Wellington Boots were originally made from Leather before vulcanised rubber was discovered. More recent polymers are now used such as PVC and PU (polyurethene)
Given that rubber wellies are hard to come by, PU is environmentally preferable over PVC and has a more rubbery feel rather than plastic one of PVC. PU is also lighter in weight.
PU wellies are usually at least twice the price of PVC but should last more than twice as long and be more comfortable. Dunlop make a Purofort range which are unduly expensive for my wants.
Enter COFRA Both Dunlop and COFRA manufacture in the EU
portwest.com/pu-safety-wellington-s5-ci-foPortwest was of interest but their PVC wellies are made in Turkey so NO thanks
I have been using Dunlop that are made in Portugal for £12 and less from Goulds, Ebrington St, Plymouth but have found they split within a year. These cheapo wellies from Dunlop are PVC, so that one of the more problematic plastics. Polyurethane is far less toxic to make and to dispose of and COFRA are not only an Italian company but the wellies are made in Barlletta, Italy.
I have bought two pairs of COFRA, a safety type and a non-safety version.
COFRA website ::New Hunter : Non safety
Bought sorbus-intl.co.uk/cofra-wellington-safest-boots-black (Other colours inc. black from other websites at £10+ and more)
Manufactured in Italy :: http://www.cofra.it/en/
T: 01373 475540 :: 8.30am - 5.30pm Monday-Thursday :: 8.30am - 5.00pm Friday :: 9.00am - 12.00pm Saturday
24th July had pair of Hunter, not New Hunter as I had thought but they seem fine. Will be emailing Cofra about the Safest I bought as there are few issues. I'll copy the email to them as a comment when done.
The two piece design consisting of a circular lattice wall (kana), commonly some 4 to 5 feet high, to surround an area some16 feet across, with a sloping radial roof.
The kana's length will be the circumference of a circle who's width is know. The kana is usually made of section for convenience or handling and storage.
The parameters in constructing a kana are dependent upon the spacing which in turn is dependent upon the strength of individual slats.
The formulae below shoes the relativity of the horizontal length of the kana, which is a multiple of B relative to the distance between the cross-over distance in each strut (A)
If (A = 30cm)
B^2 = A^2 + A^2 = (a x a + a x a) = a(a + a) = a x 2a = 2a²
B = √ ( 2a²) = √2 x √a² = √2 x a = 1.414a
Then (B = 30 *2^ 0.5 = 30 x 1.414 = 42.42cm
A yurt with a 4 metre diameter (approx 13.5ft.) will need a kana of 4 x Pi = 4 x 3.14159 = 12.6 Metres. (circumference)
42.42 x 30 = 12.726 :: close to 12.6 Metres needs 2 x 30 or 60 poles at some length.
Height = 1^ 0.5 x (length of battens) i.e. .707 x (length of battens)
Tableof Tie Distances and Batten length to give approximate height and diameter of erected kana.