Model of the Month May 2009
"Isibutu" by Keith Bucklitch
"Isibutu" was built by Messrs. Bagnalls of Stafford as one
of a batch of ten locos built for the Tongaat Sugar Co, of Natal,
South Africa in 1929. Latterly she was transferred to the
Sezela Sugar Estate in Natal where for a period she (he) bore the
name "Robert Armstrong". The loco has since been returned to the
United Kingdom and latterly has been travelling round the country,
appearing at a number of live steam railways. When I first saw
the loco, she was sitting in the narrow gauge shed alongside the
GWRy at Toddington, Gloucestershire where I was subsequently able to
climb all over her to take both measurements and photographs.
Photograph of 'Isibutu' when named 'Robert
Armstrong' in Natal
by kind permission of Paul Catchpole,
Locomotives International
'Isibutu' as running today on the
Statfold Barn Railway
by kind permission of Tim Edmonds,
Marlow &
District Railway Society
"Isibutu" was built purely for the two-foot gauge and has
mainframes that are only some 32" apart. However to appeal to
a larger number of modellers, I have used modellers license to
increase the frame spacing to accept 45mm gauge wheelsets. The
driving wheels can be adjusted on the axle for different gauge, but
it will be necessary to change the bogie truck entirely in order to
change gauge.
I also wished to design the locomotive so that as far as
possible it could be constructed with the use of hand tools, and the
purchase of suitable commercially available components. I had
a pair of Roundhouse cylinders to hand, so using these, with the
wider frame spacing, the overall width of the loco is 4mm (3")
overscale. I then sought out other commercial components to
use in the model. Therefore, a potential builder can purchase
the following items. (Names in italics are possible sources of
components.) It is probable that this is not a complete list of
either components available or suppliers.
- Cylinders - Roundhouse
- Valve Gear - Roundhouse
- Smokebox - Roundhouse, 'Billy'
- Boiler - Finescale Engineering (Tony Sant)
- Safety Valve, boiler filler, dome - Roundhouse
- Steam manifold, banjo fittings, regulator, pressure gauge and siphon - Roundhouse
- Lubricator, gas tank, gas burner - Roundhouse
- Gas control valve - PPS Steam Models, Roundhouse
- Wheels, axles, bushes, cranks & crankpins. - Essel Engineering, Finescale, Roundhouse
- Sprung buffers. - Brandbright, Essel Engineering
- Handrail knobs - Blackgates Engineering, MES
etc. (Use 2 1/2" / 3 1/2" gauge items.)
My construction series for "Isibutu" will commence in the May
2009 Association SMT Magazine where a complete set of drawings
will be available. It will be necessary for the builder to make the
following components: - Main frames, buffer beams, cab, side
tanks, bunker and small details. If there is sufficient
interest, I can probably obtain sets of frames, modified valve gear
rods etc laser cut. A set of etched brass components for the
superstructure may also be made available.
