Hello all At about 1352hrs today I was on a Victoria line train southbound between Green Park and Victoria when there was a noticeable banging noise and some of the doors along the right-hand side of the train were pushed inward. The motion of the doors and the general type of noise suggested that it wasn't a strong air current, such as you get in tunnels. I am aware that it would seem similar to this common phenomenon to most people, but it most certainly wasn't that. I have been using the Victoria line very frequently in the last month and have never seen or heard anything quite like this. The only logical conclusion I can think of is that there was some piece of the tunnel infrastructure flapping or infringing on the path of the train, but I have no idea what. There were some small indentations I imagine were consistent with an item touching against the train, with very little paint damage, on a few of the doors, between the window and the area where you might expect damage from feet. I feel it is important to point out that I reported this to a member of TfL staff at Victoria station immediately after coming up the escalator, and they said they would report it to someone relevant. I have not heard of any disruption so I can only assume this was a minor fault. They did take a few details about the incident which I presume were important for diagnosis. Any ideas? Thanks.