Conversion to 16.5mm gauge
(available in blue, green and Furka Oberalp
The Tm 2/2 diesel is a model of one of two locos that were supplied
to the Alsen'sche Cement Works at Itzehoe, north of Hamburg by Schöma in
1960. They were built to 860mm gauge, had 230hp Deutz diesel engines and
bore the numbers 11 and 12. In 1976, the locos were later converted to metre
gauge by Schöma and re-sold to the Furka Oberalp in Switzerland.
has been building small locos for many years and many narrow gauge
(and private standard gauge) railways in Europe have locos built by Schöma,
and as such
it is reasonable to convert it to 750/760mm gauge. For instance, there are very
similar Schöma locos running on the narrow gauge lines on the islands of Wangerooge and
off of Germany's North Sea coast.
This loco is from a range of models (all based on Swiss prototypes)
that has been made by several different manufacturers all using the same
tooling: Utz, Fama, Kiss and
latterly Roco; though none are now in production. All of the other models in the range are "typically
Swiss" and are not really generic enough to be used on a non-Swiss
Metre gauge works out to be 22mm in
0-scale and out of the box these models are not usable on 16.5mm gauge track.
Roco "full" version
|ROCO made two slightly different versions of the model:
- The version sold separately (cat. num. 50300)
- The version in starter set 50100. This is missing some detail
parts (fewer handrails, no brake
hoses and the top front headlight and cab side windows are
missing; which you cannot get as spares)
Otherwise (as far as is know), the model is exactly the same
as that sold by Fama - with the exception that the Roco "full"
version comes with a socket for a DCC decoder.
As it is not possible to convert the chassis of this loco to
16.5mm gauge, it is necessary to use an H0 (or 00) scale
This article does not cover every last detail of this conversion
as it is assumed that
modellers would be able to work out some of the
smaller details for themselves.
Materials and tools you will need: Assorted thicknesses of Plasticard
(20thou, 40thou), Steel rule (150mm or 300mm long), Razor-saw, Rail cutters (Xuron or similar), Modelling knife with plain and chisel blades, Flat files - large and small (called "needle" files), Liquid polystyrene glue and small paint brush (size 0 or 00), 1.5mm diameter drill and pin-vice or mini electrical-drill.
first problem is how to get the shell off.
I have owned several of these over the years and some are very
difficult to get in to, others come apart easily. It seems to
depend on how well the body shell is glued together in the
You will find some coffee-stirrers or match-sticks useful.
There are 3 "lugs" on the frame, 2 on the left side, 1 on the
right (assuming the long-hood is front and you are looking from
the cab forward).
Carefully insert a screwdriver in between the motor-block and
the side frames. As you lever the sideframes apart, insert a
coffee-stirrer or match-stick in the gap to stop it closing up.
The chassis can be a tight fit but take your time and you can gently
lever it out of the body.
Due to the construction of the chassis block it is not possible
to convert it to 16.5mm gauge so it is necessary to find a
replacement. The large cutaway on the left of the frame is so
that the cab is kept completely empty. If you don't use the
Bachmann chassis described below, the replacement chassis
might obscure part of the cab.
Your replacement chassis will need:
- Wheelbase of 60mm +/- 1mm
- Wheel diameter of 19mm +/- 1mm
- It doesn't matter if there are intermediate wheels as these can
- The chassis cannot be longer than 87mm - but that doesn't mean
you can't saw the ends off to make it 87mm
The Bachmann Branch Lines (British) 00-scale, Great Western 8750
class Pannier tank has a wheel size and wheelbase which is an
almost perfect match for the Tm 2/2 if you remove the centre
set of wheels. This is a nice little loco and almost seems a
shame to throw the body away. Catalogue number 32.201, 32.202, etc., available on-line from a
number of UK model shops.
The chassis is only gear-driven to the rear axle, the coupling
rods transferring the drive to the other wheels. However, as the chassis is hidden,
this is not really a problem as none of the rods are visible
once the model is on the track.
Before you start cutting the loco to pieces, verify that all is
well and that it runs OK. You will not be able to claim a
replacement if it is defective after you have cut it apart. To
remove the body, lever-out the coupler pockets with a small
screwdriver. This will reveal two screws, one behind each buffer
beam. Remove these and the body will simply lift off.
taking the body off, remove the small metal weight under the
circuit board (already done in this view). This will fit in
under the cab keeping the inside clear.
Then pull off the backhead detail, which is still in place to
the left of the motor in this view.
This is the "point of no return", after this, the modifications
to the chassis are not reversible!
Bachmann's credit, the model has jointed coupling rods - which
is awkward for us, we cannot just remove the centre set of
wheels otherwise there would be no way to transfer the drive to
the other set.
Firstly remove the crank pins from the middle set of wheels.
Then remove the keeper-plate from the bottom and drop out the
centre set of wheels.
Using a pair of wire cutters, cut off the rim of the wheel.
Clean up the resulting crank with a file. This is not visible in
the finished model so you do not need to be too tidy.
Using a pair of side cutters (such as Zuron rail cutters),
remove all the extra detail from the chassis and keeper-plate
and the current-collectors that rubbed on the centre set of
Reassemble the chassis and you should have something that looks
side cutters, remove the original centre-buffer couplers.
Then, using a razor-saw, and the edge of the coupler
opening as a guide, saw through the bodywork.
Cut right through the old backplate of the coupler (A
in the picture) and the bodyshell (B
in the picture) down to the level of the coupler opening (arrow
a square bottom to these openings is difficult. Fortunately we
need to attach a couple of pads of Plasticard for fixing the
chassis to so finesse is not critical.
These pads need to be about 1mm thick (approx. 40 thou) and 11mm
square to fit in the bottom of the openings.
Dry-fit the pads and fit the chassis in place to ensure that
everything is level. You may have to do a small amount of filing
or trimming to get it to fit.
either thin pieces of Plasticard or filing, adjust the height of
the end of the chassis so that it is in line with the brace
across the chassis - as in the view to the left.
The exact height is not critical, but ensure that the chassis is
level, otherwise the loco won't sit level on the track.
You can also see in this view that the rods and cranks are
easily clear of the inside of the body shell.
Once the glue has dried thoroughly (at least overnight), drill
the new Plasticard pads for the screws that held the original
body on the Bachmann chassis.
all that is needed now is to screw the chassis in place and fit
the couplers of your choice. I found that Kadee #5s were at the
right height if fitted to the bottom of the buffer beam. I used
some 40 thou Plasticard to fill in the opening in the existing
buffer beam and made a "platform" to fit the coupler to on the
The original Bachmann loco had extra weight in the body, and
during the conversion the ballast weight from the chassis was
also discarded so the loco is rather light. Fortunately, there
is plenty of space inside the body to fit some extra weight.
comparison, here is a Fleischmann Magic Train Deutz diesel
alongside the finished conversion.
The Schöma loco is much larger, although it has to be said that
the Deutz loco is a model of a small prototype.
Dietz - Modellbahntechnik
Micro XS (sound-only) decoder is available with the specific
sound file for the Tm 2/2. The Dietz Micro XS decoder has a SUSI
interface and can work with an SUSI-compliant DCC decoder such
I am researching the finer details of what I need in order to be
able to get this all working. Watch this space.
Roco / Fama Tm 2/2 with Wedekind
At one time,
Modellbahn made a super-detailing kit for this model;
though this is no longer in production. They do however still
produce most of the parts separately.