As has been said the Trident was a good aircraft screwd up by BEA. In those days BEA and BOAC WERE the UK aircraft design authority.
Everything was related to their airport/ field/ passenger requirements and they were great on standardisation. In fact everything was supposed to be the same.
A very good example of this is when they later took BAC 1-11 ( fortunately designed without their help) they wanted the APU changed from Garrett, (average 3,500 hrs between all removals at that time) to Turbomeca(less than 1,000 hr BTR) because thats what they had on Trident !
The Vanguard and Ambassador are a couple of other names to conjure with.
The Trident nose gear retracted sidways so it was off center. We used to tell our 727 friends that the reason for this was the Autopilot was so accurate it was to prevent passenger discomfort from the nosewheel running over all the centerline lights !