Barrett Engineering logo
Manufactures of Gauge 1
Live Steam Locomotive Model kits
and accessories in 10mm scale

Director Mr S.Barrett     Company Reg No. 8391616

GWR Churchward Heavies
Complete kit 42xx / 52xx

Complete kit 72xx

The kit can be paid for  in 12 monthly instalments
add £108 for postage

Production :-   Batch 1,   starts October 2017
Technical detail

Select technical detail to view a description of our steam kit design.


  These large tanks were designed in 1910 for use around the south Wales coal fields to move expanding coal trains of the day. With the weight of the loco sitting on eight small drivers their tractive effort was very high. Their efficiency was good since they still required only a single crew. His standardisation meant they shared many parts from the Large Prairie tanks and 28xx’s.

 Our model design is well progressed but as yet no model prototype has been completed. With our extensive range of GW locos to pick from,  development shouldn’t take long!


       Our model represents the 42xx, 52xx and 72xx classes covering the majority of the class. The model is designed with working outside cylinders which with the small wheels will give a high tractive effort. Inside slide valves are driven by a simple, robust, and easy to set, slip eccentric gear. A hand pump is located in one of the water carrying side tanks which also feeds water to an axle driven pump. The bunker will carry the meths tank.

       You will require a bench and vice, some hand tools, a drilling facility (which could be an electric drill on a stand) and a small gas torch for soldering. The work includes bending sheet metal, drilling piloted holes out to size, tapping threads in holes ( in many cases nuts could be used instead), soft and hard ( silver) soldering of small items.  The model making hobby is littered with part built projects which have been abandoned because the modeller has hit a problem. Included in the price are two hours of our time, a ‘get out of trouble’ service. It could be advice on the phone, a practical soldering training session in our works, correcting a mishap or setting valve timing. Apart from phone calls, a modest charge will be made for time spent over your two hours.

         We can also supply replacements for individual components providing they are returned for us to identify. For etched items there will be charge depending on the size. Whitemetal returned with stamped addressed packing are free. Laser cut steel may be a problem as there are minimum order quantities involved and we shall only order a limited number of spares.

       The Construction  Guide comprises over  30 pages of photographs, exploded diagrams produced on 3D CAD and text, together with identification diagrams and drawings. It takes you through each stage, including jigs and methods, settings and adjustments, finishing with operation and use.


Scale            : 10mm : 1ft

Length         : 42xx/ 52xx  408mm over buffers

                     : 72xx            448mm over buffers

Radius  min  : 42xx / 52xx   2.5m   (8’3”)

                       :72xx              2.61m  (8’8”)

Weight         : 5 Kg   estimated.

Fuel               : Alchohol  (Methylated spirit) supplied by constant level feed system.

                      :  to a multi-tube ‘strand wick’ burner.

Boilers           : Internally fired, multi flue, superheated. with safety  valve.

                       : Built from copper and bronze, silver soldered throughout.

                       : Tested to 200psi  (13bar)

                       :   Max.allowable working pressure 100psi (6.86 bar)

Controls         : Regulator, blower,  pressure gauge and possible water gauge.

                       : Spirit valve in rear bunker

                       : Bypass valve on side tank for water pumps.

Cylinders      : Two,  Outside 14.3 mm dia x 25mm stroke  (9/16” x 63/64”)

Valvegear     : Slip eccentric, slide valve, between frames.

Lubrication  :  Displacement (Rosco) type with filler and drain.

Water feeds : Water carried in both side tanks

                       : Hand pump with bypass valve in side tank.

                      : Axle driven pump with its pipework, clack valve and boiler feed.

General         :  Loco suspension, buffers and coupling hooks sprung.

                        Wheels and axles are to Gauge One ‘Standard’ dimensions.

Move over pictures to magnify