R23X-class airship

R.23X series

Company type	Military airship series
Industry	Aviation, Military
Founded	1918
Founder	Vickers (design), William Beardmore and Company (R.27), Armstrong Whitworth Aircraft (R.29)
Headquarters	United Kingdom
Products	Rigid airships (R.27, R.29)

The British rigid airships classified as the R.23X series were developed amid World War I, drawing on operational experience from the earlier 23 class. Although four units were initially planned, only two—R.27 and R.29—were constructed. Both entered service by mid-1918; however, R.27 was lost to a hangar fire just two and a half months after commissioning. In contrast, R.29 distinguished itself as the most effective British wartime rigid airship, being the sole vessel to engage enemy forces directly and successfully sink a submarine.

Design and development

Control wheel from airship R29, Museum of Flight

The 23 class rigid airships, designed by Vickers as elongated and adapted derivatives of the No. 9 model, never saw combat deployment. Nevertheless, the four vessels in this category accumulated extensive training hours for British airship personnel and supplied critical experimental data to engineers and designers. These insights led to significant design modifications and enhancements for the subsequent R.23X series. Initially, four ships—designated R.27 through R.30—were intended for production, but after the forced landing of L 33 (Z33) at Little Wigborough, Essex, on 24 September 1916, the programme underwent reassessment. Examination of this largely intact German Zeppelin provided British engineers with crucial understanding of enemy rigid airship technology, prompting cancellation of R.28 and R.30. Resources were redirected toward developing an advanced design that culminated in the R33 class.

Hull

The bow and stern sections were redesigned to slightly increase the gas volume, resulting in a modest boost in lift. A more significant change involved eliminating the external keel corridor present in the R.23X model. Since the keel contributed little to the hull's structural integrity, its primary role had been to support the weight of fuel tanks, ballast bags, and other heavy components, as well as to provide a passageway for the crew between the cars. Removing it led to a notable weight reduction and enhanced handling capabilities. Instead, these loads were concentrated at the bulkheads and suspended from radial wiring that preserved the hull's shape. The gas bags were reconfigured to include a new internal corridor formed by inverted U-shaped ribs positioned above the two lowest longitudinal members, facilitating access to the fuel tanks and ballast. Additionally, an upgraded piping system connected the fuel tanks, allowing quicker refueling and enabling fuel jettisoning during emergencies. Nevertheless, like earlier models, the hull's exterior was covered with doped linen; due to its absorbent nature, just a few hours of rainfall could add approximately one ton of water weight.

Propulsion and testing

The R.23X series utilized four 300 hp (220 kW) Rolls-Royce Eagle VI engines—more advanced and powerful iterations of those used in the 23r class—arranged in a comparable configuration. The front and rear gondolas each housed a single engine that powered two swiveling propellers located on either side, while the central car contained two engines, each driving a fixed propeller.

Following the removal of the external keel, initial test flights demonstrated that these airships could execute turns more swiftly than their predecessors. More crucially, lift and trim evaluations revealed that disposable lift exceeded 8½ tons—a substantial improvement over any earlier British airship—permitting increased bomb loads and additional fuel capacity for extended range.

R.27

Built by William Beardmore and Company at Inchinnan, Renfrewshire, R.27 was commissioned on 29 June 1918. Commanded by Major Ommaney, it accumulated a total flight time of 89 hours and 40 minutes before meeting an untimely end at the RNAS Howden airship station on 16 August of that year. Sharing its hangar with R.27 was an improvised SSZ class blimp assembled from an unused envelope and a spare SS Zero car. A petrol leak in this car ignited later during radio equipment testing due to a spark, triggering a fireball fueled by both gasoline and gas that completely consumed both airships. Although the hangar remained intact, one airman perished, and two additional blimps moored nearby—SSZ.38 and SSZ.54—were also destroyed.

R.29

Built by Armstrong Whitworth Aircraft at Barlow, North Yorkshire, R.29 was officially commissioned on 20 June 1918. Stationed at the East Fortune RNAS airship base in East Lothian, Scotland, her operational period spanned under five months. Throughout this time, she accumulated 335 flight hours and traveled approximately 8,215 miles (13,221 km), establishing herself as the most effective British rigid airship during wartime.

Among her numerous long-duration missions were patrols exceeding 30 hours and two additional sorties lasting over 20 hours each. She encountered German U-boats on three separate occasions: the first submarine managed to evade capture; the second was lost after striking a mine during pursuit; and on 29 September 1918, under Major G. M. Thomas's command, she engaged a third submarine, UB-115, roughly 4.5 nautical miles (8.3 km) northeast of Beacon Point, Newton-by-the-Sea, off the coast of Northumberland. During this engagement, R.29 was supported by armed naval trawlers and the destroyers HMS Ouse and Star. She deployed two 230 lb (100 kg) bombs in the attack. Subsequent intelligence confirmed the destruction of the submarine, marking the sole confirmed sinking by a British rigid airship during the war.

Following the Armistice, R.29 continued flying for an additional 16 hours. In May 1919, her midship car was replaced with a lighter model featuring a single engine driving one propeller. She then logged a further 87 flight hours, including a notable extended journey over Scotland alongside R34. The airship was officially retired in October 1919, having covered an estimated total distance of 11,334 miles (18,240 km), surpassing any previous British rigid airship in service.

Operators

Template:UK

• Royal Naval Air Service / Royal Air Force

Specifications

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|eng1 number=4 |eng1 name=Rolls-Royce Eagle IV |eng1 type=water-cooled V12 engines |eng1 kw= |eng1 hp=300 |eng1 note=

|max speed kmh= |max speed mph=57 |max speed kts= |max speed note= |max speed mach= |cruise speed kmh= |cruise speed mph= |cruise speed kts= |cruise speed note= |range km= |range miles= |range nmi= |range note= |ferry range km= |ferry range miles= |ferry range nmi= |ferry range note= |endurance= |ceiling m= |ceiling ft= |ceiling note= |climb rate ms= |climb rate ftmin= |climb rate note= |time to altitude= |lift to drag=

|guns= |bombs= 230 lb (100 kg) bombs |rockets= |missiles= |hardpoints= |hardpoint capacity=

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References

• Griehl, Manfred and Joachim Dressel. Zeppelin! The German Airship Story, 1990 ISBN 1-85409-045-3
• Morpurgo, J.E. Barnes Wallis - A Biography, Longman, 1972 ISBN 0-582-10360-6
• Mowthorpe, Ces. Battlebags: British Airships of the First World War, 1995 ISBN 0-905778-13-8
• Ventry, Lord and Eugene Kolesnik. Jane's Pocket Book 7 - Airship Development, 1976 ISBN 0-356-04656-7
• Ventry, Lord and Eugene Kolesnik. Airship saga: The history of airships seen through the eyes of the men who designed, built, and flew them, 1982 ISBN 0-7137-1001-2

External links

• The Airship Heritage Trust – HMA 23X class airships
• Template:Cite Uboat.net