> Derbyshire men drove square and rectangular shafts and Cornishmen drove
> oval shafts. In addition there are the round shafts and I can't remember
> who she said drove those. Has anyone else on the list come across this
> line of thought before, or has anyone any comments? It would be
> interesting to find out.
Interesting. I understood that the cross sections of soughs were round or
square depending on whether black powder or gelignite had been used (whether
this applied to shafts as well, I don't know). A round section would be
more "efficient" to create for a given cross-sectional area, but much would
depend on what you wanted to pass up and down it - I believe some Derbyshire
shafts were rectangular, but divided - one side for kibbles and the other
for men to climb down.
Howard.
|