Buslist BaltACD jeffhergert Met one last night and it seemed like the next platform behind the wedge was a single container, then a few double stacks. Behind them were a short mix of double and singles, then the remainder of the train were doubles. The other day it was windy and I had an empty coal hopper train. Speed would pick up about 5 mph when going through towns or other areas where trees and vegetation would block the wind. Once back out in the open going by farm fields, speed would drop off about 5 mph. Not unusual during periods when the winds are blowing hard. Jeff Can understand wind resistance with empty hoppers - any noticable wind resistance with a loaded coal train? There was some work in the late 80s with air foils on the ends and cross braces of hopper cars after it was noticed that it took more fuel to get the empty train back to the PRB than to get the loaded one out of there. Much of the work was done by BN, some in a wind tunnel in Georgia (Lockhead?) under the direction of Steve Ditmeyer. He then turned his attention to Aries and Rockwell.
BaltACD jeffhergert Met one last night and it seemed like the next platform behind the wedge was a single container, then a few double stacks. Behind them were a short mix of double and singles, then the remainder of the train were doubles. The other day it was windy and I had an empty coal hopper train. Speed would pick up about 5 mph when going through towns or other areas where trees and vegetation would block the wind. Once back out in the open going by farm fields, speed would drop off about 5 mph. Not unusual during periods when the winds are blowing hard. Jeff Can understand wind resistance with empty hoppers - any noticable wind resistance with a loaded coal train?
jeffhergert Met one last night and it seemed like the next platform behind the wedge was a single container, then a few double stacks. Behind them were a short mix of double and singles, then the remainder of the train were doubles. The other day it was windy and I had an empty coal hopper train. Speed would pick up about 5 mph when going through towns or other areas where trees and vegetation would block the wind. Once back out in the open going by farm fields, speed would drop off about 5 mph. Not unusual during periods when the winds are blowing hard. Jeff
The other day it was windy and I had an empty coal hopper train. Speed would pick up about 5 mph when going through towns or other areas where trees and vegetation would block the wind. Once back out in the open going by farm fields, speed would drop off about 5 mph. Not unusual during periods when the winds are blowing hard.
Jeff
Can understand wind resistance with empty hoppers - any noticable wind resistance with a loaded coal train?
There was some work in the late 80s with air foils on the ends and cross braces of hopper cars after it was noticed that it took more fuel to get the empty train back to the PRB than to get the loaded one out of there. Much of the work was done by BN, some in a wind tunnel in Georgia (Lockhead?) under the direction of Steve Ditmeyer. He then turned his attention to Aries and Rockwell.
Has anyone ever tried anything similar with centrebeam or bulkhead flatcars? CN runs a daily train composed entirely of empty centrebeams from Chicago to Prince George, BC, and it behaves in a similar fashion. Won't ever hit track speed, even going downhill in throttle 8. The harder you pull, the harder that train pulls back.
Crews call those cars "sailboats".
Greetings from Alberta
-an Articulate Malcontent
samfp1943 cx500 For aerodynamics, it isn't just the train speed. It may only be doing 40mph but if facing a 30mph headwind across the plains the effective wind force is 70mph. But am among the skeptics as far as the arrowwedge is concerned. As another thought some containers (perhaps older ones?) have corrugated sides instead of smooth. They probably add a tiny bit of turbulence and wind resistance to the train. Of course, like the wedge, the difference is most likely almost immeasurable. John It seemed sort of unusual to see locomotive mounted Anemometers, at the time.
cx500 For aerodynamics, it isn't just the train speed. It may only be doing 40mph but if facing a 30mph headwind across the plains the effective wind force is 70mph. But am among the skeptics as far as the arrowwedge is concerned. As another thought some containers (perhaps older ones?) have corrugated sides instead of smooth. They probably add a tiny bit of turbulence and wind resistance to the train. Of course, like the wedge, the difference is most likely almost immeasurable. John
For aerodynamics, it isn't just the train speed. It may only be doing 40mph but if facing a 30mph headwind across the plains the effective wind force is 70mph. But am among the skeptics as far as the arrowwedge is concerned.
As another thought some containers (perhaps older ones?) have corrugated sides instead of smooth. They probably add a tiny bit of turbulence and wind resistance to the train. Of course, like the wedge, the difference is most likely almost immeasurable.
John
It seemed sort of unusual to see locomotive mounted Anemometers, at the time.
I have read a Taiwanense professor's PhD thesis at Uof Illinois and AAR (funded by BNSF and CN), stating that the combined aerodyanimc drag increases linearly proportional to Container Gap Size, from 1 foot and saturates at ~12 feet. After 12 feets, the Drag starts all over again like a FIRST Frontal Drag. I also read somewhere(youtube or somewhere?) that Mike Iden of Union Pacifioc complains that the 3/5 articulated container wagons have a Gap of ~11 feet. I do not know the sizes of Independent Car/Wagon. I think they are ~20 to 25 feet length.. I think the aerodynamic drag are pretty much independent each other. Not sure much paltooning works here...
rossihttps://www.youtube.com/watch?v=OPNmJ23WhsI It is stupid as quoted. Missed a container right after Arrowedge. It does NOT help in any Wind Resistance Reduction, but add another more frontal impact resistance and trail-side Vacuum/Wake resistances..
It is stupid as quoted. Missed a container right after Arrowedge. It does NOT help in any Wind Resistance Reduction, but add another more frontal impact resistance and trail-side Vacuum/Wake resistances..
For a number of years I towed my race car behind a 1984 Dodge Daytona Turbo with a small enclosed trailer - mostly in the Mid-Atlantic, Florida and in between.
I could feel and use the 'draft' from big rigs from 80-100 feet behind. Fuel mileage on the Daytona would increase about 3 MPH when I was patient enough to follow the trucks for a period of time.
Just because there is an open box space behind the Aeroedge doesn't mean that all it's benefits are lost.
Never too old to have a happy childhood!
https://www.youtube.com/watch?v=OPNmJ23WhsI
desertdog CandOforprogress2 From my personal experance from a number of years ago ridiing a boxcar with the doors open tends to shake the boxcar at certain speeds Back in the boxcar era, I recall there was a short-lived effort by one of the Class-1s (I forget which) to close boxcar doors in order to lower wind resistance. John Timm
CandOforprogress2 From my personal experance from a number of years ago ridiing a boxcar with the doors open tends to shake the boxcar at certain speeds
From my personal experance from a number of years ago ridiing a boxcar with the doors open tends to shake the boxcar at certain speeds
Back in the boxcar era, I recall there was a short-lived effort by one of the Class-1s (I forget which) to close boxcar doors in order to lower wind resistance.
John Timm
Rules on CSX, for the past several decades have required car doors to be closed. Not because of wind resistance but because of safety issues that a falling door can present.
jeffhergertMet one last night and it seemed like the next platform behind the wedge was a single container, then a few double stacks. Behind them were a short mix of double and singles, then the remainder of the train were doubles. The other day it was windy and I had an empty coal hopper train. Speed would pick up about 5 mph when going through towns or other areas where trees and vegetation would block the wind. Once back out in the open going by farm fields, speed would drop off about 5 mph. Not unusual during periods when the winds are blowing hard. Jeff
Met one last night and it seemed like the next platform behind the wedge was a single container, then a few double stacks. Behind them were a short mix of double and singles, then the remainder of the train were doubles.
Wind resistance is a function of velocity squared so at 20 mph is is four time that at 10 mph and it gets worse the faster the vehicle is moving.
jtm
schlimm Public relations is of some importance but is UP likely to spend its resources, etc. on a "feel good" exercise with little hope of improved efficiency and some savings?
Public relations is of some importance but is UP likely to spend its resources, etc. on a "feel good" exercise with little hope of improved efficiency and some savings?
this is the pet project of a proven innovator at UP (he claims to have developed --with NRE -- the gen set for example). Look for continued tinkering till his funds run out.
http://www.up.com/aboutup/community/inside_track/arrowedge-redesign-04-27-2016.htm
Not sure what all the expermental 'evolutions' UPRR went through to achieve the building of the Arrowsedge for real world testing?
About the time the new ROW was opened in Abo Canyon, the website "friends of bnsf.com" had some photos of the installation of anemometers on some engines, to run tests; but the photos had no further explanations of 'the why' or ' the what' they were looking for? It seemed sort of unusual to see locomotive mounted Anemometers, at the time.
C&NW, CA&E, MILW, CGW and IC fan
"Tweaking" the C-17
http://www.aerotechnews.com/blog/2016/04/01/c-17-drag-reduction-testing-aims-at-saving-fuel/
Proof would be comparative fuel use on equivalent trains over the same route; one with the Arrowedge and one without.
My gut feeling is that fuel used differences would not be statistically signifigant and probably not repeatable.
BaltACD RME BaltACD Current F1 aerodynamic nose design I suspect that what you have there is an adaptation of wing slots/slats to control downforce and shape airflow around the required suspension and steering elements. Doing active aerodynamic flow shaping via airfoil elements is a different thing from just blunt streamlining. F1 aerodynamics have 3 purposes - maximize down force, minimize drag and create the most turbulent air possible behind the car. Personally, I doubt UP's aero device is worth what it costs to construct it as well as the container space it occupies. I hope UP has factual data to support their position and it would be informative if they would make it public. To my mind the overall aerodynamics of a 10K to 20K foot intermodal train mitigate any benefits of a device at the lead of the train, since rarely are trains fully double stacked with 53 foot boxes so as to minimize the distance between boxes throughout the train.
RME BaltACD Current F1 aerodynamic nose design I suspect that what you have there is an adaptation of wing slots/slats to control downforce and shape airflow around the required suspension and steering elements. Doing active aerodynamic flow shaping via airfoil elements is a different thing from just blunt streamlining.
BaltACD Current F1 aerodynamic nose design I suspect that what you have there is an adaptation of wing slots/slats to control downforce and shape airflow around the required suspension and steering elements. Doing active aerodynamic flow shaping via airfoil elements is a different thing from just blunt streamlining.
I suspect that what you have there is an adaptation of wing slots/slats to control downforce and shape airflow around the required suspension and steering elements. Doing active aerodynamic flow shaping via airfoil elements is a different thing from just blunt streamlining.
F1 aerodynamics have 3 purposes - maximize down force, minimize drag and create the most turbulent air possible behind the car.
Personally, I doubt UP's aero device is worth what it costs to construct it as well as the container space it occupies. I hope UP has factual data to support their position and it would be informative if they would make it public. To my mind the overall aerodynamics of a 10K to 20K foot intermodal train mitigate any benefits of a device at the lead of the train, since rarely are trains fully double stacked with 53 foot boxes so as to minimize the distance between boxes throughout the train.
This purely a personal observation; and a question. The conversations in this Thread all seems to revolve around various components of 'drag' as relates to container stacker trains, and racing cars.
The one thing that seems to be missing is how all this will effect the economies of a stacker train as it goes across the railroad. What kind of transit speed will a stack train have to maintain to gain the economies of a 'streamlining system' acroos the railroad?
No one seems to have mentioned the speed element in the effectiveness of attempting to 'streamline' (?) the profile of a stacker, or would one have to put an Arrowedge device in eack singled container stack position?
I have been watching some of the stackers around here (both East and Westbounds. The faster ones seem to be at track speed of about 45 to 50 mph(at my guess). I am just guessing, No benefits at thoise speeds, but at what speed would the railroad get a positive return for the efforts and expenses of 'streamling the air flow, on the trains. I would think that the train would have to maintain a speed in excess of 50 mph for quite a distance to make the effort pay back to the railroad?
The distance between container stacks on a solid move of domestic 53' containers seems to be something less than 10' (?). While a solid stacker of export cans (mixes of 40' and 45'ers) looks to be closer to 15 '+ between the stacks(?)
[I have not measured those distances, but I think my guesses are fairly close?]
I would tend to agree with other Posters that say the UP's 'Arrowedge' device may provide interesting data; If, they do not test another bridge( height over track) with another one. The expenses whole project seems to be one, to garner some 'feel good' publicity, while getting their photo published; the whole effort aimed at making someone 'feel good' while making a show at being 'green'? .
Murphy Siding BaltACD F1 aerodynamics have 3 purposes - maximize down force, minimize drag and create the most turbulent air possible behind the car. Create turbulent air behind the car? Is that to mess with the guy racing behind?
BaltACD F1 aerodynamics have 3 purposes - maximize down force, minimize drag and create the most turbulent air possible behind the car.
Create turbulent air behind the car? Is that to mess with the guy racing behind?
You've got it. Make the area behind the car so turbulent that the front wing of the following car loses its effective downforce. Keeping a following car far enough back that an effective overtaking manouver cannot be mounted.
F1 rules makers to combat this have implemented DRS (Drag Reduction System) where an element of the rear wing can be opened, reducing drag from the rear wing, and permitting a following car to attain a 10 to 12 MPH faster speed on the segment of track where DRS is implemented. The following car must be within 1 second of the lead car at specified detection points for DRS to be activated on specific straights. This applies to all cars in the field and their relation to each other. The lead car cannot open that rear wing segment, while those within 1 second of the preceeding car can.
Thanks to Chris / CopCarSS for my avatar.
Is that Quantum Physics ?
Y6bs evergreen in my mind
Balt,
Maybe it has more value as a P/R stunt for UP with the "huggers" of the world.
BaltACDCurrent F1 aerodynamic nose design
Current F1 aerodymanic nose design
tree68Aerodynamics can get really complicated. Witness the not-entirely-scientific study done by "Mythbusters" regarding driving a pick-up with the tailgate open or closed.
Yes, and even more interesting was the situation with the 'aerodynamic' tailgates with mesh, holes, or slats advertised as having 'lower air resistance' than solid ones. Those produced almost epic levels of turbulence and associated drag, while relieving some of the circulation and pressure rise that create the high-pressure volume and circulation patterns that actually streamline the airflow past the bed area.
Another interesting observation is the high pressure that builds up in the windshield root area of conventional automobiles... the thing exploited by cowl-induction systems, which seem counterproductive when first examined using 'folk aerodynamics'.
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