OKWB - A Billard T75D

[Kenton]

Yes another whimsy to get back into White metal soldering (remember I use a full power 25W, none of this limp temperature control) so I needed something to practice on, as well as something to sit on that MPD18 chassis.

 

This very French looking locotracteur was built by the company Billard located in Tours, France from early 1939 onwards. The original design was to meet a French Army requirement for use on artillery railway supply lines in and around the Maginot Line system. Some later versions (T75G, ??) were built for use in industrial locations. Billard was absorbed into SOCOFER who continued to build the loco to the same basic design. Many of the locomotives have survived and can be seen operating on French tourist lines.

 

This is another kit from the Meridian Models stable (though I believe that it was originally of a different origin) - perhaps someone can clarify?

Once again it comes in a nice plastic box with the white metal castings in plastic ziplok bags. As to be expected for an OO9 kit some of the parts are small and present a challenge for a heavy handed white-metal kit-builder (moi)

 

Tools required: A fine file, a brass bristle brush/pen, wet and dry papers, 70'C low melt solder and RED Carrs solder, 2mm drill and nerves of steel (or a temperature controlled soldering iron for wimps )

 

1. Open the box and empty out the bags and this is what you get. 26 cast parts and not a glint of brass to be seen ( what am I doing here? )
   
    
   Now I have always found that the key to soldering white metal is to have the faces to be joined as clean as possible, to have a rough surface, to be swimming in flux and to use a hot iron with speed. Low melt soldering is nothing like brass soldering and is more like gluing. The solder melts but has poor flow characteristics and goes "off" the moment it combines with the white metal alloy. It also goes off when it meets a crust of dirty or oxidised alloy. At the iron temperature I use it also boils the Cadmium content of the solder, which not only is toxic but can also make the solder joint brittle. Fortunately the flux cools the iron (a simple 25W) and I don't hang around.
    
   The parts of this kit have virtually no flash to be removed and they have been designed to fit together with tabs or shoulders. There was no distortion that I could discern and the detail (rivets, radiator grilles, etc) was excellent - for white metal castings.
   
2. We start by soldering the front and rear buffer beams to the footplate. Use an engineers square or a block of wood to hold square.
   
   
   
   
3. Identify the left side frame (yes, they are different) the one with the holes for the exhaust pipe and clear the holes with a pointy thing. Then solder to the frame and buffer beams ensuring that it is the correct way round and on the correct side.
   Remember that undoing mistakes on low melt is much harder to do than with brass - it usually results in having to boil the lot, clean the parts and start over. So always trial fit everything and trial fit it again before making the join.
   
   
4. Repeat for the right side frame, though this does not have any holes.
   You will observe that all the soldering so far has taken place on the inside of the work. A testament to a good design in my view and you will see that there is no need to solder outside the kit until the very last parts.
   
   
5. Identify the exhaust pipe and solder in place by filling the two holes where the pins pass into the frame.
   
   
6. Now is the time to fit that MPD18 chassis unit.
   Align the units wheels with the axle box detail on the outside frame and mark the position in the slot of the fixing plate. Set the chassis aside and drill out a 2mm diameter hole at that point, a hand drill is far better than a wizzy drill as you have more control. White metal alloy is quite soft.
   Thread a 12BA bolt through the hole and tin the edge of the 12BA nut with 185'C normal solder. Remember low melt solder does not take to brass and in fact degrades in contact with it, hence the coating of normal solder.
   Thread the nut on to the bolt and tighten. Lock the nut to the surface of the footplate using 70'C low melt solder.
   
   
7. Loosen the bolt and slide the chassis and motor in place. Test the unit under power. At this point I found out that crossing red and blue wires was not a good idea.
   
   

[Kenton]

Still, onwards and upwards as they say.

No time to worry about that for now

 

1. Select the main superstructure parts.
   
   
2. Solder the radiator to the top of the frame. It has two pins that fit in corresponding holes in the frame - you just cannot go wrong with this amount of care in kit design. They almost click into place.
   
   
3. Solder the cab front in place, a moments care to be sure it is the right way round and a quick check that it is vertical.
   
   
4. Solder on the left bonnet side, the grills sit slightly above mid line.
   
   
5. Followed by the right bonnet side.
   
   
6. Then solder on the bonnet top. To my amazement this just clicked in place without any fettling. Yes you can still solder this in place from the inside - you just need to be careful not to touch the sides as you go in and out with the iron.
   
   
7. Now add the cab left side, with the chamfered edge on the inside.
   
   
8. Then add the right cab side.
   
   
9. Now add the cab roof. making sure at this point that it is horizontal and parallel to the footplate.
   
   
10. Solder the left side of the rear bonnet in place. One corner is curved. Make sure that the side is at right angles to both top and back faces.
    
    
11. Repeat for the right side.
    
    
12. Now solder the rear bonnet on to the rear of the cab.
    
    
13. Finally slide this sub unit in place under the cab roof. Once content that all is square and the cab is vertical, solder in place. through the footplate.
    
    
14. There we essentially have it - the rest is just detail.
    
    
15. I decided to add the shunter's footplates, front
    
    
16. and rear.
    Though looking at the finished loco this may well prove to be a mistake.
    The layout on which this will eventually be run will have quite tight curves and I fear that these will push the coupling outside their workable ranges.
    
    
17. A quick glance inside to see the rather slapdash soldering finish - but who looks inside anyway?
    
    
18. Finally add the coupling hooks front and rear.
    
    
19. A nice little loco - even if it does look a bit French (which I guess is not surprise - as it is)
    
    
    
    
    

I have deliberately not added the lights yet as the body is now in for a rough handling in the wash to remove all that excess flux.

 

To give you some idea of how close the model is to the prototype here is one prepared preserved earlier.

and a slightly larger model (1:35) well presented.

and a later industrial version

[Kris]

Interesting little model. I guess that having all in wm solves any weight issues that you might have had with a brass model.

[Kenton]

Interesting little model. I guess that having all in wm solves any weight issues that you might have had with a brass model.

It certainly does. Though it has a distinctly top heavy wobble.