For a single visit you are supposed to get instructions by scanning the code at door, but because the signal is so poor you cannot do it. You have to upstairs where the signal is better (but the you cannot scan the code!). Then you have to register and even though you are a tourist, you should have a British post code, which you do not have! So you need to invent one (and know the right format, which I did not). Going in you are told to get a lock to the lockers at the vending machines. But there is nothing. When you ask the personnel, they say you should buy one (for a single visit!). I did not and it worked ok.