Cost of upgrading Rail

[Anonymous]

QUOTE: Originally posted by Murphy Siding

Dave: I'm not saying your premise is incorrect-that it might be cheaper to change all the heavy axle-load railcars than to change all the track structure to carry the heavier axle loads. I am suggesting that you're doing sort of a mixed-math-metaphor type of trying to quantify a number. If the engine in my car was made 15% lighter, the whole car wouldn't cost 15% less. It seems to me, that the railroads would have had to have this axle-loading vs. rail structure problem worked out in the 1960's, when they went to 286,000#. It's too late now.

First, a few corrections:

1. Someone emailed me that the 115#, 136#, etc. rail is per yard, not per foot. That would make more sense, and does change the calculations dramatically, albeit in favor of lighter rail.

2. As to that "one million a mile comes out to $20 million....", well, I have no idea where I came up with that. On reflection, it makes no sense, so on that one I am way off. All I can say is put it in the [%-)] file along with "conical driving wheels".

Well, nobody bats 1.000!

Now, I'd like to comment further on something mudchicken brought up - the "track modulus" effect, wherein (if I am correct) the rail will bend down vertically as a bogey passes over. He stated that the effect is greater with the lighter rail than the heavier rail, presumably because of less vertical rise in the rail itself, or that lighter rail is a few inches shorter than the heavier rail. And it makes sense, since the effect is the same whether it be 80 tons on a two axle truck or 80 tons on a three axle truck, 80 tons pushing down is 80 tons. Since the lighter rail would have more "bend" the supporting components underneath the rail would experience greater wear.

What I have observed today is that from a trackside standpoint a 264k car running over both lighter branch line rail and heavier mainline rail, there is no observable difference in the degree of "bend" when a loaded 264k car passes over (and they were presumably loaded because both were outbound and/or westbound), therefore is there really a significant difference in rail support component wear? The relative degree of movement in the rail looks to be the same, so where's the gain attributed to heavier rail for this particular dynamic? Are there any studies available with measurable variables to support the notion that heavier rail will cause less wear on support components? Although the heavier rail is "taller" and therefore would spread the impact more longitudinally, is that really enough to offset the 2 inch height difference?

[Murphy Siding]

Dave: A few thoughts that apply to lumber, and apparantly to rail: Taller is stronger in an exponentianly (I may have made up that word) way. An 8" tall board will carry 4 times the verticle load that a 4" board will carry. A thicker board will carry more weight than a thinner board-3"x4" will support more than 2"x4". Thus, a beefier rail will carry more more than a lighter rail of the same height. Fir is stronger than cedar, but they both make crappy rails.[;)]
As far as the ties and ballast go, I'd have to believe that the wear comes over a long period of time. It also seems logical that the human eye would have trouble seeing a perceptible difference in performance. Among other things, the stronger rail would spread the weight from above out over more substructure. That should slow down the wear on it.

[Anonymous]

Yes, taller is stronger, but both are compensated by the ties and subsequent spacing between ties. Or to take your lumber example, it wouldn't matter if a beam of lumber was 4" tall or 8" tall if both were flu***o the surface. Now, imagine both laid like rails on ties. With 10" spacing between ties, it would take alot of weight to bust either beam of lumber. You'd have to get to several feet of open space underneath before you'd get any discernable difference in relative vertical strength.

My understanding (and keep in mind I am not a lumber salesman) is that the heavier rail is needed primarily for the force of weight at the point of wheel/rail contact, and not the collective weight of the truck. The reason may have something to do with the fact that the spacing between axles is greater than the spacing between ties, so the weight of each axle is spaced at least three tie spacings between. All the rail and support components have to support at point of contact is that weight on the axle, thus less weight per axle allows for less vertically tall rail.

Maybe lighter rail would need closer tie spacing of the collective weight of the truck was heavier?

[beaulieu]

QUOTE: Originally posted by futuremodal

<snipped>

My understanding (and keep in mind I am not a lumber salesman) is that the heavier rail is needed primarily for the force of weight at the point of wheel/rail contact, and not the collective weight of the truck. The reason may have something to do with the fact that the spacing between axles is greater than the spacing between ties, so the weight of each axle is spaced at least three tie spacings between. All the rail and support components have to support at point of contact is that weight on the axle, thus less weight per axle allows for less vertically tall rail.

Maybe lighter rail would need closer tie spacing of the collective weight of the truck was heavier?

Dave, think of the rail as a bridge beam spanning the ties. With the heavier rail the increase is partially in the head (more metal to wear before needing replacement) but also in the web (greater stiffness). If you noticed in the HAL article it said that the railroads discovered that you have to weld the rail on the ends of bridges to provide better support in the transition from roadbed to bridge deck. Also the trend is to ballasted deck bridges as a counter to the differences in stiffness on a bridge. Next time you pass under a highway overpass take a look at the bridge beams underneath, then take a look at those under a railroad
overpass. You will see that those under a railroad bridge are at least twice the height of those under a road bridge. Also if you have seen a transition joint between two different weights of rail you will have seen a difference in height in the web.

[Anonymous]

QUOTE: Originally posted by beaulieu

QUOTE: Originally posted by futuremodal

<snipped>

My understanding (and keep in mind I am not a lumber salesman) is that the heavier rail is needed primarily for the force of weight at the point of wheel/rail contact, and not the collective weight of the truck. The reason may have something to do with the fact that the spacing between axles is greater than the spacing between ties, so the weight of each axle is spaced at least three tie spacings between. All the rail and support components have to support at point of contact is that weight on the axle, thus less weight per axle allows for less vertically tall rail.

Maybe lighter rail would need closer tie spacing of the collective weight of the truck was heavier?

Dave, think of the rail as a bridge beam spanning the ties. With the heavier rail the increase is partially in the head (more metal to wear before needing replacement) but also in the web (greater stiffness). If you noticed in the HAL article it said that the railroads discovered that you have to weld the rail on the ends of bridges to provide better support in the transition from roadbed to bridge deck. Also the trend is to ballasted deck bridges as a counter to the differences in stiffness on a bridge. Next time you pass under a highway overpass take a look at the bridge beams underneath, then take a look at those under a railroad
overpass. You will see that those under a railroad bridge are at least twice the height of those under a road bridge. Also if you have seen a transition joint between two different weights of rail you will have seen a difference in height in the web.

Ballasted bridge decks - wasn't that a Milwaukee idea?[^]

If you have ever been to Spokane WA, take a look at the RR bridges downtown. The NP apparently chose to go with thinner bridge beams compensated by more frequent support struts. I am sure thicker beams existed at this time, but it was probably cheaper to go with the thinner beams and increased struts. I would think this concept could be applied in other areas, aka if railroads could get away with it they would prefer their bridges over highways to have more strut support (and allowing thinner beams) rather than having to span the entire roadway. For bridges, the gross consist weight is more paramount than the point of contact weight.

I also use this example for the thinner vs thicker rail debate.

[beaulieu]

QUOTE: Originally posted by futuremodal


Ballasted bridge decks - wasn't that a Milwaukee idea?[^]

If you have ever been to Spokane WA, take a look at the RR bridges downtown. The NP apparently chose to go with thinner bridge beams compensated by more frequent support struts. I am sure thicker beams existed at this time, but it was probably cheaper to go with the thinner beams and increased struts. I would think this concept could be applied in other areas, aka if railroads could get away with it they would prefer their bridges over highways to have more strut support (and allowing thinner beams) rather than having to span the entire roadway. For bridges, the gross consist weight is more paramount than the point of contact weight.

I also use this example for the thinner vs thicker rail debate.

That may be a case of not wanting to raise the level of the roadbed and being unable to reduce the clearances over the highway. Did you ever wonder why floor joists are on edge rather than laid flat? Because they are stiffer on edge than flat . The same is true with bridge beams. A taller cross sectioned beam will provide greater weight carry capacity than the equivilent amount of steel in more but smaller beams.

[Anonymous]

QUOTE: Originally posted by beaulieu

QUOTE: Originally posted by futuremodal


Ballasted bridge decks - wasn't that a Milwaukee idea?[^]

If you have ever been to Spokane WA, take a look at the RR bridges downtown. The NP apparently chose to go with thinner bridge beams compensated by more frequent support struts. I am sure thicker beams existed at this time, but it was probably cheaper to go with the thinner beams and increased struts. I would think this concept could be applied in other areas, aka if railroads could get away with it they would prefer their bridges over highways to have more strut support (and allowing thinner beams) rather than having to span the entire roadway. For bridges, the gross consist weight is more paramount than the point of contact weight.

I also use this example for the thinner vs thicker rail debate.

That may be a case of not wanting to raise the level of the roadbed and being unable to reduce the clearances over the highway. Did you ever wonder why floor joists are on edge rather than laid flat? Because they are stiffer on edge than flat . The same is true with bridge beams. A taller cross sectioned beam will provide greater weight carry capacity than the equivilent amount of steel in more but smaller beams.

There are a few main arterials wherein the older strut support bridges were replaced by full length side girder bridges, which kept the road clearances the same as before but allowed for full width of the roadway below.

On the rail issue, aren't European rails lighter than NA rails? If you look at European freight operations, their heavy haul freight cars do have bogies of three or more axles. I think that is the basis for my premise that spread axles on US railcars would allow for using lighter rail concurrent with heavier gross car loads, and thus allow our shortlines to continue viability.

And some of their heavy freights run in triple digit speeds!

[beaulieu]

QUOTE: Originally posted by futuremodal

There are a few main arterials wherein the older strut support bridges were replaced by full length side girder bridges, which kept the road clearances the same as before but allowed for full width of the roadway below.

On the rail issue, aren't European rails lighter than NA rails? If you look at European freight operations, their heavy haul freight cars do have bogies of three or more axles. I think that is the basis for my premise that spread axles on US railcars would allow for using lighter rail concurrent with heavier gross car loads, and thus allow our shortlines to continue viability.

Yes, European rails are lighter, about the same as our 115lb. rail. But the passenger service drives the track requirements, which causes the low axle loading. High quality track for high passenger train speeds.

QUOTE:
And some of their heavy freights run in triple digit speeds!

Only in kilometers per hour. And even then those aren't the six-axle coal wagons.
and they are moving to make their track even stiffer than ours is, on the new German Rhine-Main Neubaustrecke, they are using slab track. Concrete and rebar with the rails directly clipped to the slab.

[Murphy Siding]

QUOTE: Originally posted by futuremodal
[
My understanding is that the heavier rail is needed primarily for the force of weight at the point of wheel/rail contact

Overall, I'd believe that the rail, ties, and structure beneath are all parts of a "system", to support the trains. Increasing the strength of the rail would distribute the weight better to the ties and below. Conserning spacing on ties,aren't they set at a *standard* on center spacing?

[Anonymous]

QUOTE: Originally posted by Murphy Siding

Conserning spacing on ties,aren't they set at a *standard* on center spacing?

Isn't the "urban legend" that ties are spaced at a distance that makes it awkward for people to walk on at a normal gait?

[mudchicken]

You are looking at 22-24 ties per rail length and any main line will hold the 24 ties/ rail length typical standards. Along with the beam issue distributing the load footprint, you seem to be ignoring the cyclical issue that accelerates the degradation of the track variables....If you want to throw all those extra ties in there, hope you can come up with the machinery to index and surface that works. IMHO, The "benefit" you keep pushing won't be fiscally justified (ROR for the railroad isn't there for the outlay required). Be heavy and go fast requires a massive maintenance commitment that the operating side has to buy into or the whole thing stumbles a la Powder River.


PS - Alan Zarembeski (Zeta Tech) on more than one occasion has voiced his displeasure on how some his research has been mis-interpretted or skewed to the point that he no longer recognizes it.

[daveklepper]

Continuously supported rail might make a difference.

Rail resting on very stiff neoprene or other high-density artifical rubber which is wedged into the bottom 25% of U or an inverted Pi with a very broad base, so the total area supported by ballast is even greater than what is under convenitonal ties. The inner and outer walls of the U or inverted Pi are continuous guard rails, meaning that if the impossible happens and there is derailment, the axle remains within the track structure. Since the web of the rail is held through the neoprene by heavy-duty resilient fasceners that are rigid horizontally to preserve gauge. The height of the continuous neoprene pad is held constant to very close tolerances. The U or inverted Pi is joined to its mate every meter or so by hardened rods of a steel alloy with very low temperature coefficient so gauge is maintained over a broad temperature range.

A railway system using this track would, I think, never experience a derailment when on this type of track, and sunkinks would never occur. Problems to solve are bending the works around curves and how to transition to conventional switches. And cost.

[Overmod]

Interesting idea, but...
1) Overall structural cost much higher than 'conventional' construction, I suspect.

2) Don't forget drainage and debris issues in the channels, particularly on the gauge side...

3) Interaction between ballast and channel bottom won't be as good as with ballast and crossties; I'd expect, for instance, that you'd see longitudinal shift issues in particular -- and I wouldn't want to be responsible for maintaining alignment long-term...

4) Maintenance is going to be a significant issue. How do you handle grinding, and perhaps more importantly, managing rail changes (e.g. getting the entire length of CWR up and out of that channel without chipping the rim or cracking the section)?

5) As happens, I've done analysis on a similar system of track construction (part of which used modular longitudinal box sections in concrete, with the rail sitting on formed neoprene pad attached by sprung clamps). Cross-members 'a meter or so apart' which only control gauge will be wildly insufficient. Remember, for example, that there are considerable forces rolling the railheads outward, and a mere 'gauge rod' arrangement may actually suffer stress raisers (at or near the point the rods join or enter their hardpoints in the channel) that over time might lead to catastrophic (and not-easily-detected!) fatigue failure. I would worry a bit that your 'inverted-mushroom' channel sections won't have good characteristics for achieving the required cross-reinforcement (e.g. with cross-truss arrangements instead of 'rods')

Of course, most of the issues here are just as 'soluble' with some form of continuous-cast slab construction (using 'interruptions' in the center web made via reusable pans in the formwork if you want to save a few $$ and help optimize track maintenance), cross-channels for post-tensioned tendons, etc. etc. etc. "Bending the works around curves" then becomes comparatively trivial (compared to custom-casting or fabricating precise 3D spiral curve geometry into a multiplicity of channel segments!) and your transition to switches (and crossings!) etc. can be handled relatively easily (e.g. via 'drop-in' standard modules that have any approach modulus tuning 'built-in')

Hard to beat the economy of using longitudinal rail of appropriate beam stiffness combined with a multiplicity of good, stiff crossties that have small resilient pads/spring clips a la Pandrol. mudchicken et al. can describe to you (on or off the forum) the different things involved in maintaining complex track geometry in practice -- and how difficult many of the required operations are when you have a rigid and nominally-continuous structure running on what is by necessity a less-than-perfectly-stable subgrade...

I look forward to seeing what the learned hands have to contribute here.

[Hugh Jampton]

Are you all on about something that looks a bit like what's shown on pages 16-19 of this document?

www.unife.org/Innotrans2002/documents/BBRail_Temple.pdf

[mudchicken]

It's called pac-track in this country (look at the Century Pre-cast website, they are still trying to evolve the system) and is used in tunnels, transit and road crossings with varying degreees of success. It has fastening replacement issues like concrete ties that will drive you crazy. The industry has been struggling to find a universal system that works. One of the really big issues that handicaps this system is keeping the foundation subballast uniform after installing pac track. (you can no longer effectively get at it to maintain and adjust it) The heavier the cyclic loading, the faster the failure of the system - usually because of subgrade/surface failure.

[Anonymous]

QUOTE: Originally posted by mudchicken

You are looking at 22-24 ties per rail length and any main line will hold the 24 ties/ rail length typical standards. Along with the beam issue distributing the load footprint, you seem to be ignoring the cyclical issue that accelerates the degradation of the track variables....If you want to throw all those extra ties in there, hope you can come up with the machinery to index and surface that works. IMHO, The "benefit" you keep pushing won't be fiscally justified (ROR for the railroad isn't there for the outlay required). Be heavy and go fast requires a massive maintenance commitment that the operating side has to buy into or the whole thing stumbles a la Powder River.

There's more to it than just more or less ties per rail length. What about different widths/thicknesses of ties in correspondance with differring rail thicknesses? "X-ing" ties rather than cross ties? Ect.?

I still haven't seen any studies to refute the hypothesis, mostly I presume for the simple fact that re-thinking the rail/tie interaction combined with rail wheel interaction hasn't even been broached by the R & D departments (if the Class I's even have their own R & D departments anymore outside the TTC!) If there are any studies out there that have examined relative rail thicknesses as they interact with varying axle weights and truck weights, I'd like to read them.

QUOTE:
PS - Alan Zarembeski (Zeta Tech) on more than one occasion has voiced his displeasure on how some his research has been mis-interpretted or skewed to the point that he no longer recognizes it.

I have had email correspondences with Alan, and he has never alleged any misinterpretations of my POV's regarding the ZetaTech HAL studies. Again, if Mr. Z has issue with anything I've hypothesized here, I'd hope he'd respond.

[Overmod]

I'm not going to be able to get to

https://www.regonline.com/HTMLEditor/custImages/240971/Program%20Preview%20Only.pdf

but if anyone will be going, an AWFUL lot of the stuff being bandied about in this thread will be intelligently addressed...

[Tim Burton]

QUOTE: Originally posted by edbenton

Since you are looking at roughly 30 million a mile to lay all new trackager and ballast figure on roughly 6 mil a mile rough guess remember there is no need to put down new subroadbed and ballast just redoing the track figure on the rough guess of 6 mil a mile. That 30 mil a mile comes from what it is costing the BNSF to double track the transcon.

You're telling me that there is no other way to lay a mile cheaper than 30 mil?

[Underw8]

QUOTE: Originally posted by samfp1943

Has any manufacturer, beyond Buckeye Steel Castings ever produced 3 axle trucks in any appreciable quantities? I have only seen them used on loco tenders and some heavy weight flat cars [ mostly DOD] for hauling tanks. I would think that to produce them would have to be an off shore operation, in light of govt regs nowdays.

The 6-wheel trucks were also used on wrecker cranes in the 40s, 50s, etc. due to heavy tonnage. HOWEVER... since these cars are pressed into service primarily at times of derailments, it would be FAR more difficult to tell the amount of derailments / miles travelled! e.g., in Baltimore, there was a wrecker train which lay 'parked' at Camden Station during my days as a Block Station Operator. This car was a 12-wheeler, with 2 3-axle trucks. Of course, with the demolition of Camden Station, it is no longer there. As to its present whereabouts, I am not sure.

Continuing my point, this crane was used principally in case of derailments, to be able to hoist engines, loaded cars, etc. back onto the rail. For example, were the derailment at Laurel, MD, the distance to travel would be [ballpark] 30 miles each way, plus any additional movement which the crane had to make at the site of the derailment. IMHO, this is hardly adequate mileage to determine 'derailment ratio' and/or track wear rates from operation of this crane.

In addition, the crane had a speed restriction of 30 mph. This would also not reflect the effects of 50-70 mph speeds on "manifest trains."

Remember, you may have to use desperate measures to overcome desperate situations. That doesn't mean the "desperate measures" would be justified in normal rail operation.
Yer Hillbilly friend in TN...

Underw8
PROUD father of an American Soldier