rrnut282 wrote: Limitedclear wrote: the railroads will be required to load rate bridges (a complex inspection and report including complete calculations by a structural engineer on each bridge) many of which have never been load rated at significant cost in addition to likely new requirements for annual inspections and perhaps even regulations detailing exact repair or rehabilitation methods. This will be an absolute NIGHTMARE for many railroads.LCI have to ask, if these bridges were not load rated, how did the builders know if they will support the load they were designed to carry?During a proper inspection, the engineer will review the original design calculations (if the paper hasn't turned into dust) and compare them with the current traffic they are carrying before passing judgement. The only real concern should be corrosion and whether it is affecting the strength of structural members of a particular bridge. (let's hear it for CSX's unpainted bridges) Let's not overlook the fact that a lot of bridges carrying rail traffic were built before or during the time of steam locomotives. Big steam was as heavy or heavier than today's locomotives and therefore bridges built for them will still have a lot of "useful life" left in them as they are carrying loads less than what they were designed for.
Limitedclear wrote: the railroads will be required to load rate bridges (a complex inspection and report including complete calculations by a structural engineer on each bridge) many of which have never been load rated at significant cost in addition to likely new requirements for annual inspections and perhaps even regulations detailing exact repair or rehabilitation methods. This will be an absolute NIGHTMARE for many railroads.LC
the railroads will be required to load rate bridges (a complex inspection and report including complete calculations by a structural engineer on each bridge) many of which have never been load rated at significant cost in addition to likely new requirements for annual inspections and perhaps even regulations detailing exact repair or rehabilitation methods. This will be an absolute NIGHTMARE for many railroads.
LC
I have to ask, if these bridges were not load rated, how did the builders know if they will support the load they were designed to carry?
During a proper inspection, the engineer will review the original design calculations (if the paper hasn't turned into dust) and compare them with the current traffic they are carrying before passing judgement. The only real concern should be corrosion and whether it is affecting the strength of structural members of a particular bridge. (let's hear it for CSX's unpainted bridges) Let's not overlook the fact that a lot of bridges carrying rail traffic were built before or during the time of steam locomotives. Big steam was as heavy or heavier than today's locomotives and therefore bridges built for them will still have a lot of "useful life" left in them as they are carrying loads less than what they were designed for.
Some were initially constructed before Cooper load rating was an accepted practice and have been rebuilt since in kind. Others were perhaps rated at one time but through the decades and bankruptcies, mergers, wars, acquisitions and otherwise the original designs and rating information was lost or destroyed. Accordingly, many existing bridges would need to be rated or re-rated by a structural engineer. Of course, railroad bridges are heavily overbuilt as a rule and often remain safe well beyond their actual use.
Limitedclear wrote: rrnut282 wrote: Limitedclear wrote: the railroads will be required to load rate bridges (a complex inspection and report including complete calculations by a structural engineer on each bridge) many of which have never been load rated at significant cost in addition to likely new requirements for annual inspections and perhaps even regulations detailing exact repair or rehabilitation methods. This will be an absolute NIGHTMARE for many railroads.LC I have to ask, if these bridges were not load rated, how did the builders know if they will support the load they were designed to carry?During a proper inspection, the engineer will review the original design calculations (if the paper hasn't turned into dust) and compare them with the current traffic they are carrying before passing judgement. The only real concern should be corrosion and whether it is affecting the strength of structural members of a particular bridge. (let's hear it for CSX's unpainted bridges) Let's not overlook the fact that a lot of bridges carrying rail traffic were built before or during the time of steam locomotives. Big steam was as heavy or heavier than today's locomotives and therefore bridges built for them will still have a lot of "useful life" left in them as they are carrying loads less than what they were designed for. Some were initially constructed before Cooper load rating was an accepted practice and have been rebuilt since in kind. Others were perhaps rated at one time but through the decades and bankruptcies, mergers, wars, acquisitions and otherwise the original designs and rating information was lost or destroyed. Accordingly, many existing bridges would need to be rated or re-rated by a structural engineer. Of course, railroad bridges are heavily overbuilt as a rule and often remain safe well beyond their actual use.LC
rrnut282 wrote: Limitedclear wrote: the railroads will be required to load rate bridges (a complex inspection and report including complete calculations by a structural engineer on each bridge) many of which have never been load rated at significant cost in addition to likely new requirements for annual inspections and perhaps even regulations detailing exact repair or rehabilitation methods. This will be an absolute NIGHTMARE for many railroads.LC I have to ask, if these bridges were not load rated, how did the builders know if they will support the load they were designed to carry?During a proper inspection, the engineer will review the original design calculations (if the paper hasn't turned into dust) and compare them with the current traffic they are carrying before passing judgement. The only real concern should be corrosion and whether it is affecting the strength of structural members of a particular bridge. (let's hear it for CSX's unpainted bridges) Let's not overlook the fact that a lot of bridges carrying rail traffic were built before or during the time of steam locomotives. Big steam was as heavy or heavier than today's locomotives and therefore bridges built for them will still have a lot of "useful life" left in them as they are carrying loads less than what they were designed for.
"Of course, railroad bridges are heavily overbuilt as a rule and often remain safe well beyond their actual use." -LC
Part of that overbuilding is termed a "factor of safety" in engineering circles. Highway structures and buildings tend to be built with a factor of safety of somewhere between 1.5 and 2.5....Older railroad structures approached values closer to 4. A lot of this overdesign came due originally not because of concerns about degradation/deterioration (although it was NOT ignored), but because of materials sciences. 100 years ago, many properties of materials were not well understood, if they had been studied at all. Nobody ever heard of destructive testing. In addition, engineering structural design principles changed as engineers learned from mistakes made by bridgebuilders of Howe and Pratt's era and from what happened too often on lightly built narrow gage lines between 1845 and 1885 where economy concerns almost did in some railroads. As structural science, material science and soil mechanics (Carl Tergahzi, et al.) evolved, so did the new bridges which became lighter and stronger. (Everybody also forgets, that before computers, the arduous task of solving horribly complex equations was time consuming and made worse by the size of the bridge. As you kept evaluating variables looking for weak links in critical members, you often just made thinks stronger/bigger just to mitigate calculations that had to be done.)
All you have to do is go back to 1900-1905 to see where highway engineers and railroad engineers parted company. One of the many reasons that AREA (now AREMA) and the railroads parted company with ASCE was that ASCE's accepted standard practice/ theory did not sit well with the practical reality that railroad engineers had with heavy structures. The railroaders politely went their own way and built beefier structures based on their practical experience. (I work in a company that has both breeds of engineers. They don't always agree even now.)
If you go back and read GAO and FRA links to the subject, you see both wanting/insisting the bridge ratings be done/supervised by railroad qualified bridge engineers. I agree. I also agree with LC that much of this is politics (and the politicians do not hold the high ground) and unjustified knee-jerk fear mongering. What I don't want to see is the local state DOT sticking it's nose into railroad affairs (many, like Colorado, are not qualified to do so...as would be the clowns in Covington,KY and other places who do not savvy superficial surface blemish) ...Not disagreeing with Kathy either in what she is saying (she and I were in the same meeting room more than once this year); FRA could re-allocate their meager resources (few structural inspectors) and look into what's happening with some of the little guys.
And contrary to political, media and public perception, FRA is not supposed to be this mean spirited/ overbearing arm of the politicians. If that ever happens, safety has nowhere to go but into a steep decline along with other consequences.
Poppa_Zit wrote: I have far better things to do than be obsessed with someone like you.
I have far better things to do than be obsessed with someone like you.
Yeah, so you now claim, but your actions betray your pretense of indifference.
I'll tell you what is REALLY stale poppa zit, your all too predictable repertoire of lashing out personally against posters who dare to post materials that run contrary to yourPOV. Not just me, but seemingly anybody... anytime. Let anyone mention their dissatifaction with the government, it's policies, the president, wallmart, the war, etc and you immediately launch a targeted attack against the messenger. In fact what is humorous is the very predictability. Like winding up a toy soldier just to watch him march, preying upon your insecurities with your own convictions is as easy as childs play.
Go ahead, and launch one of your tirades of sarcasm, and prove to me just how much you 'don't care' LMFAO!!
Convicted One wrote: I'll tell you what is REALLY stale poppa zit, your all too predictable repertoire of lashing out personally against posters who dare to post materials that run contrary to yourPOV. Not just me, but seemingly anybody... anytime. Let anyone mention their dissatifaction with the government, it's policies, the president, wallmart, the war, etc and you immediately launch a targeted attack against the messenger. In fact what is humorous is the very predictability. Like winding up a toy soldier just to watch him march, preying upon your insecurities with your own convictions is as easy as childs play.
You're still hurting because someone exposed your silly little game of musical screen names. That hasn't gone away.
Here's your problem: You come here to a site devoted to talk about railroads and railroading and you do everything you can to hijack topics into a prohibited area where you can inject your unwelcome opinions on "the government, it's policies, the president, wallmart, the war, etc". It's gutless. And do you know what? NO ONE HERE CARES about what you think about "the government, it's policies, the president, wallmart, the war, etc". They come here to read about railroads. And you've been told that many times.
All this has nothing to do with me -- you just don't like having your political cynicism challenged by anyone. It's been said here many times by the Kalmbach folks -- politics and religion are forbidden topics.
And I'll tell everyone why you come here for a soapbox -- because you don't have the intellectual ammo to compete in real debate on forums where those topics are not prohibited -- forums whose sole purpose IS to discuss such hot political issues. In those environs, though, you're way out of your league. They'd chew you up and spit you out and bruise your little ego. So you come here and browbeat the nice people who come to talk about railroading. And who knows where else? The forum at quilting.com?
If anyone is insecure, it is a person who comes to a railroad-oriented board to make snide remarks about the war or the president when those topics are prohibited, then acts hurt when someone calls him on it. How childish.
Chad?? Where's Chad and the popcorn machine???
Ah well....Anyway, I had always wondered what the heavier locomotive was, steam or diesel. I guess I have my answer. Wasn't there a steam locomotive(s) that had a weight of either at, or near 1,000,000 pounds??? If that was the case then, I can see how the older bridges would have some "safety factor" built into them, if they were built during the steam era.
TimChgo9 wrote: Wasn't there a steam locomotive(s) that had a weight of either at, or near 1,000,000 pounds?
Wasn't there a steam locomotive(s) that had a weight of either at, or near 1,000,000 pounds?
I believe the C&O Allegheny locomotives weighed in at roughly 775,000 lbs., just ahead of the Big Boys.
More
Enjoy your popcorn.
Poppa_Zit wrote: TimChgo9 wrote: Wasn't there a steam locomotive(s) that had a weight of either at, or near 1,000,000 pounds? I believe the C&O Allegheny locomotives weighed in at roughly 775,000 lbs., just ahead of the Big Boys.MoreEnjoy your popcorn.
LOL.... Actually I can't eat the stuff.....causes, uh...let's just say "discomfort" and leave it at that. (I just couldn't resist calling for the popcorn machine...
Thanks for the link, made interesting reading.
....It's a discussion that goes back and forth....The Allegheny and the Big Boy in weight configuration. Accept the fact both were heavier than modern 5,000 hp diesels.
Over the years, it seems the 1,000,000 lb. was a figure one could pull up on each in ready to run status....Coal, water, tender and engine, etc...We might conclude they both required mighty strong bridges, for sure.
I saw Alleghenies operate but never any Big Boys.
Quentin
On a Histroy Channel documentary on bridge construction its was said that prior to today's more exacting computer engineering, in the early 1900s when they built many of the rail over water bridges in places like NY and Pittsburgh, the designers purposely built them extra heavy duty. This so if they did err on their calculations, they wouldn't end up with a train in the river. This is why so many are still in use today.
Chico
PS. what is the inside joke about popcorn i see here often?
Railroad bridges have been the topic of numerous threads, and the point is often made that they were mostly designed for the era steam locomotives. And since steam locomotives have a higher loading than diesels or at least impose a higher dynamic load from the driver imbalance, most bridges remain overbuilt for today's diesel trains.
It is true that bridge strength must be sufficient for the heaviest load, and the heaviest loads are locomotives. But as I understand it, the fact that a bridge is designed to take a given load is not the end of the story. The bridge also has a life. The life is used up not only by deterioration from the elements, but also, by the number of times it is loaded, and the amount of each load.
The locomotive loading may have gone down, but the carload weight has gone up. Freight cars have undergone a substantial increase in weight from an average of 80 tons gross in the steam era to 150 tons gross or higher today. Moreover, the incidence of the car loadings outnumber that of the locomotive load by a large factor; perhaps an average of fifty-to-one.
I think what needs to be compared between the steam era and today, in terms of what is carried by bridges is not the weight of the locomotives, but rather, the total gross tonnage. I am guessing that on average, that figure has increased many times since the steam era.
.....But the one time that 500 ton steam engine and tender and fuel pass over that bridge...and it can't handle it, that's the end of the bridge. I fully realize those "big ones" were not everyday traffic in some cases, but it just takes one time for a too much overload and the bridge would be ruined.
Poppa_Zit wrote: You're still hurting because someone exposed your silly little game of musical screen names. That hasn't gone away.Here's your problem: You come here to a site devoted to talk about railroads and railroading and you do everything you can to hijack topics into a prohibited area where you can inject your unwelcome opinions on "the government, it's policies, the president, wallmart, the war, etc". It's gutless. And do you know what? NO ONE HERE CARES about what you think about "the government, it's policies, the president, wallmart, the war, etc". They come here to read about railroads. And you've been told that many times.All this has nothing to do with me -- you just don't like having your political cynicism challenged by anyone. It's been said here many times by the Kalmbach folks -- politics and religion are forbidden topics. And I'll tell everyone why you come here for a soapbox -- because you don't have the intellectual ammo to compete in real debate on forums where those topics are not prohibited -- forums whose sole purpose IS to discuss such hot political issues. In those environs, though, you're way out of your league. They'd chew you up and spit you out and bruise your little ego. So you come here and browbeat the nice people who come to talk about railroading. And who knows where else? The forum at quilting.com?If anyone is insecure, it is a person who comes to a railroad-oriented board to make snide remarks about the war or the president when those topics are prohibited, then acts hurt when someone calls him on it. How childish.
After a geyser of vitriol like that, do you still expect us all to believe you really could care less?? That's an impressive catalog of angst you seem to be carrying there for someone claiming to have better things to do than care about the likes of me . tsk tsk Gee, you DO care, after all.
My comment was on topic, until you launched your assault of attempted recrimination(s).
You truly are a man obsessed, and I find it flattering, in a way, to be the focus of your contempt
Convicted One wrote: Poppa_Zit wrote: You're still hurting because someone exposed your silly little game of musical screen names. That hasn't gone away.Here's your problem: You come here to a site devoted to talk about railroads and railroading and you do everything you can to hijack topics into a prohibited area where you can inject your unwelcome opinions on "the government, it's policies, the president, wallmart, the war, etc". It's gutless. And do you know what? NO ONE HERE CARES about what you think about "the government, it's policies, the president, wallmart, the war, etc". They come here to read about railroads. And you've been told that many times.All this has nothing to do with me -- you just don't like having your political cynicism challenged by anyone. It's been said here many times by the Kalmbach folks -- politics and religion are forbidden topics. And I'll tell everyone why you come here for a soapbox -- because you don't have the intellectual ammo to compete in real debate on forums where those topics are not prohibited -- forums whose sole purpose IS to discuss such hot political issues. In those environs, though, you're way out of your league. They'd chew you up and spit you out and bruise your little ego. So you come here and browbeat the nice people who come to talk about railroading. And who knows where else? The forum at quilting.com?If anyone is insecure, it is a person who comes to a railroad-oriented board to make snide remarks about the war or the president when those topics are prohibited, then acts hurt when someone calls him on it. How childish. After a geyser of vitriol like that, do you still expect us all to believe you really could care less?? That's an impressive catalog of angst you seem to be carrying there for someone claiming to have better things to do than care about the likes of me . tsk tsk Gee, you DO care, after all. My comment was on topic, until you launched your assault of attempted recrimination(s).You truly are a man obsessed, and I find it flattering, in a way, to be the focus of your contempt
Guys,
This is one of the first good threads that I have seen in a long time. I was just wondering why I hadn't seen a thread like this for a while. Now, I remember.
Gabe
Steam Is King wrote: ChicoPS. what is the inside joke about popcorn i see here often?
Thanks to Chris / CopCarSS for my avatar.
Interesting article on timber railroad bridge inspection. Covers many of the basics.
http://www.chronline.com/story.php?subaction=showfull&id=1193506167&archive=&start_from=&ucat=1
#8 N' Sand
EightNSand wrote: Interesting article on timber railroad bridge inspection. Covers many of the basics.http://www.chronline.com/story.php?subaction=showfull&id=1193506167&archive=&start_from=&ucat=1#8 N' Sand
Is #8 N' Sand the rule regarding emergency reverse when a train is out of control on a grade? If that article in Trains (or Trains Classic) was yours, it was a good one.
There is no such thing as perfect safety, the opinions of lawyers and the technologically challenged media notwithstanding.
That said, I can think of a number of railroad bridge misadventures, though nowhere near the number of highway bridge failures (especially if you throw in the rural bridges on county roads that seldom make even the local news.) The most serious, in terms of loss of life, was caused by an idiot towboat pilot who rammed a bridge over a waterway he wasn't supposed to be on! (Of course, there was the idiot towboat pilot who took out the I-40 bridge in Oklahoma because he was a couple of spans over from the channel...)
The big difference? If a highway bridge has a problem, it never gets out of the local news area unless the accident kills a bunch of folks or involves a spectacular fire (like the one in the East Bay recently, where the fire took down a section of freeway ramp.) OTOH, a rail bridge that fails makes the national news, even if the only casualty is an empty box car.
Chuck
Bucyrus wrote:Railroad bridges have been the topic of numerous threads, and the point is often made that they were mostly designed for the era steam locomotives. And since steam locomotives have a higher loading than diesels or at least impose a higher dynamic load from the driver imbalance, most bridges remain overbuilt for today's diesel trains.It is true that bridge strength must be sufficient for the heaviest load, and the heaviest loads are locomotives. But as I understand it, the fact that a bridge is designed to take a given load is not the end of the story. The bridge also has a life. The life is used up not only by deterioration from the elements, but also, by the number of times it is loaded, and the amount of each load. The locomotive loading may have gone down, but the carload weight has gone up. Freight cars have undergone a substantial increase in weight from an average of 80 tons gross in the steam era to 150 tons gross or higher today. Moreover, the incidence of the car loadings outnumber that of the locomotive load by a large factor; perhaps an average of fifty-to-one. I think what needs to be compared between the steam era and today, in terms of what is carried by bridges is not the weight of the locomotives, but rather, the total gross tonnage. I am guessing that on average, that figure has increased many times since the steam era.
csx engineer
csxengineer98 wrote: Bucyrus wrote: Railroad bridges have been the topic of numerous threads, and the point is often made that they were mostly designed for the era steam locomotives. And since steam locomotives have a higher loading than diesels or at least impose a higher dynamic load from the driver imbalance, most bridges remain overbuilt for today's diesel trains.It is true that bridge strength must be sufficient for the heaviest load, and the heaviest loads are locomotives. But as I understand it, the fact that a bridge is designed to take a given load is not the end of the story. The bridge also has a life. The life is used up not only by deterioration from the elements, but also, by the number of times it is loaded, and the amount of each load. The locomotive loading may have gone down, but the carload weight has gone up. Freight cars have undergone a substantial increase in weight from an average of 80 tons gross in the steam era to 150 tons gross or higher today. Moreover, the incidence of the car loadings outnumber that of the locomotive load by a large factor; perhaps an average of fifty-to-one. I think what needs to be compared between the steam era and today, in terms of what is carried by bridges is not the weight of the locomotives, but rather, the total gross tonnage. I am guessing that on average, that figure has increased many times since the steam era.you read my mind..i was just about to post something alone the same lines..but you said it better then i can about the overall loading of a bridge in regards to the weight of the total train..not just the locomotives..csx engineer
Bucyrus wrote: Railroad bridges have been the topic of numerous threads, and the point is often made that they were mostly designed for the era steam locomotives. And since steam locomotives have a higher loading than diesels or at least impose a higher dynamic load from the driver imbalance, most bridges remain overbuilt for today's diesel trains.It is true that bridge strength must be sufficient for the heaviest load, and the heaviest loads are locomotives. But as I understand it, the fact that a bridge is designed to take a given load is not the end of the story. The bridge also has a life. The life is used up not only by deterioration from the elements, but also, by the number of times it is loaded, and the amount of each load. The locomotive loading may have gone down, but the carload weight has gone up. Freight cars have undergone a substantial increase in weight from an average of 80 tons gross in the steam era to 150 tons gross or higher today. Moreover, the incidence of the car loadings outnumber that of the locomotive load by a large factor; perhaps an average of fifty-to-one. I think what needs to be compared between the steam era and today, in terms of what is carried by bridges is not the weight of the locomotives, but rather, the total gross tonnage. I am guessing that on average, that figure has increased many times since the steam era.
Trains crosing over bridges are considered live loads and are calculated as such by the structural engineers load rating the bridges. Obviously, there are many different factors depending upon the materials and construction of the bridge that are considered in such calculations including the maximum weight of the cars in lading in a train.
The dirty, grungy, look of those black steel railroad bridges is caused by the accumulation of greasy gunk from the inherent polluting qualities of railroads,either past or present. These bridges do not need to be freshly painted, they already have a free coating of self-sealing weatherproofing. Of course, if they were nicely painted and "kept clean", the paint would crack,moisture would leach in, and rust would take over underneath the paint and create nasty little blisters between the paint and steel. This is the problem with every older steel highway bridge that I have ever seen.
Of course,road salt during the winter also hastens highway bridge problems...
...but still, this whole media thing is like something out of a 1950's domestic policy article of the saturday evening post: on this topic,folks,let's clean the world around us from what works, then white-wash it with what doesn't (and actually chronically does more harm than good), and, oh yeah, mabye we should get the government involved...
OldArmy94 wrote:A faulty assumption at-play by an ignorant media is that rust is evil. Rust, if controlled, is PROTECTIVE. Why do you think brand new freight cars have rusty wheels? It's not due to laziness or being cheap; it protects the wheels.
Actually, rust on new railcar wheels, protective though it may be, is present because railcar wheels cannot be painted. They MUST remain unpainted to allow detection of defects through visual inspection under AAR rules and FRA regulations. Couplers also cannot be painted for the same reasons.
That's right. Blame the media.
Unless the bridge is fabricated using Cor-Ten or a similar "self-rusting" steel, and designed accordingly, rust is generally not protective for the steel members and fasteners in a bridge. However, rust may not have diminished the section of the member or fastener enough to matter, either. Or, there may be other redundancies or sufficient safety factor in the design of the bridge enabling members to be completely rusted through, and not matter.
RWM
Seems like this is a bridge we've already crossed a time or two?
It would seem to me that cities such as Covington and Henderson KY are just spinning their wheels trying to fight bridge deterioration locally. Clearly, the right way to go about it is at the state level.
Afterall, if New York City was able to successfully force the RR's to electrify (or to a lesser extent, dieselize) all operations within their limits via an act at the state level, then clearly this is the right path for the bridge people to pursue remediation through.
We may, however, be reaching a limiting factor.
Some years ago, UP brought its 4-6-6-4 to the Chicago area for an excursion on the former C&NW New Line. While planning for this event, it was discovered that trios of the latest and largest diesels exceeded local bridge capacities. Since that time, the trios were broken up with two engines on the point, and a third pushing at the rear.
Cars and locomotives are getting heavier, and one would hope the railroads are planning for the future.
Dan
AltonFan wrote: We may, however, be reaching a limiting factor.Some years ago, UP brought its 4-6-6-4 to the Chicago area for an excursion on the former C&NW New Line. While planning for this event, it was discovered that trios of the latest and largest diesels exceeded local bridge capacities. Since that time, the trios were broken up with two engines on the point, and a third pushing at the rear.Cars and locomotives are getting heavier, and one would hope the railroads are planning for the future.
Our community is FREE to join. To participate you must either login or register for an account.