The lift schedule for Tower Bridge notes that a “vessel” is due to pass through today at around 5:15pm, but doesn’t indicate what sort of ship it will be.
That normally hints that it is a military vessel, but the lack of tugs suggests not.
Fortunately, the rather excellent Marine Traffic website keeps an eye on all the ship movements in the London area, and I can see that a tall sailing ship is heading up river and its destination is Tower Bridge.
Mystery solved – and a very good looking solution it is too!
The Stavros S Niarchos is a British brig-rigged tall ship owned and operated by the Tall Ships Youth Trust. It would seem that the sailing ship will be tied up in the Pool until Saturday morning, when she leaves at 7:15am.
You can watch the ship pass through Tower Bridge via their webcam if you can’t get down there in person.