The cache container and logbook are not at the published co-ordinates, but to reveal the final gz location you will need to visit there and collect some information. The cache will be found at:
N51° 34.ABC, W003° 44.DEF ... where:
A = d
B = (e x a) + b
C = a + e + c
D = (d + a + b) – 1
E = d – e
F = a + d
a = Number planks forming base of bridge
b = Number handrails
c = Number of posts supporting handrails
d = Number staples in down-stream end of planks
e = Number staples in up-stream end of planks
Checksum = 11
You can validate your puzzle solution with certitude.
Having enjoyed finding quite a few 'Little Bridge' series caches I was amazed to discover there were only three, at time of creating this mini-series, in the whole of South Wales. Just over the Severn Bridge in England is the heart of the series with literally hundreds of LB caches. The concept has spread over much of England & North Wales since 2009. There are some superb little bridges to be found, also some very simple ones. I hope you enjoy discovering the little bridges now highlighted in this area.
Roadside parking is available near the start of the footpath leading to these caches, but please be considerate to the local residents. The caches can be retrieved without leaving the public footpath, but it would be advisable to wear appropriate footwear, especially during the winter months, as the paths can be quite muddy.
Well worth continuing up to welshman65's cache "Brombil" above the reservoir, if you haven't already found it.
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, Damian from Winter Foxes has created and updates a list of cachers who has 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 Damian’s list.