The Royal Greenwich Observatory (RGO) has a rich and wonderful history. It currently operates as a museum. Educating the public about the history of astronomy, time and frequency. Although the RGO may still be the home of Greenwich Mean Time, its no longer the official home of UK timekeeping.

That responsibility goes to the National Physical Laboratory (NPL) in Teddington. NPL operate a fleet of atomic clocks to deliver the UK's official UTC(NPL) timescale.

The atomic clock currently on display in the RGO museum was donated by NPL back in 2002. I lived in Greenwich at the time and took photos of its arrival. Both institutions are close to the river Thames so the clock travelled in style. By royal barge of the Jubilant Trust and accompanied by the late Alan Coren dressed as King George.

Twenty one years later NPL have donated a second clock to the RGO. This time a modern optical atomic clock. And again it was delivered on the Royal Shallop Jubilant with a 15-strong flotilla. I look forward to visiting it next time I'm in Greenwich.

Photos courtesy of the Jubilant Trust, the Port of London Authority (PLA), and the National Physical Laboratory (NPL).