|
|
| Cold weather = broken or cracked rails (1337206) | |
 |
|
| Home > SubChat | |
[ Post a New Response | Return to the Index ]
|
|
| (1337237) | |
Re: Cold weather = broken or cracked rails |
|
|
Posted by Sand Box John on Sun Feb 1 07:25:14 2015, in response to Cold weather = broken or cracked rails, posted by GOlD_12tH on Sun Feb 1 00:29:29 2015. On Wednesday morning, a rail broke between Naylor Road and Southern Avenue stations on the Green Line, wrecking the commute for thousands of riders. But cracked or broken rails are not unique to Metro.The rail that broke Wednesday was installed in 1998. That tells me the rail that broke was originally installed by the track work contractor prior to the opening of the segment. The southern Green line between Anacostia and Branch Avenue opened on 01 13 2001. John in the sand box of Maryland's eastern shore. |
|
|
| (1337246) | |
Re: Cold weather = broken or cracked rails |
|
|
Posted by SelkirkTMO on Sun Feb 1 07:45:33 2015, in response to Re: Cold weather = broken or cracked rails, posted by Sand Box John on Sun Feb 1 07:25:14 2015. Rails installed last week can do that too. CWR is the rage these days, longer sections, more stress over longer distances and grade, it does catch up just as sun kinks do when it gets hot. The longer you make your sections without adequate compensation for "expand and contract" with temps, the more likely steel will break even if it was done right in the first place.CWR has its advantages, mostly cost. But it has its downsides too. New costs. |
|
|
(Sponsored) |
iPhone 6 (4.7 Inch) Premium PU Leather Wallet Case - Red w/ Floral Interior - by Notch-It |
|
| (1337259) | |
Re: Cold weather = broken or cracked rails |
|
|
Posted by Steve B-8AVEXP on Sun Feb 1 09:45:07 2015, in response to Re: Cold weather = broken or cracked rails, posted by SelkirkTMO on Sun Feb 1 07:45:33 2015. Denver's light rail system uses CWR. No broken rails so far, but you could say it's just a matter of time, especially on the original 1994 segment. |
|
|
| (1337266) | |
Re: Cold weather = broken or cracked rails |
|
|
Posted by SelkirkTMO on Sun Feb 1 10:21:49 2015, in response to Re: Cold weather = broken or cracked rails, posted by Steve B-8AVEXP on Sun Feb 1 09:45:07 2015. Metal moves. If something gets in the way that interferes with that movement, snap! :) |
|
|
| (1337363) | |
Re: Cold weather = broken or cracked rails |
|
|
Posted by Sand Box John on Sun Feb 1 17:04:13 2015, in response to Re: Cold weather = broken or cracked rails, posted by SelkirkTMO on Sun Feb 1 07:45:33 2015. I have never heard reports of broken rails on the Baltimore Metro, they also use CWR. I think one of the reason why is because they have insulated joints on both ends of all platform track circuit.John in the sand box of Maryland's eastern shore. |
|
|
| (1337393) | |
Re: Cold weather = broken or cracked rails |
|
|
Posted by SelkirkTMO on Sun Feb 1 21:47:10 2015, in response to Re: Cold weather = broken or cracked rails, posted by Sand Box John on Sun Feb 1 17:04:13 2015. Could be, it's all about giving the metal enough room to do its thing. |
|
|
| (1337399) | |
Re: Cold weather = broken or cracked rails |
|
|
Posted by Sand Box John on Sun Feb 1 22:33:07 2015, in response to Re: Cold weather = broken or cracked rails, posted by SelkirkTMO on Sun Feb 1 21:47:10 2015. Could be, it's all about giving the metal enough room to do its thing.I once saw a CSX track gang replacing rail on the Capital Subdivision in Laural Maryland burning smudge pots along roughly 300' of the end of a section of rail to lengthen it to connect it to the next section of rail. As I recall the ambient air temperature that day was in the 40s. John in the sand box of Maryland's eastern shore. |
|
|
| (1337401) | |
Re: Cold weather = broken or cracked rails |
|
|
Posted by SelkirkTMO on Sun Feb 1 22:54:18 2015, in response to Re: Cold weather = broken or cracked rails, posted by Sand Box John on Sun Feb 1 22:33:07 2015. Yep. The meatball technique. They have cars that flame the rails as well. This photo is from Alaska, but Plasser & Theurer's are everywhere.
|
|
|
| (1337402) | |
Re: Cold weather = broken or cracked rails |
|
|
Posted by Jackson Park B Train on Sun Feb 1 22:56:16 2015, in response to Re: Cold weather = broken or cracked rails, posted by SelkirkTMO on Sun Feb 1 22:54:18 2015. Ya know, fishplates were absolutely great expansion/contraction joints. |
|
|
| (1337404) | |
Re: Cold weather = broken or cracked rails |
|
|
Posted by SelkirkTMO on Sun Feb 1 23:04:52 2015, in response to Re: Cold weather = broken or cracked rails, posted by Jackson Park B Train on Sun Feb 1 22:56:16 2015. Yeah, but labor cost money to keep tightening the nuts, and the joints tended to get battered by wheels. CWR is much cheaper to run except when it snaps or summer comes along. :) |
|
|
| (1337416) | |
Re: Cold weather = broken or cracked rails |
|
|
Posted by Jackson Park B Train on Mon Feb 2 00:59:31 2015, in response to Re: Cold weather = broken or cracked rails, posted by SelkirkTMO on Sun Feb 1 23:04:52 2015. so iot ios cheaper except whenit isn't Seems to me that a FEW joints/expansion/contraction points would be worth the cost. |
|
|
| (1337423) | |
Re: Cold weather = broken or cracked rails |
|
|
Posted by SelkirkTMO on Mon Feb 2 01:20:19 2015, in response to Re: Cold weather = broken or cracked rails, posted by Jackson Park B Train on Mon Feb 2 00:59:31 2015. Economically, CWR is MUCH cheaper than jointed. And jointed rail breaks too. That's why God gave us track circuits to detect them. The real issue with CWR though is sun kinks in very hot weather. You have to be going slow enough to spot them because the track circuits won't detect that issue. |
|
|
| (1337424) | |
Re: Cold weather = broken or cracked rails |
|
|
Posted by WillD on Mon Feb 2 01:22:47 2015, in response to Re: Cold weather = broken or cracked rails, posted by Sand Box John on Sun Feb 1 17:04:13 2015. Rail can definitely crack in cold weather on track with IJs and low frequency AC impedance bonds. |
|
|
