Former Car Maintainer Is the flange too thin or the wheel depth (wheel face) wrong? Couldnt the pointed frog part be widened? How was a non standard frog purchased for a standard track gauge? Are the wheels non standard? Need a lot of dimensional drawings to see the big picture... https://www.researchgate.net/figure/Schematic-representation-of-the-wheel-set-crossing-over-the-frog-view-from-above-2_fig1_319898593
Is the flange too thin or the wheel depth (wheel face) wrong? Couldnt the pointed frog part be widened? How was a non standard frog purchased for a standard track gauge? Are the wheels non standard? Need a lot of dimensional drawings to see the big picture... https://www.researchgate.net/figure/Schematic-representation-of-the-wheel-set-crossing-over-the-frog-view-from-above-2_fig1_319898593
I would not conclude that either the flange or the entire wheel is too narrow. The gap between the outside of the flange and the inside of the rail appears too wide, especially if the wheelset is centered on the track in the photo. Also the outer edge of the wheel running on the rail head is abnormal; even if the wheelset is shifted as far left as it will go with this wheelset on this track. Even in that circumstance, the outer edge of the wheel should be overhanging the outside of the rail.
So, with what is shown in the photo, I assume that the track gage is as it was intended to be. I also assume that the wheel profile is as intended, including tread and flange.
I think the problem is a mistake in specifying the wheel set. There is a dimensional error on the axles locating the axle shoulders against which the wheel hubs bottom on when being pressed onto the axle. Basically the shoulders are too near the center of the axle. So the wheelset ends up pressed too far onto the axle, thus resulting in a wheelset gage that is narrower than the track gage, when the two should match.
One solution would be to replace the axles with the correct shoulder to shoulder dimension, and then remove the wheels from the incorrect axles and reinstall them on the correct axles.
It also may be possible to remove the wheels from the existing axles, and press on a new spacer bushing on each side that bottoms out on the existing shoulders, and has a width that will properly space the wheels to gage when they are pressed back on and bottom out against the new spacer bushing.
This overall problem would be the most likely mistake to have been made. That is to wrongly specify the wheelset gage. This is because there is no hard line feature on the wheel that represents the gage datum. So it is the most likely measurement to be misstated or misunderstood.
Even the way this is being reported is ambiguous and symptomatic of the same ambiguity that probably led to the error in the first place. The news says the wheels are too thin and the tracks are two wide. This is gobbledygook. Furthermore, they seem to only see an issue with the wheels striking the guard rails of the frogs. That is a problem, but it is not the only problem. The entire problem also includes the danger of derailment over the entire line because the incorrect wheelset would allow excessive truck hunting, resulting in instability that could cause derailments.
It would be like the old “Compromise Wheels” used in the 1800s to allow trains to run on multiple gage tracks by using an extra wide wheel tread. They proved very unstable because when running on the widest gage track, their flanges were too far inward from the rails, so the wheels could wander side to side. The wandering could gain momentum and force the flange to climb the rail when it suddenly bottomed out hard on the side of the rail.
I heard Professor Slaby muttering about 'postwar technology' looking at this stupidity.
Note the trendy high-speed flat-tread wheels, pathetic excuse for flange fillet. No cone means full excursion to flange contact. How 'wider wheels' are supposed to fix the stated issue, given the rather clear if distorted-perspective picture "B" provided, is not clear; the prospective effect on self-guarding frogs (a problem for stable hi-rail vehicle design!) is even less clear.
Prospectively, a little selective taper or 'transition' ground into the engaging wing going into the frogs would (I think) serve to locate and then guide the 'off' flange enough to pull the flat-tread wheelset off what is presumably flange bearing against the point side. They might have to learn to dress the back side of the flange at wheeltread-turning time. Such is the price of stupid design and requisition.
Selectively flange-greasing the backs of the flanges is a weird idea, but it would have... I think... relatively little propensity to migrate to tread contact, and would simplify the issues with almost-certain screeching and shuddering as these kludged cars go through the switches...
I'll be highly interested to read FCM's thoughts on this, as I think he'll have had extensive professional familiarity with some of these issues.
That is a major screw-up in which the wheelset gage does not match the track gage. The wheelset gage is too narrow in relation to the track gage, so the backs of the flanges interfere with the guard rail features of the switch frogs. So, to tiptoe though the interference zones, they will slow to 15-20 mph. But apparently they will run full speed of 55 mph on the rest of the track.
In my opinion, they are trying to put a happy face on a disastrous error. So they are doing this by only slowing down for the track-to-track crossing frogs. But there is plenty of danger by running on the rest of the track while allowing such excess side to side oscillation due to the mismatched track/flange gage.
The system should be shut down and completely repaired, rather than to save face by falsely minimizing the problem to just the frog interference. I find it hard to believe they are doing that.
Saw this recent article for HART. https://www.staradvertiser.com/2021/05/16/hawaii-news/search-continues-to-fix-oahu-rails-too-narrow-wheels-and-too-wide-tracks/
Can't see what they are talking about in the picture but sure seems like a SNAFU
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