Nowhere near there, it was near heathfield. I have found a video on the net about a colony near heathfield but this is a totally different location about 2 miles away.
It is not F. sanguinea, rufibarbis and most probably not pratensis either. Last colony of F. pratensis is evidenced on Channel Islands only. My guess is Formica lugubris (but only if it's very hairy)...