Find the black box next to the lock gates and the manufacturer name. Convert the letters to their place in the alphabet. A=1, B=2 etc.
The cache can be found at:
N 53 05. A B C
W 000 48. D E F
Where:
A = Ninth letter
B = Sixth letter
C = Seventh letter - First letter
D = Third letter
E = Sixth letter - Eighth letter
F = Fourth letter - Tenth letter

The Little Bridges series was started by Stanthews in 2009 to highlight small footbridges in remote parts of Wiltshire. Since then the series has been expanded by others all over the country and starting to spread fast. There is a stats listing run by Billiethecat, so you can see how many Little Bridges you have found, you can find it here:- https://littlebridgesseries.wordpress.com/ . If you would like to add to the series, please contact Stan on stanthews@aol.com and he will give you a number for your bridge, to qualify, the bridge must be a foot bridge too small for vehicles, please make sure your title exactly matches “Little Bridges # xxxx then the name” including spaces so it will get picked up and added to stats list.