G3 Made Simple
Locomotive Project No. 1
A Live Steam 0-4-4 Tank
A step-by-step construction guide provided
by our contributor "Ginger".
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Whilst leafing through a bound copy of the Model Railway Constructor for 1952, I came across a series of articles titled "a Gauge O steam loco for beginners". I expect many of you have never even seen a copy of the MRC which with MRN and Railway Modeller were the only three magazines published at that time. The MRC series arose from a request by the readers for advice and guidance on how to do it. In a sense that is the essence of this series of articles where the approach is "why not give it a go?"

Reading through the MRC articles, written by "1211", for constructing a live steam tank engine half the size of Gauge 3, it is clear how the construction techniques from 60 years ago are just as valid today. I have to admit that some of the advice given is in some respects better than that provided by LBSC, who often times assumed that readers did not need to be told how to perform simple operations, for example tapping a hole in steel plate without breaking the tap. But one must not forget that back then, the majority of schools taught metal working or woodwork. Regrettably many folk today have difficulty wiring up a 3 pin plug without the risk of electrocuting themselves and as for reading a map - well nuff said.

Off the shelf parts
For a beginner in the creative art of locomotive construction, undoubtedly the two most important off the shelf components are the boiler and the cylinder block. So let us first look at the types of boilers that could be used for the tank engine. Boiler making is actually quite easy, all you really need is a Sievert torch and propane gas bottle, some fire bricks and a supply of lemon juice - and try not to burn the hairs of the back of your hands. However, if this does not turn you on, or seems a bit daunting, you can buy one ready made.
The boiler illustrated above is the well tried single flue, dry firebox type used for the Gauge 1 Project provided by Maccsteam. This design is generally attributed to Victor Harrison and Freddie Wrighton who built excellent models with this type of boiler over 50 years ago. The large ¾ inch diameter single flue is visible below with the blower socket on the left, and the steam take off socket on the right. Although Freddie was best known for his Gauge 1 engines, he built several very fine ones for Gauge 3.
Boilers built by the model engineering fraternity for hauling people are generally coal fired and follow well established techniques, largely replicating full size practice. Coal firing is also to found with many larger Gauge 3 engines, however for a beginner it is advisable to start with a boiler that is easier to make and to uses other forms of firing. The boilers built for Carson and Basset-Lowke were the Smithies type and externally fired. Where a boiler is not solid fuel type, they generally follow Gauge 1 practice that has evolved over many years.

It has to be said that the topic of boiler design gets some folk fired up and has led to many heated debates which continued in the pages of the Gauge 1 magazine for over 25 years. Apart from the merits of methylated spirits compared to gas there are those who favour a single flue or several flues; internal firebox or external firebox; pressure gauges or none; axle pumps or none; hand driven or radio controlled etc. Having owned or built all of these types and also some of the hybrids evolved by some constructors, it best to say that "it is horse for courses" and a lot depends on the type of cylinder, size of engine and method of firing.

The advantage of the Project type compared to the "C" type used by Aster is that it is more suitable for prototypes with a low set boiler as it features an internal firebox (see picture below) which permits a high flame from either meths or gas firing.
In Gauge 3, the boiler back plate should allow plenty of room for the attachment of fittings such as the clack, water gauge, blower and regulator. The two picture below show two different arrangements. The Project boiler with a single flue (left picture) has the "Dee" type of internal regulator with an elbow above for the water gauge.
The one on the right is a modified or hybrid "C" type with only two flue pipes of ½ inch diameter, with an external firebox and uses a screw-in type of regulator that is connected to a super heater pipe passing through one of the flue pipes. This type of regulator was designed by Messrs Models Ltd in 1913 for 2 in. and 2 ½ in. gauge engines and later modified by Bonds O Euston Rd.

Maccsteam can also supply the regulator, safety valve, the gas burner parts and the gas cylinder and valve set up - in other words a one-stop-shop. The other boiler parts such as pressure gauge, clack, water gauge etc. are supplied by the usual traders.

The Cylinder
The cylinder block for one of the engines will be a single cylinder Project type in this case supplied by Keith Cousins. Keith has been making these excellent cylinders for many years and they are used for many of his Gauge 1 locomotive designs. All that is needed to complete the cylinder is the O ring and paper gaskets which Keith can also supply.

In order to install the cylinder block in a Gauge 3 engine, particularly one with a low set boiler, it will be necessary to turn the block through 90 degrees. The valve chest cover will need to be modified by attaching a spacer block made of brass to enable the block to be attached to both sides of the locomotive frames. (see Part 3 for an illustration). Using the single cylinder block enables the beginner to build the "working bits" relatively quickly as the slip eccentric valve gear is very simple and easy to make.

The cylinder for the other engine will be a twin cylinder type, more about this later.

To finish this episode, the drawing below, unearthed from the Plans Draw, is of a North Eastern Railway Back Tank designed by Fletcher. These were very attractive with their flowing lines and reminiscent of Art Nouveau designs. The drawing was purchased a few years ago from the "Smoke-box" in Kingston which was a veritable Aladdin's cave of Railway ephemera, regrettably no more. The drawing is taken from "The Engineer" dated October 1874 and as you can see, is now showing its age.
Keith Cousins, Jackdaw Corner, Old Linslade Road, Heath & Reach, Leighton Buzzard, Beds LU7 ODU. Tel : 01525 234086 Mobile : 07738 460 250

Maccsteam, www.maccsteam.com Tel : 01625 619784