Alternatives to the One Drum Donkey Boiler

Several alternative schemes have been devised, addressing one or other deficiency of the one drum boiler. Perhaps, the most common is the upright boiler with one or more flues through the middle:

My Second Version of the One Drum Boiler

On the occasion of my marriage, I moved to a newly constructed homestead and it was time to design and construct my Mark II donkey boiler:

My First One Drum Boiler

When the latest version of our classic design of Rhodesian boiler stopped working, during my teens, I got to thinking about making improvements on this classic design. Time was limited (I wanted a hot bath), and there were neither text books nor the web to assist me in those days.

Variations and Efficiency of the Rhodesian Boiler

Those of you from colder climes will be wondering how these open air, wood  burning monsters survived for so long. The design of the Rhodesian boiler must, however, be evaluated in the context in which they evolved, and from the origins of its most primitive ancestor:

Design Considerations

Every example of a Rhodesian boiler was built with whatever materials were to hand. As a result, there are nearly as many different designs of boiler as they are boilers. Nevertheless, this basic design is common to most:

Essentials of the Rhodesian Boiler

The essential feature of the Rhodesian boiler is the use of a single 200 liter (44 imperial gallon) drum as both hot water storage tank and air/water heat exchanger. In the days before WWII, I presume other types of drums were used, but thereafter they are mostly constructed with a standard international 200 liter (tight head) drum.

Origins of the Rhodesian boiler

Having established that the 'donkey boiler' takes its name from auxiliary maritime boilers, I then turned to finding the origins of the classic Rhodesian boiler as seen next to nearly every colonial rural homestead throughout the Rhodesian federation, and further afield in East Africa: