That and it would be a different part to stock and not able to be thermite welded.
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.
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.
Pardon the interruption, but streetcar girder rail is not the same thing as flangeway fillers or guards at road crossings on heavy freight lines.
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.
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.
+1
But you are fighting against old thinking on the railroads.
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.
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 ?
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.
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
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?
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.
It would seem to me that a separately applied solution would be cheaper, and easier, never mind the other issues being raised.
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...
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)
Overmod. Euclid is right, and the monthly magazine of the UK-based Light Railway Transport Association devoted considerable space to this subject in issues abut a year ago. But you are correct about noise, and even here in Jerusalem I hear the screetch when the flange oilers are not working properly or just have not been refilled. If you think back to the days when your riding streetcars was common, you may recall that screetch. It was more noticeable witih rubber-in -suspension PCC cars and Third Avenjue's 626-645, which had much less general clatter and banging than those conventional streetcars having nothing interrupting metal-to-metal between car-body and motors and gears and rails. So the screech was the primary noise on curves without proper flangeway lubrication.
Again, the New Haven Division of Connecticut Company used girder rail only on curves, and West Penn used a metal strip with tabs for spiking to the ties.
Welding dissimilar rail types on street railways was normal practice, and large sysems had one or even several full-time track-welding crews, and inspections and repair were routine.
Erik_MagThe 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.
I understand what you are saying about the flangeway protection function of girder rail. I do find references that seem to say that is the only function of girder rail. However, I also find references to the function being as I describe to prevent derailing on ultra-sharp curves found on tramways. If you read the links and quotes I posted on the previous page, they go into intense technical detail about this function of using girder rail to double the flange contact from 2 points to 4 points per wheelset. They also say that this function has been widely misunderstood by the users of girder rail.
So taken all together, I assume that there are two completely different and unrelated functions claimed for girder rail. I do not know if this was the original intent. I completely understand the logic of the derailment protection function. But I don’t quite understand the logic of the flangeway protection option.
If the U-shaped appendage of girder rail only has the function to act as curbing to keep pavement away from the flangeway, it seems like there would be far more cost effective way to provide that advantage than to integrate that heavy curbing into the rolled stock rail. Also, while the rail flangeway has the ability to resist encroachment of paving, dirt, rock, etc., it also has the ability to harbor those materials if they do happen to get kicked into the U-shaped trough. And then these contaminants are entrapped precisely in a perfect manner to damage wheels, flanges, and the rail if impacted by the flanges running in that U-shaped trough. So is the trough feature actually protecting the flangeway or turning it into a hazardous entrapment for debris?
Also, while the trough acts as curbing to define the smallest flangeway possible, to protect pedestrians and horse hooves, all of the accumulating broken pavement and debris from the crossing structure is still right there in the crossing as a hazard to pedestrians, bicyclists, horses, and people in wheelchairs.
It would seem cheaper to just use T-rail and add a second timber or iron to define the flangeway. The crossing provides plenty of solid structure to which the extra flangeway feature could be nailed or bolted to.
On the other hand, the girder rail does provide a ready-made flangeway that may save time in installation. And for street railway systems with extensive trackage embedded in the street paving, I can see why they might like to embed the U-shape trough with the pavement finished accurately right up to the trough. I would not be surprised of some street railways used girder rail for flangeway definition alone, and had no need for using it on curves. So the entire user/company institution in such cases may never have been aware of the function of girder rail as providing better guidance though curves.
Euclid It would seem cheaper to just use T-rail and add a second timber or iron to define the flangeway. The crossing provides plenty of solid structure to which the extra flangeway feature could be nailed or bolted to. On the other hand, the girder rail does provide a ready-made flangeway that may save time in installation. And for street railway systems with extensive trackage embedded in the street paving, I can see why they might like to embed the U-shape trough with the pavement finished accurately right up to the trough. I would not be surprised of some street railways used girder rail for flangeway definition alone, and had no need for using it on curves. So the entire user/company institution in such cases may never have been aware of the function of girder rail as providing better guidance though curves.
Hilton and Due's book on interurbans has several paragraphs on the choice of rail for tracks in the street. The interurbans very much wanted to stay with standard T rail (or girder T rail) as opposed to girder grooved rail. The use of girder grooved rail was mostly dictated by the terms of the franchise granted for permission to use city streets. The book does mention the problem of debris in the groove.
Many of the sources I've alluded to date back a century or more, revealing the thinking at "the time of the trolley". This was also the time that street railways were starting to use rail that was close to steam RR T sections as opposed to inverted "U" channels and other shapes. As for "girder" rail, the broadest definition is a tall (e.g 8" to 9") section as opposed to 5" to 7" height for standard T rail. The increased height of the rail increased the vertical stiffness to help keep the rails in vertical alignment with the pavement.
Since crossings compose a very small portion of track, it would probably be most efficient to bolt the sections to form the flangeway. That way the main portion of the rail would be of the same section as adjoining rails. OTOH, ther may be an advantage to having a special section with a much greater vertical stiffness for crossings.
I hope by now everyone has read the references that Euclid cited, including the part where their author specifically points out why proper 'tram' groove rail has little place on conventional track. Much of what Euclid is saying is best understood with specific reference to the precise section involved, of which this is a representative example:
http://www.tautonline.com/wp-content/uploads/2015/08/Wheelrail-part-2.jpg
The immediate thing to note here is the assumption of partial flange bearing for even slight deflection from centerline (note the portion that is 'eased' for sharp curves). This is specifically referenced at a couple of points in the author's discussion, including his note on "diamond" crossing design in part 2. This appears to involve precisely the sort of thing leading to the proscription on flange bearing in United States practice where higher than tramway speed is expected.
I also noted the author's mention of PCC truck design at the end of part 2, specifically in a discussion of low running noise. It seems to me that at least some of his thinking is that the flexible wheels inherently damp the noise of double-faced contact, whereas Mr. Klepper treats the screech as almost a matter of course on curves sharp enough to warrant full flange bearing (against the angled gauge face) and back bearing.
I would conclude that fairly frequent re-turning of wheels to accurate profile would be needed to preclude severe noise, with diameter being comparatively little concern down to the tread wear limit, the condition being that the whole of the wheel, including the flange diameter and profile and the back 'gauge face' all being machined each time -- not just the 'normal' tread and fillet areas.
Erik_MagSince crossings compose a very small portion of track, it would probably be most efficient to bolt the sections to form the flangeway. That way the main portion of the rail would be of the same section as adjoining rails.
[/quote]OTOH, there may be an advantage to having a special section with a much greater vertical stiffness for crossings.[/quote]This was anathema for many years, and even after the Amtrak-sponsored research into bridge tuning, I still consider it so. A typical crossing, whether 'paved' or sectional, has a dramatic effect on resonance of the track. You often see this in wear patterns in the railhead a few feet back, or in signs of repeated rail repairs or welds in the approach. Making this worse with an abrupt change in modulus that INCREASES the effective stiffness seems counterproductive to me. Having a better approximation to a tuned transition, for example welding multiple short lengths of different section in the shop with the running and gauge faces aligned, then normalizing and finish-grinding, would be a better idea (it would be to known length and easily field-welded with proper tieplating to match) but this would be a relative lot of work for what is supposed to be small actual gain ... at least up to any current PSR-economical track speed.
Euclid I understand what you are saying about the flangeway protection function of girder rail. I do find references that seem to say that is the only function of girder rail. However, I also find references to the function being as I describe to prevent derailing on ultra-sharp curves found on tramways. If you read the links and quotes I posted on the previous page, they go into intense technical detail about this function of using girder rail to double the flange contact from 2 points to 4 points per wheelset. They also say that this function has been widely misunderstood by the users of girder rail.
I took a quick look through the links, and noted that the emphasis was on U.K. practice with American practice being a bit different. In US practice, there was a modification of the grooved rail design where the lip on the gauge side of the groove was raised higher than the head, where standard groove rail the top of the lip was approximately level with the head. There were guard rails that were designed to bolt on to the web of T rails.
OM:
The groove rail sections that I've seen show the bearing portion of the railhead directly above the web, with the outside edge of the groove on the gauge side of the web.
I believe New York City was one f the cities that required new track in pavement to be girder rail for streetcar companies.
The needs and practice of streetcar companies are different than main-line railroads. The loads carried by wheels are far lower and speeds generally lower. And curves are generally far sharper. Treads are typically narrower, with exceptions, and flanges shallower. On a main-line railroad, the flanges are helped by the wheell taper and the fillet jointing the flange to the tread. with their often doing more of the guiding than the flanges. because of the outer rails see a larger diameter wheel, effectively, than the inner wheel. All this doesn't apply to streetcar operation, where the flanges do the job.
If ware is equal nn the gauge face face of the outer raili and the guard face of the inner (Girder) rail, then maximum life of the rail installatim for the cdurve is insured, and both rails will need replacement at the same time. And guage integeraty will be maintained. This also means ware on both sides of wheel flanges.
I do not believe I have had enoough "real railroad" hands-on experience to weigh-in on wether or not any of Euclid's ideas are applicable to the "real railroads" Overmd and NP Eddie and others are far more qualified. I can point out that as far as I remember, South Shore still uses regular T-rail in the concrete-paved Michigan City street. But refreshing memory with a photo, I see North Shore did use (some?) girder-rail in MilwaukeeL
daveklepperI do not believe I have had enoough "real railroad" hands-on experience to weigh-in on wether or not any of Euclid's ideas are applicable to the "real railroads"
Dave,
I don’t understand what you mean by this comment. It sounds like you are saying that I have proposed applying girder rail to heavy rail lines, and you don’t know if that would work. To be clear, I have never proposed anything of the sort.
Perhaps others here believe that girder rail would improve crossing flangeway safety on heavy rail systems. But if they do, they have not actually said so, or described how it would be done.
What I have clearly stated is that I believe most of the solution to flangeway safety issues at heavy rail grade crossings would be made safer by the use of a modern, manufactured product that is on the market today. This product would be attached by having several features that would fit to the stock rail features, and then made secure by the use of some form of clips.
This product is apparently called a “rail seal,” but I don’t know if that is a brand name or a generic name. The rail seal basically seals up the flangeway groove at a grade crossing so the flangeway is shallower than the full depth flangeways used on many heavy rail crossings.
These full depth flangeways are about 3-4” wide and extend down to the ties where there are open voids between the sides of the ties, under the rails, and into the voids contained in the crushed rock ballast. Snow can fill many of these voids, then partly melt, releasing water, which then freezes to form ice. This is a problem for the railroad company because it can cause derailments.
The other problem with flangeways is the safety issue of people getting stuck in them and the discomfort of driving over them due to the bump effect of the wide open flangeway. This is not a problem for the railroad company other than perhaps some degree of legal liability. So there are two problems; a safety problem for the public and another safety problem for the railroad industry.
The railroad industry sees the solution to their problem as having the largest flangeways possible. The reasoning seems to be that if you have a small space that catches and traps debris, then make the small space bigger. If the railroads had their way, they would make the flangeway so large that there is no longer any crossing.
The public crossing users see the solution to their problem as having the smallest possible flangeways. So they have developed a version of the rail seal that is actually a flangeway filler. It actually eliminates the flangeway for any passage of pedestrians, bicyclists, or wheelchair users. But when a train shows up, its flanges compress the flangeway filler to make way for the flanges.
Generally I read that the railroad industry does not want to use these flangeway fillers that require the flanges to compress the rubbery material used for the fillers. Apparently, the industry regards any move to reduce their full flangeway size as being objectionable, and the smaller it becomes, the more they object. They seem to draw the line at the point of completely filling the flangeways with the resilient rubbery material.
But there is a compromise position that I think is ideal and both sides would be well served. For the public, the flangeways will be as shallow as practical, and so wide that it solves most of the pedestrian-related dangers. For the railroad industry, the wide, and shallow flangeway combined with a debris exclusion feature of the rail seal will practically eliminate any problem with ice or debris accumulation. This compromise solution is called the “Shallow Flangeway Rail Seal.”
This device has a flangeway that is always open enough to clear the flange, but the size of the flangeway is only about 4” wide and about 1.5” deep. This flangeways groove is too shallow and wide to get bicycle or wheelchair wheels, or pedestrians’ feet stuck in it. The only hazards it does not eliminate are the chance of pedestrians stepping on the rail, and bicycles being diverted by their wheels following the flangeway and being guided by it.
The only issue the heavy rail industry would have with this solution is that it makes their preferred largest possible flangeway smaller. So they see that as worsening the problem of collecting packed debris and production of ice fouling.
However, it is claimed that the new Shallow Flangeway Rail Seal prevents debris packing and ice buildup just by the design shape that seals the underlying deep well flangeway that normally collects debris when left open. And its flexible, non-stick material aids the passing wheel flanges ability to clean out the ice with each pass.
So this Shallow Flangeway Rail Seal solves the railroad’s problem that they believe to be caused by flangeways being too small, and yet it does this by making flangeways smaller. At the same time, it eliminates most of the flangeway danger to the public.
Euclid, I know you are recommending treatment other than girder-rail for "real railroads." But I did want to affirm that you are correct about streetcar curves.
New Haven Division, Connecticut Company, used girder rail for curves and switches, T-rail elsewhere. And their Manufacturers Railway subsidary did move freight cars through those curves and switches.
1. I posted a buch of newly scanned 71-73-year-old photos of Connecticut Co. on the Classic Trains Forum, and several show T-rail - girder-rail joints.
2. Question for those more knowledgable: What about slab-track for grade crossings?
daveklepperWhat about slab-track for grade crossings?
I find I do not remember how significant the difference is between, say, slab and concrete ties when the same pads under the rails and clips/anchors are used. It is possible that only minimal stiffness or tuning issues might be observed.
But the crossing would have to be installed top-down, very carefully, and any settlement or cracking would have to be carefully and attentively managed. Of course this would also affect the line and surface of the road, particularly at the edges.
Meanwhile no practical type of main-line slab track embeds the rails in the slab, so you continue to have the entire cost of decking the crossing; the only real advantage being you can cast the bearing points for the decking a bit more precisely and so maintain alignment a bit more thoroughly. Flangeway issues would therefore be exactly as they are for existing crossings -- concrete, plastic, or elastomer -- as would the type and maintenance of any strips or pieces used to reduce flangeway depth.
One wrinkle I haven't seen discussed yet. Flangways only present a real obstacle to wheelchair users and cyclists when crossing at a shallow angle. Most crossings are at 90-degrees between rail and alternative modes of travel. How many incidents have happened at 90-degree crossings where the flange caused the issue?
I can see the benefit to those users at shallow angle crossings, but not so much at the square crossings. If only applied to shallow angle crossings, that greatly reduces the need or utility of flangeway remediations.
rrnut282How many incidents have happened at 90-degree crossings where the flange caused the issue?
Overmod rrnut282 How many incidents have happened at 90-degree crossings where the flange caused the issue? The one that started all these discussions, for instance. The issue of flange gaps (and railhead slickness) is of minimal importance for 'constrained' 90-degree crossing (hence the difficulty about being unable to constrain crossing to that angle with above-the-railhead "guides") but in the particular case you had someone in a power scooter who appears to have tried zero-turn on the crossing, which led to one of his directional casters dropping into the flangeway and becoming wedged there. The same might occur for a bicyclist changing line when passing over a crossing, for example to avoid another vehicle, and having the front wheel abruptly jerked into the line of the flangeway and precipitating a spill if not worse damage. Aall the good intentions and careful signage in the world will not eliminate problems like those.
rrnut282 How many incidents have happened at 90-degree crossings where the flange caused the issue?
The one that started all these discussions, for instance. The issue of flange gaps (and railhead slickness) is of minimal importance for 'constrained' 90-degree crossing (hence the difficulty about being unable to constrain crossing to that angle with above-the-railhead "guides") but in the particular case you had someone in a power scooter who appears to have tried zero-turn on the crossing, which led to one of his directional casters dropping into the flangeway and becoming wedged there. The same might occur for a bicyclist changing line when passing over a crossing, for example to avoid another vehicle, and having the front wheel abruptly jerked into the line of the flangeway and precipitating a spill if not worse damage. Aall the good intentions and careful signage in the world will not eliminate problems like those.
The situation was caused by having the crossing protection stanchions in the middle of the side walk area on either side of the crossing. Who or what created that situation thereby prevented the power chair operator from being able to have a 90 degree angle of attack unless he took the power chair out into the roadway.
Never too old to have a happy childhood!
I surmise that there are other factors that caused this incident.
While the placement of the crossing protection devices is poor at best, scooters such as the victim was using have a virtually zero turn radius. One could be within three feet of the rails and do a 360 degree turn.
If only a caster wheel was caught it would be one thing. But one of the main drive wheels was caught as well. This means the scooter had to have been turned to align with the flangeway.
The video from the officer seems to show the gates starting to come down as the officer arrives. It appears the scooter was already stuck at that point.
So, the question is why the operator turned around on the crossing.
Also unanswered is how familiar the operator was with the crossing, and/or the scooter . Was this an everyday event for him? Or was this his first time on a crossing or with the scooter?
How much wheelchair or bike traffic uses this crossing?
It's possible that some sort of flangeway protection might have prevented the incident, but I'd like to hear answers to the other questions.
tree68So, the question is why the operator turned around on the crossing.
Like railing on stairways, we put guards on things where a hazard may be unrecognized
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