 JACK WINDMILL (NGR : TQ303134)
A new lease of life for Jack Windmill :
A diary of her refurbishment
By David Meares, Michael Peat and Simon Potter
|
 |
| |
| With the arrival in May 2012 of Jolyon and Claire Maugham as new owners the of Jack and Duncton Mills, came a refreshing enthusiasm not for just stabilising the fabric of Jack but for restoring much of the damage done to her by neglect and exposure to the weather over a period of more than 30 years. 
The repair work started in early September with an exploration by Sussex Mills Group volunteers of what would be necessary to release and remove the existing weather-weary cap. |
A FLAT CAP FOR THE TOWER
Part 1: 29 September 2012
| | | |
|
The truck wheels, it was found, latch under a lip on the curb and consequently it was realised that these would have to be removed before the cap could be lifted. Fortunately it was discovered that the spindle around which each truck wheel rotates was threaded at its top end and could be knocked through the wheel, to release it, once the nut was removed.
| 
One of the truck wheels, showing the curb lip and the spindle partially removed
|
Fan stage showing the tethering ropes on the fan star shaft |
Also at this time, with items of timber and metalwork falling off the fan stage, ropes were slung around the fan star and its shaft with the hope that this might to prevent them from falling and being damaged in the process. As precise details of this assembly are specific to Jack Windmill, replacement if damaged could be very expensive.
|
|
During this phase, Jolyon decided that the best way of working on the outside of the tower would be to scaffold it right up to cap level. This would prove most useful both during cap removal and prior to that when removing the remaining two sweeps (two having been lost to the elements more than a year ago). It would also help considerably in the work needed to stabilise, or even partially dismantle, the fan stage prior to lifting the cap. As a result on 15th September ropes were slung through the sweeps which were then turned to lie horizontally. One windshaft clamp was then re-tightened to hold the sweeps in this position until their removal.
| 
Sweeps set horizontally
|
|
At about the same time UK Power Networks diverted overhead power lines, which would have prevented a lifting crane from approaching Jack's tower in order to lift the cap. Over a three day period, they laid new underground cables and switched the supply from the overhead lines.
|
|
|
|
|
|
If the plan is to remove the existing cap for repairs, it is obviously essential for the tower to receive a temporary cap during this repair period. To that end a back-of-the-envelope design was drawn up and discussed by the Sussex Mills Group volunteers and a finalised design was agreed with the owners. |
|
 
Original sketch plan for the temporary cap. (Note the hatchway - see later)
|
A number of small trees and bushes were cut back in order to provide an area large enough to accommodate both the temporary cap and the existing cap, as these will need to be placed next to each other on the day that they are exchanged. 
|
|
Construction work started on this temporary cap on the 22nd September 2012, first laying out the joists and then fitting and screwing in place the multiplicity of noggins. 
| 
Starting to assemble the cap framework. Note the trammel and reference pivot point
|
First half nearly complete
|
| | |
|
As of the 29th September the first half of the unclad structure of the temporary cap has been completed, requiring 7 joists, 75 noggins and 429 screws. Work will continue, weather permitting, on construction of the second half of the structure, the cladding of the whole structure and the fitting of the appropriate skirt.
|
Part 2: 23 October 2012 | | |
|
The early part of October saw the completion of the second half of the framework and the start of cladding this with plywood boarding. Progress was however not particularly fast owing to the weather. One of the wettest years on record was being compounded by what seems to be the wettest Autumn on record. Thus several potential working days were lost and the temporary cap had to remain under its tarpaulin.
| 
Second half of framework nearly complete. Note the two larger noggin gaps, one of which will become the hatchway through the roof to allow the lifting strops to be removed once the cap is on the tower
|
The framework for the temporary cap under its tarpaulin
|
|
At about this time, serious discussions started on how the temporary cap was to be held in place on top of the tower. Whichever method was chosen, it had to be able to withstand the force of Mother Nature and her Winter winds. Equally well it had to be able to be loosened in fair weather conditions to allow partial lifting of the temporary cap to facilitate de-rusting and repair of the curb as required. The chosen solution is to use ratchet-straps distributed around the perimeter of the temporary cap with an additional one in the centre. These are to be hooked over metal bars fastened to the temporary cap framework. At dust floor level (at the top level of the tower) the fixings cannot be allowed to rely on the strength of the floor boards alone and so a design was developed which will take bolts through the floor boards and through substantial planks of wood which are themselves to be positioned below that floor's joists. Thus the restraint will be the strength of the joists themselves.
| 
Working sketches, on scraps of timber, showing details of how the cap would be fastened in place
|
 |
Weather permitting, work has continued on the cap structure. Checks have been made to ensure that the hatch will fit and that it is large enough to squeeze through - better to check now than when the cap is on top of the tower. Finally, the top plywood cladding of the frame has been fitted and cut to its circular outline with a router on a purpose made trammel bar.
|
Temporary fitting of hatchway - fortunately just large enough to get through !
| 
Cutting the circular edge of the board with a router on a trammel
|
|
Composite picture showing the last of the top surface cladding boards being fitted
|
|
One problem still remains to be solved. Despite approaching many firms, Jolyon has discovered that scaffold firms are not willing to be charitable with the price of their quotations for the planned scaffolding of the tower. In addition, to date it had also proved impossible to obtain insurance cover for our volunteers working at height and with woodworking tools. As a result, it seems that the sweeps may have to be turned back to the vertical in order that they can be removed by the tried and tested 'crane and cherry-picker routine'. Hey-ho - such is life!
Part 3: 19 November 2012 | | |
|
In the latter part of October, additional support timbers were added to the cap to help hold the skirt in place, rather than only relying on the fixings to just the ends of the joists and noggins. Sections of timber, 3in by 1in, were therefore cut to the same curvature as the outer edge of the cap and these were trimmed to length and fitted under the cap's cladding plywood.
Once these timbers had been fitted, work commenced on fitting the skirt to the cap. Great care was taken to ensure the top of the skirt was level with the top of the cap plywood and to ensure that an even curvature was obtained. Two layers of skirt plywood were installed ensuring that the second layer overlapped all joints in the first layer.
| 
Additional support timbers for the skirt
First section of skirt being fitted
|
|
First piece of the second layer of skirt timber clamped whilst the glue cures
|
Whilst all this was taking place, the hatch, which had been prebuilt off-site, was being fitted. Firstly a batten was screwed around the aperture to fix the depth at which the hatch would be installed. Next the hatch itself was pushed down to the batten and screwed into the adjacent joists and noggins. Finally a triangular trim was fitted around the hatch so as to ease the curvature of the roofing felt (the final waterproof outer layer), which will need to be folded up around the sides of the hatch. |
Installation of the hatch
|
Completed hatch
|
View from underneath the cap showing the restraining bolts on the hatch lid
|
Work also continued off-site to make the metal shackles and to select the ratchet straps needed to complete the fastening down of the temporary cap once on the tower. These are shown below, together with one part of the ratchet strap. |
Metalwork for fitting to the floor of the dust floor
| 
Metalwork to be fitted to the cap joists
|
A total of eight ratchet straps and the associated metalwork will be distributed more-or-less evenly around the cap, with at least one additional strap in the centre.
Saturday 10th November saw the last of the woodworking activities on the temporary cap. The final section of the second layer of skirt plywood was screwed and glued into place. Tools were packed up, scrap timber off-cuts were removed and the tarpaulin was tied in place until the roof felting was done.
|
The final sheet of plywood skirting is fitted into place
|
|
Part 4: 4 March 2013
The roof was felted using one coat of Bitumen primer, one layer of Bailey 2mm contract underlay [full bonded] and a top layer of Bailey classic charcoal mineral felt [fully bonded] |
FANTAIL AND CHAINWHEEL
On 13th April 2013, a scaffold platform was erected by Independent Scaffolding Brighton Ltd to provide access to the fanstar and spindle.
It took several hours to clean up and then free the gear train and the fan spindle, which had last rotated by wind in 1909. Penetrating oil and elbow grease finally worked their magic. |
 |  |
A review of photos from 1906 suggested that a 9 foot radius fan would fit within the fan assembly, so a jig was constructed to confirm the measurements. |
 |  |
The Fanstar was removed for refurbishment off site
 |
THE CHAIN WHEEL
On a dark and stormy night fifteen years ago, around the turn of the century, Jack's cast iron chain wheel and its supporting timber frame gave up the fight against the storm and crashed down onto the Mill Yard.
Two spokes snapped off near the hub and another one broke in half. Three curved ends shattered and two split with rust where boltheads had expanded.
The mill is going to be restored and now will be a good time to get this piece of history back in working order.
The first thing to do is to clean off 100 years of lead paint. A disc of ¼" plate, 16" diameter was made with a 0.4" square hole in the centre for the shaft and 4 iron wedges. This disc was bolted to the good spoke and then the broken ones were also bolted to the disc. All bolts are in staggered formation. This method produces very strong components. All ends are cut off to a Trammel line and 8 ends made to the same profile as the originals with a 6" shank. These were bolted onto the end of the spokes.
Chain Wheel
| 
Fanstar
|
All red-leaded and looking good and strong. Three oak rings were made, all tongued and grooved ends, 8 segments to a ring, then laminated together with staggered joints. The finished size is 3" thick by 4½" wide then fitted over 8 spoke ends ..... thin cut lines are needed here .... then grooved round the outside to fit the chain.
Text by Michael Peat
Please click here for details on both Jack and Jill Windmills
| |
