A Staircasean Mystery

This staircase was built without nails and should have come crashing down long ago. The type of wood used to build the staircase has also never been identified...

"Two mysteries surround the spiral staircase in the Loretto Chapel: the identity of its builder and the physics of its construction.

When the Loretto Chapel was completed in 1898, there was no way to access the choir loft twenty-two feet above. Carpenters were called in to address the problem but they all concluded access to the loft would have to be via ladder as a staircase would interfere with the interior space of the small Chapel.

Legend says that to find a solution to the seating problem, the Sisters of the Chapel made a novena to St. Joseph, the patron saint of carpenters. On the ninth and final day of prayer, a man appeared at the Chapel with a donkey and a toolbox looking for work. Months later the elegant circular staircase was completed, and the carpenter disappeared without pay or thanks. After searching for the man (an ad even ran in the local newspaper) and finding no trace of him, some concluded that he was St. Joseph himself, who came in answer to the sisters' prayers...."

Link: Loretto Chapel.

Comments

[dog's beard]

oh come on!
church folk mystified by physics?? since when did that lot become interested. (tourists must like physics.)

anyways... if you consider just the vertical negative space up through the center of the stair case... now consider the vertical elements that infer that tube shape. in essence those wood and steel elements form a hollow column. since it's not a complete column one might think of it as a spring, but since there's a second column (partial tube) of a larger diameter held up, in part by the stairs which provide a cantilever type support there is a tensile strength (a force that holds against expansion,)that keeps the shape of the whole from expanding outward which is what it would have to do t compress downward...all the while considering that the balustrade is NOT made of spring steel, but rather it looks like a whole lot of trusty rod iron. it also helps that the construction is securely anchored to the upper floor.
in other words: a pair of tubes that reinforce each other by means of a WELL BUILT stair case. it's for good reason that these stairs have risers (the vertical face of stairs that is sometimes but not always used in staircase construction.) which are perhaps the most powerful element resisting the compression that gravity can bring. also, because the underside of the stair care is sheathed i suspect that there are iron pieces connecting the inside and outside "tubes."

two notes: 1) to build something like this, you'd likely use a lot more bracing that is then removed only once critical elements are secured in place. 2) wood craftspersons such as furniture makers don't often depend on nails the same wall a house carpenter would, their purpose, if used at all is to hold wood elements together until the chemical bond of plastic or hide glue can work it's magic.

[Steven Augustine]

The donkey is a nice touch, though.