Great Tower Bridge stuff, Georgie. Marvellous construction. Sailed under it countless times when working on Thames boats. Could also draw/paint it from memory since our school art-room had a direct view from about 300yds away and if art master was feeling lazy, it was chalk and charcoal and “draw the bloody bridge”. Back in the day it was solid black, from coal dust not that nice stone colour.
Don’t know what procedures are for a vessel to get it to open now but when the Upper Pool of London was a proper port, all you had to do was fly a black ball from the foremast and it’d swing up for you!