From the Vulcan Aircrew Manual:
'Rear crew members can leave the aircraft down to a minimum height of 250ft at a maximum speed of 250kts. Wherever possible, speed should be reduced to 200kts and the aircraft be in a shallow climb with the undercarriage raised, prior to escape.'
The pilots had to initiate ejection of their own seats - there was no command ejection facility. 2 of the rear crew had 'swivel seats', which were mounted on rails so that they could slide back clear of the worktable. The Nav Radar and AEO seats could then be swivelled inboard so that the occupants were facing the door in the floor. The rear seats were also fitted with 'assister cushions, which the guy inflated and it had the effect of forcing him to his feet to help him on his way to the door. The Nav Plotter had no swivel action and had to clamber out of his seat as best he could. The door was opened by feeding high-pressure nitrogen to the jacks which forced it open against the airflow. It also acted as a shield for the crew against the airflow, and a slide to help them escape. As Beags said, with the gear down the gymnastics required were unbelievable; there was only a few feet between the door and the nose leg, so the guys had to grab the door jack and swing into the airflow to avoid the nose leg (it was done for real and worked). Crews went monthly to the escape trainer, a cockpit section in a building where all the abandonment and ditching drills could be practised.
In my experience, rear crews were philosophical about their chances. We spoke openly about it - my crew knew that I would give them my best shot at giving them the chance to get out, but there would come a time when it was them or me… They did not expect others to die needlessly.
I wholeheartedly agree with Beags - it was one of the most shameful decisions ever to come out of the defence hierarchy not to fit rear bang seats. It cost a lot of good men their lives.
