Editing Whitchurch Lock (section)

==History==
[[File:Flash Lock Thames 1786.jpg|thumb|left|Sketch of the flash lock before the building of the pound lock]]

There was a [[flash lock]] recorded at Whitchurch in the 16th century. The sketch map shows the main dam, which was solid and rose to a height above normal high water level. Near the southern bank, there was a sluice (marked "E" on the sketch), which was {{convert|30|ft|m}} wide, and was fitted with flood gates and overfall boards, to accommodate a drop of {{convert|3|to|4|ft|m}} in the river level. The flash lock was in the centre, with a winch on the north bank to haul the barges through against the current. It was {{convert|23|ft|m}} wide, which was the standard size for all flash locks below [[Abingdon-on-Thames|Abingdon]].  Near to the island was a "tumbling bay", an overfall weir with its crest just below normal low water level. It was about {{convert|35|ft|m}} wide and is marked "H" on the sketch. In common with most of the weirs on the Thames, the width of the tumbling bay was gradually increased, until it formed most of the weir, apart from the sluice.{{sfn |Skempton |1996 |pp=154-155}}

The pound lock, built of oak, was installed at the island in the summer of 1787. Two alternative sites were originally considered. One would have expanded the mill stream on the Whitchurch side, and another would have involved a cut across land occupied by the Swan public house at Pangbourne. A lock house was built on the island in the 1830s. In the later 19th century local people used to cross over the weir to avoid paying tolls on the bridge. The lock was rebuilt in 1876 and access across the weir was closed. The right of way from Whitchurch to the lock was closed in 1888.<ref name="ReferenceA">Fred. S. Thacker ''The Thames Highway: Volume II Locks and Weirs'' 1920 - republished 1968 David & Charles</ref>