Scratchbuilt C&M 0-6-2T

The prototype
Atlantic is based on a locomotive once owned by the 2'-3" gauge Campbeltown & Machrihanish Light Railway, which ran in Scotland from around 1906 to 1932. Atlantic was ordered from Andrew Barclay & Sons in 1907 and was the last locomotive the railway purchased. It was virtually identical to Argyll, purchased from the same company a year earlier. (Roundhouse Engineering currently offers a 16mm-scale model of Argyll.) Both engines were used for both passenger service and coal hauling, which was the principle freight carried by the line. In fact, the C&M began life in 1877 as a colliery railway. (For further reading: The Campbeltown & Machrihanish Light Railway, Nigel S.C. MacMillan, Plateway Press, 1993.)

The model
The model under scrutiny was scratchbuilt by Cyril Clarke in England. I have never had the pleasure of meeting Mr Clarke, having acquired his engines from others. He is up in years and, I am told, sold his locomotives because back problems made his ground-level railway problematic. In cooperation with a friend, Peter Brookbank of Rugby, he completed a number of pairs of locomotives, including Russels, C&Ms, and Indian 4-6-0 tender locos. This loco is one of the pair of C&M 0-6-2s.

The locomotive is nicely made and was neatly painted and lined out by David Hardy. It is a pot boiler, with a gas burner similar to an internal-flue-poker, but mounted under the boiler. The gas tank resides in the bunker. Gas flow is controlled by a valve on top of the tank that must be actuated with a screwdriver. The engine, including the cylinders, was constructed entirely without castings. The double-acting cylinders are controlled by the usual D-valves. These are run with an abbreviated Walschaerts-type valve gear. Reversing is accomplished via a lever in the cab. The model has disc drivers, whereas the prototype had spoked wheels. This is not too noticeable, since the wheels are inside the frames. The only noticable major deviation from the prototype is the fact that the model has a center-buffer coupler at each end, while the prototype had a pair of buffers with chopper couplers.

Boiler fittings include a pressure gauge, a water glass, a safety valve, and a check valve for feedwater, which is supplied through an Enots-type fitting below the left-hand cab door. The lubricator resides in the right-hand side tank and is accessible by removing the cap atop the tank. Both side tanks are stuffed with insulating material. The roof is removable for access to the cab.

The engine was originally designed for, and fitted with, radio control. I prefer manually controlled locomotives, so removed the R/C gear. This was a simple task for the throttle, but not so for the reverser, since there was no proper reversing lever. The reversing gear worked off a rotary crank that was actuated by the motion of the servo mounted in the cab. Without having to rebuild the entire system, I was able to fit a manual rotary lever in the cab that took the place of, but functioned in the same way as, the servo.

The run
After the usual oiling around, filling the boiler, gas tank, and lubricator, I set the engine on the track and struck a match. Cracking the gas valve until I could hear the flow of gas, I stuck a lit match under the engine. The fire ignited instantly with a muffled pop. After a very few minutes, pressure began to build. It was a very hot day out, which no doubt contributed to this.

When pressure reached blowoff, the safety valve let go. It makes a loud, rude noise similar to Archangel valves. On this engine, it takes quite a bit of travel to get much action out of the throttle, so I opened it wide. After a little pushing back and forth, the engine took off. It ran smoothly in both directions, but with some knocking of the rods, perhaps due to wear.

I hung a pair of proper Campbeltown & Machrihanish coaches onto the rear of the locomotive, and it looked just right pulling through the heath. In adjusting the gas flow, I discovered that there has to be a good balance between the fire and the boiler. Too much gas, and the safety valve blows off. Too little, and the boiler loses pressure.

Even with the throttle wide open, the engine had no tendency to run away. Slow-speed performance was excellent, though the engine is sensitive to the dips and bumps of the railway. As long as it has sufficient steam, though, it does quite well.

When the water reached the bottom of the glass, I shut off the fire and let the engine run off the residual pressure. Then I uncoupled it from its train, ran it a few feet down the line and opened the blowdown to release the remaining pressure and also ensure a vacuum didn't form inside the boiler. I always like to wipe down a hot engine with a dry rag. The oil and dirt comes off easily then and does not congeal. Thus ended a satisfying run of a satisfying locomotive. I wish they were all like this.