Jamaica Line Posted July 23, 2013 Share #1 Posted July 23, 2013 Looking at this photo really got me wondering, what's the purpose of those inner rails you'd find inside a curved piece of track? Link to comment Share on other sites More sharing options...
mtattrain Posted July 23, 2013 Share #2 Posted July 23, 2013 This is a very great question that I have also been trying to answer... I am not the engineer around here but maybe those inner rails serve as guards to prevent a train from derailing. Link to comment Share on other sites More sharing options...
Harry Posted July 23, 2013 Share #3 Posted July 23, 2013 In railroad use, guard rails are placed parallel to regular running rail along areas of restrictive clearance, such as a bridge, trestle, or tunnel. These have the effect of keeping the wheels of rolling stock in alignment in case of derailment. It also helps to minimize damage to the structure and allow easier post-accident cleanup.Guard rails (railroad) Link to comment Share on other sites More sharing options...
realizm Posted July 23, 2013 Share #4 Posted July 23, 2013 In railroad use, guard rails are placed parallel to regular running rail along areas of restrictive clearance, such as a bridge, trestle, or tunnel. These have the effect of keeping the wheels of rolling stock in alignment in case of derailment. It also helps to minimize damage to the structure and allow easier post-accident cleanup. Guard rails (railroad) He nailed it. Exactly. I guarantee you any MTA Subways T/O or MNRR/LIRR railroad engineer will confirm this as correct. We have plenty of track setups such as this in our subway system along curves. Protocol track construction with the Subways, SIR, LIRR or MNRR networks, all over the system on the IRT, BMT or IND divisions in the case with Subways. Link to comment Share on other sites More sharing options...
itmaybeokay Posted July 23, 2013 Share #5 Posted July 23, 2013 He nailed it. Exactly. I guarantee you any MTA Subways T/O or MNRR/LIRR railroad engineer will confirm this as correct. We have plenty of track setups such as this in our subway system along curves. Protocol track construction with the Subways, SIR, LIRR or MNRR networks, all over the system on the IRT, BMT or IND divisions in the case with Subways. If I'm not mistaken, the way guard rails are deployed often in subways, positioned much closer to the running rails than on the tresle pictured, can actually serve to prevent derailments in addition to simply expediting their cleanup. Link to comment Share on other sites More sharing options...
JustLok Posted July 23, 2013 Share #6 Posted July 23, 2013 You're getting guard rails confused with emergency protection rails (EPRs). Guard rails are installed on the low side of curves parallel to the running rail as to reduce the wear on the high side rail from the force of the train taking the curve due to superelevation. The inside of the flanges on the car wheels literally grinds against the guard rails and help to prevent side wear on the high rails. EPRs are installed in locations where there is no structural protection on the sides of the train in case of a derailment, to prevent a catastrophic derailment. Those EPRs are placed where there's no walls, benchwalls, columns or other structure (or land) that might stop a train from further damage or falling in a derailment. When a train derails, the car truck would hit either of those EPRs (depending on the direction of the derailment) and stop the car from moving further off the track or structure, a somewhat controlled derailment. EPS are placed on structure, open cuts in the subway and other locations in Transit. In that picture above, it's placed on the bridge to help prevent the train from falling off during a derailment. See how they bring the EPRs to a tapered end at the bottom of the picture? That's because they would no longer be needed after that point due to the surrounding land returning to the track at that point. Link to comment Share on other sites More sharing options...
Mtatransit Posted July 23, 2013 Share #7 Posted July 23, 2013 Looking at this photo really got me wondering, what's the purpose of those inner rails you'd find inside a curved piece of track? First that is a very beautiful picture. Where is that? Second I think there is inner rail because it prevents the wheels from coming off and falling into the water. Link to comment Share on other sites More sharing options...
Jamaica Line Posted July 23, 2013 Author Share #8 Posted July 23, 2013 First that is a very beautiful picture. Where is that? Second I think there is inner rail because it prevents the wheels from coming off and falling into the water. I have no clue as to where that is. I'm guessing it's along some subdivision on the Union Pacific as those are Union Pacific locos. Not sure about that red one thou... Link to comment Share on other sites More sharing options...
Vistausss Posted July 23, 2013 Share #9 Posted July 23, 2013 I have no clue as to where that is. I'm guessing it's along some subdivision on the Union Pacific as those are Union Pacific locos. Not sure about that red one thou... That's in Joso, Washington. http://www.railpictures.net/viewphoto.php?id=405076&nseq=4 (in the description under the picture you can see the location) Link to comment Share on other sites More sharing options...
JustLok Posted July 24, 2013 Share #10 Posted July 24, 2013 Oh yeah, forgot to mention you can tell the difference between guard rails and EPRs by their distance to the running rails. Guards rails are usually no more than 1in-2in from the running rail. EPRs are usually 2ft-3ft from the running rails, laid in the gauge. Link to comment Share on other sites More sharing options...
realizm Posted July 25, 2013 Share #11 Posted July 25, 2013 You're getting guard rails confused with emergency protection rails (EPRs). Guard rails are installed on the low side of curves parallel to the running rail as to reduce the wear on the high side rail from the force of the train taking the curve due to superelevation. The inside of the flanges on the car wheels literally grinds against the guard rails and help to prevent side wear on the high rails. EPRs are installed in locations where there is no structural protection on the sides of the train in case of a derailment, to prevent a catastrophic derailment. Those EPRs are placed where there's no walls, benchwalls, columns or other structure (or land) that might stop a train from further damage or falling in a derailment. When a train derails, the car truck would hit either of those EPRs (depending on the direction of the derailment) and stop the car from moving further off the track or structure, a somewhat controlled derailment. EPS are placed on structure, open cuts in the subway and other locations in Transit. In that picture above, it's placed on the bridge to help prevent the train from falling off during a derailment. See how they bring the EPRs to a tapered end at the bottom of the picture? That's because they would no longer be needed after that point due to the surrounding land returning to the track at that point. +1 for breaking this down to a science, werd. Well appreciated. Link to comment Share on other sites More sharing options...
koolmazin Posted July 25, 2013 Share #12 Posted July 25, 2013 I ser those tracks all over the place in the subway and i see them usually when a train has to make a turn like between Dekalb ave and Altantic Ave on the 4th ave line Link to comment Share on other sites More sharing options...
Jamaica Line Posted July 25, 2013 Author Share #13 Posted July 25, 2013 +1 for breaking this down to a science, werd. Well appreciated. Agreed. Link to comment Share on other sites More sharing options...
Jamaica Line Posted July 25, 2013 Author Share #14 Posted July 25, 2013 Found another good example of EPRs... Link to comment Share on other sites More sharing options...
realizm Posted July 25, 2013 Share #15 Posted July 25, 2013 And in the case of Subways, the distinction between guard rails and EPRs on the trackbeds as shown in the pics below (according to JustLok, and Harry's descriptions) : Guard Rails (This is on the West End Line @ 18th Ave) : Credits to Peter Erlich -- Link: http://www.nycsubway.org/perl/show?92259 EPR's (on the BMT Jamaica El @ Halsey Street): Credits to Chistopher Sattler -- Link: http://www.nycsubway.org/perl/show?26235 Link to comment Share on other sites More sharing options...
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