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A Gaggle of J15s

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I ended up modelling the 101 Class almost by accident. I set out too many years ago with the intention of modelling the Mayo Road in the 1950s & scratchbuilt a number of locos including a 650 Class and a 594 Midland standard goods, ten along came the TMD J15 in 1985-85.  My early scratchbuilding efforts ran reasonably well but looked a bit rough, I was impatient and did not have the steadiest hand with the piercing saw. I scrapped my scratchbuilt engines keepings the wheels gears and motors castings and other bits with the intention of building replacements, but I am only getting round to it 30 years later, though I did build quite a few brass and whitemetal kits both Irish & UK.

I seem to go through a pattern of building a J15 every 8-10 years and currently have a total of 5. Two working, one part built and two unbuilt kits.


I 1st assembled 193 (loco on left) between 1986-7, it did not run the best so I rebuilt it 7-8 years later and flowed up with 191 in 1995. I acquired my 3rd J15  as part of a job lot of part built & unbuilt TMD/SSM  kits at Expo EM around 2000, the builder of this loco had attempted to assemble the loco with a compensated chassis to S4 standards and ran into problems with the chassis assembly.

I acquired a further pair about 10 years ago, when my modelling interests turned towards the Limerick-Sligo line where the 101 Class handled the majority of freight workings from the Amalgamation to the end of steam. The basic idea is to retire 193 and have 4 locos available for freight service, with at least one with a superheated boiler and heavier frames, to free-up a set of frames.

I prepared a set of test etches for converting the SSM kit, I hope to cover off the test assembly of the superheated loco using these parts in the thread.

I though it would be useful to review how I approached the challenge of assembling and motorising 193 & 191, before considering the build completion of further locos.

191 & 193 have different motors and gearboxes, and I decided to standardise on Mashima 10X20 motors and Branchlines Road Runner + gearboxes on the "new" locos to bring a bit of standardisation into the fleet. A bit like the GSR my attempts at standardisation will only add to the variety of the fleet.


193 has lost some of her tender springs and 191 some of its tender axlebox covers which were glued on, I soldered them on to the white engine!


193 has a sprung chassis, with Anchorage DS10 (Tenshodo?) open frame motor and Sharman milled brass gearbox with 40:1 reduction gearing, Sharman B profile wheels set to 21mm gauge with a back to back of 19.5mm. Pick up is through the axles and bearings on the "American system" with the loco picking up power on the opposite side to the tender, the driving and tender wheels are shorted out on one side with fine brass wire. The phosphor/bronze wire soldered to the frame space may be to aid power pick up from the  axle to the frames and motor.

This system has operated reliably at exhibitions and at home except when I lubricated the bearings with a Labelle oil for the Inchacore 150 Exhibition. I flushed out the bearings with a solvent and oiled the beraings with my usual Fleishmann oil and the locos ran perfectly on the second day of the exhibition.


Initially assembling the chassis almost defeated me, I fitted new frame spacers, sprung hornblocks and flywheel during the 1993-4 rebuild, unfortunately I discarded the brake gear during the 1st attempts at assembling the loco as I did not have any suitable bits to drill 0.45 or 0.7mm holes.

The DS10 motor was one of the smallest available at the time and is a bit high revving for a goods loco, the Sharman gearbox is fully enclosed with an Ultrascale 40:1 gear set. I will probably re-use the motor and gearbox in a passenger loco when 193 is retired from service.


191 is fitted with a Mashima 12X24 motor and Branchline Slimline open frame gearbox with 80:1 gearing, which gives more realistic handling and top speed for a goods locomotive. This loco is fitted with a compensated chassis with a fixed rear axle and the leading and driving axle free to move up and down approx .5mm from center. Smoother slow speed running compared to a loco with a rigid chassis (as a result of improved pickup with all 6 wheels in contact with the rails) is probably the main benefit of a suspension system in a small loco. 


I build my locos in removable sub-assemblies to allow a loco to be dismantled for painting, and maintenance. The loco brake hangers and pull rods are a removable sub-assembly, which allow the wheels, gearbox and motor to be dropped out. I soldered a piece of brass rod to the brake stretcher bars to reinforce a very fragile sub-assembly. The brass strip under the tender is an afterthought that serves the same function! The insulated loco-tender drawbar is a piece of C&L abs plastic sleeper strip, power connection between the loco and tender is a very neat single pin connector that was sold by a UK kit/part supplier possibly Crownline or Comet at exhibitions.


191s compensation beam may also perform a power pick up function. 



The "White Engines" frames after removal of hornblock system. The white engine was originally fitted with an early version of the Perseverence Hornblock system and a Mashima motor and Branchlines gearbox similar to 191. I initially tried to re-use the chassis with the minimal amount of effort,  by reaming out the existing bearings and fitting Sharman B Profile wheels.

The original builder had become stuck at the same point with a number of engines and gave up in frustration, mainly weak soldered joints possibly as a result of insufficient heat soldering frames to spacers and axles seizing in their bearings due to a combination of inadequate preparation and flux contamination.

I was dis-satisfied with running so I ended up removing the existing hornblocks to fit MJT hornblocks similar to those used on 191, the solder joints between frames and machined brass spacers failed as a result of the heat, so its probably simpler to use one of the nickle silver chassis from one of the un-built kits to get this loco into service, than try and rebuild the existing chassis. 

The photo also exposes a major weak point of the chassis for a builder who intends fitting a suspension system, there is precious metal left above the hornblock cutouts at the rear of the chassis once the half etched lines are cut out. 

I fitted reinforcing strips to the rear of 191 & 193s chassis as a result of a lesson learned during my first attempt at assembly of the same loco.

There has been a lot of development in fine scale chassis since I 1st assembled 193, I am looking at the feasibility of fitting the 3 new chassis with a continuous beam suspension system which has become popular during the past 20 years rather than compensation like 191 or sprung hornblocks like 193, I am also looking at the pros and cons of mounting the motor in the tender with a flexible drive to the loco compared with mounting the new smaller 10X24 motor between the frames in order to maximise weight in the boiler and firebox and increase adhesion weight.

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A most interesting and informative read. Craftsmanship.

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Fascinating, not least because I am currently researching it's big sibling in 7mm scale - an unmade TDM kit from the Richard Chown estate. The instructions appear to be the same for the 4mm version and my first job will be to type them out in bullet point format, so they are easier to read. No castings, so just as well the Reading 0 gauge trade show is coming up soon. Even in 7mm scale the frame cut outs for compensated/sprung bearings leave previous little metal left over, so the advice here seems very good.

 Certainly hope that my model turns out as well as these beauties! Am hoping 193 has the sloping smokebox? One less casting to buy, while presume it was also a loco that worked up to Sligo.?

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Excellent John

I have 2 of them in 4mm to do and this is very helpful, keep it coming


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6 hours ago, Mayner said:

.... at least one with a superheated boiler and heavier frames, to free-up a set of frames.

I prepared a set of test etches for converting the SSM kit, I hope to cover off the test assembly of the superheated loco using these parts in the thread......

The Z-boilered variant is the one I'm particularly looking forward to reading about, especially if you do decide to make the conversion etch available to the public....

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4 hours ago, Horsetan said:

The Z-boilered variant is the one I'm particularly looking forward to reading about, especially if you do decide to make the conversion etch available to the public....


Apart from yourself there has been little or no interest in the Z boiler conversion kit. 

The conversion etch is one of my early designs, there are a number of assembly issues which I need to highlight or eliminate before I could consider selling  the etch to the public.

I will review the situation once I have assembled the superheated loco. 

If there is sufficient demand (8 or more in this case) to offset the cost of a new photo tool I will revise the artwork, if not the potential buyer should be in a position to make a decision if the conversion etch meets their requirements.

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3 hours ago, Mayner said:


Apart from yourself there has been little or no interest in the Z boiler conversion kit. ....


That's a shame. 186 is the one I wanted to model eventually.

Edited by Horsetan

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The "white engines" frames turned out to be in better condition than they 1st looked, so I am planning to re-assemble the frames and running gear as a replacement chassis for 193. This will bring 193 mechanically into line with 191, with similar compensated chassis, wheels, motor and gearing should be good for another 30 years hopefully!


Dismantle chassis before clean up.


A dunk in airbrush cleaner removed oil, grease and most of the paint, excess solder removed with an old file. I will re-use the frames, motion bracket and compensation beam and fit L & U shaped fold up frame spacers.

I thought it worthwhile to set up the running plate and valences on one of the new locos to check clearances within the splashers for 21mm gauge wheelsets. Most of my 21mm gauge steam locos are fitted with Mike Sharman B profile wheels which were intended for OO/EM use but have a tyre width of 2.03-2.06 rather than the 2.28mm recommended by the EM Gauge Society and used by a number of British wheel manufacturers including Ultrascale and Alan Gibson Workshop.

While 191 & 193 operated satisfactorily, there were clearance problems with the white engine with the wheel tyres occasionally shorting on the inside of the splashers.

The J15 running plate is designed around a base plate, which incorporates inner splashers, buffer and drag beam to which the valences are attached, the valences are reinforced with sacrificial plates to help keep the running plate assembly flat while the locomotive body is assembled.


I used an "Etchmate" bending tool and an engineers square to fold up the splashers from the running plate.


Running board with valences attached. I  fixed the baseplate to a piece of MDF (cut slightly narrower and shorter than the baseplate) with small woodscrews before soldering the valences to the baseplate.

I test fitted a Mashima 10X20 Motor and High Level-Road Runner gearbox to the chassis to check clearances within the body before making a final decision on mounting the motor.


There is sufficient space to mount the motor at a slight angle from the vertical within the firebox, though I would prefer to mount the motor horizontally within the firebox & boiler and fit a flywheel.


Sharman wheels 19.5mm back to back overall width of wheelset 23.56

Min width between splashers  24.56

0.5mm clearance each side between wheel set and side of splasher



Alan Gibson wheels 19.3mm back to back overall width of wheelset 23.76 (0.8mm shims between wheel set and splasher)

Min width between splashers  24.56

0.4mm clearance each side between wheel set and side of splasher.

The wheel set is mounted on a 1/8" extended axle available for outside framed locos.



RP25 110 (Hornby) Tyre width 2.60-2.66

19.3mm back to back overall width of wheelset 24.62

Min width between splashers  24.56

Clearance  between wheel set and side of splasher Zilch!

During the test assembly I noticed that the distance varied between splashers on all three axles, with clearance at the center axle tightest. 

I will check align the splashers using a steel straight edge before attaching the running board overlays and outer splashers.

Clearance appears to be adequate for assembly with EMF profile wheels with minimal sideplay which will restrict the locos to curves of 3' radius or greater.

RP25 110 & Markits wheels would be a non runner with a J15 and the majority of Irish steam locos even if suitable wheels and axles were available.


Edited by Mayner
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The chassis of the white loco was originally assembled with the square section brass spacers supplied with the kit. The spacers were originally supplied bored out to clear 8 or 10BA studding, the intention was that the builder would use a threaded bar/through bolt arrangement to align and clamp the frames together, before final assembly by soldering. The soldered joints between frame and spacers on the white loco were weak, one had already failed and difficult to re-make without dismantling the chassis.

Studio Scale Models replaced the square section frame spacers with more conventional turned brass spacers tapped 10BA which considerably simplifies chassis assembly.

I though some form of chassis alignment jig would be useful as I intended to use my own L shaped frame spacers rather than the brass bar originally supplied with the kit.

I fabricated a set of frame alignment jigs from stainless steel bar and springs bolts and washers from some C&L track gauges.


The basic design is based on a frame alignment jig originally supplied by Kean Magib modified for the wider gauge. I ended up using stainless and aluminium rod of similar diameter is unavailable locally.

The turned shoulder is designed to locate in a standard hornblock cut out.




Jig set up I cheated by taking the photo after everything is soldered in place 😄


The assembled frames. I added a strengthening plates above the rear axle hornblock cut outs, the plates are L shape to provide a securer fixing to the frames, otherwise the solder connection is a butt rather than a lap joint.

I added additional frame spacers behind the motion plate and above the ashbox to stiffen up the frame assembly,


I used MJT hornblocks and bearings some fettling was needed to allow the bearings to slide up and down in the blocks.


I used hornblock alignment jigs with tapered pins and the original coupling rods. I took the photos "real time" this time working back from the leading axle using an Antex 18W iron with a fine tip 145 solder and phosphoric flux. (small paint brush to apply flux and very little solder works best). This form of hornblock jig seems to be more accurate than the stepped type as the rods can be pushed in until tight against the shaft. 


Starting to look like a rolling chassis, I test fitted a small Mashima motor and High Level gear box as I cannot find the larger Mashima motor and Branchlines Slimline gearbox from the original loco.

The chassis will be ready for painting once I fit the compensation beam and brake hanging rods. I will fabricate the brake hangers and pull rods as a separate sub assembly so that the wheels and motor can be removed for painting and maintenance.


The white loco re-united with its chassis. Many parts were missing when I acquired the loco, I will probably replace the reversing lever with the more common linkage type used on the majority of the class including the preserved 184 & 186 and I will replace the crooked riveted strip between the bottom of the cab side sheet and running board. A more extensive re-build as a superheated engine may be on the cards as 101 retained its original frames when re-built.

I am planning to build one of the un-built kits as a Coey J15 229 with detail differences from the majority of the class and the second loco as a superheated J15 with heavier frames similar to 186. This should leave a spare chassis so 193 could remain in service a bit longer!

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As an alternative to MJT hornblocks, High Level produce some very acceptable (and compact) hornblocks and bearings - takes seconds to assemble and requires hardly any solder until ready to fix in the frames.

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The MJT hornblox under 193 are very old stock, 101, 229 are due to be built with High Level Hornblocks and CBS suspension system, I bought the High Level CBS jig from Chris at Warley or Glasgow round 2001 or 2002🙂. The combination of beam compensation with MJT hornblocks, Mashima motors with Branch Lines slimline gears boxes should make an interesting comparison with the locos with the 3 new chassis.


193 frames compensation beam and brake hanger mounting pin fitted. I ran into a sang with the brake gear supplied with the kit and decided to replace the brake hangers and pull rods with those of my own design. The original gear supplied with the kit was very fine and forming the brake hangers to shape is more difficult as the etched components are now in more rigid nickel sliver rather than the original brass.


229 part assembled with running board overlays, cab and splashers sides and buffer beam fitted. Parts for superheated engine laid out with spectacle plate and firebox of my own design (2012).

I made the mistake of assembling the running boards without reading the instructions and forgot that the "temporary splashers" incorporated with the engine base plate should be removed before the permanent splashers are fitted.


229 with permanent splashers tacked to the temporary splashers. This results in the loco being 0.8mm (2.5")wider across the splashers than and the splasher sitting 0.2m higher than originally intended.


Running board overlays these were installed by sweating in place working from the front of the engine using brass bar to curve to the profile of the valences and pressing down with small blocks of wood. I trimmed off the small tabs which are too high to fit beneath the "temporary splashers". I used 193 solder and an 18 watt Iron with a fine tip to attach the valences to the running plate of 229 and a 25watt soldering iron with a wide tip and 145 solder to sweat the overlays in place.

I used a piece of hardwood cut to fit between the buffer beams and valences as a base for supporting the running board during assembly.


Superheated and saturated J15s. The kit is basically designed to break down into boiler/firebox/smoke box and cab and running board sub assemblies.

I first tack soldered the cabsides in place on the running board and offered the spectacle plate/cab front up to the sides before soldering in place, the firebox is located by tongues on either side of the spectacle plate.

I decided to follow the instructions for installing the splashers on the superheathed loco which lead to some re-work, not sure in the end whether it was worth it!


Splasher soldering jig ceramic soldering board using brass pins to hold everything in place, I used 193 solder to attach the splasher top and 143 solder to attach the sub assembly to the running board.


Completed splasher sub-assembly.


Starting to look like locos going through Inchacore or Limerick shops!.  Splashers fitted and cleaned up, next stage detailing cab running board assemblies.


Coupling rod assembly one of the most critical stages of the build. I 1st opened up the crank pin holes up to 1.2mm with a tepered broach while holding the rod with a pin chuck.


Assembly jig. Drill bit used as a mandrel in a block of hardwood for laminating the rods together. I used a vertical drill to locate the drill bits. Drills are jointed on the middle axle for sprung/compensated chassis, so location of the central pin is less critical than a rigid chassis.


Belpair firebox showing formers.


Mock up superheated loco, smokebox is from a test etch I made up about 5-6 years ago, boiler wrapper from SSM kit. I will probably follow Martin Finney approach to forming belpair boilers with additional formers to for the rounded corners at the front of the box, with a bolted connection between boiler and smokebox similar to my Midland 2-4-0 kits.


Edited by Mayner
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Has an interesting experience today: I managed to break two 1.2mm drill bits while boring out some frame spacers in the lathe for tapping last night.

Went to one of the local machine tool suppliers, two of the assistants were playing in the stock room the other sulking behind the counter.

Didn't have the sized I needed in stock, said "I only work here" when I asked him if there was an engineering supplier in town. He eventually muttered that there was another supplier in town but "they are terrible people".

The "terrible people" turned out to be very helpful and friendly and had the bits in stock, I guess I wont be going back to the 1st supplier.

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41 minutes ago, popeye said:

You just can't get the staff these days. :mad:

They had a bit of a brass neck alright. :)

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