C2 Boiler Mountings

On top of the locomotive boiler are the chimney, the steam dome and sandbox, the turbo-generator, the safety valves and the steam manifold. There were many variations among the 5000+ locos built to this basic design, and these are considered on this page. The text focuses on chimneys but the photos have been selected to show some other boiler mounting variations which are mentioned in the captions.

The external appearance of a locomotive's chimney is a key part of its character, but the chimney internal shape is also critical to the steaming performance. Locomotive working primarily in forests are often fitted with spark arrestors to reduce the risk of starting fires. The Russian and Eastern European 28-tonne locos that were predecessors to the C2 had three different types of chimney fitted, depending on the place and date of construction. The Chinese introduced further variations, including some bizarre designs of spark arrestor.

The standard chimney on the 28-tonne locomotive was a neat, tapered fabrication, usually with a small rim around the top. There were minor variations in the shape of the cone. Most C2s carried this chimney, as did many of their predecessors built in Hungary, Finland and Czechoslovakia and Russia.

The KP-4 drawings that we have show a spark-arresting chimney of the classic 'American' shape working on the centrifugal principle. It appears that many of the Polish KP-4s and Russian VP-1s were built with this, and some of the early Chinese locos may have followed these drawings too. The design does not seem to have lasted long in China, being replaced by the standard chimney in most places.

One batch of the Russian-built locos designated VP-4 carried a very ugly fabrication on top of the smokebox, with a spark arrestor mounted above. I have seen this described as a 'steam gas drier' which suggests it is a type of superheater, although its position is more typical of a feedwater heater.

Several C2s were fitted with Giesl-type ejectors in China. The Giesl is a form of multi-jet exhaust that is claimed to improve draughting and steaming. Those used in China may have been unlicensed copies. Looking closely at the photos they in shape and details, as shown below.

At the Sanchazi Forestry Railway, a peculiar form of spark arrestor was used on most locomotives. A large pipe was connected to the top of the chimney, running horizontally to the cab, where it turned upwards to exhaust.

Some of the 28-tonne locos at Pengzhou sported a chunky parallel-sided chimney, which they retained after transfer to the Jiayang Coal Railway (Shibanxi). This chimney appears to be a casting, whereas all other C2 chimneys are fabricated. These locos had been rebuilt (possibly built) at a works in Chengdu, and had several other unusual features including an extended frame at the front.

And finally, something unusual on a locomotive boiler, though occasionally seen on traction engines. The Russian class VP-2 was nearly identical to the KP-4 and C2, but featured a corrugated firebox crown instead of a conventional flat crown with stays. This pair of abandoned boilers at Huangjinggou in 2007 are of this type, and may have originated in Russia.