I went to visit NMSI Wroughton yesterday, the old RAF airbase where much of the big bits of the NMSI museums' collections are stored. It's a huge site, near Swindon, and quite amazing to visit.
The collections themselves are stored in huge old aircraft hangers. Inside there are airplanes, buses, fire engines, bits of machinery, lumps of re-inforced concrete (including the first made example), and quite a few things that no-one knows what they are.
One of things that most impressed me was the old Wood Press, acquired in 2001 as the only surving part of the Fleet Street presses. It's an enormous 140 tonne hulk of wood and steel, which used to produce the Daily Mail and the Evening News. Moving it into storage must have been some operation. Apparently some of the left over bits of the presses were simply buried in concrete to save having to remove them. See pictures from the Science and Society picture library.