Afraid of heights? This is not the job for you | SciTech Now

the iconic st. Louis Gateway Arch an engineering wonder the towers high above the skyline is now 50 years old discoloration on the stainless steel exterior has building doctors climbing 630 feet up the arch to examine the cause of some of those mysterious stains here's a look well we are we're building doctors or what we're doing is we're doing a very careful diagnosis of the building but there is no other building quite like it st. Louis's Gateway Arch officially the Jefferson National expansion memorial is now 50 years old an extensive interior inspection determined it is structurally sound but outside well years ago people began to notice that the shiny stainless steel surface was well staying here and there and the National Park Service decided it needed to know is that just dirt or is it damaged for this part of the job the firm of Wisc Janney Elsner associates brought members of their appropriately named difficult access team our safety manager has referred to this project as Mount Everest this is the same company that inspected the stones and mortar on the Washington Monument after damage from an earthquake but the arch is taller and it's curved on the top side and they were able to repel up and down and inspect all the welds but it was the underside that presented the real challenge and the most interesting and worrisome stains the guy being lowered down and attaching himself with suction cups his Dave Meg early I was the one that everybody saw right here at station 35 though we stopped and took some samples we took some silicone samples that gave us the texture of the stainless steel that everyone was concerned about there was some staining there that they wanted to test with some cleaning methods a lot of what he tried were just common household Pat's and cleaners but in different places they used gunshot residue tape to pick up the dirt in the particulates for examination under an electron microscope and laboratory analysis the final report would not come out for six months so when we're looking at construction materials of any type they all corrode just as our bodies corrode it's called aging there was a lot of interest in this by architects engineers and historic preservationist s-- and the news for the Gateway Arch was good surface discoloration is is superficial it will have no effect it's all from industrial pollutants I think I mean in other words the arch is dirty and discolored but not uniformly when it rains the topside gets a good washing but on the underside the dirt collects on the welds and any other scratches and imperfections when the arch was nearing completion of metal bridge or strut was used to keep the two legs apart and there are now stains where it was attached these are the three places where the strut grant the I believe this is a Salt Lake and as for those stripes the report says that during production the polishing of the metal plates left very subtle scratches and where they overlap that's where the discoloration has emerged so the question was will be arch be cleaned the National Park Service says for right now no too complicated too expensive again maybe we're opening long term thinking - cleaning because who knows there may be a way someday but I guess we need to to think about how that could even be done you know this this this rope-access that was used to get to the exterior is is perfect for for doing that investigatory work but to actually be able to to have work platforms that people can work from to actually clean that's that's something that we don't know how it would be done this is by far the most technically challenging job I've ever done you don't mind if they don't ask you to clean it them no I've got some ideas on how to plate it but it would be a daunting task to paint

Channel: SciTech Now

Views: 1,037,889

Keywords: social media, scitech, scitech now, scitechnow, gadgets, technology, science, tech, techcrunch, scishow, crashcourse, pbs, asapscience, St. Louis' Gateway Arch, arch, St. Louis, skyline, stains

Id: 7ZLXjOo15Ro

Length: 4min 53sec (293 seconds)

Published: Mon Feb 29 2016