07-09-2008, 11:52 PM
Wow, sometimes Wiki has really good stuff!
I learned a few things from that useful link, thank you. Unfortunately, it doesn't address the questions of ratchets, swivels, or wheels. The reproduction crane shown in Germany seems to have none of those features, but it gives a very clear idea how it might have worked.
And I may be able to find the Deutsches Museum publication through a local university library, but it's still about a medieval crane. (But the medieval treadwheel crane shown seems to have a swivel base, and it looks like the treadwheel itself acts as the counterweight.
On further thought, it becomes clear that a swivel crane demands a counterweight. The polyspastos shown in the German reproduction uses guy lines to secure it rather than a counterweight. If that's the standard construction, that would pretty much rule out swiveling.
Good start. Any further knowledge?
I learned a few things from that useful link, thank you. Unfortunately, it doesn't address the questions of ratchets, swivels, or wheels. The reproduction crane shown in Germany seems to have none of those features, but it gives a very clear idea how it might have worked.
And I may be able to find the Deutsches Museum publication through a local university library, but it's still about a medieval crane. (But the medieval treadwheel crane shown seems to have a swivel base, and it looks like the treadwheel itself acts as the counterweight.
On further thought, it becomes clear that a swivel crane demands a counterweight. The polyspastos shown in the German reproduction uses guy lines to secure it rather than a counterweight. If that's the standard construction, that would pretty much rule out swiveling.
Good start. Any further knowledge?
Wayne Anderson/ Wander
