Wartime, as always, saw many new additions to the forces inventory. Here officers announce some changes in details of evacuation plans by the use of a new-fangled loudspeaker. A task that would now be more efficiently performed by local radio. This photo shows a police sergeant shepherding children on the steamboats by loud speaker - then they were evacuated in the early hours of Sunday (taken 3rd September 1939 near the pier at Gravesend, Kent)