Bachmann Class 3F 0-6-0

Another loco aimed mainly at our extended "Little Histon" layout, for the 30s time period.

LMS Class 3F Number 3520 at Histon Station


Locomotive Application:

Our village layout models Histon Station over a number of time periods. Small 0-6-0 Midland locomotives were used to haul passenger services in the 1930s, between Kettering and Cambridge several times a day, passing through Histon station, but only stopping upon the request of on-board passengers. The line passed over some very fragile bridges between Huntingdon and St Ives. (The piers of which can still be seen from the footpaths near Houghton Mill.) This placed severe limitations on the maximum weight of locomotive able to use the line. Midland Class 2F were often used to to haul the service.  The Bachmann Class 3F may be a shade heavy for the job in hand, but its the closest RTR model we could find to perform the task. 


DC Running Test:

To make sure there are no inherent mechanical or electrical issues with the drive system, the loco was placed on a two yard test track and powered from my DC bench power supply. Movement was OK with quite reasonable slow running performance.


Showing the 3F with its train of non-corridor Midland coaches.


DCC Sound Fit:

The only available space for the decoder, speaker and stay-alive arrangements is in the tender. Although this is quite long, there is very limited head height and I decided to use a miniature Zimo MX648 sound decoder, driving a "sugar cube" speaker within the tender body. An AVX 6800uF 15Volt super-cap with zener diode charging voltage protection provides the stay alive storage medium. The decoder with a suitable sound project on board, plus the super-cap are sourced from Digitrains and I already had a Zimo sugar cube speaker in the spares box. 


Lighting Arrangements:

Due to an imminent display, there was no time to add LED lighting. Although not shown in the photos, a headcode disc will be mounted on the top bracket. A Firebox lights and headcode lights maybe fitted later when time and other commitments permit.


Decoder CV Adjustments:

Normal Zimo housekeeping, CV267 adjusted to produce 4 beats pre driving wheel revolution (2 cylinder loco) and re-mapping to align the sounds with our standard village layout scheme.


Another photo of the train at Histon, with the massive Chivers jam factory forming the back scene.


Adding the bagged items and re-testing:

Having added the extras and a Bachmann train crew, I resumed testing.

The sugar cube speaker provides very acceptable performance within the tender body despite its small size. It behaves much better when enclosed within the tender than it did when initially installed externally on the Derby Lightweight trailer car! The small MX648 is easy to accommodate compared to a full size OO gauge sound decoder.

The loco motor control is "good enough" although I think it will benefit from further running-in as its not the smoothest of slow runners under DCC control within the fleet.



Supplier website links:
Hattons    The 3F was sourced from Hattons
Digitrains    Source for Zimo stay alive super cap and Zimo DCC decoder


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