Phylis, you don't get it, we're not clobbering things, but touching is almost inevitable. As you say, your boat is too beamy for a narrow lock, meaning i guess you never go through locks less than 6 feet wider than your boat, whereas Ripple, in the bottom lock at Hurleston, actually touches BOTH sides! One lock on the Ashtead flight has an alignment so awkward that the only way Ripple could leave was to catch the masony bridge, her left hand (port) side was in contact with the canal wall while the right hand (starboard) side hand rail scraped the bridge, judging by the paint marks she wasn't the first boat to do this.
And I agree with Sara, accepting that boats will touch the bank and each other is no excuse for playing bumper cars as you down the canal, but that's not what most of us are doing