Modelling: Kit corner
Cambrian’s ‘OO’ gauge BR ballast hopper wagon kits are now decades old and the ‘Dogfish’ has since been produced as a ready-to-run model by Heljan. With no commercial model available for the ‘Catfish’, however, the Cambrian kit is the only way to model th
Reviving interest in kit building with the Cambrian Models ZEV ‘Catfish’ ballast hopper wagon.
CAMBRIAN MODELS remains an important source of kits for wagon models not currently available as commercial models in ‘OO’ gauge. When they were at their peak, modellers relied on them for signature wagons such as the SSA scrap steel wagon and various ballast hopper wagons. Many a West Highland line was populated with OTA timber wagons built from Cambrian’s plastic kits.
Quite a few kits from the range have been superseded by ready-torun models, yet remain available to buy. They offer the chance to model wagons when the ready-to-run version is unavailable and variations within wagons are often easier to incorporate by kit-bashing rather than converting a commercial model.
The ZEV ‘Catfish’ is not available as a ready-to-run model, making the
Cambrian kit the only way to model this distinctive 19-ton four-wheel ballast hopper. The kit is far from perfect and a recent purchase shows that the moulds are showing their age, requiring some careful preparation of parts before they could be used. It can be tricky to build, but does make up into a reasonably accurate model if care is taken.
Naturally, the kit can be enhanced with etched brake wheels, sprung buffers and different pattern of axle boxes – the original tooling having selfcontained buffers and oil axle boxes. How you finish it is entirely up to how much time and additional money you wish to put into the project.
The prototype
Construction of the 19-ton ZEV Catfish was undertaken concurrently with the larger 24-ton ZFV Dogfish wagons, the fleet of nearly 2000 wagons sharing many common features including the basic underframe. The various construction batches were interwoven with each other, with the same basic design being used throughout, effectively creating a standard BR ballast hopper design which replaced older designs such as the ‘Herring’ and ‘Trout’.
As each successive batch of Catfish and Dogfish were completed by builders Metro-Cammell, Charles Roberts & Co and BR Shildon, the design was upgraded with Oleo buffers and roller bearings. Catfish enjoyed a long operating life, lasting to see the Privatisation period. Documents show that very few conversions were undertaken including the single ZCV ‘Puffin’ which had its hopper chute removed along with the control wheel.
A wooden floor was fitted so it could be used as a spoil carrier.
Liveries included black upon introduction in the mid-1950s; the short-lived gulf red scheme which survived on some wagons in the early 1990s and the more common BR olive green livery. The 1980s saw the application of engineers yellow and grey scheme to those wagons receiving overhauls. Markings varied from wagon to wagon and were rarely standard. As time progressed, the liveries were overcome with rust and fading overlain with staining from ballast loads.
The Cambrian kit
Composed of two plastic sprues and a hopper moulding, the kit appears simple in design. One sprue holds most of the underframe parts which makes
up into an underframe composed of the solebar and axle guard assemblies and the headstocks. The end platforms which slot in behind the solebars, one larger one for the operating wheel end and one smaller one for the brake cylinder end, are located on the second fret. The hopper sits into the frame which is then detailed with brake gear, bracing and buffers.
The plastic is quite soft and that makes the kit both forgiving of adjustment on one hand and easy to damage through the excessive application of solvent cement on the other. Some parts are better applied with a scientific CA type glue for awkward plastics but at the cost of making further adjustment difficult and that is important with the Catfish kit.
One thing about the earlier Cambrian kits is that the fit of some parts is less than precise and there are compromises you will have to incorporate into the model, but that’s modelling. However, there is sufficient space between the frames for ‘P4’ and ‘EM’ wheels and the kit, if carefully assembled, will performwell. Finding somewhere to conceal some muchneeded ballast weight is a challenge. Some weight can be concealed under the platforms and a load should do the rest. Empty wagons could have a
small amount of ballast or ‘liquid lead’ placed beneath the hopper bracing and painted the same rust colours as the hopper interior to disguise it.
Preparation
Many of the parts are moulded close to the main sprue with minimal tags making them awkward to remove, including some of the smaller parts, without damaging them. Sprue cutters should be used to take a section of sprue out with the relevant part. It is prepared by carefully paring the excess plastic away and finishing with a fine cut needle file and abrasive papers.
Most parts can be cut out of the sprue with a modelling knife against a cutting mat. All of the parts should be given a good clean file along the edges with fine abrasive paper – wet and dry paper is definitely your friend when preparing Cambrian kits for assembly.
Lastly, look for the reference letters on some of the parts which indicate which way round they should be fitted, including the hopper, platforms and chute bracing.
Underframe building
Two jobs are worth carrying out before putting the underframe together. Look at the inside of the axle guards and note the plastic collars on the inside of the axle boxes. The kit accepts ‘OO’ gauge wheels with 24.5mm and 25mm long axles which were more common when it was designed.
To use today’s standard 26mm long axles, pare away the plastic collars flush with the rear of the axle guard moulding. Use a 2.1mm diameter drill to open out the axle box so that 2mm diameter rolling stock bearings will drop in. Secure them with a spot of solvent cement which will not prevent adjustments being made. Secondly and strange as this might seem, carefully measure the length of both solebar mouldings. Depending on how they were cut from the sprue, bearing in mind the comments above regarding the way the parts are moulded close to the sprue, they might be of unequal length. Trim the longer one before assembling the underframe.
The solebars and headstocks go together first, as two assemblies of one solebar and headstock which are left to harden before bringing them together. A little fettling is required to drop in the end platforms and no matter howmuch filing you do, the joins won’t be perfect. Assembly of this critical part of the Catfish should be done on a flat surface such as glass, with the wheels clipped in, to check that all is square.
Allow to harden up overnight before adding the brake shoes. Some adjustment may be required if the frame is not square and true when checked on a piece of glass. This is a little out of the instruction sequence, but allows you to fit the shoes with the wheels fitted to assist with alignment. Trim the top of the mounting lug of each shoe so they do not interfere with the underframe platform mouldings. Solvent cement will allow the shoes to be adjusted later if required or CA glue will ensure they are well attached!
Fitting the hopper
It’s the trickiest job of them all and requires a lot of patience to seat it correctly on the upright stanchions. Those at the operating wheel platform end have to be trimmed slightly to achieve a level hopper and some fiddling round with the chute side plates is needed for a good fit. Once level with the solebars, the hopper
can be glued in place and detailed with the internal bracing piece, noting the orientation letters. This part is a compromise and does not fit as intended. Even when aligned with the reference letters at the correct end, it will not fit correctly and it sits too deep into the hopper too. You may either dispose of it and make up a new one and add the additional bracing to the hopper for a repaired wagon or live with it. A load is the perfect way to disguise this detail if it truly offends.
A little fiddly work follows in fitting the vacuum cylinder and hopper bracing at the outer end of thewagon. A frame supporting the discharge chute wheel also requires some fettling for a good fit. This small detail takes time to prepare, including the discharge wheel. There’s the danger of flooding themodel with solvent at this point in assembly, so be as sparing as you can be – those bracing pieces will melt in a flash.
Detailing parts
With the hopper sitting snugly in its underframe, the wagon can be detailed with buffers, couplings hooks, vacuum brake pipes and brake shoe yokes.
The models built for this article were modified with different styles of roller bearing using both MJT Components parts and some left over from another kit. Buffers can be replaced with sprung Oleo buffers by Accurascale or better cast metal self-contained buffers alongside vacuum brake pipes from Lanarkshire Models and Supplies (www.lanarkshiremodels.com).
Final jobs include fitting wire grab rails and the tiny brake wheels which require much care in their preparation. A pack of brass wheels of various types is available from 51L Models if a finer type is desired (www. wizardmodels.ltd).
Couplings are always the preference of individual modellers. The kit will accept both cosmetic and working scale ‘Instanter’ couplings, with plenty of room behind the headstocks for the spring and split-pin. Mounts for tension lock couplings are supplied with the kit and other working coupling systems such as the Dingham Autocouplers will fit with a little fettling.
Painting and transfers
Leave the completed model for several days to allow any last vestiges of solvent to dissipate and softened plastic to fully harden before painting.
Livery colours are readily available under the Phoenix Precision and Railmatch labels. Liveries such as black, gulf red and olive green are straightforward and easy to apply with airbrushing being the best way.
Detail painting includes black to the various underframe members and white to grab rails and the discharge wheel. Some masking is required to separate the yellow band from the Railfreight grey body colour. Beyond that, care is all that is needed to finish the underframe and details.
Transfers are a little more tricky. Modelmaster offers some useful waterslide transfer sheets for wagons which can be adapted, including sheet No. BR403 ‘Numbering for Post 1964
Engineer’s Departmental Wagons’.
Some numbers and TOPS code letters have to be cut from a number of different wagon data panels to make up the appropriate markings, using photographs as a guide. Once complete, a coat of matt varnish and weathering follows.
Catfish, like many engineer’s wagons, became quite rusted, particularly the hopper interior and end platforms. Awide range of different colours are available to re-create everything from the very dark brown rust shades which underlie the lighter rusts hues found in a regularly used wagon.
Loading and discharge is abrasive and leaves distinct tide lines of different rust colours and some dusting on the interior. Externally, the body colour becomes abraded and eventually rusts with staining from rain water adding to the character. Rust and frame dirt can be used to finish the underframe, including any couplings and of course, the wheels.
Kit building is a very satisfying way to add something different to the layout, amodel you have built for yourself and especially when the desiredwagon is not available in any other form.
Older and experienced modellers find that tackling a Cambrian kit for the first time in years will bring back memories of having to build them routinely, including the dodges and weaves one had to do to make them work. But when they did work and ran well on the layout, the feeling of having achieved something was always very positive. Next...!
Catfish No. DB 983805 survived in gulf red when photographed in 1992. Note the rust shading on the platforms and solebars. Roller bearings and Oleo buffers are fitted to this wagon.
A view of the interior of a Catfish hopper showing the tide lines of different rust shades.