VATICAN CITY — Vatican workers installed the simple stove in the Sistine Chapel where ballots will be burned during the conclave to elect a new pope and began taking measures to block any electronic interference with their deliberations, as jockeying continued Saturday outside over who among the cardinals is in the running.

The Holy See released a video Saturday of the preparations for the May 7 conclave, which included installing the stove and a false floor in the frescoed Sistine Chapel to make it even. The footage also showed workers lining up simple wooden tables where the cardinals will sit and cast their votes starting Wednesday.

The engineer overseeing the works, Silvio Screpanti, said workers were also deactivating all the electronic sensors that have been installed in the Sistine Chapel in recent years to help protect its precious frescoes. Such work is part of the technological blackout that accompanies a conclave to prevent bugging of the secret deliberations and ensure the cardinals have no contact with the outside world.

In the coming days, all the windows of the Apostolic Palace facing the Sistine Chapel will be darkened. On the eve of the first vote, some 80 seals will be erected around the perimeter of the space where the cardinals will live — between their residence and the Sistine Chapel — to keep outsiders away, Screpanti said in comments posted on the site of the Vatican city state.

On Friday, fire crews were seen on the chapel roof attaching the chimney from which smoke signals will indicate whether a pope has been elected.

The preparations are all leading up to the solemn pageantry of the start of the conclave to elect a successor to Pope Francis, history’s first Latin American pope, who died April 21 at 88.