Sail Windmills In Lassithi Eastern Crete Marcus Sherman 1975

7 Pages·1975·0.05 MB·English

Appropriate Technologies
for Semiarid Areas:

Wind and Solar Energy
for Water Supply

Gorman Foundation
{or Internallonal Developmesat
‘Seminar Centre lor Economic
and Social evelopment
see fest)
6,000 HANO-CRAFTED SAILNING WINDMILLS OF LASSITHIO0, GREECE,
AND THEIR RELEVANCE TO NTROMILL DEVELOPMENT IN RURAL (NDIA

Marcus M. Sherman

1, Abstract

‘The author visited Lassithiou, Crete, Greece, to ascer>
tein the reasons for the widespread ure of windmills ther
and te determine if any of the details of their design
enuld be incorporated in the design of water-puaping wind-
mills currently being developed for widespread use tn rural
Indta. The success of the Greek windaills way be attributed
to thelr use of inexpensive and lightweight cloth sails,
maximum use of local hand-craftsmanship in construction and
Sinplichty in design af the steel turntable, the wooden main
hearings, and the crankshaft.

2. Introduction

Lassithiou ts a broad fertile plain tsolated in the moun-
teins of Crete, the Targest of tha Greek talands. Zeus, the
Kind of Greek Gods, fs said to have been born (na cave
overlooking tha area. Farmers froa several villages surrounds
ing this plain produce expert quantities of beans, cabbage,
corn, potatoes and other vegetables through intensive cul~
tivation of I-Z-acre plots during the warm season of May
through September, Winds during this season are light to
moderate, The general prosperity of this area may be par>
tially attesbuted to the widespread use of Aeolfan energy
for the pumping of irrigation water.

In the Mediterranean region large stone toner windwitls
rigged with trisagular cloth sails were trad{tionaliy used
for grain grinding and of) pressing, In 1918 this tradition~
al windnsl) design was adopted to smaller lightweight struc-
tures for pumping water, At the present time at least 6,000
of these simple devices are in seasonal use. Not including
pup and storage tank, a Lassithtou windmill costs 10,000
deachnas to instal {Rs 2,500).
3, Lassithtou Windmt 11 Design
The Lassithiou windmill design consists of eleven baste

elenants: base well, pump-storage tank, tower, turntable.

carriage, tail, main bearings, crankshaft, hub, spars, and

sails.

2.1 Base well

A Us-cm thick concrete slab covering a 2-m diameter,
1O-m deep well forms the base of the windmi1l.

3.2 Punp-storage tank

Mounted on the base in the centre of the tower 15 a 13-
cm diameter, 15-cm strake piston purp made of a discerded
W.W.1T German cannon shell, fitted with a Teather foot
valve and 9 leather-sealed pisten. Puaping 2 litres par
stroke, 40 strokes per minute, this pump fills a 3 metre x
4 metre x 80 cm deep concrete storage tank {n two hours.
The pump corte 1,200 drachmas (Rr 300) and the storage tank
4,000 arachmas (Rs 1,000),

3.3 Tower
The four-legged S-netra nigh, L.S-metre square base tover

fg made from S-cm aiid steel angle iron riveted with flat

steel cross bracing, The tover 1s bolted and wired to the

bate.

3.4 Turntable

The turntable riveted to the tep of tha four tower legs
iz mada of @ 160-cm long piece of & cn MS angle tron bent
{nto a 50-cm diameter ring to forms flat horizontal bear~
ing surface for the carriage te rotate upon.

3.5 The earrtage
The carriage 1s simply 3 rectangular-angle iron frame
35 em wide and 140 cm long, The carefage 1s bolted down
with four bolts to two 3S-cn pieces of angle iron rive
to a 48-cm dlaneter flat steel ring which rotates on the
bottom inside surface of the turntable ring. This arrange-
ment keeps the carriage firmly attached to the top af the
tower while at the same time allowing {t and the attached
shaft, sails, etc., to rotate vertically when che wind di-
rection changes.

36 Tu

A tetangular tail of corrugated sheet steel 1.5 mx 1.57
K dn ty supported by two 2-metre long pieces of angle iron
from the rear of the carriage,

4.7) Main bearings

Two 34-cm-wida, 15-cm high, B-cm thick blocks of Aardwood,
each with 15 cm diameter hale bored fn the centre of the
large surface are bolted to the front and rear of the car-
rfage to support the crankshaft,
3.8 Ceankshate

The crankshaft (s made af a S-cm diameter, 160-ce long MS
steal rod which has a ‘U’ shape bent into the centre. the
1D! section has an intide width of 7 cm and a height of 7.5
cm, thus giving a stroke of 15 cm. A P-cm-dtameter steel
connecting rad attached with two bolts te a wood crank bear-
ing transfers the rotatory motion of the crankshaft fato
vertically reciprocating mation of the punp piston.
2.9 Hub

The front and of the crankshaft is inserted through a
SO-cw diameter, 15-cm thick wasden hub inte which etght
S-cm square holes are chisalad in the perimeter ta receive
the squared ends of the spars, The hub is fixed to the end
of the shaft by p bolt passing through both. An improved
hub wade of two 30-cm diameter, .5-cm thick steal discs
separated 5 cm apart by 16 smatt rectangles of 10 cn x 6
em atee] to form eight square holas has recently been
adopted. A 60-cm diameter flat steel ring around the hub fs
bolted to ench spar to keep them secured within the hub.

3:10 Spare
‘The efght 2.8-« long spars made of wood radtate out from
the hub to form a total windmit! diameter of 5.4m, Smal
stones are atteched to the tips of some spars when balanc-
ing is necessary. A central supporting spar of angle {ron
extends 2m out ta front of the hub along the main axis of
the crankshaft. Steel wires radiating back and out from the
tip of the central spar to the tips of the radial spars
provide bracing against strong winds. Steel wires between
tha tips of all the radial spars provide additional bracing.
A 60-cm diameter flat steel ring around the hub is bolted
40 each spar to keep then secured tightly within the hub
3.11 Satis

A trtangular cloth sail 2.6m x 1,2 mx 2.4 0 4s attached
along tha long edge to each of the eight radial spars, The
loose corner of each sail fs secured with rope to the tip
of the adjacent spar, thut forming a strong uniform surface
for catching the wind. The safls can be wrapped around the
spars to control the amount of tail area exposed to the
wind,

Note: AVI measurements are accurate t 10x.
Photographs are avaflable with the author.

4. Gonelustons
The Tassons to be learnt in India fram the windmilis of

Lassitntou are:

4.1 Cloth sas1 windmills can be successfully used for tr=
rigation fo some isolated areas.

4.2 Wood ts superior to metal for low-speed windmill spars
because of its flexibility and Tight weight.

4.3 Tha wooden huh used in Crete 42 similar in construc~
tlon to a typical Indian butlock-cart hub.

4.4 The steel shart normatly used far making bultock cart
axles can readily b¢ fashioned into an excellent wind-
mil) crankshatt,

4.5. Wood may be used for the
necting rod hearing.

fin shaft bearings and con-
ae
kote:

Ball bearings are not required for the turntable

MS steel angle (ron can be used to construct darsbly
towers whera long strong waod poles are not avatlable.

A storage tank is important for controlled trrigution.

As a result of these Investigations an improved de-
Sign for a windmill to be munufuctured and used in
Purel India was developed in 1975 by the avthor and
Others with technical and financial assistance from
Indtan Agricultural Sesearch Institute, New Alchel
Institute, East, and Oxford Committee for Famine
Rellef (O#FAM).