The Class 1's all have in-house weather forecast capabilities (national contract services a la The Weather Channel) and will notify trains of watches and warnings (along with earthquakes).
In case of a warning, the trains about to enter a warning zone (Determined by GIS overlay and converted to RR milepost and subdivision) are stopped, the trains inside the warning zone are reduced to restricted speed.
(Having done two accident surveys after a tornado took on TOFC/COFC trains, the results can be dramatic....The locomotive(s) stays on the rail, but the pigs do fly!)
mudchicken wrote: but the pigs do fly!
but the pigs do fly!
Oh, great! I think about all those times I've responded to an absurd question with the answer, "Yeah, when pigs fly!".......
videomaker wrote: I heard dispatchers give severe weather alerts to train crews on BNSF,dont know what the crews procedure would be tho...
....stop the train clear of any crossings (if possible), and get down on the floor or in the nose of the locomotive.
zardoz wrote: videomaker wrote: I heard dispatchers give severe weather alerts to train crews on BNSF,dont know what the crews procedure would be tho.......stop the train clear of any crossings (if possible), and get down on the floor or in the nose of the locomotive.
...and curse the gods of Microphor and/ or the Mechanical Department about "that smell"!
Just my two cents - faced with a storm live and in person, I'd also head for the nose - it's usually made to protect, even if not for a tornado. There might also be less stuff to fly around if by some chance the wind was strong enough to tip the loco (I wonder what that wind speed would be...). No windows to speak of, either.
Back in the day, it's the guys in the caboose I'd fear for. If it was me I think I'd be looking for a culvert to hide in. I suspect that a caboose would fly just like a pig.
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...
In the noses of our engines, we have the toolbox. In that toolbox we have the airhose wrench, the hammer, chisel, and at least one spare airhose (sometimes more). On the floor under the box there's the emergency chain, and sometimes a run-around hose...
Guess it'd be smart to pitch that stuff out the door first... then of course we'd get written up for not having it with us
tree68 wrote:Just my two cents - faced with a storm live and in person, I'd also head for the nose - it's usually made to protect, even if not for a tornado. There might also be less stuff to fly around if by some chance the wind was strong enough to tip the loco (I wonder what that wind speed would be...). No windows to speak of, either.Back in the day, it's the guys in the caboose I'd fear for. If it was me I think I'd be looking for a culvert to hide in. I suspect that a caboose would fly just like a pig.
It's been fun. But it isn't much fun anymore. Signing off for now.
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.t fun any
Dan
NOAA was the first to write back. Reply follows:
"Nancy Merckle" <Nancy.Merckle@noaa.gov>Good question. The Storm Prediction Center FAQ says an F2 can overturnboxcars and an F3 can overturn trains. Diesel locomotives are heavier than boxcars, so it might require a strong F2 or F3 to overturn it alone. The Fujita scale was replaced by the Enhanced Fujita Scale last year. Here are a few links for more information. http://www.noaanews.noaa.gov/stories2006/s2573.htmhttp://www.spc.noaa.gov/faq/tornado/f-scale.htmlhttp://www.spc.noaa.gov/efscale/http://www.ncdc.noaa.gov/oa/satellite/satelliteseye/educational/fujita.htmlHope this helps,NancyDan Braun wrote:> Since it's tornado season in my part of the country I was wondering > how these powerful storms interact with train engines. I amwondering > what wind speed would be sufficient to overturn a modern diesel > locomotive. Has any research been done on this?> > Thanks!> Dan
So this means winds between 158 and 206 MPH to overturn a train, according to the link to the Fujita Scale.
It doesn't surprise me that the good folks at the NWS were the first to write back.
With the new Enhanced Fujita scale, the wind speeds for an EF3 would actually be 136 mph to 165 mph, as opposed to 158 mph to 206 mph on the old F-Scale. With this in mind, it might actually take an EF4 tornado on the new scale to topple a locomotive, since EF4s pack winds of 166 mph to 200 mph.
Bottom line... F3 on old scale, EF4 on new scale.
Willy
Either way...not something I'd want to see.
Willy2 wrote: It doesn't surprise me that the good folks at the NWS were the first to write back. With the new Enhanced Fujita scale, the wind speeds for an EF3 would actually be 136 mph to 165 mph, as opposed to 158 mph to 206 mph on the old F-Scale. With this in mind, it might actually take an EF4 tornado on the new scale to topple a locomotive, since EF4s pack winds of 166 mph to 200 mph. Bottom line... F3 on old scale, EF4 on new scale.
I've never experienced winds above 80mph, but I still find it hard to believe that even winds of 200-300 mph could topple a modern high-horsepower locomotive. There just isn't enough surface area on a locomotive to generate sufficient 'lift' power.
Now perhaps, if the winds were GUSTING to over 200, and the wind gusts arrived at such intervals that they became harmonic, and then started to get the loco to sway in the wind, and then the higher gust came along at the exactly correct harmonic period in the wave crest, then MAYBE it might tip over.
But I'd bet my life (literally) on the safety of a locomotive over any other place above ground, except perhaps a properly-designed safe-room.
zardoz wrote: Willy2 wrote: It doesn't surprise me that the good folks at the NWS were the first to write back. With the new Enhanced Fujita scale, the wind speeds for an EF3 would actually be 136 mph to 165 mph, as opposed to 158 mph to 206 mph on the old F-Scale. With this in mind, it might actually take an EF4 tornado on the new scale to topple a locomotive, since EF4s pack winds of 166 mph to 200 mph. Bottom line... F3 on old scale, EF4 on new scale. I've never experienced winds above 80mph, but I still find it hard to believe that even winds of 200-300 mph could topple a modern high-horsepower locomotive. There just isn't enough surface area on a locomotive to generate sufficient 'lift' power.Now perhaps, if the winds were GUSTING to over 200, and the wind gusts arrived at such intervals that they became harmonic, and then started to get the loco to sway in the wind, and then the higher gust came along at the exactly correct harmonic period in the wave crest, then MAYBE it might tip over.But I'd bet my life (literally) on the safety of a locomotive over any other place above ground, except perhaps a properly-designed safe-room.
I honestly have no idea what it would take. I've never heard of it happening, so maybe it's not actually known. I've seen pictures of coal cars and intermodal cars tipped over, but never a locomotive. Maybe this is something to ask my physics teacher?
One of the tornadoes that occurred over the weekend was rated EF-4, with winds of around 175 mph. It picked up automobiles and carried them for over half a mile. That's a lot of power, but would it be enough to knock over a locomotive?
EDIT: Upon further thought, debris might actually be a more serious threat than the winds. If a large object, such as van or truck, was blown into the side of the locomotive at a high rate of speed, that could derail or knock it over. Also, pieces of metal and wood could penetrate deep within the locomotive, possibly placing the occupants in danger. If a fork can be embedded in a tree trunk, then lumber could probably be driven through the side of the locomotive.
I tend to believe flying debris or track damage would be the greater danger as compared to being blown over.
Unfortunately it takes far less wind than a tornado to put an intermodal train into the ditch. We've experienced several times where straight line winds in the range of 70MPH have tipped over TOFC trains and slightly higher winds have toppled doublestacks.
On the Kate Shelly Bridge on UP near DesMoines, there is an anemometer. The reading shows up on the display in the Harriman Center (Dispatch) for the dispatcher managing that corridor. If wind speeds exceed a certain limit, stack trains and TOFC trains are restricted from crossing the bridge.
BNSF has had similar problems on a bridge in Laverne, ND (near Fargo) and one is the MT Rockies.
Willy2 wrote: Upon further thought, debris might actually be a more serious threat than the winds. If a large object, such as van or truck, was blown into the side of the locomotive at a high rate of speed, that could derail or knock it over. Also, pieces of metal and wood could penetrate deep within the locomotive, possibly placing the occupants in danger. If a fork can be embedded in a tree trunk, then lumber could probably be driven through the side of the locomotive.
Possibly; however, the walls of a locomotive are very thick metal, and while there certainly are objects that, when accelerated to 300mph, could penetrate that metal, I would bet that they are relatively few. Of course, having a SUV blown at 200mph towards the cab would certainly cause some damage, especially if it hit around the windows.
However, flying debris IS the reason I suggested that the crew goes down in the nose of the unit, keeping the crash door closed. Down there you are protected my multiple layers of thick metal.
I still maintain that the nose of a locomotive would be the one of the safest above-ground place to be in a tornado.
zardoz wrote: I still maintain that the nose of a locomotive would be the one of the safest above-ground place to be in a tornado.
Second that motion.
A modern locomotive has a broadside "sail" area of about 1200 square feet - around 37 sheets of plywood for a comparison. Given the narrow stance (~5' for a 10' wide locomotive), and a center of gravity probably 5+ feet up, I find it conceivable that a sufficient sustained wind hitting a locomotive broadside could tip it. The physics experts will have to do the math.
Given that the Oklahoma City EF5 (and maybe more) tornado of a few years ago had documented winds well over 300 mph, I'd put this in the realm of possibility. Where's the Mythbusters when we need them?
tree68 wrote: zardoz wrote: I still maintain that the nose of a locomotive would be the one of the safest above-ground place to be in a tornado.Second that motion.A modern locomotive has a broadside "sail" area of about 1200 square feet - around 37 sheets of plywood for a comparison. Given the narrow stance (~5' for a 10' wide locomotive), and a center of gravity probably 5+ feet up, I find it conceivable that a sufficient sustained wind hitting a locomotive broadside could tip it. The physics experts will have to do the math.Given that the Oklahoma City EF5 (and maybe more) tornado of a few years ago had documented winds well over 300 mph, I'd put this in the realm of possibility. Where's the Mythbusters when we need them?
+1
I think I've heard something similar while listening to the BNSF and there was severe weather in the area.
BTW - if you really wanna scare the cream cheese outta yourself, put your Bearcat scanner on the Weather Alert setting and go to bed. Then, when a severe thunderstorm warning for a suburb about 45 miles south of where you live occurs, the scanner will set-off that terrifying air raid siren sound, then the three warning tones, then that hideous computerized voice from NOAA starts talking... if the tornado doesn't kill you, the coronary heart failure will.
I'm no physics teacher or professor - just a civil engineer - but real quickly here, I roughly (crudely ?) calculated that the windspeed threshold for tipping a modern loco would be around 220 MPH continuous wind speed, applied broadside, based on that portion of the Davis resistance formula for railroad vehicles, as obtained from the following web page at/ from the University of Wisconsin- Milwaukee:
http://www.uwm.edu/~horowitz/PropulsionResistance.html
The portion of the formula for wind force is CAV**2 - note that this force varies with the square of the wind speed ! I used:
C = 0.0025, as for "other locomotives"
A = 1,000 Sq. Ft. (16 ft. high x 60 ft. long = 960 sq. ft., say 1,000 Sq. Ft.) (Maybe tree68's 1,200 sq. ft. would be more realistic - if you think so, make the substitution and do the calcs again yourself)
V = 220 MPH (V**2 is V squared).
So, wind force = 0.0025*1,000*220*220 = 121,000 lbs.
Applying that force at half the height of the locomotive (1/2 of 16 ft. = 8 ft.) = "overturning moment" of 121,000 lbs. x 8 ft. = 968,000 lb. - ft. = 968 Kip-Ft. (a Kip is a "Kilopound" = 1,000 lbs., a shorthand notation often used by engineers for these big numbers).
The "righting moment" - which has to be greater than or equal than the overturning moment above for the loco to stay on both rails - is the weight of the locomotive downwards, which is applied at a point about 1/2 the gauge from each rail - or 1/2 of the center-of-rail-head to center-of-rail-head distance of 5.0 ft. commonly used, as tree68 mentioned before, or 2.5 ft.
Using the loco weight as 200 tons = 400 Kips x 2.5 ft. = 1,000 Kip-Ft. Righting Moment, which is just slightly greater (fortunately) than the 968 Kip-Ft. Overturning Moment as calculated above.
Note that the height of the center of gravity of the loco above the rails - 5+ ft. up, again per tree68, a figure that I agree is generally valid - doesn't enter into this calculation at all, which merely addresses the forces needed to make the loco start to tip. Once that starts to happen, the center of gravity will start to move closer to the rail that it is still resting on, which will start to reduce the righting moment's "lever arm" distance of 2.5 ft., which will reduce the righting moment and just accelerate the process. Through the initial motions, the center of gravity might rise a little, but not until it gets beyond one of the rails will the loco tip over. When that happens, it doesn't matter how high the COG is.
Actually, I solved for the value of V where the moments were equal for these numbers, which was 223 MPH, but I thought it would be more informative to show the work through and magnitude of the numbers rather than just the algebraic exercise of rearranging the terms for the solution. Intuitively, the 220 MPH figure seems about right. Does anyone know of an instance where a loco was overturned in a tornado, and what the windspeed was for it ? I suspect it's pretty rare.
Of course, there are lots of factors that are assumed, unstated, and/ or ignored, etc., in any such analysis, and particularly this one. One that comes to mind is the restraining effect against overturning of the couplers with the adjoining units and cars, if they too are not being subjected to the same or greater wind force at the same time - many tornadoes are only a couple of hundred feet wide - and if either the train or the tornado move past each other before the overturning has completely occurred - a couple of seconds at least.
Finally, I remember this question being asked about a year ago, and one of our forum members answered with what may have been his screen name - in any event, I though it was pretty funny:
"Run 8 and sand !"
Hope this is informative.
- Paul North.
Paul_D_North_Jr wrote: I'm no physics teacher or professor - just a civil engineer - Of course, there are lots of factors that are assumed, unstated, and/ or ignored, etc., in any such analysis, and particularly this one. One that comes to mind is the restraining effect against overturning of the couplers with the adjoining units and cars, if they too are not being subjected to the same or greater wind force at the same time - many tornadoes are only a couple of hundred feet wide - and if either the train or the tornado move past each other before the overturning has completely occurred - a couple of seconds at least.
I'm no physics teacher or professor - just a civil engineer - Of course, there are lots of factors that are assumed, unstated, and/ or ignored, etc., in any such analysis, and particularly this one. One that comes to mind is the restraining effect against overturning of the couplers with the adjoining units and cars, if they too are not being subjected to the same or greater wind force at the same time - many tornadoes are only a couple of hundred feet wide - and if either the train or the tornado move past each other before the overturning has completely occurred - a couple of seconds at least.
Paul, nicely done.
You may not be a physics teacher, but I would think that the term "just" preceding your occupation of Civil Engineer is not warranted. I feel as though Engineers are some of the unsung heros of the technological culture.
Regarding your posit that forces from coupled cars might have on a tipping locomotive: I submit that the coupled cars would have an exacerbating influence. The freight cars in question would certainly tip first, possibly assisting in bringing the locomotive over.
Doublestack wrote:Unfortunately it takes far less wind than a tornado to put an intermodal train into the ditch. We've experienced several times where straight line winds in the range of 70MPH have tipped over TOFC trains and slightly higher winds have toppled doublestacks.
What about double stacks? I've done that with a model...ran it in front of a fan, all the top containers went flying....
The nose of a loco would definetely be safest, as long as the walls are thick enough to withstand flying debris. I guess it depends on what kind of debris it is, plywood reacts a whole lot differently that say....a tree trunk. And a house....ouch. Then again, if the tornado can lift a house, then it would proably pick up the loco. But if you get with a container or a piggy trailer....
Lots of things to hit you out there...then again, most tornados aren't Worst Case Scenerios, so it wouldn't be things like trailers and trees hitting the train, more like random debris. I would guess the nose of a loco would protect you, it is made to withstand collisions after all.
Leaf blower will filp a Gscale loco...
Adrianspeeder
USAF TSgt C-17 Aircraft Maintenance Flying Crew Chief & Flightline Avionics Craftsman
Zardoz -
Thanks for the compliment !
And yes, you're right, in most cases the cars would tip before the locomotives - esp. hoppers and boxcars, to name just a few. Then again, a trainload of flatcars loaded with strings of welded rails - or a gondola loaded with scrap - might never tip over. And I wonder how a smooth-sided tank car would react - far less drag than the "squarer" corners of a locomotive or the above cars. Notice the dramatic decrease in these drag coefficients from the same source as in my prior post - though these are intended for "head-on" air resistance computations:
C = drag coefficient of air .0017 streamlined locomotives, .0025 other locomotives, .0005 for trailing freight cars and .00034 for trailing passenger cars.
Note that this last is only about 14 % of the value for a locomotive, but a passenger car's weight is way less too, so it may come out about the same. Interesting to consider and contemplate . . .
Thanks again. Your posts are usually pretty good food for thought, too.
rrnut282 wrote:I've heard NS dispatchers call crews out on the road right after the NWS issues high wind or tornado warnings. Sometimes they say General Rule 37 ?? is in effect. Does that mean movement of the train is up to the discression of the engineer?
well I have no idea why they would tell a train rule 37 is in effect? Rule 37 has nothing to do with weather that i can think of. Oh and if you must know rule 37 pertains to roadway workier incharge and dont think it is anything to do with 27.... that is dealing with cell phone use...how your not allowed to be making dates with your girl friend for the motel and then calling your wife and telling her your to tired to have her company....
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