this is quite a grey area in my opinion, if you can't carry a 3" knife or over for a specific legit reason like the above or like previously mentioned then how the hell can you legally buy one over a counter only to be nicked outside the shop door...crikey, go into tj hughes buy a set of carving knives, go about the rest of your shopping and then get nicked for carrying a fixed blade over 3"...fecking joke
...... it dont matter if the blade is fixed or not the legal limit is 3" full stop .... if you have reason to have it in your possesion you will be ok if not you will be charged this also