Month: August 2014

East Greenwich tide mill – later 19th century accounts

Below are two accounts of the East Greenwich Tidemill – which stood on the east bank of the Peninsula roughly wear the jetty is which had very recently got a theatre group on it.   It dated from 1802 but the following pieces are written in retrospect as part of wider works on tide mills.  We understand that chapters about the mill are to be included in two forthcoming books.

Recently we were shown an assessment of the site prepared by archaeologists for English Heritage/Greenwich Council/developer.  To our surprise the site was described by the highly paid consultant with no reference to the tide mill at all.

By following links it should be possible to find a great deal more information on the tide mill on this site – and sorry about any errors in a document which was far from easy to scan.

Extract from The Engineers and Mechanics Encyclopaedia of Machinery 1836

A tide mill was erected at East Greenwich on the right bank of the Thames under the direction of Mr. John Lloyd, an engineer of Westminster, of which the following will convey an idea: the details are given by Dr. Gregory in his mechanics vol.11

This mill is intended to grin corn and works eight pair of stones. the side of the mill parallel to the course of the river, measures 40 feet within; and as the whole of this may be opened to the river by sluice gates which are carried down to the low water mark in the river, there is a 40 feet waterway to the mill. Through the water way the water presses during the rising tide into a larger reservoir which occupies about four acres of land. beyond this reservoir is a smaller one in which water is kept for the purpose of being let out occasionally at low water to cleanse the whole works from mud and sediment which would otherwise in time clog the machinery

The water wheel has its axle in a position parallel to the side of the river, that is parallel to the sluice gates which admit water from the river. The length of this wheel is 26 feet in diameter, 11 feet, and the number of float boards 32.  These board do not each run on in one plane from one end of the wheel to other but the whole length of the wheel is divided into four equal portions and the parts of these, belonging to each of these portions fall gradually lower than another, each by one fourth of the distance from one board to another, ensuring on the circumference of the wheel.

This contrivance is intended to equalise the action of water upon the wheel and prevent its moving by jerks. The wheel with its incumbent apparatus weighs about 20 tons the whole of which is raised by the impulse of the flowing tide, when admitted through sluice-gates. It is placed in the middle of the water way leaving a passage on each side of about six feet for the water to flow into the reservoir, besides that which in its motion turns the wheel round. soon after the tide has risen to highest (which at this mill is often 29 feet above the low water mark) the water is permitted to run back again from the reservoir into the river, and by this means it gives a rotary motion to the water wheel in a contrary direction to that with which it moved when impelled by the rising tide

Extract from The Engineer 12 VII 1901

 

The largest and most, complete tide mill we have   account of was erected on the bank of the Thames at Greenwich about midway between the spot now occupied by the Blackwall Tunnel and Woolwich.  It was designed by John Lloyd an engineer of Westminster, and was intended to obviate the disadvantage caused by the   gradual diminution of power as the river and reservoir got nearly full or empty. The mills were intended to grind corn for the London Company for the Manufacture of Flour.  the mill house was parallel to the bank of the river, and had a 40ft waterway, Within which was a wheel 26ft long 11ft  in diameter and carrying thirty-two floats on its circumference. To lessen the shock of the water these floats were not continuous but divided into four sections breaking joints with each other.  The wheel with the whole of its apparatus weighed about 20 tons. The side spaces of 6ft. or 7ft. were to allow the water to get freely in or out of the reservoir. But apparently could have been occupied by a larger wheel or additional small ones.  The wheel revolved in a. stout wooden framework which rose and fell with the tide by the action of what were virtually bellows. Planking hinged to the floor of the frame and to the base of the beams or posts which served as guides to the framework, projected backwards towards the inner pond. The tide could not get through this – whereby it would have diminished the power  available for the wheel  – but gradually forced It up as it rose, thus keeping the wheel at a suitable level. The reverse action of course took place when the reservoir was emptying maintaining the wheel again at a good working level.  on each end of the drum or water wheel was a ring of cogs engaging by bevel gear with the base of upright shafts rising  into the mill to turn the machinery. There were two bevel wheels on each shaft a lever being provided for changing from one to the other when the motion of the wheel was reversed after the necessary stoppage at the change of tide.  A system of counterweighted gates was employed regulate the flow of water to the wheels. A patent no 2411, for tide mills constructed in this manner was granted  on June 10th 1800 to William Johnson of Bromley, Kent, gentleman. In a long advertisement published six months later he anticipated the construction of the East Greenwich mills and describes the merits of his plan in a glowing style not unusual with inventors. It required a smaller reservoir than usual as the water ran over the top of the gates down upon the wheel. and acted by its weight Instead of by Impulse as on the undershot method. He estimated that where tide rose 15 ft., a basin 125 yards square and 21ft deep would hold enough Water to grind and dress 468 bushels of wheat every twenty-four hours, or every twenty working hours four being allowed for stopping to let the tide get a good start. A large Part of the pond attached to these mills is still traceable though a good deal has been filled up with cinders and the works of the Blackheath and Greenwich District Electric Company occupy nearly the site of the old tide mill.  As a bank 8ft or 10ft high surrounds the pond it was evidently able to hold water up to the top level of the tide. Though now choked with mud the bottom of the pond must have been lower at one time. This Rapid filling with mud was ono of the drawbacks of the system

One of, the earliest of Richard Trevithick’s high pressure engines was employed pumping at East Greenwich tide mills:  while the basin was excavating. It had cast iron boiler 6ft. In diameter and from l in. to l 1/2 in. thick in different places, according to Trevithick himself. This boiler blew up in September, 1803, killing -three men and injuring others:

The boy in charge had gone off to catch eels in the-basement of the mill, and a labourer had stopped the engine because it was going too fast. This is a characteristic specimen of the happy-go lucky enginemanship of those days. A boiler of the same kind may be foun at the south Kensington Museum

Return to New East Greenwich and the Tide Mill

 

 

Advertisement