Hornby J15


Another loco aimed mainly at our extended "Little Histon" layout, to add to our LNER period rolling stock operating in the station area.

Hornby photo of 5444

Likely configuration:

There is not a lot of spare volume available for add-ons in this locomotive. The boiler is full of motor and flywheels, with insufficient space behind the firebox door for my usual LEDs and series resistors. So for once, I'm limited to just adding a sound system and stay alive super-cap in the tender.

I'm going to use a Zimo MX648 decoder with Paul Chetter's generic LNER two cylinder sound project on board. This will drive an 8 ohm 28mm speaker in Hornby's speaker location. For the 28mm speaker, I'll seal the speaker back from its outside facing front, using blue Tack. A Zimo SC68 supercap with zener diode based protection circuit may also go in the extreme rear of the tender, if pick-up causes problems.....However to make room for this, I will have to swap the 8 pin connector for solder joints insulated with heat shrink sleeving. The decoder will be housed under the coal load in the coal bay. The holes for the wiring to the decoder will be sealed with Glu 'n Glaze. When its all tested and working, I will attempt to seal around the bottom of the tender sides with a removable sealing agent (to create a fully sealed speaker enclosure).

I will also add a footplate crew.


DC Testing:

The locomotive is a very smooth runner in DC configuration, straight out of the box. Slow speed running is amongst the best I have ever seen for a Hornby steam loco under DC control. Using my bench power supply which provides pure DC, the motion is virtually silent.



Decoder CV Adjustments:

Some motor control adjustments:   CV29 to 7 (Hornby motor wiring colour code back to front), CV3 & CV4 both to 75 (acceleration and deceleration rates), CV9 to 87, CV57 to 80.

Fine tuning the chuff rate to 4 per driving wheel revolution: CV267 to 60.

Also boosted the sound volume of the Westinghouse brake pump on button operation.


Key Number

Function Description



F1 Sound ON
F2 Brake Key
F3 Long Whistle
F4 Long Long Whistle
F5 Heavy Train (off) / Light Engine (on) Selection
F6 Coal Shovelling (This sound is also a random sound)
F7 Live Steam Injector (This sound is also a random sound)
F8 Blower
F9 Wheel Flange
F10 Safety valves lifted (This sound is also a random sound)
F11 ?
F12 Tender Water Filling -  variable length
F13 Steam Brake
F14 Buffering
F15 Cylinder Drains Opened
F16 Buffer clash / Wagon Snatch
F17 Short Whistle
F18 Guard’s Whistle
F19 Fade All Sounds

Westinghouse Pump  (This sound is also a random sound)

F21 -
F22 -
F23 -
F24 -
F25 -
F26 -
F27 Overall Volume Down
F28 Overall Volume Up




Adding the Hornby Detailed parts & the loco crew:

The loco and tender brake hose parts were glued in position using gel super-glue and the brake linkage was sprung into its slots on the loco and tender underside.

The remaining driver and fireman were then removed from a Bachmann loco crew pack and super-glued in place within the cab.

The dead LNER oil lamp that failed on the B12 was also fitted in the stopping passenger train top location, ready for a video using the Gresley coaches.


Something that will probably come back and bight ! :

While adjusting the CV values for the first time, the loco suddenly refused to move or programme..... A symptom of an open circuit in the motor wiring. Checking with a multimeter revealed a motor resistance of 43 ohms and no apparent discontinuity. A quick check on DC (with the blanking plug restored) was fine, followed by and equally fine run on DCC when re-fitted with the decoder connector. So I guess I've got a mystery intermittent break in one of the wires or a dicky connector. I'm sure I will have to revisit the problem at some point in the future!


  The completed J15:






DCC Running :

Very smooth without the need for any tinkering with the motor control CVs.  Also the motor and drive are virtually silent, so no sound camouflage needed during slow running!


A video will follow soon!


Supplier website links:
Hattons    J15 was sourced as a Hattons sale item.
Digitrains    Source for 28mm speaker.


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