Hornby class 47
T4X decoder installation

Pictures and text by Robert Lewis of Tilehust, Reading, United Kingdom

This locomotive is a Hornby class 47, in the original British Railways two tone green livery. This is an early model in the "silver seal" series. I have used a TCS-T4X decoder for this installation.

Important  The motor chassis is "live", connection to the rail is via the metal wheel/axle assembly, The outer non-traction tired wheels need to be replaced with insulated geared wheels. These are available from www.modelspares.com

Unfortunately I found the un insulated wheel problem after I had smoked a decoder, with the model on its side there was no continuity between the wheels and the motor terminals, only when the locomotive was on the rails with the weight pressing down on the axle did the short circuit occur. Lesson learned !!
Picture 47-1.  To remove the body you will need to pry away the body in 4 positions underneath each cab door, it should then lift up easily.

Picture 47-2.  Remove all the existing wiring, diodes and motor capacitor. Lift off the cab interiors and pull out the 2 (each end) bulb retaining plugs, retain the 2 headcode bulbs.  Then remove the 2 slotted screws which hold the bogie sideframes to the motor chassis, the motor block can then be removed from the bottom of the sideframe moulding.

Picture 47-3.  The all metal wheels can be removed by tapping the axle through with a fine punch. Then refit the new wheels on the axle, the insulated centre and gear teeth will ensure that the metal rim cannot touch the motor frame.  Then refit the motor frame to the plastic bogie frame  with the 2 screws.

Picture 47-4. Solder the orange and grey wires to the brush terminals, and the blue and yellow to the head code bulb, sleeve the bulb joints. The sleeving/wires can run through slots of the cab interior moulding.

Picture 47-5.  Connect the red and black decoder wire to the un powered bogie pickups. The blue wire will have to have another piece of wire spliced into it to feed the other bulb, along the the white wire, connect these in the same way as the bulb at the motor end.

All the un used wires have been sleeved and coiled up into the fuel tank recess, there is also space here for the decoder, which has been held in place by double sided tape.
The cab interiors can also be held down with a piece of double sided tape, this helps when re-fitting the body. Test the installation. Refit the body.