Bristol Tramp

Infobox Aircraft
name=Bristol Type 37 Tramp and Type 44 Tramp Boat


caption=
type=Passenger aircraft
manufacturer=Bristol Aeroplane Company
designer=Frank Barnwell
first flight=
introduced=
retired=
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primary user=
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produced=
number built=2
unit cost=
developed from=Bristol Pullman
variants with their own articles=The Bristol Tramp was a British "steam-powered" passenger and airmail transport aircraft. It was built but never flew.

Development

The Tramp was a development of Bristol's earlier Pullman passenger aircraft. In 1919 Frank Barnwell entered discussions with the Royal Mail Steam Packet Company about the feasibility of using flying boats as auxiliaries to ocean liners cite book|author=Barnes C.H.|year=1964|title=Bristol Aircraft Since 1910|publisher=Putnam & Company Ltd|id=ISBN 0-370-00015-3] . The Royal Mail Steam Packet Company had very limited experience with internal combustion engines, but long-term and deep knowledge of steam turbine powerplants, and so suggested the use of a steam turbine to power the aircraft. As Bristol's heavy bomber the Braemar, the progenitor of the Pullman, had originally been designed to have a central engine room with drive shafts to wing-mounted propellors, the Pullman seemed a suitable candidate as a testbed for the installation of a steam turbine engine room.

The powerplant was to consist of two 1,500 hp steam turbines of the Ljungstrøm type, with closed-circuit high-pressure flash boilers. The unprecedented 3,000 hp would be delivered though drive shafts and clutches to a four-bladed tractor propellors mounted on the each middle wing (the Braemar/Pullman/Tramp family were triplanes). In the end, the only problem encountered with the steam turbine itself was that it delivered far too much power for the Tramp airframe, which had been designed to handle the 1,600 hp of four 400 hp Liberty L-12 engines. The main problem turned out to be in designing a reliable lightweight closed-circuilt boiler and condenser.

Two examples of the Tramp were completed in 1921, powered by four 230 hp Siddeley Puma piston engines, but the power transmission system, particularly the clutches, gave continual trouble, and neither ever flew. They were moved to Farnborough in 1922 where thet were used as ground test rigs for several years .

The Tramp Boat was a proposed flying boat development of the Tramp.

pecifications

aircraft specifications

plane or copter?=plane
jet or prop?=prop

ref=

crew=3
capacity=
length main=60 ft
length alt=18.29 m
span main=96 ft
span alt=29.26 m
height main=20 ft
height alt=6.10 m
area main=2,284 ft²
area alt=212.2 m²
empty weight main=12,000 lb
empty weight alt=5,440 kg
loaded weight main=18,795 lb
loaded weight alt=8,527 kg
max takeoff weight main=
max takeoff weight alt=

engine (prop)=Lungstrøm
type of prop=steam turbine
number of props=2
power main=1,500 hp
power alt=1,140 kW

max speed main=
max speed alt=
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cruise speed alt=
range main=
range alt=
ceiling main=
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climb rate main=
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loading main=
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guns=
bombs=

ee also

aircontent
related=
* Bristol Types 24 and 25 Braemar
* Bristol Types 26 and 44 Tramp

similar aircraft=

lists=

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References