Bristol Type 172
| Industry | Aerospace, Defence |
|---|---|
| Founded | 1910 |
| Headquarters | Filton , United Kingdom |
| Products | Aircraft, aero engines |
Bristol Type 172
The Bristol Type 172 was a conceptual British long-range bomber featuring four engines, developed by the Bristol Aeroplane Company. It shared strong connections with the Type 174 and Type 176 design proposals.
Following the Second World War, as interest grew in advancing the capabilities of strategic bomber aircraft, Bristol initiated design efforts in late 1946 to create a new bomber incorporating emerging aviation technologies such as turbojet engines and a swept-back wing. The Type 172 quickly attracted attention from the Air Staff, prompting the Air Ministry to issue Specification E.8/47 to Bristol on 23 July 1947. Subsequently, the company embarked on detailed studies to evaluate the aerodynamic characteristics and other critical performance features of the Type 172.
To facilitate experimental testing, Bristol developed a half-scale, flight-capable model designated the Type 174. This scaled version maintained geometric similarity to the full-sized Type 172 but was powered by a single Rolls-Royce Nene turbojet engine rather than four. During development, it became apparent that excessive subsonic flow turbulence at the wing-fuselage junction would require significant wing redesign. Consequently, work on the Type 174 was discontinued in November 1947, and on 8 June 1948, a revised version of Specification E.8/47 was released, introducing numerous updated design criteria. In response to these changes, Bristol proceeded with designing the Type 176.
Progress on the Type 176 advanced to the mockup phase by late 1948. However, company leadership decided to prioritize other projects, notably the Bristol Britannia turboprop airliner, due to limited engineering resources. As a result, development of the Type 176 was halted. No complete aircraft—neither full-scale nor models—were constructed during this programme. Nevertheless, insights gained from these efforts were applied to several subsequent Bristol proposals, including the Type 182, also referred to as the Short Range Expendable Bomber.
Design and development
Following the conclusion of the Second World War, the British government demonstrated a strong commitment to advancing the Royal Air Force's strategic bomber capabilities. This ambition was notably present within the Air Ministry, which aimed to develop a high-speed, long-range bomber powered by four turbojet engines. In October 1946, the Bristol Aeroplane Company submitted its own proposal, identified as the Type 172. This design featured a high-wing monoplane layout with wings swept back at a 45-degree angle. The Air Staff responded positively to Bristol's proposal, prompting plans for an experimental program to thoroughly assess the aircraft's stability, control, and maneuverability. Subsequently, on 23 July 1947, the Air Ministry issued Specification E.8/47 ("Prototype Flying Models to Operational Requirement 250") to Bristol.
The experimental program included the construction of a half-scale flying model named Type 174. This model maintained geometric similarity to the Type 172 but was powered by a single Rolls-Royce Nene turbojet engine and designed for a solo pilot seated within a pressurised cockpit. The engine was centrally mounted, with air supplied via bifurcated intakes; these, combined with carefully shaped tailpipes, were engineered to replicate the expected external airflow patterns of the full-sized aircraft. Additionally, the design incorporated provisions for boundary layer control through suction, intended for evaluation during later flight tests. The Type 174 aimed to match the projected speed and altitude performance targets set for the Type 172.
Aerodynamic studies revealed that the initial configuration was unsuitable due to problematic high subsonic flow characteristics at the wing-body junction, necessitating a redesign with a swept leading edge on the wing. Consequently, work on the Type 174 was halted in November 1947 and Specification E.8/47 was revised. The updated specification, issued formally on 8 June 1948, called for a smaller monoplane at three-tenths scale powered by the more advanced Rolls-Royce Avon engine. Additional modifications included adopting a swept shoulder-mounted wing, a conventional swept tail unit, a single nose air intake, and tandem landing gear.
In response to these evolving requirements from the Air Ministry, Bristol had already initiated development of an updated design known as Type 176 by February 1948. Aviation historian C.H. Barnes notes that progress on this model advanced further than either previous iteration; however, by October 1948’s mock-up review meeting, Bristol’s management recognized that their engineering resources were stretched across multiple projects. Priority was given to ventures such as the Bristol Britannia, an innovative airliner featuring pioneering turboprop engines capable of routine transatlantic flights.
As a result, work on the less critical Type 176 was suspended in favor of other company projects. Nevertheless, Bristol maintained a small team dedicated to this line of development who continued producing design materials and submitting tenders aligned with various specifications. These ongoing efforts culminated in the creation of the Type 182, also known as the Short Range Expendable Bomber, which was designed for operational use similar to that of the V-1 flying bomb deployed by Nazi Germany during World War II.
Variants
- Bristol Type 172
- Conceptual design for a four-engine, extended-range bomber; this model was never constructed.
- Bristol Type 174
- A half-scale prototype intended for design assessment of the Type 172, powered by a Nene engine; this version remained unbuilt.
- Bristol Type 176
- A 3/10th scale modified development aircraft of the Type 172, equipped with an Avon engine; only a mock-up was created, and it was not completed.
Specification (Proposed Type 172)
Citations
Bibliography
- Barnes, C.H. (1964). Aircraft by Bristol since 1919. London: Putnam. ISBN 0-85177-823-2.
{{cite book}}: ISBN / Date incompatibility (help) - Buttler, Tony (2003). British covert initiatives: jet bombers post-1949. Hinkley: Midland. ISBN 9-781-85-780130-9.
- Darling, Kev (2007). Avro Vulcan, Volume 1. Lulu.com. ISBN 9-781-84-799237-6.
- Meekcom, K.J.; Morgan, E.B. (1994). File of British Aircraft Specifications. Tonbridge, Kent: Air-Britain. ISBN 0 85130 220 3.