greyhounds wrote: They gave up on streamlining and concentrated on reducing tare weight. That's where the payoff is.
They gave up on streamlining and concentrated on reducing tare weight. That's where the payoff is.
Nobody "gave up" on streamlining. Modern high speed passenger services are extraordinarily engineered around streamlining. Wake up.
For freight service, it just never made much sense, and I doubt anyone has argued that it ever did. The numbers just don't justify any effort in that direction.
A streamlined engine at 100 mph offers 3,035 lbs of resistance compared to its unstreamlined counterpart at 3,995 lbs. [3k hp, 6 axles]. That's just about a 25% improvement, and represents the motion resistance of an entire passenger car. At 120 mph, resistance is 4,048 lbs compared to 5,430, a 34% improvement. At 160 mph, it is nearly 40% difference.
The streamlining reduces the aerodynamic drag alone by 47% at 120 mph.
At 50 mph, only a 20% difference in total motion resistance can be gained from streamlining, just 300 lbs, which is less than .07% (seven hundredths of a percent) of the resistance of the 80 car train at that speed, whereas at 120 mph, the total resistance savings offered by streamlining represents nearly 9% on a 12 car passenger train.
Nobody "gave up" on anything, there are simply appropriate applications and inappropriate applications.
Fortunately for railroad companies, they don't have to go out and spend millions getting "real world" data, they can see it in the simulation right of the bat.
spbed wrote: Were those Hi HP loocos or low HP locos on that train I paced?
Were those Hi HP loocos or low HP locos on that train I paced?
Doesn't matter, the point was that double stacks on the BNSF have less hp per ton than a pig train would. Did the train run over a scale why you were pacing it so you could figure out the hp/ton? Didn't think so. As I said before BNSF stack trains are allowed 70 MPH and do run at that speed at times, however they are not powered to ensure that they will. Pig trains on the BNSF ARE powered to ensure running at the limit, and to make sure that they get up to the limit quickly. Unless you know what the wieght of the train was that you paced was, the HP of the locos is a moot point.
Bert
An "expensive model collector"
MichaelSol wrote:Fortunately for railroad companies, they don't have to go out and spend millions getting "real world" data, they can see it in the simulation right of the bat.
Why would you think we have to spend "millions" to obtain real data? We run hundreds of trains per day systemwide. Christ, all the performance data we need is there for the taking
Yup, lots of 120 mph streamlined freight trains out there, aren't there?
You are making me giggle too much.
Remember these questions from school?
A hot TOFC (piggyback/trailer) train with +3.0 hpt leaves Los Angeles at the exact same time as a medium priority COFC (container) train with 2-3 hpt and they each train travels east to Chicago at a maximum authorized speed of 70 mph, where permitted, (factoring in a wind resistance of who knows and who cares??). Where will each train be in exactly the amount of time that it takes Michael Sol to argue a meaningless point with half of people on this board in regards to a subject that only is remotely is close to the original topic???
Answer - The TOFC (trailer/piggyback) train will have arrived at Willow Springs (or, as I called it... Western Springs. Duh). The COFC (stack/container) train might be somewhere in Missouri depending on traffic.
That is the answer to the original question from like three days ago.
I'll save M Sol the trouble of replying to my post and reply for him...
OBJECTION!!!
lawyers...
I'll rate myself with a high degree of wind (read hot air) resistance on this one,
CC
greyhounds wrote:So BNSF offeres different service levels at different prices. The highest service level is used by the most service sensative customers. UPS and perishable commodity truckers like Stevens Transport are examples. This freight moves TOFC on the BNSF. There are some extra steps with COFC that at least have the potential to slow things down. I recall the BNSF standard for this level of service as being 750 miles/day.
I think the fastest freight trains on the BNSF system are the trailer on flat car (TOFC) trains on UPS service because these trains run on a time-sensitive basis. These trains, in effect, are the direct descendants of the famous Santa Fe Super C service of the 1960's and 1970's.
You know, if Wabash National can figure out how to build a RoadRailer trailer that meets UPS' requirements, that could speed up UPS trains even faster since RoadRailers eliminate the step of having to physically load and unload the trailer off the spline car.
MichaelSol wrote: Why would you think we have to spend "millions" to obtain real data? We run hundreds of trains per day systemwide. Christ, all the performance data we need is there for the taking Yup, lots of 120 mph streamlined freight trains out there, aren't there? You are making me giggle too much.Do grown men actually giggle?
They don't have data on flying cows either. It would be about a useful as data on 120 MPH streamlined freight trains.
And you do induce giggles. In fact, you, Mr. Sol, deserve a title, an honor, and recognition. You are dubed Sir Michael Gigglesnort, the profound proponent of steam over diesel, the Milwuakee Road's Pacifric Coast Extension, the statement that the Milwaukee was in receivership because it had too much business, and other such giggle inducing foolishness
TomDiehl wrote: chad thomas wrote:With the same horsepower per ton at higher speeds the stacker will have higher wind resistance therefore the TOFC will be slower. Beyond that it's depends on many factors. A hotshot UPS Z train will get more HP/T then a stack train and would be faster. As big and heavy as any train is, the wind resistance is a very small factor. Dating back to the first streamliners, designers such as Lowey and Dreyfus used to refer to them as "Streamstyled" because they recognized this.
chad thomas wrote:With the same horsepower per ton at higher speeds the stacker will have higher wind resistance therefore the TOFC will be slower. Beyond that it's depends on many factors. A hotshot UPS Z train will get more HP/T then a stack train and would be faster.
As big and heavy as any train is, the wind resistance is a very small factor. Dating back to the first streamliners, designers such as Lowey and Dreyfus used to refer to them as "Streamstyled" because they recognized this.
Among the first six posts were the preceding.
Now, if train priority was the determining factor, it could have been a short thread.
However, if the first few comments suggested that "wind resistance" is or is not a factor that anyone wants to consider, then the proposition requires 1) recognition that aerodynamic drag is a significant factor and more so as the speed gets higher, and requires specific information about 2) the weight of the loaded car, 3) the cross section area of the car, 4) the resistance coefficient for the car type, 5) the number of and car types on the train, 6) knowledge that time tested industry-recognized algorithms exists which utilize that information to provide an answer to the questions/comments contained in the above posts.
In the case of TOFC, aerodynamic turbulence increases its aerodynamic resistance significantly beyond what its cross section area might suggest. It has an accordingly higher coefficient.
It did indeed take five pages to "discuss" those facets of the "question." I am gratified that two grown men who obviously didn't understand a shred of it were at least reduced to giggling fits between their fascination with episodes of the Jerry Springer show.
It took a discussion on aerodynamic drag to bring out the best in them.
Hugh Jampton wrote: user="BuyCSXrailroadStock!"] Greenbrier and Gunderson are making Light Wieght Aluminum Coal Cars.... Must be a reason for this. The fuel savings on a 100 car 10,000 ton freight train? Also I have seen Allunimun Hoppers....So it is only a a matter of time before we have Allnimim Intermodal Flats.. Not fuel savings. With coal for every pound you remove from the tare weight of the vehicle it allows an extra pound of coal, given that railroads are limited by the axle load.Intermodal cars don't even come close to reaching the limit, and until they rais the maximum load of a comtainer to the point where aluminum cars become necessary they'll be made of goos old cheaper steel.
user="BuyCSXrailroadStock!"] Greenbrier and Gunderson are making Light Wieght Aluminum Coal Cars.... Must be a reason for this. The fuel savings on a 100 car 10,000 ton freight train? Also I have seen Allunimun Hoppers....So it is only a a matter of time before we have Allnimim Intermodal Flats..
Greenbrier and Gunderson are making Light Wieght Aluminum Coal Cars....
Must be a reason for this. The fuel savings on a 100 car 10,000 ton freight train?
Also I have seen Allunimun Hoppers....So it is only a a matter of time before we have Allnimim Intermodal Flats..
True. The weight savings that comes from using aluminum over steel in intermodal apps is focussed on the boxes/trailers themselves, since highway weight limits do affect the cargo vs tare equation.
Oh look, Michael and Tom and fighting again. I'm shocked.
Come on fellas, we're all adults here (for the most part, anyway). Can we try to behave in a civilized manner? Try not to nit-pick each other to death.
Bergie
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