US Capitol Dome

[roadman65]

I was always fascinated with the dome that tops our nation's landmark building that houses our legislative branch of our US Government.  To me it is an outstanding work of engineering of all cast iron at over 8 million pounds.  However, I recently discovered that there is more to it than meets the eye. 

While trying to locate the stairway that leads to the top of the dome and balcony beneath the Statue of Freedom, I noticed that there in reality is two domes and not one!  That is why on the outside there are three sets of windows and inside the rotunda you only see one set, being the bottom row of windows.  Inside the rotunda you will see the dome curve above the windows before rounding out at the painting up on the top to another small dome in which the fresco is painted on that is a mere 180 feet above the floor while the top of the Statue of Freedom above it all is 288 feet to its top.

Many renderings show the a profile view of the dome and the stairs in partial of how they start up to the first balcony just around the area where the main windows are.  Then another winding stair takes you up to another balcony that is barely visible just below the fresco.  The curve of the dome looks flush with the painting, but in reality the painting starts ten feet above it as there is an indent for the second balcony.  Then another stairway is above the painting that leads to the outside just under the statue with a fourth stairway leading to the statue itself for maintenance purposes.

Basically there is a wide open space between the inner and outer domes and the second and third set of windows do shine in light to the open areas. If you are lucky enough to be allowed to tour the dome (as you must know a member of congress to accomplish that)you will be able to look out some of them as well.  The tour was at one time open to the general public, but in the past people with height fears were getting sick and some had to be assisted back down as it was told by a tour guide inside the Capitol that was the reason behind this.

What I cannot figure out is the fact that there is no space between the windows themselves on the bottom of the dome for even a small narrow stairway to fit.  In addition you see from the inside of the rotunda no stairs visible in front of the windows nor in between them.  Now of course there is an outside area located behind the columns visible on the dome's outer facade and it appears deep enough for a walkway, but in all the photos it is too dark to make out if the stairs could be visible or not.  So does anyone know how the stairs get past the first set of windows en route to the top? 

Has anyone ever gotten the chance to climb the dome in their lifetime and have any stories to share?  Most of all currently the US Capitol is undergoing a dome facelift and restoration as cracks and watermarks have been found on our beloved landmark.  Currently the Capitol's dome is covered in scaffolds and getting a picture of the building will not show the glory of the dome but an ugly skeleton instead.  This thread can be about that if any wish to talk or anything engineering related to it.  Sorry to be so long, but talking about this magnificent building is so much especially from an engineering standpoint.

[NE2]

Domes are cool.

[Pete from Boston]

Check it:

http://www.cbsnews.com/news/the-capitol-domes-150th-anniversary/

[1995hoo]

I actually think the scaffolding looks reasonably cool when I see it at night.

[Alps]

Domes are cool.

I'm just going to assume that's the tl;dr of the roadman novel.

[SteveG1988]

[vdeane]

The tour was at one time open to the general public, but in the past people with height fears were getting sick and some had to be assisted back down as it was told by a tour guide inside the Capitol that was the reason behind this.

They could have just as easily advised people who are afraid of heights to not take the tour rather than restricting it.

[roadman65]

The tour was at one time open to the general public, but in the past people with height fears were getting sick and some had to be assisted back down as it was told by a tour guide inside the Capitol that was the reason behind this.

They could have just as easily advised people who are afraid of heights to not take the tour rather than restricting it.

Really, as I would love to walk up all those steps to the top just for the thrill.  I do have height issues myself, but I would definitely stay away from the parapet then, especially the one near the painting.

I think many of us here if given the chance would take the tour if offered being it is not as much the thrill seeking is as to admire the construction of it.  I am sure most of us here are just as much building geeks as we are road geeks.

[Duke87]

The tour was at one time open to the general public, but in the past people with height fears were getting sick and some had to be assisted back down as it was told by a tour guide inside the Capitol that was the reason behind this.

They could have just as easily advised people who are afraid of heights to not take the tour rather than restricting it.

I think it was more a question of the stairs and walkways being narrow and inadequately guarded such that by modern standards they are not fit for public use. Because liability, OSHA, etc.

I'd say security paranoia but I'm pretty sure the public tours ended long before 9/11.

[vdeane]

That's an interesting point.  The current ADA regulations might be responsible; all government buildings are supposed to be fully accessible to all members of the public.

[Pete from Boston]

That's an interesting point.  The current ADA regulations might be responsible; all places of public accommodation are supposed to be fully accessible to all members of the public.

FTFY, though there may be the difference that while existing places are often grandfathered, government policy may be that they don't need to wait for reconstruction/repurpose/etc. to be required to be brought up to code.  Building codes generally do not require compliance of pre-existing structures unless a certain threshold of reconstruction or reuse is reached.  That said, long term closure and reopening would probably trip the compliance requirement.

[roadman65]

If you are talking about the stairs being narrow and not being compliant with ADA rules, try the Statue Of Liberty then.

The stairs leading up to the crown are very narrow and steep.  Plus when you finish climbing them and I mean not from the bottom up, but from the bottom up and back down, your legs get the same workout as it would doing leg exercises at the gym.  For days after I climbed them, my  leg muscles were so sore from that adventure.

I was there back in the 70's and they did not allow tours up there either long before a twisted mind could figure out how to implode two 110 story buildings using typical passenger jets.  I have to say its definitely not security reasons that access is denied to the stairs.