Upminster Windmill

Upminster Windmill is a tall octagonal smock mill with a timber frame on a brick base, dating to the 19th century. It stands on St Mary's Lane in Upminster, in an open patch of maintained grass with housing set back on three sides.

The brick base, re-pointed in cement, is part colour-washed with remains of an earlier possibly tar coating visible in places. The horizontal weather-boarding (renewed) is painted white, though early photographs show it was darker. Windows on three floors have been wholly renewed with fixed small-pane glazing covered with protective polycarbonate, which involved sill removal. Two opposing ground floor doorways are segmental-arched with boarded doors (renewed but retaining original fittings); the rear door is blocked. Blocked oculi are visible to the sides.

At first floor level, the lower gallery comprises wooden boards supported by struts cemented into the wall with a wooden balustrade rail, all renewed. Square-headed doors at this level provide access to the sails, which could be controlled by a rope connected to the rope wheel above. The main sail structure is renewed and in situ, but the shutters have been removed and stored. These shutters, numbering 12 bays on each side of each double sail with 3 shutters per bay, mostly date from the mid-19th century patent sail installation and are marked with their position in Roman numerals. Their cast-iron fixings survive. The boat-shaped cap (roof and vertical boarding of petticoat renewed) rotates to keep the sails facing the wind. At the junction of the four sails is the metal spider, the mechanism connecting the levers operating the shutters with the striking rod and rope wheel on the opposite side of the cap. The fantail (renewed) comprises 6 wooden vanes set at right angles to the main sails, with a system of gears to turn the cap and sails to the wind. The metalwork, including the spiky rope wheel and the rails to the upper gallery, appears unrenewed.

The interior is arranged over 5 levels. Some of the outer shell of timber-framing has been renewed, including the wooden sills originally resting on the brick plinth (replaced by concrete). The structure comprises cant (main) and intermediate posts and studding with attached external weather-boarding. Some probably original wide floorboards are retained. Ladders or steps to each floor are set against the east wall. Some posts supporting the machinery are lightly chamfered and stopped. The machinery is virtually complete and potentially workable, with much surviving from the early period together with later modifications, particularly from the mid-19th century, which are usually identifiable through the different colour of the wood.

The Dust Floor below the Cap contains the Brake Wheel with cogs of apple or pear wood, the Windshaft with Striking Rod (cast iron, 1890s following a storm), connecting the Spider and the Rope Wheel, the Curb ring beam, and the Wallower, the horizontal gear wheel transmitting wind-power to the machinery through the main shaft. The Cap structure has been replaced but some original ribs are retained in store on the Ground Floor. The Bin Floor, where grain was stored before being fed through chutes to millstones, houses the Main Shaft with Universal Joint, Grain Bin and Sack Hoist (moved here in the 1950s). The Stone Floor or milling floor contains the drive to the Sack Hoist, the Wire Machine (used to separate flour from bran, later adapted to remove fungus from grain) with quality panelling, the Grain Hopper, 4 pairs of Millstones in wooden Vats with iron hoops (the 4th pair added in the 1850s), including a French Burr mill-stone from the Paris Basin. The Meal Floor has the great Spur Wheel, the large gear wheel at the bottom of the main shaft with mid-19th century modification, storage bin and bolter (the belt-driven drum-sieve), and a trap door connecting with the sack hoist on the Bin Floor. The Ground Floor now has a concrete floor.