The Grand Union Canal links Birmingham to London with a waterway which is 145 miles long and contains 166 locks. This cache is one of a series to be found along or close to the Hertfordshire/Buckinghamshire stretch of the canal.
Half a lock!!
The Wendover Arm became the first of several feeders to the Grand Union summit level, which always had a problem with water shortages. Work started on the construction of the Wendover Arm in the summer of 1793 and followed the 390 ft. contour line to join the summit of the Grand Junction Canal at Bulbourne Junction on the Tring summit level. Although the Wendover Arm was primarily built to supply water for the locks at Marsworth and Cowroast it was served by many wharves along its length sending local produce to the London markets and also receiving coal, timber and manure for use on the land. Commercial traffic on the Grand Junction Canal increased very rapidly - the canal was the "M1" of its day - so much so that a great number of reservoirs were built in the Tring area to collect water for canal use. But the life of the Arm was short and by 1855 some 25 locks of water were escaping by leakage from the arm. By 1897 the leakage was so large that the Arm was actually taking water from the main line.
The stop lock by this cache was constructed to permit the Arm to be used for traffic should the water situation improve, but prevent water leaking out. Eventually, despite massive protests from local people, the Royal Commission for Canals and Waterways, and the County Councils of Herts. and Bucks., the Grand Junction Canal Company blocked the canal above the stop lock and Little Tring, de-watered the next 1¼ miles and lowered the water level on the remaining 3¾ miles. The Arm was closed in 1904.
The Wendover Arm Trust was formed in February I989 as a voluntary body, set up to promote the restoration of the Wendover Arm of the Grand Union Canal
This cache has now been changed to a Trad because one of the virtual clues went AWOL.