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1 second 2 seconds 3 seconds 4 seconds 5 seconds 6 seconds 7 seconds 8 seconds 9 seconds 10 seconds 11 seconds 12 seconds 13 seconds 14 seconds 15 seconds 20 seconds delay, loading photo...          2004. Grand Union Canal lock at Dudswell, north of Berkhamsted.  Author: Q Barrett,          1935. Grand Union Canal lock at Dudswell, north of Berkhamsted. From the collection of the Berkhamsted Local History & Museum Society.  Author: Berkhamsted Local History & Museum Society,