Waiting by the bow was a tug, the Svitzer Laceby (oddly registered in Grimsby). There was another at the stern, but I didn't get a good view.
Hang on, here's something you don't see every day...
With a blast on the fog horn, the Berlin was under way, to be reversed under tower bridge by the two tugs.
Leaving the impressive lines of HMS Belfast between Tower Bridge and the Tower of London.
There's no mistaking her purpose though, bristling with guns. Apparently these can fire a 6" shell up to 14 miles - meaning if fired now they would land beyond London.
HMS Belfast was built in 1939 and served in the Second World War in the North Atlantic, Normandy, and the far East; and the Korean War. As well as being an interesting historical ship, it tells a fascinating story. The tour is quite hard work - lots of up and down ladders and corridors - but well worth it, both adults and kids found it interesting.