Editing Grand Central Terminal (section)

===Structure and materials===
The station and its rail yard have steel frames. The building also uses large steel columns designed to hold the weight of a 20-story office building, which was to be built when additional room was required.<ref>{{harvnb|ps=.|New York Central|1912|p=8}}</ref><ref name="Schlichting pp. 126-127" />

The facade and structure of the terminal building primarily use [[granite]]. Because granite emits radiation,<ref>{{cite web|url=http://www.world-nuclear.org/information-library/safety-and-security/radiation-and-health/nuclear-radiation-and-health-effects.aspx|title=Nuclear Radiation and Health Effects|date=December 2013|publisher=World Nuclear Association|access-date=September 10, 2017|archive-date=September 6, 2017|archive-url=https://web.archive.org/web/20170906102948/http://www.world-nuclear.org/information-library/safety-and-security/radiation-and-health/nuclear-radiation-and-health-effects.aspx#.UhSw15LIVoY|url-status=live}}</ref> people who work full-time in the station receive an average dose of 525 [[mrem]]/year, more than permitted in nuclear power facilities.<ref>{{cite web|url=http://www.fusrapmaywood.com/projmain.html|title=Radiation in the Environment|last=Formerly Utilized Sites Remedial Action Program|date=August 1998|publisher=US Army Corps of Engineers|access-date=September 10, 2017|archive-date=May 9, 2016|archive-url=https://web.archive.org/web/20160509194124/http://fusrapmaywood.com/projmain.html|url-status=live}}</ref><ref>{{cite book|url=https://books.google.com/books?id=aQ2Lw-FqDXAC|title=Radiation: What It Is, What You Need to Know|last1=Gale|first1=Robert Peter|last2=Lax|first2=Eric|date=2013|publisher=Alfred A. Knopf|location=New York|page=190|access-date=September 10, 2017|isbn=9780307959706}}</ref> The base of the exterior is [[Stony Creek (Branford)|Stony Creek]] granite, while the upper portion is of [[Indiana limestone]], from [[Bedford, Indiana]].<ref name="NYCRR p. 12" />

The interiors use several varieties of stone, including imitation [[Caen stone]] for the Main Concourse; cream-colored [[Botticino]] marble for the interior decorations; and pink [[Tennessee marble]] for the floors of the Main Concourse, Biltmore Room,<ref name="Restore" /> and Vanderbilt Hall,<ref name="nyt20160407" /> as well as the two staircases in the Main Concourse.<ref name="RN p. 84" /><ref name="Langmead p. 175" /><ref name="nydn19980930" /> Real Caen stone was judged too expensive, so the builders mixed plaster, sand, lime, and [[Portland cement]].<ref name="RN p. 84" /> Most of the remaining masonry is made from concrete.<ref name="NYCRR p. 12" /> [[Guastavino tile|Guastavino tiling]], a fireproof tile-and-cement vault pattern patented by [[Rafael Guastavino]], is used in various spaces.<ref name="Langmead p. 174" /><ref name="RN p. 89" />