At right is the gearbox of a 6 foot Defiance windmill. It clearly shows some of the distinctive features of this interesting design. As can be seen, the gearbox is of welded steel sheet and tube with a galvanised side cover and pressed steel cap. Numbers appear stamped into the side cover but as yet no confirmation has been received as to their meaning. Also, as they are on a removable part of the windmill, the cover may not even be off the particular gearbox.
The hub is of the later design and is a welded piece held on to the shaft with a bolt in the end of the shaft. The 'V' type round bar spokes are, in this design, held in place with a pressed steel clamp bolted to the hub flanges. The two rods attatched to the collar on the black stem section below the head are the mounts which the tail arm is clamped to and allow the tail to furl by the collar riding around a screw thread arrangement on the pipestem.
The date of origin of the windmill is not known precisely but indications are that it may have been produced from c1928 by ALTONA INDUSTRIES in Perth (no records exist in the company). The earliest known advertisement is from the WESTERN MAIL of 25/10/1934. This was offered by HARRIS, SCARFE & SANDOVERS LTD. who appear to be the operating company. Advertisements have been collected up to 1954.
Three sizes 6, 8 and 10 foot were available and during the life of production several minor changes occurred in the design including the windwheel blades, the hub and bearing types.
At left is an 8 ft DEFIANCE with the side cover off and showing the cast twin gear arrangement and the angle iron crosshead guide bars which were designed to hold a convex crosshead roller. The hub brake rim which was fitted to the 8 ft and presumably the 10 foot models is also visible as is the brake band mounting, welded to the front of the gearbox.
To the right is a 1934 drawing of the windmill showing the original hub windwheel mounting arrangement which must have been almost impossible to work on once the windmill was in place.