

But once the holes are in place, installing the wash-out plugs is very easy. On the left-hand photo, the JB Weld used to secure them can still be seen on the right-hand plugh. These remnants were of course removed later.

Air pump

Regulator rod

The rod itself is not difficult. In this case, the problem was in attaching it to the tilting rod that runs into the steam dome. On the one hand, it mustbe prototypical, and on the other hand, it must be feasible and ableto take some handling.

I turned the rough shape from brass rod

I then milled the surfaces in a collet and drilled the mounting hole for the rod. The part was then returned to the lathe for parting and facing.

A little bit of filing literally and figuratively rounded off the part.

Again, the same motto applies here: it's all very small.

When I tried to drill the hole for the lever, my drill bit broke. While I was fiddling around trying to get it out, the steam dome broke off without warning. So much for the much-praised qualities of JB Weld as an adhesive. In this case, it was a blessing in disguise for me, because it allowed me to remove the stuck drill bit without too much effort and start again.

This allows it to be glued in place, this time with two-component epoxy.

The regulator rod was bent quickly enough.

I'm not entirely happy with it. I think it's a bit clunky. Here's a photo of a forked regulator rod as it most likely looked in real life. I want to try and make one, but in 1:87 scale it will be very fiddly. I smell a challenge!