In the nineteenth century, at the same time as steam ploughing was gaining in popularity, there was a widespread belief that digging by fork produced a superior result to ploughing - indeed there were travelling gangs of contract diggers who would hand dig a farmer's fields. No doubt there were some reputable firms in the business, although stories of soil that looked beautifully worked on top, but two inches below the surface were untouched, abounded...
Into this came Thomas Darby, a farmer/inventor from Essex who over twenty years produced - in conjunction with several different traction engine builders including McLaren and Savages - nearly two dozen steam digging machines. The first were self-propelled on legs, later machines used wheels and proceeded "broadside" across a field, digging with crank-driven forks as they went.
In the 1960s, Colin Tyler and John Haining, both men with an interest in steam, and steam cultivation in particular, set out to research, design and build a series of models. Their designs were serialised in "Model Engineer" magazine at the time; they published "Ploughing by Steam" together, Colin Tyler went on to write "Digging by Steam" (which I recommend, it's a thoroughly good read and details the development of the broadside diggers).
This model was built by Colin Tyler in 1976 using Savage's works drawings. I remember reading the articles in the "Model Engineer" - I was building a "Tich" at the time, the Darby-Savage looked like a project of unimaginable complexity!. Believed to be one of only two models ever made, it has been in North America for many years, thence to Canada from where we repatriated the entire Tyler collection late last year, along with a large number of stationary engines. The other model is believed to be in the possession of the Darby family.
The engine runs on air - gearing is a bit stiff from lack of use over the last fifty years (
although can be seen digging lustily on a clip recorded in the 1970s here).
scale |
2 inch |
length/inches |
40 |
width/inches |
30 |
height/inches |
21 |
weight/kg |
114 |
cylinder material |
cast iron |
valve type |
slide |
valve gear |
Stephensons |
reverser type |
pole |
governor type |
Watt |
lubricator type |
mechanical |
year built |
1975 |
boiler maker |
non-commercial |
CE mark |
n/a - non-commercial |
working pressure/psi |
75 |
boiler material |
copper |
boiler construction |
silver soldered |
road speed(s) |
2 |