A Hunslet Mallet - The 7mm Narrow Gauge Association

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Narrow Lines 202
A Hunslet Mallet
Andrew Young describes the building of ‘Boadicea’, runner up in the John
Stitson Shield competition at the Association’s 2012 Exhibition.
Photographs by the author.
One of the more sociable aspects of the hobby is being a
member of a club or an association where ideas and inspiration
for new projects, or ‘silly ideas’ can be discussed at length. Over
the years there have been no shortage of silly ideas amongst
the members of the Association’s Trent Valley Area Group
(meeting in the pub might have something to say about that)
and the emergence of online forums only goes to aid this.
Whilst some prefer prototypical modelling, my fertile
imagination often heads into the world of freelance modelling.
The key to believable freelance modelling is to make convincing
models that would work if they had been commissioned; after
all there are numerous prototypes which only ever existed on
the drawing boards of the loco manufacturers of the past.
Personally, I find there's something unerringly elegant about
Hunslet products, especially those from the Edwardian era. (I
think that the graceful curve of the cab opening has something
to do with it.) However, this model is more a figment of my
imagination than an actual product of the Jack Lane works, so
any rivet counters might want to look away now.
Like most of my freelance models, this one had a long gestation
period and the model that resulted is very different to the one
originally envisaged. The physical starting point for this model
is the Slimrails kit for the 4-6-0 side tanks that Hunslet built for
the War Department during the First World War, or more
specifically the castings for the body from this kit, while the
inspiration came from a discussion thread on the Narrow Gauge
Railway Modelling Online discussion forum www.ngrmonline.com by David Taylor (he of Charmouth and Bridport
fame). He was using the castings to make a narrow gauge
tramway loco inspired by the 2-4-2 standard gauge locos of the
Bideford, Westward Ho! and Appledore Railway.
An email to Simon Chivers followed by a cheque very quickly
resulted in a set of Hunslet castings (and very nice they are too).
My first idea was to build a 2-4-2 tank using a chassis I already
had, though a quick comparison of the castings and the drawing
of the 4-6-0 soon showed that this wouldn't look right, so back
to the drawing board I went. Some people rather like their
Garratts, or their double Fairlies. However I'm a big fan of the
Mallet loco. I think this stems from a family holiday in France as
a teenager when we travelled on the Chemin De Fer
D'Abreschviller behind their Heilbronn Mallet. The fact that the
railway's 700mm gauge is very similar to the 2ft 3in of my
favoured Talyllyn might have something to do with it. Hunslet
didn't do much in the way of articulated locos, with the notable
exception of 'Gowrie' for the NWNGR (and some geared locos
of Avonside parentage), but my thinking quickly progressed
along the lines of ‘what would an 0-4-4-0 Mallet loco look like
had Hunslet built one sometime pre WW1?’
It was time for some research. This is, I find, one of the most
enjoyable parts of this hobby, especially when it involves pulling
a few books off the shelf and settling down with a cup of tea or
a glass of something stronger. Looking for Mallets, my idea soon
centred on building a Hunslet version of the small O&K Mallet,
one of which is Pakis Baru No 5 as restored at Statfold Barn.
This has the right proportions for the Hunslet parts, plus I have
a drawing of the original inspiration, the Heilbronn built Mallet
at Abreschviller. The result was a Mallet based on the Hunslet
WD loco, but with certain aspects, such as the arrangement for
the pivoting front bogie design, from ‘Gowrie’.
Having decided on a Mallet loco, the next stumbling block was
a suitable chassis. Thankfully, fellow Trent Valley Group member
Tim Allsopp (and fellow instigator of silly ideas...) had a Roco
H0 Mallet chassis waiting for a suitable silly idea to be put under
The ingredients: The Roco chassis (Left) and the castings as supplied by Slimrails (right).
Narrow Lines 202
which he was happy to sell on to a good home. Now that I had
a chassis, a sketch (to use the term drawing would be an insult
to draughtsmen!) was made using the chassis and body casting
dimensions and was tweaked until it looked right in my head.
Finally, I was able to make a start on the model.
The first job was to clean up the castings (which didn’t take
much as there was little flash) and dismantle the chassis,
followed by extending the chassis using Evergreen Styrene (from
Association Sales - quick plug) to the size needed. First, the
chassis was built up at the rear to form a solid base for the cab
floor to sit on (and be secured to). The floor casting only needed
a small amount cut away to clear the rear gear box and proved
a good fit. This was lined up so that the leading cylinders were
in line with the chimney, as they would be on a real Mallet. As
a result, the valve gear lifting links for the front bogie are in
front of the side tanks, just as they are on the WD Hunslet. The
height was decided upon by eye, high enough to give the
traditional ‘gangly’ Mallet look, but low enough for the boiler
to hide the drive shaft to the leading axle. Compared to the
drawing, the difference in height to the WD Hunslet is only
1mm.
Before progressing any further, it seemed prudent to arrange
how the body and chassis fixed together as this would be very
difficult to change later. The design of the body has the cab,
tank, bunker and boiler castings built up on the footplate/tank
base casting so I inserted a bolt through a handy hole in the
chassis casting, drilled a hole to suit in the footplate casting and
soldered a 10BA bolt to the top of this. Whilst the chassis looks
like a Mallet chassis, it is in fact rigid, with no swinging front
bogie, but allowing the wheels enough sideways movement to
manoeuvre round curves. This made the front fixing easier and
I settled on a bolt through the characteristic Mallet steam pipe
up into the smoke box.
Having settled the mechanical fixing, the next stage was to
assemble the main body castings. These are lovely and crisp and
in an evening I soldered up the main cab, firebox and tank
components. Adding a few other castings rested against these
gave me the first idea of what the finished loco would look like.
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I find this important to do at various stages of a project like this,
as the old adage that ‘if it looks right, it is right’ is often true.
With the body and chassis fixing at the rear sorted, the next
job was to do the same at the front of the loco. The bottom of
the boiler casting was cut away so that it fitted over the gear
box and drive shaft, while the smoke box casting had the saddle
part removed as this would look wrong for a Mallet with the
front bogie floating underneath the smoke box. The base of the
smoke box casting was drilled and a piece of styrene tube
inserted and fixed firmly with glue. The tube was tapped 10BA
on the inside, a hole drilled through the chassis casting in the
right place and a 1¼ inch long 10BA bolt inserted. Next the
boiler and smoke box castings were soldered to the rest of the
body castings and with the fixing points resolved, my attention
returned to the chassis.
The front gear tower was filed down in an attempt to minimise
its impact as far as possible and the chassis was built up front
and rear using Evergreen styrene, quite a fiddly process, but
worth taking time with to get a square and strong model. At
the front, a new piece, including coupler mount, was built up
out of styrene sheet and strip which slides over the front part
of the chassis. The top plate acts as a base for the front fixing
point - a bolt inside the threaded main steam pipe - to locate
on. At the rear, the chassis extension is fixed firmly to the metal
chassis, with a bolt through as a rear fixing.
Detail work was the final stage in completing the chassis; this
was where photographs of ‘Gowrie’ were the most useful. First
the bunker rear casting (as it came, this included the rear buffer
beam but this was sawn off) was soldered to the other body
castings and the rear buffer beam was shaped and fitted. The
handbrake mechanism was fitted to the fireman's side and the
steam brake casting on the driver’s side (using castings from the
kit) with the actuating arm and cross shaft built up out of styrene
strip and brass wire. At the front the sandboxes were made up
and fixed on in the same position that ‘Gowrie’ had them, also,
handily, helping to disguise the front gear tower further.
Apart from one or two fettling bits to be done after priming,
this completed work on the chassis. It was then dismantled,
cleaned up and primed to see whether there were
any glaringly obvious parts that needed changing.
Once I was happy, the chassis was painted and
weathered. The fiddly job of reassembling the valve
gear completed it.
With all the structural work complete, it was time
to add all the detail parts to the body, the stage I
find most enjoyable. Taking care that the detail
parts look right can often make the difference to
creating a more believable model. A good number
of detail castings came from Slimrails and these
were used along with parts from my well stocked
bits boxes; a variety of loco fixings which I’ve
collected from various sources over the years,
from which I can choose the most appropriate for
the project in hand.
The chassis complete: At this stage the boiler fittings were just placed on but not
fixed in order to give an idea of what the loco would look like.
With the aim of producing an Edwardian Hunslet,
reference was once again made to photos of
‘Gowrie’ and other contemporary Hunslet
products. The chimney is the WD Hunslet one, as
is the dome, but modified with the safety valves
replaced with a set of Ramsbottom valves moved
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Narrow Lines 202
Two view of the loco with all the detail applied,
showing just how cramped that cab is!
to the top of the firebox along with the whistle. Lamp brackets,
tank stirrups, cab steps, turned smoke box dart, vacuum pipes
and blower and ejector pipe runs were all added to the body.
Inside the cab, hand brake and sanding controls were fitted on
the cab back. The firebox backhead was shortened to clear the
rear gearbox and detailed with all the fittings, pressure gauges,
brake controls and plumbing that would be there glued in place
after painting. Finally, a driver and fireman were provided they’re securely fixed in place with one leg drilled and tapped
10BA and a bolt inserted.
The final stage was to strip the loco down one last time and
give everything a good clean before priming and painting. Once
cleaned, a spray with Halfords primer followed and then a spray
of Railmatch LMS Crimson Lake. I read somewhere that this is
a very translucent paint and can be affected by what undercoat
you use. As I wanted a darker/browner shade than the
lighter/orangey colour that can result, I primed using red oxide
primer rather than the grey. The rest of the loco was brush
painted before being lined out. Here my initial thoughts for
replicating the full Hunslet Edwardian lining were reined in to
something less fussy, and more manageable with my bow pen.
Hunslet style name and works plates came from Narrow Planet
- first time I've used them and very good they are too (usual
disclaimer applies). These works plates are even right for when
Hunslet built the loco (well, in my head anyway) - 1910. The
name 'Boadicea' was chosen as being suitably grandiose for the
Edwardians and with all that outside valve gear it reminds me
of tales of Boadicea's chariot.
Once looking pristine, a spray of satin varnish was followed by
the fiddly job of glazing using small pieces of clear styrene. A
cab roof was made up, curved to shape and fitted, some coal
added to the bunker and the model assembled for the final time
before some subtle dry brushed weathering. The completed
loco was checked over and run in on my rolling road and then
given an outing on the Trent Valley Group’s layout. It coped
with curves and gradient changes well, just requiring the
pick-ups to be tweaked to cope with the movement and keep
electrical contact without the pick-ups fouling the spokes. Once
tweaked, the loco runs very sweetly.
My aim was to make a Hunslet Edwardian might have been, with
a Gowrie-esque look about it. The resulting loco I'm happy with
(though I must learn to put rivets on bufferbeams in a straight
line next time!) Thanks to Dave Taylor for sowing the initial
seed and for those on NGRM and fellow Trent Valley Group
members for their suggestions and comments on the way. This
Hunslet-bashery is strangely addictive. I suspect this won’t be
the last of the Hunslet inspired silly ideas I have...
‘Boadicea’ before weathering, with the paint highlighting the cab fittings. The styrene box covering the rear gearbox is hidden behnd the
driver and fireman.
Narrow Lines 202
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The finished locomotive in service on the Trent Valley Area Group’s ‘Henmore Dale Light Railway’ layout, heading a goods train out into the
Henmore Dale.
Book Review
The Isle Of Man Railway - Colour Photographs 1963-1971
Eric Bird - A Railway Modeller Special
Published by PECO Publications and Publicity. ISBN: 978-0900586439
Softback, 108 pages including covers. UK RRP £14.95p
This is a third book on the Isle of Man railways from PECO,
who supplied the review copy. It is primarily a book of
photographic images of the railway as it was in the 1960s and
just after. The supporting text concentrates on providing a
historical context for those images. All the pictures were
taken by Eric Bird who was an IoM resident for part of the
period covered.
Apart from a small selection of black and white images from
the early 1960s , all the photographs are in colour - useful
for deriving information on liveries. However, most of them
are of trains on the single track out in the countryside. Unlike
the David Odabashian pictures from the 1950s contained in
the companion book reviewed in NL 199 this collection
contains no detailed shots of rolling stock and few of the
stations.
The Ramsey, Peel and
Port Erin lines are all
covered. Some of the
photographs of the
viaducts
on
the
Ramsey line - steel
girders on stone piers
- could be useful to
freelance modellers wishing to construct a British alternative
to the trestles so beloved of the 0n30 fraternity. There is
also a good shot of the ex-County Donegal railcars 19 and
20 in revenue earning service on the Port Erin line.
Overall, however, this is more a book for the IoMR
enthusiast than for the modeller looking for detail.
Reviewer: Peter J Page