Bristol DIDN'T design it. Flight International artist HAVE DESIGNED it.
It could be his provisions based on information of 1955 33.800 lbs Bristol Type 194 (unbuilt VTOL based in unbuilt Type 192C), a compaund tandem helicopter, actually an stretched type 192 Belvedere with new fuselage, stub wings design and 4 de Havilland Gnomes powering two six-bladed 55 ft rotors. 48 passengers, dimensions 77 ft (L), 40 ft (WS) 24 ft (H)
All info is fron excellent Richard Payne's "Stuck on the Drawing Board".
Other sources say of 5-bladed rotors and 35 passengers.
From 'Flight...' http://www.flightglobal.com/PDFArchive/View/1958/1958-1-%20-%200168.html
"Other offshoots of the Bristol twin-engined tandem-rotor family
are two studies for civil aircraft. The first is the Type 192C,
which could be built on the same jigs and with virtually the same
powerplant, transmission and rotors as the military version. A
seventeen-seater, it would have a still-air range of 390 n.m. with
2,180 lb payload or 200 n.m. with 4,000 lb payload. But Bristol
feel that the ideal specification for a passenger transport would
be a larger helicopter capable of carrying about 35 passengers over
a 150-mile stage. The cruising speed should be at least 160 m.p.h.,
and to achieve this speed a stub wing carrying about 40 per cent
of the gross weight is necessary. Bristol have prepared a design
study to this specification, designated Type 194. It would be
longer, but have the same rotors, power being provided by two
free turbines of about 2,400 rated s.h.p. each. Maximum gross
weight would be between 22,000 and 25,000 lb."