cabin window size

[Fastship]

I was wondering why the VC10 did not share the same cabin windows as the Vanguard. The fuselage of the two types seem to share much else.

[Jelle Hieminga]

Good question, but the development of the VC10 moved away from the Vanguard based fuselage at an early stage. With thanks to John McCrickard, here is a quote from his upcoming Air Britain book:

The VC10 had originally been planned (Vickers VC10 MksIV and V during early-1957) to employ the Vanguard fuselage, including cabin windows.

However, the finalised VC10 (later Type 1101) ordered by BOAC in January 1958 was enlarged to provide North Atlantic route capability (at the express request of the airline); it was at this stage that the Vanguard fuselage was dispensed with, superseded by a wider one to enable comfortable six-abreast seating, not possible with the Vanguard; redesigned cabin windows/spacing was introduced at the same time.

The move to enable six-abreast seating was in response to Boeing's 707 design. Boeing had started with the model 367-80, aiming to develop this into both the military KC-135 as well as the civil 707, but with the KC-135 well under way they found out that competitor Douglas was going to offer a six-abreast cabin on their first large jet airliner, the DC-8. Boeing then, at great cost, modified the fuselage design to a wider variant for the civil 707 family, which means that to this day, the KC-135 and 707s have different fuselages, even though the look very similar. The first flight of the civil 707 took place in December 1957 and it is safe to say that the design changes for the VC10 were a response to the 707's design. More about the 707 here.

Have a look at this image for a comparison between the Vanguard and VC10 fuselage widths at the cabin floor level: