Haio Zimmermann is an archaeologist who works in Germany and in the Netherlands. He is working on a publication about a traditional hoisting instrument to screw up heavy loads like timber houses, water- and windmills, ships etc.
The picture here is of a Norwegian example.
It is on an average 1 - 1,10 m broad. Haio can follow the design back to medieval times and it was used in most European countries, according to preserved instruments and early written sources. From Great Britain however he knows of only one instrument and one mention in a handbook.
Can we help?