First a small non-rigid, built by Messrs. Willows, was bought by the Navy to be used for the training of airship pilots. In addition an Astra-Torres airship was ordered from France. This was a ship of 229,450 cubic feet capacity and was driven by twin Chenu engines of 210 horse-power each. She carried a crew of six, and was equipped with wireless and machine guns. The car could be moved fore and aft for trimming purposes, either by power or by hand. This was, however, not satisfactory, and was abandoned.

In April 1918, Messrs. Vickers were asked to forward proposals for a rigid airship which afterwards became e known as No. 9. Full details of the vicissitudes connected with this ship will be given in the chapter devoted to Rigid Airships.

In July, approval was granted for the construction of six non-rigid ships. Three of these were to be of the German design of Major von Parseval and three of the Forlanini type, which was a semi-rigid design manufactured in Italy. The order for the Parsevals was placed with Messrs. Vickers and for the Forlaninis with Messrs. Armstrong.