Sistine Chapel serves as setting for historic papal vote

(CBS News) ROME - The cardinals have not set a date for the upcoming papal election. But on Tuesday, the Sistine Chapel was closed to visitors to get it ready.

It is the most beautiful polling station in the world for the world's most secret vote.

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But before the Sistine Chapel is used to elect the next pope, it must undergo a transformation.

Tourists who pour in to gaze at Michelangelo's famous ceiling are banned.

Chairs and long tables are added for the 115 voting cardinals who will elect the new pope.

Retired Cardinal James Stafford of Baltimore took part in the last conclave in 2005. "I was overwhelmed with the profound history that is everywhere present to us," he said, "the creation of the human race above us."

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To keep the "princes of the church" from modern temptations, cell phones and computers are forbidden. The frescoes are swept for bugging devices. A false floor is installed to cover electronic jamming equipment.

On the wall Michelangelo's "Last Judgment" looms as cardinals place their vote in urns in front of the painting.

The new pope must be elected by a two-thirds majority. A special stove is used to burn the ballots after each vote. If there's no winner, a chemical is added to produce black smoke. White smoke signals that a pope has been chosen.

In the early days, cardinals slept in the chapel in makeshift huts, which sparked some unholy rivalry, according to Vatican art expert Arnold Nesselrath.

"Everybody had his little hut and there was even competition," he said, "because three times in a row the cardinal was elected slept underneath the handing over to the keys to Peter."

Watch Cardinal Francis George of Chicago talk to "CBS This Morning" about what qualities the conference will be looking for in the next pope:

After he's elected, the new pope goes to what is called "The Room of Tears" to be dressed for his first appearance, often a deeply emotional moment.

"For example Pope Pius X as Cardinal Sarto wept in 1903," said Stafford. Asked if they're weeping from joy or fear or penitence, he replied: "Basically tears of fear. Unworthiness. It's too much."

The Sistine's glorious artwork serves as a reminder of just how challenging the job will be.