The B class blimps were patrol airships operated by the United States Navy during and shortly after World War I. The Navy learned a great deal from the DN-1 fiasco. The result was the very successful B-type airships. Dr. Jerome Hunsaker was asked to develop a theory of airship design, Lt. John H. Towers returned from Europe having inspected British designs, the Navy sought bids for 16 blimps from American manufacturers. On 4 February 1917 the Secretary of the Navy directed that 16 nonrigid airships of Class B be procured. Ultimately Goodyear built 9 envelopes, Goodrich built 5 and Curtiss built the gondolas for all of those 14 ships. Connecticut Aircraft contracted with U.S. Rubber for its two envelopes and with Pigeon Fraser for its gondolas. The Curtiss-built gondolas were modified JN-4