THE 165-year old Belle Tout lighthouse at Beachy Head was jacked 650mm into the air this week.
The move was in preparation for next week's 17m slide back from the cliff edge onto a new basement structure.
Main contractor Abbey Pinford constructed new concrete beams under each load-bearing wall in the 850t structure. Four slide track beams were then cast below the new foundations connected to the basement structure.
The jacking operation, which began on Monday evening, separated the two layers of beams and created space for slide rails and greased skates to be inserted.
Weather permitting, Abbey Pinford will begin the slide next Wednesday.
BBC1's Tomorrow's World programme will be showing the slide live at 7pm on March 17.
The full story will appear in next week's NCE.