Thames Slipway

Walking back to the tube from the Tate, I noticed this old slipway, below the OXO Tower, that had been uncovered by the falling tide. Having read about Mark Dion's 'Archaeology' project at the Tate and seen the Time Team programme about the Thames foreshore I would love to know more about this slipway; when was it originally built? Who built it? What for? When did it go out of use? How was it constructed? What is it constructed from? Perhaps I'm just nosey, and this is certainly not a good time to start trying to find out but perhaps someone else has had the same thought and I will be able to find out from them at some time in the future.