The usual method of constructing riverboats was to erect them at the builder's yard, take them to pieces for shipment, and upon arrival rivet them up prior to launching. This option was not available to the British Government for the gunboats to be used on the Zambesi and Shire Rivers and it was decided to adopt a method used by Messrs. Yarrow and Co. on two other occasions, viz. to build the hulls in floatable sections, that could be shipped to their destination, and then reassembled.