Historical Development of the Windmill - Wind Turbine Technology: Fundamental Concepts of Wind Turbine Engineering - page 24

Applications of European Windmills

Thus far we have taken the European mill to be a grain mill, but it was also used in
a host of other ways. One very considerable application was for pumping water; one
naturally thinks of The Netherlands in this regard, because the Dutch were always engaged
in either keeping out the sea or turning it back when it got in. Although they were not the
irst to adapt the windmill for drainage, the Dutch quickly developed the wipmolen or
hollow post mill , one of the designs developed speciically for pumping water. This
“pumping” was done by a scoop wheel , as illustrated in Figure 1-13, with a lift limited to
1.5 m at the most. The plane of rotation of the scoop wheel had to remain stationary when
the mill structure yawed with the wind. To
accomplish this, the solid main post of the
original post mill was replaced with a hollow
one that allowed the vertical shaft from the
wallower to extend down the inside of it. At
the bottom end, there was a right-angle drive
to the scoop wheel formed by a second cog-
and-ring mechanism. Note the provision for
the shaft of a tandem scoop wheel. In later
years, the tower mill was also adapted as a
drainage mill; these were often grouped
together to drain the Dutch polders and keep
them drained. A most striking example is
the Kinderdijk group mentioned earlier.
Another special windmill application,
which again was developed and used widely
in The Netherlands from 1600 onwards, was
as a sawmill. It, too, was originally an
adaptation of the post mill, called a paltrok,
in which the brake wheel drove a vertical
gear wheel that turned a horizontal crank-
shaft. The end of a long, vertical connecting
rod from the crank was ixed to a saw as-
sembly, which cut the timbers longitudinally
into planks by an up-and down motion.
Tower mills were also used later as saw-
mills, because their greater size and power
allowed somewhat larger logs to be sawn or
more saws to be used in parallel, leaving the
smaller work to the paltroks.
There was a multiplicity of industrial applications of windmills in the seventeenth
century and onward, particularly in The Netherlands. The countless waterways from the
sea allowed timber, spices, cocoa, snuff, mustard, dyes, chalk, paint pigments, etc., from
all over the world to be processed straight from the cargo ship and transported throughout
Europe and beyond. The Zaan district was the industrial center, and windmills were the
electric motors of their day. Some odd applications have been suggested over the centuries,
and one must admire the ingenuity of two of these, both for military use. One was as the
motive power for what might be called an armored chariot (a suggestion which preceded
that of the tank by about six centuries), and the other for hurling hives of bees over the
walls of fortiications (perhaps a precursor of shrapnel or anti-personnel bombs).

Figure 1-13. Diagram of the power train
of a Dutch wipmolen , a post mill adapted
for pumping water. The wallower shaft
passes through a hollow main post.