AboutChris Holliday Expertise Questions related to contemporary passenger rail vehicles and their technology, including subway, light rail, commuter and intercity rolling stock. Includes all vehicle systems and features along with integration of the vehicles into the general railroad system.
Experience I have over 22 years of experience in the passenger rail vehicle business as both an engineering manager at a car builder and as a provider of engineering services to commuter railroads and transit agencies in the US. I have worked to apply the latest technologies to passanger rail equipment. I have worked with leaders in our industry to develop and establish Standards and Recommended practices.
Expert: Chris Holliday Date: 11/30/2007 Subject: Rail composition and loadbearing
Question 1) What types of metals and in what percentages are they used in a typical rail? 2) How much weight can rails support per foot or any other measure? We want to use rails in the pier and beam foundation of a building and need this information for the structural plan. (We got the rails for free with the property.)
Answer Joe:
Thanks for your question. Here is some information in response to your question. There is an organization called American Railroad Engineering and Maintenance of Way Association (www.arema.org) who develop and maintain standards for the rail used in North America. Apparently, there have been some updates recently to the standard chemical composition of rail. The composition of rail typically includes: Carbon, Manganese, Phosphorus, Sulfur, Silicon, Nickel, Chromium, Molybdenum, Vanadium. The amounts of these materials can vary within specified ranges, but weight percent are typically less than 1 for each of these materials. For about $600, the AREMA folks will let you purchase the Manual of Railway Engineering, where you will find the details of the percentages of these materials.
To respond to your second question, I would suggest that railroad rail is not a material you want to use for beams. The cross section is designed to be uniformly supported beneath; you'll notice it sags under it's own weight if simply supported over more than a few feet. It is very heavy per unit length compared to the structural I-section steel which you will typically see used for beams. I would suggest that the rail could used to reinforce a floor, foundation footing, or a wall which can provide uniform support under the bottom flange of the rail. Even then, the dimensional variation of the rail material, if subject to temperature swings could crack concrete of you plan to embed the rails in that material. Basically, rail is at best a mediocre solution for the type of use you are contemplating.
Please note that my comments above are not be taken as a substitute for a careful examination of your plans by a licensed engineer who is familiar with your application. You should always insure that plans for structures and buildings are properly reviewed and approved before construction.
