This had to be a multi due to the close proximity of other caches, but is easily completed while doing the other two Little Bridges in this short series.
The headline coordinates will take you to a wooden footbridge,where you can obtain values to complete the following equation.
The number of rails on one side (not lengths of wood) = A
Total number of uprights on the bridge = BC
Total number of planks on the deck of the bridge = DE
The cache can be found at N51 04. (A-B) C (C+D) W001 49. A (E-C) A
Checksum for A+B+C+D+E=19
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. A list of cachers who have found 10 or more little bridges and can be found here, 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 # xx then name” including spaces so it will get picked up and added to the list.