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Discussion: The Miracle Of The Loretto Chapel Staircase Explained 1

Ron247

Ron247

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Heard about this in the 80s while in college. Never saw a picture, nor read an article about it until today. Out of curiosity, I looked on the internet for it.

The 2nd website aligns with the story I heard 45 years ago except the guy showed up on a bicycle and not a donkey. The catch phrase from my source of information who was putting down engineers in general was "Several structural engineers investigated this and said it was impossible it was standing."

When I heard the tale in college, I said it sounded like someone built 2 wooden slinkies and attached them to the ceiling based on a totally verbal description, so I was not that amazed.

https://www.grunge.com/770563/the-miracle-of-the-loretto-chapel-staircase-explained/

https://tincanpilgrim.com/2020/03/08/the-impossible-stairway-a-gift-from-saint-joseph/

Anyone ever lay eyes on this or know any more about it?
 
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Yes I have seen it in person. Quite impressive and interesting. Don't really have any detailed insight into the construction.
 
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The story I heard, they said the choir said it felt like you were walking on clouds as you traveled the stairs. I see why it does.

They also said the guy steamed the wood as he curved it. Someone saw at least a little of what he did if they are correct. Of course, wood is hard to bend/curve if not steamed.
 
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Fascinating story and beautiful staircase. The Tin Can Pilgrim story states the hand rail was added 10 years after original construction - climbing those without the railing appears to be an act of faith.
 
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Brian Malone said:
The Tin Can Pilgrim story states the hand rail was added 10 years after original construction - climbing those without the railing appears to be an act of faith.
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Did not notice that when I read the 2nd article. Your right, that is gutsy.
I know why he did not want the sisters watching him work. He did not want to get rapped on the knuckles with a ruler every time he made a mistake or took a break.
 
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Ron247 said:
"Several structural engineers investigated this and said it was impossible it was standing."
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With that type of attitude, I would suspect that they were not very good ones. It is lovely.
 
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I still see it as 2 wooden slinkies, so structurally, not that amazing to me. Either the engineers were not really structural engineers, marginal at best, lacked mental creativity, or gave up too easily.

But from a shear construction, on-site design and workmanship standpoint of the period it was created, it is amazing.

I even wonder how he did it with no helpers. I am a fairly good carpenter, and I would have quit 3 days into the job without a helper. For the time, the Architect was apparently the Gold Standard for Architects. Design a loft that cannot be accessed, leave it up to the engineer or someone in the field to figure it out. Probably had a note on the drawing; "Stair by Others".😊
 
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Ron247 said:
I still see it as 2 wooden slinkies, so structurally, not that amazing to me.
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Same. Steam and curve the wood, creating a pair of wood compression springs. The craftsmanship is the amazing thing - it's really beautiful.
 
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Ron247 said:
"Several structural engineers investigated this and said it was impossible it was standing."
Click to expand...
Dik: With that type of attitude, I would suspect that they were not very good ones. It is lovely.
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I suspect they were actually architects or contractors. LOL. They always think they know more than engineers, but are amazed by things that are structurally simple concepts because they are outside the norm of what they've seen.

FWIW, spiral staircases are not all that uncommon anymore. They just usually have a little more room to work with.... and they often have a central column. This staircase is still quite beautiful. Honestly, the date of the construction (late 1800s) I would think there would have been a good number of people that could have built such a staircase.... The story is still quite inspiring. For believers, it's easy for us to see the hand of God at play.... Though this is not the type of story (IMO) which many non-believers would consider particularly "miraculous".
 
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JoshPlumSE said:
amazed by things that are structurally simple concepts because they are outside the norm of what they've seen.
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That is why I like seeing things that are unique in a structural sense, and like seeing the wide range of responses when one happens or is finally noticed. While many people have never seen BigFoot, and many have never seen a Unicorn, I have seen this:
1754405978317.png
 
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Ron247 said:
"Several structural engineers investigated this and said it was impossible it was standing."
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Reminds me of the bumblebee that couldn't fly. I think that was explained some years ago.

Regarding the staircase, I think it is a beautiful example of what can be done with wood. Especially impressive if it was built by one person alone.

What I see when I look at pictures from different sites is a curved bottom that seams to be in one piece. The sides seem to be relativly high so the stairs are hidden. That means that if the staircase was sliced it would probably show a load supporting box with varios heights. The part of the sides passing the stairs would not be part of the box. The picures obviously don't show if there is anything inside the "box".

How are the parts connected? In the pictures there is something following the sides of the curved bottom. The article mentions wooden pegs and specifically "no glue". I don't know how the parts are connected but obviously they are connected. Another thing I read is that it is only supported by the floor. I would be surprised if it wasn't supported at the top since there is a natural support.

In some cases there is a strong need for keeping a mystery alive. I can agree that "the design was innovative for the time". But I would be interested in the design considerations that "still perplex experts" today, what are they?

My reasoning here is based on an analyses I made some years ago. That staircase was higher and wider but it was also made of steel. But a box, wood or steel, is good when the structure is supporting the load with torsion.
 
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ThomasH said:
The article mentions wooden pegs and specifically "no glue".
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I imagine the pegs may have been a swelling material when wet, to grip possible "layers of stringer".
ThomasH said:
Another thing I read is that it is only supported by the floor. I would be surprised if it wasn't supported at the top since there is a natural support.
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I think the top almost has to be supported to some degree. As I imagined it, stretch a slinky up, fasten it to something, and insects can crawl up it. In this case, it may be a combo wood slinky but the coils have some inherent "column stiffness" added to the mix. I wonder if they limit how many people at a time can climb up it?
ThomasH said:
But I would be interested in the design considerations that "still perplex experts" today, what are they?
Click to expand...
Knowing wood is difficult to "moment-connect" adds to the "how did he do it factor".
 
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The stair is impressive, but the railing is likely more work. The work to create the railing in that era would be monumental. They use a lot of 5 axis CNC for these now. Without any nails there are a lot of hand chopped mortise and tenon joints.

Some still make stairs a little like this, but they are not as tall since now most codes dictate landings at no more than 12'-0". You can find some woodworkers chatting about how they make these at Wood Web spiral stair discussion.

The glues they had access to back then would make the stringer fabrication very tricky. Now we have access to many different epoxies that limit any springback when the clamps are removed.

Modern method to bend stringer. I expect they used thinner plies and far smaller clamps.

1754416292001.png

I went searching for high quality images, but I do not see many. I think the stringers are trimmed given the decorative moulding. It is an impressive piece of artwork. Even the railings are very unique looking at their connection.

1754417789851.png
 
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Ron247 said:
Heard about this in the 80s while in college. Never saw a picture, nor read an article about it until today. Out of curiosity, I looked on the internet for it.

The 2nd website aligns with the story I heard 45 years ago except the guy showed up on a bicycle and not a donkey. The catch phrase from my source of information who was putting down engineers in general was "Several structural engineers investigated this and said it was impossible it was standing."

When I heard the tale in college, I said it sounded like someone built 2 wooden slinkies and attached them to the ceiling based on a totally verbal description, so I was not that amazed.

https://www.grunge.com/770563/the-miracle-of-the-loretto-chapel-staircase-explained/

https://tincanpilgrim.com/2020/03/08/the-impossible-stairway-a-gift-from-saint-joseph/

Anyone ever lay eyes on this or know any more about it?
Click to expand...
Ron,

After any home carpentry project, if people stare at some feature and wonder how the hell you did it, you have won.
 
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Another thing I found odd about all those people who could not figure out anything is how it appears to me that you could have run spindles top to bottom except at the entrance and exit to make it more stable. Even those could have headered at the entrance/exit.

Am I missing something? Oh yeah, it would not look so impressive anymore. Mark of a true engineer, looks don't matter.
 
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Ron247 said:
Another thing I found odd about all those people who could not figure out anything is how it appears to me that you could have run spindles top to bottom except at the entrance and exit to make it more stable. Even those could have headered at the entrance/exit.

Am I missing something? Oh yeah, it would not look so impressive anymore. Mark of a true engineer, looks don't matter.
Click to expand...
I see now Brad posted of pic of this very thing. Just saw the pic.
 
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Brian Malone said:
Wikipedia entry has an extensive discussion on the staircase.
en.wikipedia.org

Loretto Chapel - Wikipedia

en.wikipedia.org en.wikipedia.org

The staircase has been loaded significantly in the past: https://nanoten.com/travel/Santa-Fe/Loretto-choir-lowres.jpg
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Thank you, that was interresting. For some reason Wikipedia didn't show up in my Google search.

What I notice is that in the article the word "glue" shows up twice. The first time is when it is stated that there is "no glue" used. The second time is for the analysis of a professional carpenter says that the assembly of the stringers from overlapping segments joined by wood glue creates a laminate that is stronger than the wood alone. My interpretation is that there is glue in this.
 
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It would be interesting to see someone in modern times build this, even with glue. But by themselves, and no modern tools that did not exist in the era of the original construction. Kind of like a Forged in Fire episode. Just having to use a handsaw alone would run me off.
 
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