|
|
| Re: Wheel Axles (343401) | |
 |
|
| Home > SubChat | |
[ Post a New Response | Return to the Index ]
[1 2] |
||
|
Page 2 of 2 |
||
|
| (343979) | |
Re: Wheel Axles |
|
|
Posted by Jace on Mon Nov 27 10:52:31 2006, in response to Wheel Axels, posted by Fulton Frank on Sun Nov 26 08:12:36 2006. Low floor trams/light rail cars have either axle-less trucks or drop (crank) axles between independent wheelsets. These are some complicated units especially for full low floor vehicles where you have powered axle-less wheelsets. The reason these designs developed and are used is that you get a low boarding height and no interior steps to contend with - a big plus for street operations, but even here the complexity of the wheel set design has made full low floor cars a lot less popular compared to partial low floor cars (cars with standard motor trucks on the ends and only unpowered independent axles in the middle). Aside from this specialized application, there really is no need for single axle wheels - they're a lot of added complexity, cost and maintenance with no real benefit.The real way to deal with flange wear (and hence noise) is by matching the profile of the wheel to the profile of the railhead. Included in this (ideally) is the design of the spirals (entry to curves) and the superelevation of curves. Subways have a harder time playing with the curves than any other railroad since they're pretty much fixed by the tunnel or el, but they do work on the wheels and the rail. The wheelsets are kept at a specific profile by regular visits to the wheel truing machine. The railhead is kept in shape by rail grinding. Freight railroads in the US don't re-profile freight car wheels (they use only one wear wheels) but they are very aggressive in rail grinding. Subways typically watch the wheels more so than the railheads but there is some rail grinding done - Speno or LORAM has a small grinder they rent out to subways and NYCT has had rail grinders in the past (don't they have a new one on order?). |
|
|
| (344029) | |
Re: Wheel Axels |
|
|
Posted by Olog-hai on Mon Nov 27 14:14:24 2006, in response to Re: Wheel Axels, posted by Jace on Mon Nov 27 10:10:03 2006. The Talgo XXI prototype was built to Tier I specs. That of course limits any potential top speed running to 125 mph, assuming that sufficient signaling is in place (top tested speed was 152 mph). The Talgo TPU that runs on the Cascades service is, as you noted, grandfathered. |
|
|
| (344213) | |
Re: Wheel Axels |
|
|
Posted by Dutchrailnut on Mon Nov 27 22:02:45 2006, in response to Re: Wheel Axels, posted by Olog-hai on Mon Nov 27 14:14:24 2006. The Talgo XXi has a design for tier 1 but was never built.The European Talgo XXI was not a big succes untill electric motor cars were built. Unless Talgo is willing to built a XXI demonstrator they have about as much chance as snowball in hell to get one sold in USA. Note their website has not been updated for ages. And current Talgo's are still running under waiver as they can not be made compliant. |
|
|
(Sponsored) |
iPhone 6 (4.7 Inch) Premium PU Leather Wallet Case - Red w/ Floral Interior - by Notch-It |
|
| (344227) | |
Re: Wheel Axles |
|
|
Posted by tracksionmotor on Mon Nov 27 22:31:06 2006, in response to Re: Wheel Axles, posted by Jace on Mon Nov 27 10:52:31 2006. Wheel profile is set by contract upon initial purchase...the most common for MTA 36" wheels is #239 although I have encountered a few #235s. The Simmons machine has two horizontal profile cutting heads which approximate the profile. Excessive wheel truing loses original profile...most passes are clean outs to remove minor defects and flatzzzz. In my time I have not encountered a 'thin flange.' Subways are pretty good as far as wheels are concerned...flatzzz are small and monitored. M7 EMUs have much larger flatzzz along with shelling...spalls are not so bad. As for freight, they run the trucks until wheels go 'square'......tread thickness after truing must exceed 16/16ths of an inch to return to service...passenger rail must exceed 20/16ths with flange height 17/16ths.For those reading this post 'without a clue,' railroad wheel measurements are made in 1/16ths of an inch using a wheel gauge that measures the thickness of the wheel, the height of the flange and how much metal must be machined off to restore the wheel to its closest original shape. The 'flange' is that big lip on the inside side of the wheel designed to prevent the train from leaving the track. Few flanges are too thick...a thin flange offers possibility of breakage and or derailmant....a high flange offers derailment when engaging interlockings and switches. Wheel Profile 101. RRCI Peter |
|
|
| (344245) | |
Re: Wheel Axels |
|
|
Posted by tracksionmotor on Mon Nov 27 22:58:29 2006, in response to Re: Wheel Axels, posted by Dutchrailnut on Sun Nov 26 19:52:31 2006. You mean that little base loop? I have NO gauging for it....it is part of original wheel profile not part of inspection. RRCI Peter |
|
|
| (344264) | |
Re: Wheel Axels |
|
|
Posted by Train Dude on Mon Nov 27 23:52:47 2006, in response to Re: Wheel Axels, posted by tracksionmotor on Sun Nov 26 15:22:23 2006. Peter, with all due respect, he didn't allude to any part time 4-wheel drive. He said independently mounted wheels with short axles. So you are reading things into his post that do not exist.I'm not sure what his actual experience is but in this field I'm pretty sure that my experience exceeds most here in the field and I stand on it. |
|
|
| (344265) | |
Re: Wheel Axels |
|
|
Posted by Terrapin Station on Mon Nov 27 23:57:50 2006, in response to Re: Wheel Axels, posted by Train Dude on Mon Nov 27 23:52:47 2006. eter, with all due respect, he didn't allude to any part time 4-wheel drive. He said independently mounted wheels with short axles. So you are reading things into his post that do not exist.He never said that he did. Peter was just giving another example of a similar problem. I see nothing wrong with that. |
|
|
| (344267) | |
Re: Wheel Axels |
|
|
Posted by tracksionmotor on Tue Nov 28 00:09:15 2006, in response to Re: Wheel Axels, posted by Train Dude on Sun Nov 26 21:25:59 2006. Next FRA inspection I do....'double take.' Wheels are clearly marked '239' in paint. FRA undercar inspection requires complete cleaning of important identification markers and safety signage...the OEM labels applied to axles are often damaged and obliterated. MNCR ran an PI on my first PI and came up with a list...it was all post-road damage. One trainset had PCE failures attributed to my inspections in error...the contactor arc chutes dropped pieces into the horizontal contactors preventing total contact indicated by the microswitch....vendor problem. These are not R68s where you can tear everything down for proper inspection and maintainance. RRCI Peter |
|
|
| (344268) | |
Re: Wheel Axels |
|
|
Posted by tracksionmotor on Tue Nov 28 00:10:57 2006, in response to Re: Wheel Axels, posted by Jace on Mon Nov 27 10:15:41 2006. Delicate balance where 'rubber meets the road.' |
|
|
| (344269) | |
Re: Wheel Axels |
|
|
Posted by tracksionmotor on Tue Nov 28 00:23:17 2006, in response to Re: Wheel Axels, posted by BIE on Sun Nov 26 21:46:29 2006. I own a GG-1......original postwar Lionel. Just what is NRHS? I'm trying to find a way to connect in western NJ. I see signs for Santa Trip....why would I go on a trip with Santa? |
|
|
| (344272) | |
Re: Wheel Axels |
|
|
Posted by BIE on Tue Nov 28 00:29:56 2006, in response to Re: Wheel Axels, posted by tracksionmotor on Tue Nov 28 00:23:17 2006. National Railway Historical Society.www.nrhs.com |
|
|
| (344282) | |
Re: Wheel Axels |
|
|
Posted by tracksionmotor on Tue Nov 28 01:16:36 2006, in response to Re: Wheel Axels, posted by WillD on Sun Nov 26 18:34:41 2006. This is a PCC LRV and not a 'heavy passenger railcar' weighing 128K pounds. BTW: regenerative braking in rail usually means seeking and finding trainset taking power nearby. |
|
|
[1 2] |
||
|
Page 2 of 2 |
||
