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Hornby R2491 & R4238

Potter "Hogwarts Castle" Express Locomotive & Composite coaches

Review & DCC
Decoder installation -
Text & photos by Doug Teggin

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The engine used for the Harry Potter film was originally GWR "Hall" Class 4-6-0 No.5972 "Olton Hall". Built at Swindon in 1937, No.5972."Olton Hall" was one of a class of 330 versatile mixed traffic locomotives, designed by Charles Collett for the Great Western Railway. No.5972 is now set to find new fame as the "Hogwarts Express" locomotive in the Warner Brothers' film of the phenomenally successful Harry Potter stories.

Renamed "Hogwarts Castle" and repainted into fictitious Hogwarts Railways bright red livery, No. 5972 appeared
in the first session of filming at

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Goathland, on the North Yorkshire Moors Railway.
More filming took place at Kings Cross (on "Platform 93/4") in early 2001, taking
No.5972 further into new territory.

The most recent films have used part of the
West Highland line. The scene of "Hogwarts Express" traveling across a viaduct was filmed on the Glenfinnan Viaduct, some 16 miles west of Fort William.

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This was a fun project for one of my kids
who's birthday is coming up. So he'll be getting this lovely 4-6-0
Hogwarts Castle locomotive and two Hogwarts Express Composite coaches.
This was an eBay purchase and there was no brake coach.

The loco is very well detailed and made
to the excellent standard of recent Hornby locomotives coming out of their
production center in China. Likewise the corridor coaches are well made,
sturdy, with a weight that will give the loco something to do to the

Overall the ensemble is very pleasing.

I'm not sure if Hornby modeled the model
from the "Olton Hall" as there
are a few difference that are clearly visible. Perhaps they had moulds
from a similar locomotive and used those. Anyway, there is no point in
counting the rivets as this is a fantasy train. The kids won't mind I'm

The locomotive (with tender) can pull
1.68 kg (6 x 150g coaches + 6 x 130g coaches).

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Decoder Installation

Follow the supplied instructions to
take the loco apart. One screw to remove the front bogey, then one more under the front bogy
and the screw to the rear under the cab to remove the chassis and you're done. You don't have to force
anything - if you do it right, it comes apart easily.

I installed a Arnold Digital 81201
into the Loco. As there are no extra functions required by
the locomotive a simple, but robust decoder is fine. The 81201 can
handle 1.5 amp.

The installation was a little bit
tricky, not as easy as the previous installations due to the lack of
NEM 652 (NMRA Medium) socket and more importantly: a lack of internal space for the
DCC decoder. Where installing a DCC decoder in a loco that has a NEM
socket may take about 10 minutes, this installation takes over an hour
because you have to do some trial fitting and adjustments.

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Note: The TV interference
suppression capacitor and in-line resistors have to be removed for DCC use.

A capacitor is only needed for conventional operations to prevent radio interference.
With DCC operation a capacitor corrupts the data format and the error free data transfer is disturbed.
A snip with a small cutter does the job.

Cut off the NEM Plug from the decoder if
it has one and
following the wiring diagram, attach it to the pickup wires and motor
terminals. The red decoder wire is attached to the wire from the right
wheels on the loco and the black to the left. The orange decoder
wire goes to the motor terminal that was connected to the right wheels and
the grey decoder wire going to motor terminal that was connected to the
left wheels. I somehow got this mixed up. So my orange and grey wires are
the wrong way around in the upper right photo. Either switch them around
or add an extra point to CV29 which reverses the direction (therefore
fixing the direction) I usually have CV29=2, so for this loco: CV29=3.

The DCC chip sits attached to the top of the ballast weight, inside of the boiler roof in front of the motor.
I cut a section away from the lead weight with a metal hacksaw to make
space for the decoder. Cutting the lead is very easy if it is held in a
vice whilst cutting. A few layers of double-sided tape keeps the decoder
secure on the lead, also insulating the components from the metal. Tape everything
in place with black electrical tape and close up the body. This may sound
complicated, but I tried the decoder behind the motor and on the side of
the motor - all to no avail - there is simple not enough space. If you
ever get around to installing DCC in this type of loco, trim the ballast
and put the decoder there.

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Note: This locomotive does not have
lights so the function wires are not used.

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DCC CV Settings
for the Hogwarts Express
CV172Address (The loco
CV22Minimum Speed (V Min at
step 1)
CV34Acceleration delay
CV44Brake Delay (0-15)
CV5160Max speed (V High)
CV640Acceleration Curve (V
CV293Decoder Configuration
CV490Decoder specific values
CV5020Decoder regulation

The rest of the CV's are left
untouched (factory default).

A very attractive model. Beautifully made
with the good detail.

The kids love it and they can have plenty
of fun running it with the other locos on the layout. I let my kids use
the DCC controllers as they are very simple to use and are very robust.
The kids don't have to worry about isolated sections and the limitations
of a conventional DC layout. What a wonderful time to grow up.

- April 2005

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All text, photos & graphics ©2005
Doug Teggin - All rights reserved.

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