Lockham Farm Bridge

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Key Dimensions
Existing Structure:	Width at water	6.05m	Width of roadway	3.93m
	Headroom	low	Depth (to rubble bottom)	1.4m
			Flow rate (est 30 Jan 2002)	3km/hr
Proposed Replacement:	Width at water	6.05m+	Width of roadway
	Headroom	2.4m
	Draft	2.0m
Owner

Background Information

Just upstream of the site of Lockham Aqueduct, the Frome is crossed by a low fixed concrete farm bridge which also carries a public footpath. A bridge is show at this location on the 1955 OS map at this point so it pre-existed the removal of the canal crossing.

Replacement Structure

If the river, rather than the canal, is to be used for navigation at this point, this bridge will require raising or replacement. Like the bridge at Whitminster Lock, it is on the flood plain and the greater headroom required, the less practical a fixed structure becomes. Unlike the bridge at Whitminster Lock, this one is spanning the river and therefore has to have a larger span of perhaps 6.1m.

Another potential issue is flow rate. At this point, the river is just over 6m wide and about 1.4m deep. At the time of measurement, the flow rate was estimated to be about 3km/hr at a time when the flow rate was fairly, but not exceptionally, high.
Some basic designs for this and other similar bridges (fixed) appear in the W.S.Atkins Report of April 1991.








Lockham Farm Bridge. Note that headroom will vary with river flows under a raised bridge and this needs to be taken into account.



















Lockham Bridge viewed from farm track. Note that the river is contained in relatively high flood banks at this point so the track drops away significantly already even though air draft over the river is currently small. Significant embankments would be needed to provide the headroom for a fixed bridge (applies to River Route only).






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