(23 Sep 2014, 11:48 am)Andreos1 wrote Not sure there is much difference between a 10 1/2 t HGV or a 10 1/2 t PCV either :s
The subtlety is that HGVs can be 38 tonne artics (or even trucks with drawbar trailers).
Corbridge bridge has a 7.5 tonne weight limit (apart from buses). The actual 'limit' is 18 tonnes, but if they allowed 'HGVs' over 7.5 tonnes then some would chance it with 38 tonners.
In the case of the Black Boy bridge (road), I suspect that they don't want two (or more) 38 tonners trying to pass each other on a regular basis - thus they 'dissuade' HGVs with the signs.