Spritsail barges on the Thames

The nearest of three spritsail barges is shown stern-on from a distance of some 100ft moored to a post from which a gangplank reaches the riverside wall of London County Council's County Hall under construction (it was opened in 1933). Like the barge ahead of it and the third barge moored off the river shore, the nearest barge's sails are brailed. The barges are evidently being used to deliver stone or other building materials to the site.