tree68Consider that fact that the girder rail being discussed would have to be somehow spliced into the rest of the rail. Any mechanical joint represents a point of failure. Welding the girder rail into conventional CWR will likely raise issues of its own.
Were this approach to be used, the 'girder rail' would be reserved only to crossings, and perhaps only to the portion of a crossing reserved as 'handicapped/differently-abled' access- no more than a few feet. On either side the extension would be cut and ground smoothly back to rail profile. No more than a couple of feet of normal profile would be needed for field welds, either flash butt or thermite. As crossings are sometimes jig-built and brought for installation as panels, fabrication of sections of winged rail of any shop configuration could easily be made under controlled conditions, especially at the small scale needed for pedestrian-only (no bicycle accommodation)
It would seem to me that a separately applied solution would be cheaper, and easier, never mind the other issues being raised.
Let's consider the actual number of crossings compared to total mileage.
If we use an average crossing width of 100', and use my county as an example (mostly rural, a few "urban/village" crossings), there are approximately 25 crossings in fifty miles, for just 2,500' of track. That 50 miles is CWR, like the rest of the line.
There are areas where 25 crossings would cover several hundred miles.
Consider that fact that the girder rail being discussed would have to be somehow spliced into the rest of the rail. Any mechanical joint represents a point of failure. Welding the girder rail into conventional CWR will likely raise issues of it's own.
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
Heavy rail systems using girder rail to make flangeways safer for the public is the last thing in the world that heavy rail management would do. It runs completely contrary to their preference for large flangeways. They worry about ice and debris in their flangeways, and also don’t trust the flexible, normally flush flangeways to open for their flanges in cold weather. So what are they going to think of a heavy, rolled steel flangeway that is no larger than that contour of their flange cross section?
blue streak 1But is a flangeway rolled onto 132 rail will perform at a much lower pound rating.
There is kinda-sorta the ability to do explosive welding of a 'girder-style' flangeway onto the side of head-hardened rail ... but how it would be cost-effective, I can't say. I thought about doing this for just the walkway section of rail through a crossing (laser keyhole welding with preheat is an option for fabrication before placement) but I think the future, if there is one, for flangeway 'safing' still will belong to separate elastomer filler strips
Bear in mind that grovved rail was almost entirely made for street railway use, where axle loads were often below 10 tons and rarely much above 10 tons.
Having "said" that, the extra steel used for the groove does provide some vertical stiffness, though doesn't provide much material for wear.
But is a flangeway rolled onto 132 rail will perform at a much lower pound rating. Anyone know the individual weight of a standard flangeway ? Need to add the weight of the flangeway to stock rail to get the desired operating rail weight. that is a 40 pound flangeway would need a 172 pound rail stock to get 132 pound rated rail for loaded trains ?
Just for grins, I re-read the grade crossing section in W.M. Camp's Notes on Track, 2nd ed. (C) 1904. Quite a bit of discussion on flangeways, with horses' hooves as the main concern. Some configurations had the danger of ripping off a good chunk of the hood by catching on the shoe. The descriptions of placements for planks in the crossing were for right angle crossings only.
The writing implied that grooved rail was a fairly recent thing in 1904.
The writings I've come across on grooved rail indicate that the primary purpose was to accommodate vehicles by providing a flangeway precisely defined by steel as opposed to pavement - paving stones or bricks can chip or shift, concrete can chip and asphalt can plastically deform. Little is said about the groove acting as a guard rail.
+1
But you are fighting against old thinking on the railroads.
We are discussing girder rail because it was brought up as a suggestion that the purpose of girder rail was intended to be the minimization of the flangeway size. It seems clear to me that the purpose is to reduce the propensity for derailments on the extremely sharp curves of tramways. Girder rail does have an integrated grove that can at least sometimes virtually match the contour of the flange cross section. And if that girder rail were embedded in a grade crossing surface, it would indeed look like the smallest flangeway possible.
So one might assume that girder rail often used on trams mostly operating in streets would have very small flangeways to minimize the discomfort felt by people in vehicles, so frequently crossing the tracks with vehicles, because the tracks are in the streets and share the streets with vehicles.
Interestingly, the current thinking in heavy rail circles is that the smallest, least intrusive flangeways are exactly what they don’t want even if they are more comfortable and less dangerous to pedestrians. What heavy rail seems to want is the largest possible flangeways. This is because they see flangeways as constrictions that entrap snow, ice, and other debris which can become a derailment hazard as it is packed in by the passing trains. The larger the flangeway is, the more it can hold, which reduces the frequency of needed cleanings, and also limits the ability for trains to compact and lodge the debris.
While this view may be historically true, I think is it wrong to conclude that the new generation of flangeway fillers, rail seals, and shallow flangeway rail seals would contribute to the historic problem of causing derailments due to makeing the flangeway smaller. Those new products might actually end the problem of flangeways becoming blocked by snow and debris, as opposed to outdated thinking that adding the new devices just introduces one more form of flangeway blockage.
And if the new devices do end the flangeway blockage problem by making the flangeways self-cleaning, they will also end most of the danger to bicyclists, people in wheelchairs, and other pedestrians.
It is not, but we can discuss the idea of rolling a flangeway onto, say, 132lb rail to look at the implications. We don't have to get into the fabrication, hardening, grinding and resonance issues with such rail, or the reasons FRA bans nonflexible shallow flangeways entirely, until after he has worked the more basic stuff out.
Pardon the interruption, but streetcar girder rail is not the same thing as flangeway fillers or guards at road crossings on heavy freight lines.
EuclidBut with girder rail, you have two guidance means per wheel, working in opposite directions. So this doubles the rail holding grip provided by the two flanges of the wheelset.
What I thought was precisely what you noted earlier: if the outer wheel starts climbing the rail then the inner flange backside starts to make contact, just as on a bridge guardrail, and precludes derailment. Normal running (centered on cone without flange contact) and all the normal fillet transition to full flange bearing would not cause even transient contact of inner flanges.
blue streak 1 Is it possible tht heavy rail does not want girder rail because there are always a few RR cars that the guage of an axel is not corrrect and that would cause a problem ? c
Is it possible tht heavy rail does not want girder rail because there are always a few RR cars that the guage of an axel is not corrrect and that would cause a problem ? c
Girder rail is for making rail climbing events less likely on the most extremely sharp curves, which are found on tramways as they follow street layouts. For the most part, heavy rail systems have to need for girder rail because they have gentle curves.
In a rail climbing derailment, the wheel naturally climbs the outer rail of the curve. With a loss of flange contact as the outer wheel climbs up and over the side of the rail head, the opposite wheel on the rail of the inner side of the curve is free to be simply be pulled off of its rail as the outer wheel climbs over its rail. The flange of the inner rail is not in a position to prevent the wheel being pulled off the rail as the outer wheel flange climbs over its rail. So when a wheel flange tends to climb its rail, the flange on the opposite wheel cannot prevent it.
However, girder rail provides an additional flange guiding surface for each wheel. So when a flange tends to climb the outer rail of on a curve, the inner wheel is prevented from being pulled off its rail by the backside of its flange being retained by the extra rail surface provided by the “U”-shaped groove in the girder rail.
So with normal rail, a wheelset has two flanges with their outer faces being active in guidance. That is one guidance means per wheel and it only works in one direction of lateral shift of the wheelset. But with girder rail, you have two guidance means per wheel, working in opposite directions. So this doubles the rail holding grip provided by the two flanges of the wheelset.
That and it would be a different part to stock and not able to be thermite welded.
.
I do not recall ever reading of an incident due to an out-of-gauge wheel-set.
Brooklyn, The Bronx, Queens. and Manhattan streetcar tracks in pavement were nearly all girder rail. One unusual exception was on Surf Avenue, Coney Island, tracks not replaced from horsecar days, "L-rail," the flangeway without the guard-rail. T-rail was used on unpaved track with normal guard rails on curves.
A possibly more important reason is that railheads are slowly worn down, which means at some point the groove will no longer be deep enough to clear the flanges. While it is possible to make the groove deeper by grinding, the process would be a royal pain in the posterior. The other possibility is to have a deeper groove initially, but that tends to defeat the purpose of using grooved girder rail.
I'm guessing that wheelsets that are out of gauge sufficiently to cause problems with grooved rail will also cause problems with frogs on switches and crossings.
Considering that the context of street railways is like one boundless grade crossing, it might be expected that they would be designed with the smallest flangeways to provide the least inconvenience to vehicles and pedestrians. And, girder rails do provide the smallest flangeway possible.
The heavy rail industry, however, seems to prefer the largest flangeway possible in order to provide the least possible chance of fouling the flangeway. So this position places them in conflict with the public desire for the least flangeway disruption to pedestrians and vehicles. Thus, large versus small seems to be the flangeway dilemma.
So, while the girder rail can serve the purpose of flangeway size reduction, I would be surprised to learn that it has ever been installed in heavy rail grade crossings for that purpose. Heavy rail systems are in perpetual conflict with the public interest on the matter of flangeway size, and only regulatory pressure can reduce flangeway size on heavy rail systems.
I have never seen an actual girder rail that I recall. I have only seen references to them in railroad equipment catalogs, and was slightly curious about their purpose. So, with the subject mentioned here, I have sought to find the purpose of girder rails, and find that it is to increase the guidance in the extra sharp curves of tram systems. I have not found any reference to the purpose being to minimize flangeway size to reduce interference with road crossing traffic. But there may indeed be such references.
Here is 2-part reference to the function of girder rails that gets into a lot of detail about how they use the backside of the wheel flange to achieve guidance in addition to that provided by the rail side of the flange:
Understanding the wheel/rail interface – part one
http://www.tautonline.com/understanding-the-wheelrail-interface-part-one/
Understanding the wheel/rail interface – part two
http://www.tautonline.com/understanding-the-wheelrail-interface-part-two/
Most of the information I refer to is in Part Two. This includes a highly detailed cross section drawing of the interface between flanged wheel and girder rail.
Both Eric and Euclid are correct. There was at least one streetcar system, and Connecticut Company's New Haven Division, that used girder rail only on curves. Somehow, flangeways were kept clear of enroaching pavement. It's not a prolem with concrete pavement or with traditional paving stones.
West Penn did not use any girder rail. even on curves in street trackage. They either used traditional railroad-type guard rails or a plain steel band with flanges bolted or spiked to the ties under the pavement. Their one-time trolley-freight connection, Pittsburgh Railways used lots of girder rail, and PAT light rail may still have some on the over-the-mountain emergency connection for use when the Mt. Washington Tunnel is closed. And possibly some where RoW is shared with buses.
Jerusalem iLight Rail is almost 100% (German) girder rail, even on the limited un-paved RoW. All tracks on on private RoW, except that most is paved for emergency vihicles.
The only tracks not girder rail are in the yard and shops.
The purpose of grooved girder rail was to provide protection for the flangeway as well as making the flangeway as small as possible. The metal on the gauge side of the groove was to prevent pavement away from the gauge side of the rail head.
A fair amount of girder rail was rolled specifically to handle streetcar wheels with smaller flanges than normal RR wheels to minimize trapping of wagon and early truck wheels (think steel tired wood wheels). Normal RR wheels would be riding on the flanges and not the treads.
There may be grade crossing flangeways made by bolting a channel or maybe a “Z” shape length of steel to the rail web. However, the girder rail in a grade crossing would look like an intended flangeway, even though it continues as the stock rail and is not just confined to the crossing as a flangeway would be.
However, if perceived as a flangeway in a crossing, the girder rail flange groove would indeed suggest the tiniest of flangeways intended to offer the least discomfort and danger to vehicular and pedestrian traffic. So it would easy to perceive that as being its purpose.
My understanding is that the girder rail is intended to provide more protection against derailment for trams rounding exceptionally sharp curves. Rather than just the one outer wheel (to the curve) being protected against rail climbing by the field side of its flange; the inner wheel adds protection against rail climbing by the back side of its flange bearing against the corresponding field side of the groove in the girder rail. So each flange uses both of its sides to guide the wheels.
Overmod Bolted? What you're describing sounds like 'girder rail', which I always thought was rolled in one piece to that profile, not fabricated, and which was a mainstay of street running where 'permanence' was important.
Bolted? What you're describing sounds like 'girder rail', which I always thought was rolled in one piece to that profile, not fabricated, and which was a mainstay of street running where 'permanence' was important.
I've seen a drawing for a bolt on guard rail, but I agree it is much more likely to be a rolled section. I've seen that section called both "grooved rail" and "grooved girder rail" - both were definitely rolled to that profile and not fabricated. Richey's "Electric Railway Handbook" uses "girder rail" to describe profiles taller than standard profiles for a given weight, and were available in "tee", "tram" or "grooved" profiles. Doane's "Electric Railway Engineering" uses "girder" rail to refer to the "tram" proflie, with a flat surface, the tram, projecting from the gauge side of the rail head to form a flat bottomed flangeway.
One concern with grooved rail was dirt or other stuff accumulating in the groove and causing a derailment.
blue streak 1I have observed on streetcar and light rail lines what appears to be a metal U shaped flangeway bolted to the gauge side of rails.
Bolted? What you're describing sounds like 'girder rail', which I always thought was rolled in one piece to that profile, not fabricated, and which was a mainstay of street running where 'permanence' was important. As you note this was 'paved in' and thereafter kept swept out -- I sort of ASSumed that traction flangers had 'fingers' that would run in girder rail to clean out anything that wouldn't 'broom'.
Personally the problem I have with such a thing on main lines is that, if you have a rock wedged in such a particular hard place, the thing that's going to give on impact is the metal in the wheel. And that is something that is never good, whether it is only a piece of the flange or a larger chunk of tread or split across the web.
This poster is confused. I have observed on street car and light rail lines what appears to be a metal U shaped flangeway bolted to the guage side of rails . On the inside of the 2 rails the pavement is completely filled with concrete or asphalt. Would that be more expensive but more permanent ?
Some form of the shallow flangeway type must be what the UP is using at five or more crossings in my town. The mainline is three tracks and many heavy freight trains plus Metra daily. It's one of the busiest spots in the US for freight. No derailments.
SD70Dude Euclid SD70Dude We have enough problems with derailments caused by obstructed flangeways. Good luck convincing the railroads and regulators to deliberately put stuff in them. According to the product claims, the purpose and benefit of the flangeway fillers is two-fold: To eliminate the flangeway hazard to the public using the crossing. To eliminate the flangeway ice and debris obstruction hazard to trains. How much real-world testing have they done? How many crossings are they installed on? How much cleaning and maintenance do they require?
Euclid SD70Dude We have enough problems with derailments caused by obstructed flangeways. Good luck convincing the railroads and regulators to deliberately put stuff in them. According to the product claims, the purpose and benefit of the flangeway fillers is two-fold: To eliminate the flangeway hazard to the public using the crossing. To eliminate the flangeway ice and debris obstruction hazard to trains.
SD70Dude We have enough problems with derailments caused by obstructed flangeways. Good luck convincing the railroads and regulators to deliberately put stuff in them.
According to the product claims, the purpose and benefit of the flangeway fillers is two-fold:
To eliminate the flangeway hazard to the public using the crossing.
To eliminate the flangeway ice and debris obstruction hazard to trains.
How much real-world testing have they done?
How many crossings are they installed on?
How much cleaning and maintenance do they require?
I don't know those answers to those questions, but am looking into finding them. Generally what I find and conclude is that the concept did not exist before about 2008, and at that time, I find one case of research and development grants being offered, along with a set of guidelines.
At this time, I conclude that full height flangeway fillers are being used on LRT lines, but none are used for heavy rail lines. However, there is also a new development of flangeway fillers that are not full height, but rather, set at the elevation half way from the bottom of the rail ball to its top. This appears to be under development and referred to as a ”Shallow Flangeway Rail Seal."
This design approach does not require much, if any, flexing of the seal body to accommodate the passage of interfering flanges. Also, the entire body of the rail seal is installed to act as a gasket to keep snow, dirt, other debris, and most water out of the crossing pocket that encompasses the embedded rail.
With much current practice, there are deep and wide open gaps not only on the flange side but in many cases also on the field side. Rail seals completely fill the field side gap and fill the flange side gap to the extent of leaving a relatively smaller flangeway, but not as small as the shallow flangeway version of a rail seal I mentioned above.
For the “shallow flangeway” version, the flange gap is about 2.5" wide by 1.5" deep. I expect this to be developed for use with heavy rail applications that include freight trains. It has a flangeway that is not so small that it requires the flangeway floor to compress as flanges pass over it; but still wide enough and shallow enough to eliminate much of the foot, or wheel entrapment hazard. It is the “sweet spot” size configuration.
The full flangeway fillers are really not necessary for wheel chairs. But the sweet spot flangeways are still able to pose a hazard to bicycles, although it is a greatly reduced hazard compared to the jumbo wide and full rail depth flangeways currently in use on many freight railroads.
So the very best are the full flangeway filler, but I think that is a bridge too far. With them, the rail seal elastomer material does totally interfere with the passing flanges, so the material must compress about 1.5” under each passing flange and then rebound to normal height after the train passes. And this does have to happen at high train speed, so the severe compression and release may even build up significant heat in the material.
As this design has been tried in the recent past with freight railroads, I suspect the rail seals may have been molded with a solid cross section. And also there were likely some poor choices of elastomer material used. Solid section material chilled to sub-zero temperatures may very well have rendered the flangeway fillers to be incompressible by the flanges. Then the flange weight on the solid material might have caused it to fracture and spall out, thus causing short life and frequent replacement as has been mentioned to some extent in various references. Yet the concept has been adopted for LRT railroads and must therefore work okay for them.
The most important claim for the industry is not only does the Shallow Flangeway Rail Seal not constitute a flangeway obstruction that adds to the snow, ice, and debris that needs to be cleaned out of flangeways, but it also renders the normal flangeways able to remain free of those blockages by making the crossing flangeways self-cleaning.
With the latest versions of these devices, the ideal elastomer material is probably used, and instead of being molded solid, they are extruded with hollow cores. You can see that in several patent illustrations. So if these shallow flangeways do happen to collect snow and ice, the flanges will much more easily compress the elastomer by collapsing its hollow cores, as opposed to the extra force it would take to compress solid elastomer material that was likely tried in the past.
Ice that freezes to adhere to these more flexible floor shallow flangeways will not bond as well as it does when sticking to concrete, wood, and steel of the conventional jumbo flangeways. And an ice buildup in the flexible flangeways will interfere with the passing flanges, thus tending to cause the flanges to lift. But the flexible flangeway material, the poor ice bond to that material, and the extreme weight on the flanges will result in the flanges easily cracking the ice and shattering it, and expelling it from either side of the flangeway.
charlie hebdoThere must be some reason why fillers are so resisted on here, even though many are around and in use on major US railroads even in norhtern Illinois which has plenty of snow and ice. No derailments at crossings with fillers here. Perhaps out-of-date thinking?
Perhaps the difference between Main Line trains at track speeds of up to 79 MPH, or in some cases more and secondary lines and industrial spurs being operated on at Restricted Speed.
Never too old to have a happy childhood!
There must be some reason why fillers are so resisted on here, even though many are around and in use on major US railroads even in norhtern Illinois which has plenty of snow and ice. No derailments at crossings with fillers here. Perhaps out-of-date thinking?
Greetings from Alberta
-an Articulate Malcontent
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