A B-Class Blimp just after takeoff. This type would be the first in a long line of USN patrol blimps. [US National Archives]The B-Class Blimp was a type of non-rigid airship used for training and patrol duty by the United States Navy during, and after the First World War. The type would be the first successful patrol blimp series the Navy would field and would be used until the early 1920s. Its success would prove the effectiveness of coastal patrol airships in the US, and would mark the beginning of a long line of airships operated by the Navy.
A Rocky Start
Two B-Class blimps during a training exercise. Two spherical observation balloons can also be seen. [US National Archives]The First World War was one that saw considerable technological breakthroughs, with many different ideas coming to fruition for the first time or previously small endeavors in weapons now being used in large numbers. Nowhere was this more clear than with aircraft design. Aside from conventional airplanes, lighter-than-air aircraft also saw their first widespread combat use, ranging from the large Zeppelin raids on London, to the observation balloons at the front. Britain would develop their own unique series of non-rigid dirigibles for the sole purpose of patrolling their coastlines and surrounding waters to search for enemy ships and submarines. At first, the Sea Scout class of airship would fill this role, but later the much larger North Sea and Coastal-classes of airship would also be built. These airships would prove very effective in their patrol duties, with some capable of patrolling for hours on end without stopping. The success of these airships would inspire the United States Navy to begin work on their own design in 1915.
An example of a British coastal patrol airship is the Sea-Scout class, which were heavily used during the First World War to patrol the coastline. This type in particular would serve as a basis for the B-class Blimp [Imperial War Musuem]The first of the Navy’s patrol airships would be the DN-1, later considered the A-Class but never officially known as this. The DN-1 was built by the Connecticut Aircraft Company in 1915 using intelligence from German and Austrian non-rigid airship designs of the time. The DN-1 would prove to be a massive failure, having a poor top speed, inadequate lift, and engine troubles which led the type to not be mass produced. Seeking to avoid a repeat of the DN-1, the Navy would begin looking for a more successful design. Their search would lead to the creation of the improved B-Class
The B-Class Blimp
Rear view of the B-1, the first of the B-Class. [US National Archives]The designers at the Bureau of Construction and Repair (Bu. of C&R) would instead look towards the British for inspiration for their improved design over the German/Austrian based DN-1. The result would be the B-Class. Its overall design took heavy inspiration from the British Sea Scout class of airship. The design would be drafted by the Bu. of C&R. There were several expected requirements to the B-class. The airship had to have a top speed of at least 45mph, a 35mph cruising speed with an endurance of 12 hours, communication range of 150 miles, a crew of three, and it had to be able to land on water for emergencies or towing. The design was approved on January 26th by the General Board and a day later by the Navy. An initial order for two B-class blimps was arranged, but this would change on February 4th when a total of 16 were now ordered. This amount was too much for a single company to construct, so instead 5 companies were approached; Goodyear, Goodrich, the Connecticut Aircraft Company, Curtiss and U.S. Rubber. All of these companies, despite being rivals, would work closely together on the construction of the B-class blimps. Three companies would construct the main balloon section themselves, Goodyear, Goodrich and Connecticut. Goodyear was tasked with building B-1 through B-9, Goodrich would build B-10 through B-14 and Connecticut would build B-15 and B-16. Curtiss would focus on building the gondolas of the B-class, which were modified JN-4 Jenny fuselages, as well as building the OXX engines and fins for the craft. U.S. Rubber would supply Connecticut with fabric for the skin. At the start, Curtiss was meant to build three blimps but these would be instead given to Goodrich, as Curtiss had other aircraft projects to focus on. Building military airships was a new endeavor for most of these companies, aside from Connecticut who produced the previously mentioned DN-1. Goodyear had the most experience in terms of production of lighter-than-air aircraft, as they had already produced a number of free and kite balloons for the Navy, and were found to be the most prepared for production of this scale. Thus the first few B-Class were assigned to them.
Design
Underside view of a B-Class and its gondola. [US National Archives]Closeup view of the modified Curtiss JN-4 Jenny fuselages used as the gondola for the B-class. [US National Archives]The B-Class was a blimp designed for patrolling the offshore waters of the American coastline during World War One. The B-Class had a large, teardrop shaped body that was filled with hydrogen. It would be 160 ft (48.8 m) long. The overall volume of the B-classes differed between the companies that built it. At the rear of the body were several fins, two horizontal, one ventral and one dorsal. Each of these, except the dorsal fin, would have control surfaces to move the airship in the desired direction. Hung underneath the body was the gondola. The gondola was a modified Curtiss JN-4 Jenny fuselage with its wings and tail surfaces removed. An additional third seat was added compared to the standard two seats of the JN-4. In the nose of the gondola was a single Curtiss 100 hp OXX-2 engine powering a two-blade wooden propeller. On the two Connecticut B-classes, 100 hp Hall-Scott engines would be used instead. Beneath the gondola, the B-Class originally retained the landing gear from the JN-4, but these were swapped out later for two flotation bags. On the last B-Class built, B-20, a completely new gondola was designed and the craft was much larger than the standard design.
For armament, the B-class would have a Lewis machine gun. For anti-submarine duties, it could carry depth charges or bombs. Additional equipment for the crew included a radio transmitter and receiver, flashlights, a flare pistol with green and red flares, life preservers, rations, drinkable water, maps, a camera, carrier pigeons and signal books.
The B-Class in the War
A B-Class blimp above the Goodyear hangar at Akron. Two Upson kite balloons can be seen in the hangar. [US National Archives]The first B-Class, B-1, would be completed by Goodyear sometime in April/May of 1917. At the time of its creation, Goodyear had been working on building a facility in Akron to house and operate airships, but it was still under construction when B-1 was completed. Thus, Goodyear had to transport the B-1 to the Goodrich facility near Chicago to inflate the craft. The craft was finally inflated and first flown on May 24th, 1917, with Ralph H. Upson at the controls. Upson was an airship engineer and pilot at Goodyear, and a pioneer in the lighter-than-air field, winning an airship race in 1913 and designing his own kite balloons at Goodyear only a few years earlier. He was thoroughly impressed with the first test flights. Upson would take the B-1 up again 5 days after the first flight and would try to fly from Chicago all the way to Akron. His flight started at midnight. Due to an oil leak, he would have to set the craft down at noon, just 10 miles outside of Akron. Despite not making it to his intended destination, Upson had achieved a record for lighter-than-air aircraft travel distance in America. The Navy had doubts surrounding the B-Class after the failure of the DN-1, but with the type already achieving world records on only its second flight, these doubts were quickly amended. The type was already proving its effectiveness even before entering active service. Production of the rest of the 15 B-classes soon commenced and the B-1 was shipped to Pensacola on August 7th, 1917.
B-Class at Akron, Ohio. [US National Archives]As production continued, the various B-Classes would be sent across America to different air stations for duties. These included Naval Air Stations; Pensacola, Cape May, Montauk, Key West, Rockaway, San Diego, and Coco Solo in Panama. B-classes would also be stationed at Hampton for mostly testing purposes. Several improvements of the B-class would occur during its service, improving its top speed from 40mph to 48mph. The B-Class was responsible for patrol and rescue operations off the coastlines of America, and hunting for the dreaded U-Boat. It was found that blimps were much better for patrol duties than airplanes thanks to their long range, extended endurance time, and the ability to hover in midair assisted in spotting enemy warships. The B-Class would perform this duty until the end of the war. If a B-Class encountered a U-Boat, it could deploy depth charges or bombs, or radio in for aerial support from the NAS the aircraft was stationed at. During its service life, at least two B-classes would spot a U-boat and attempt to destroy it, but none would be sunk by the B-Class. The service of the B-class was impressive. It is estimated that the B-classes together patrolled for over 13,600 hours across 400,000 miles. Aside from patrol duties, another impact the B-Class had on the military was its extensive use as a training craft. Several B-classes would be stationed at the aforementioned Goodyear Akron facility solely for the purpose of training. Over 170 aviators would train and be certified on the B-Class, with many headed overseas to operate European dirigibles in service with France and Britain. No B-class blimps were ever sent to Europe.
A B-Class preparing for takeoff. [US National Archives]The B-class was not without its accidents. Throughout their service life, many B-class blimps would suffer damage or be completely destroyed while on duty. B-4, B-5, B-6, B-7, B-9, B-12, B-14 and B-16 were all destroyed in accidents before the end of the First World War.
B-Class at Akron Ohio. [US National Archives]Despite its effectiveness, the B-class was found to be lacking as a patrol craft, and the Navy would order a successor design in September of 1918 to amend the shortcomings of the B-class. This was the C-Class (no relation to the aforementioned British Coastal Class which was also known as the C-Class coastal airship) and it took many aspects of the B-Class and improved upon them. The shape of the balloon itself was overall the same, but the C-Class had a much larger gondola that sported two engines instead of one, granting improved speed and maneuverability. The C-Class however wouldn’t be ready before the end of the war, but was instead operated postwar.
The B-Class Postwar
View of a B-class during operations patrolling the Atlantic. This photo was taken from a USN submarine. [US National Archives]The First World War would end on November 11th, 1918, with the B-Class having served well in its duties. Despite the C-Class approaching production, the B-Classes still in service would continue to operate, however a few were stricken off to reduce the fleet size. Three B-Class blimps would be rebuilt reusing the envelopes from previously damaged blimps. These would be B-17, B-18 and B-19. B-17 is known to have reused the envelope from B-1, which was damaged on June 17th, 1920. B-18 likely used the envelope from B-13. Details on B-19 are lacking. It is known that these three blimps were constructed sometime in 1920. The final B-class built would be the B-20. Details are also sparse on this craft but it is known to have had a completely unique gondola design and was much larger than the standard B-Class. In the bureau number list, B-20 is listed as being before the aforementioned rebuilt gondolas. Interestingly, these B-classes were all built after not only the introduction of the C-Class, but even after its successor, the D-Class. All postwar built B-classes were constructed by Goodyear. The remaining B-classes continued to serve into the early 1920s, with many of them being scrapped due to accidents or deterioration with age. By 1924, three B-classes remained, B-3, B-8 and B-15. B-8 was heavily deteriorated but B-3 and B-15 were still in operational condition. By this point however, the B-class was heavily outdated, and with its services no longer required, the last 3 were surveyed and scrapped in 1924. The B-class actually wound up being in service longer than its successor, as the few remaining C-Classes had been scrapped in 1922.
Conclusion
A B-Class above the Naval Air Station at Key West, Florida. [US National Archives]The B-Class was an important achievement to the United States Navy, proving the effectiveness of patrol airships and paving the way for a long line of succeeding designs. The B-Class would train aviators that would go on to protect allied countries in foreign built dirigibles, and would protect the American coasts from U-Boats. B-Class blimps would serve the Navy well past its expiration date, even surpassing its own successor. The Navy’s LTA airship fleet began with the humble B-Class, and would continue for almost five decades later.
One of the early B-Classes built by Goodrich. Notice the double ventral fins. [US National Archives]
Service List
B-1: The first in the B-Class series, B-1 would survive the war. On June 17th, 1920, B-1 would be damaged at Pensacola and would be stricken off. The gas bag was later reused on B-17.
B-2: B-2 would survive the war and would be stationed at Key West. On February 28th, 1919, B-2 would completely wreck.
B-3: B-3 would survive the war and continue to serve until it was surveyed in 1924. The ship was damaged several times but was fully repaired each time.
B-4: Stationed at Hampton NAS for testing. On August 8th, 1918 the craft was damaged and stricken. The blimp was salvaged for spare parts.
B-5: Stationed at Akron. While on maneuvers, it would be completely destroyed on November 21st, 1917.
B-6: Service details are lacking, stricken from the Navy on September 7th, 1918.
B-7: Stricken June 8th, 1918.
B-8: Survived the war and served until March 19th, 1924, where it was surveyed due to deterioration.
B-9: Stationed at Key West. On April 21st, 1919 would completely wreck due to engine failure.
B-10: Stationed at Cape May. During maneuvers on December 7th, 1918, it would be heavily damaged. The craft was sent back to Goodrich but the repairs were considered too expensive and B-10 was scrapped. The envelope was torn up and distributed to other air stations to serve as repair materials on other blimps.
B-11: Shipped to Pensacola, service ended on August 15th, 1919. Service unknown.
B-12: B-12 wrecked while on patrol on July 26th, 1918.
B-13: Damaged numerous times during service at Montauk Naval Air Station. Envelope appears to have been salvaged and later reused but on what aircraft is unknown, possibly B-18. It was recommended to be stricken off at two different stations in 1919, at Montauk and Rockaway.
B-14: Wrecked July 20th, 1918 at Montauk(?).
B-15: Served at Pensacola through the war and after. Was finally surveyed on April 22nd, 1924.
B-16: Official report is spotty but on June 17th, 1918, the craft was destroyed.
B-17: Rebuilt gondola, reused the envelope from B-1, service unknown.
B-18: Rebuilt gondola, envelope possibly from B-13. Service unknown.
B-19: Rebuilt gondola, service unknown.
B-20: Last B-class. Built in 1920. Completely new gondola design. Service unknown.
Variants
Goodyear/Goodrich B-Class (1 through 14) – B-classes built by Goodyear/Goodrich would use Curtiss OXX-2 engines. The first few of these had double fins but these were later changed to a single fin.
Connecticut B-Class (15 & 16) – The two B-Classes built by Connecticut would use Hall-Scott engines. These two appear to have the double fins as well. Unknown if any of these were later changed.
B-20 – The last B-class produced. It would have a unique gondola design.
Operators
United States of America – The 20 B-classes built would be operated by the United States Navy for patrol and training purposes until 1924.
B-Class (Goodyear) Specifications
Length
160 ft / 48.8 m
Diameter
31.5 ft / 9.6 m
Volume
(Varies between companies)
77,000 ft³ / 2180.4 m³
Engine
1x 100 hp ( 73kW ) Curtiss OXX-2 8-cylinder engine
USA (1917)
