Johanna is what the Dutch call a "Grondzeiler". It is a three storey tower mill. There is no stage, the sails reaching almost down to ground level. The cap is covered in
dakleer. Winding is by tailpole and winch. The sails are
Common sails. They have a span of . They are carried on a
cast iron windshaft, The windshaft also carries the
brake wheel, which has 68 cogs. This drives a
lantern pinion wallower with 29 staves, which is situated at the top of the
upright shaft. At the bottom of the
upright shaft is the
great spur wheel, which has 66 cogs. This drives a pair of diameter
millstones via a
lantern pinion stone nut with 23 staves. The millstones consist a French Burr runner stone and a Cullen bedstone. ==Public access==