Welcome to Fenny Bridge
1:43 scale, 7mm, 'O' Gauge Modern Image Layout,
built by Keith
Powell & Steve Weeks.
The Idea -
after Warley 2004 that Keith and I decided to build a 7mm
gauge modern image layout together. With Keith’s attention
to detail and many years of modelling experience along with
my DCC knowledge / Electrical background we both felt we
could achieve something to be pleased with.
had to be of exhibition standard, be easily transportable,
require no more than 4 operators, have a yard area with
operational shunting independent of passenger traffic and be
DCC controlled. The overall length could be no longer than
28 feet as this is the size of Keith’s garage, where the
layout would be constructed and used once built. This would
also give easy access for loading and unloading.
divides nicely into seven boards measuring 4’ x 18”. The
width allows the layout to be transported in a custom built
rack within my van. The boards are made of plywood frames
with reinforced ends. The bases are 1” thick pink modelfoam
available from builders merchants, making them ridged but
light weight. Once complete any cracks were filled and
sanded to a smooth finish. Boards are aligned together
using ply dowels and locked in place by over centre catches
fitted to the sides. All boards have tubular metal legs
with flat feet which screw to the underside. Board 4 has
four legs and is the first to be erected. Remaining boards
3,2,1 are joined to the left, 5,6,7 to the right and fitted
in that order. These have two legs only and piggy back one
another. The use of 300mm raised legs means it can be
exhibited on standard tables and for use at home, sits on a
kitchen worktop in the garage.
plan, 28' x 18” is of freelance design with hand built track
and point work from
C & L Components. The bridges, tunnels,
platform and retaining walls are scratch built and use
embossed plasticard from
South Eastern Finecast
ranges. Platform and line side accessories are from
Clark Models. The Colour light signals were custom built by
Roger Murray (No longer available).
of locomotives is carried out manually by the operator using
DCC control, however all route setting and signalling is
carried out by a computer. This combined operation with
track occupancy provides prototypical block signalling inc
SPAD's, route selection and interlocking.
spent many hours learning about signalling and signal box
operation I wanted the front end, in our case a laptop,
running Traincontroller Gold software to feel and operate
very much like a modern signal box but with an early display
panel. This I feel has been achieved by using photographs
of actual signal box panels in order to gain graphic
Interface between computer and DCC system is LocoBuffer USB
2 from RR-Cirkits.
showing route selection.
A big thank you has to go
to Roger Manton for his assistance with our Signalling
and I had Digitrax systems already and as there was still
nothing better in 2004 we decided to stick with it. The
layout is split into three sections called districts DCC/1
to DCC/3. This separation will reduce in the event of a
fault, complete shutdown during an exhibition. Each
district supplies accessory decoders used for the operation
of colour light signals and BDL168 (Block detection, for
loconet with 16 detection sections and 8 transponder zones)
in order to monitor track occupancy. This information is
then fed back to the command station via loconet.
We have one
DCS 100 command station and two DB 150 boosters named
Command, Booster 1, Booster 2. Handsets are DT 400 which
offer twin pots for independent control of loco’s with a
shared keypad with 12 F keys giving access to functions such
as lighting and sound.
have a further DB 150 booster named Booster 3 which only
supplies DCC power for the operation of point motors. For
this to happen we use a PM42. (Power manager, with 4
sections, 2nd version) This divides the booster
output into four sections of which three are called P1, P2,
P3. These supply DCC information and power to DS52 modules
which operate Tortoise point motors.
event of a short being caused by an operator not
concentrating and driving a loco into a wrongly set point
the booster supplying power to the loco will shutdown. The
points however can still be operated without the need to
touch the loco as they are fed from Booster 3. Once the
offending point has been operated the booster supplying
power to the loco will auto reset and allow the loco to
section is for a service lead with croc clips used mainly
for wheel cleaning operations and called S1.
programming is carried out on the layout using a siding
wired through a double pole change over switch with an
Lokprogrammer installed underneath board 1.
station and boosters have a rating of 5 Amps each.
Therefore a 5 Amp transformer is required for each one. We
have used four MT10 from
Wiring is rated greater than or equal to the max output of
the command station or booster. Cable runs were kept as
short as possible to keep volt drop to a minimum. Therefore
the cable selected is 1.0 mm squared multistrand and has a
rating of 6A. All cables are distributed from underneath
board four, the central location for all power supplies and
DCC command station / boosters. This has given trouble free
DC power is
provided from a PC power supply and offers both 5v used for
colour light signals and 12v to power the BDL 168.
are from the 1980/90 era, without any definitive timeline
and operate unassisted at low speed. All are sound fitted
South West Digital
ltd and have working lights.
to the question we have been asked many times "how do you
get your loco's to run so smooth".
all traction is sound fitted with volumes reduced to give
localised sound this has to take 2nd place over running.
After many trials during the last 10yrs only ESU decoders
are now used in 128 speed step mode with
ABC gears. This
combination with plunger pick ups gives very fine, quiet
unassisted control at low speed. This is because the motor
is only driving the gearbox, the gearbox is doing all the
hard work. Track, wheels and pick ups must be kept clean.
Any failure with good house keeping will result in loco's
stopping and sound being interrupted.
fitted with two motors are wired in series NOT parallel as
the decoder back emf is now only controlling one load not
two. This will result in top speed being reduced but the
control at the low end is superb. Parallel wiring will give
more top speed but will judder at the low end as the back
emf can't control two motors. One way to achieve both is to
order 6v motors not 12v as standard and wire in series.
has nothing to do with choice or the cost of a DCC system.
It is all to do with choosing the right decoder for the job,
decoder setup, motor / gear ratio and cleanliness.
kits 37, 25, 20 are from
JLTRT, built and
Workshops, DJH RTR 03, modified by
ABC gears, Westdale 108 / 122, built and painted by Dave Hampson,
and 31 from
MMP, built and painted by
The Wagon &
Carriage works brings operational interest with a variety of
mixed traffic such as GUVs, VGAs, Hoppers, tanks and
coaches etc being brought in for service and or repair.
There are a
mixture of kits mainly
JLTRT built and painted by
Workshops but also kits from
Parkside Dundas built and painted by Keith. There is a rake of tanks
from Skytrex and the MK1 coaches are from
Easy Build, built
and painted by Richard Pogson.
were spent discussing what coupling to use as shunting would
be a large part of the operation and be very visible at
exhibitions. Therefore this had to be automated and very
reliable. For this purpose we chose the
These were ordered from Trevor Shaw and duly fitted. These
worked very well as stock could be uncoupled on the move by
electro magnet whilst being propelled. However there were
limitations when used with bogied vehicles as the coupling
had no sideways movement.
We then had
another look at Kadee Couplings and decided to purchase the
height gauge and some couplings from
P & H Models in order
to convert a few vehicles for testing. This worked well but
again we did not like the fact that each vehicle has to be
stopped in order to uncouple it.
point in time our heads were rather low and during a moment
of madness “out came the Dremel”. We decided to remove the
buck eye from it’s shank and replace it with the Dingham.
This immediately brought a smile to our faces and is now
jokingly called the “Kading”. We now have the best of both
worlds with sideways movement and uncoupling on the move.
the future -
presentation is very important to us and Exhibitions are
viewed like a band would a gig. We are there to entertain
the paying public in a professional manner.
completed our maiden voyage without any problems thanks to
help from Roger Fithyan, we are recruiting a fourth member
and can now continue our ongoing attention to detail and any
improvements felt necessary as they arise. This will
include adding lighting and resistor wheel sets to rolling
surprised at the level of interest in computer control form
both novice and experienced modellers. However, over the
two days noticed that older people would look at the layout
first and then the computer, whereas younger people would do
the opposite. The link with technology is vital, especially
for the younger generation to whom the hobby must encourage
we have taken comments on board and in future will not only
show the benefits of DCC control to operate trains around
the layout, but also include the use of a large screen with
a signal box view as part of our overall presentation.
have been made within the text to companies and individuals
that have helped bring Fenny Bridge to life.
like to say a special thank you to Caroline for her
enthusiasm and putting up with the pair of us.
Latest news -
Fenny Bridge at the
Nailsea & District MRC show in
See RM issue 61
Feb 2010 for a
Class 20 from Tower has been sold and replaced with a JLTRT
version. Simon Varnham assures me he is well under way
with the MMP CL 31, and we now have some Pressflow wagons
from JLTRT. Two Heljan 47's are in the workshop along side a
Bachmann 08 which is being modified by ABC Gears.