Wal-Mart aero-mods 1,000 of its 7,000 semi-trucks?

[trikkonceptz]

Originally Posted by Big Dave

A lot of what railroad carry today is indeed intermodal. Not much TOFC (trailer-on-flat-car) but rather COFC (container-on-flat-car). This combines the long-distance efficiency on the train with the door-to-door flexibilty of the truck.

Awesome history lesson ... also the reason TOFC is not as popular is because you can only fit 2 trailers on a flat car, whereas COFC can fit 4 containers, making it more efficient.

[Big Dave]

The box car is an endangered species. COFC is running it off the tracks. In the not-so-distant future all rail cars will be either containers or specialized bulk freight cars.

COFC could reduce long-haul truck traffic, but I think we're another innovation or two away in the truck-train or ship-train interface. There is still a lot of labor involved in the mode change.

Even better would be electrification of main lines. That way transportation could take advantage of coal or nuclear power and cut the importation of oil. This is within reach. The US has maybe 12,000 miles of mainline where most railroad fuel is used.

[jamesqf]

Originally Posted by Big Dave

Even better would be electrification of main lines. That way transportation could take advantage of coal or nuclear power and cut the importation of oil. This is within reach. The US has maybe 12,000 miles of mainline where most railroad fuel is used.

Could start seeing major benefits by electrifying a lot less track than that, too. Just do the mountain passes, where additional engines are used for the climb, as for instance the ~100 miles between Sacramento & Reno, with a climb (eastbound) from sea level to about 7000 ft, then a descent back down to 4500. Electrify that, do regenerative braking on the downhills, and fuel consumption (& emissions) plummet. Then you can extend the electric line into the Bay Area, making the air quality folks happy...

[aerohead]

Originally Posted by jamesqf

Somehow I doubt that military security was a major factor. I think you have to look more at management inertia & union featherbedding, which kept the railroads mired in early 20th century technology.

jamesqf,I value what you say and don't want to in any way discount what you've posted.My thought is that in light of "rescues"afforded other industries,the vitality of the railroads did not constitute a priority to the US Govt.,or things would have unfolded differently than they have.

[aerohead]

Originally Posted by Big Dave

The box car is an endangered species. COFC is running it off the tracks. In the not-so-distant future all rail cars will be either containers or specialized bulk freight cars.

COFC could reduce long-haul truck traffic, but I think we're another innovation or two away in the truck-train or ship-train interface. There is still a lot of labor involved in the mode change.

Even better would be electrification of main lines. That way transportation could take advantage of coal or nuclear power and cut the importation of oil. This is within reach. The US has maybe 12,000 miles of mainline where most railroad fuel is used.

Thanks Big Dave for the concise history.If you make it down to Texas,I owe you dinner or an omelette or something.------- The upkeep,maintenance,rationalization,and modernization of the R-R industry seems like a technological imperative,on all continents,if we want to maximize the potential for overland freight.-------- Perhaps,soon,we will tear down what barriers there are,which presently constrain optimization and figure out a symbiotic relationship where more people win.

[Big Dave]

Phil, we need to talk. I may have a window of opportunity to make the ultimate pickup truck bed. Not just a cap but the whole shootin' match, fenders and all. If I do it, I wanna shoot the whole clip at the problem.

[Unforgiven]

Originally Posted by tasdrouille

Super single tires are great. Considering rolling resistance at highway speed is almost equivalent as aero drag for a loaded semi, it makes a lot of sense to work on this aspect. Any reason why it's not common place? If they save >10% off you fuel costs they must pay for themselves relatively quickly.

Rolling resistance is not as claimed, and running super singles in snow is NOT fun at all. Add to the fact that chaining up a super single is a nightmare since a commercially available chain is not offered yet (at last dig) Finally, truckers tend to rely on the fact that if one tire goes out on the highway, they can still roll to a repair shop to get that replaced. With super singles, that option is out, increasing road call costs are basically making the super single not that attractive to the industry.

[Big Dave]

Mountain passes are the first places to electrify but by no means the only ones. Even here in pool-table-flat Indiana there is much benefit from using coal, nuclear, or maybe even wind for transportation and offsetting some petroleum.

You realize this technology could be made to work on the Interstate for Class 8 trucks. Hang catenaries on the right lane and bury a signal wire alongside the road. The truck runs on its diesel til he is fully into the electrified lane, then he raises his collector and runs on electricity from the catenary. Like the trains trucks would be massed at the top of hills and at the bottom to use regenerative braking. This technology is already used in some big copper mines to run ore haul trucks.

[aerohead]

Originally Posted by Big Dave

Phil, we need to talk. I may have a window of opportunity to make the ultimate pickup truck bed. Not just a cap but the whole shootin' match, fenders and all. If I do it, I wanna shoot the whole clip at the problem.

Big Dave,I'd be happy to share anything I've got.I began a mockup of a complete back for the Dodge pickup shortly before the T-100 showed up in my life.Plan taper begins right behind the cab,with the body narrowing towards the rear,just clearing the rear tires.The sides taper and also increase in tumble- home,rolling into the roofline as they progress rearwards.At the rear of the new"bed",the body section is a squashed semi-circle above the bed,and sidewalls/skirts drop below the bed to integrate with the bellypan.------------ There is just enough room for full sheets of plywood to slide in,and the "rails" are cubby-holed toolboxes running the full length of the bed on both sides,much like today's utility beds from Koenig,etc...---- As I was telling akashic,the rear of the bellypan forms a closet for the spare tire (no more getting down on the ground ).--------- Since the whole thing tapers,and grows in curvature,as following the perfect teardrop template,the wake is the bare minimum and there should be no vorticity,just random turbulence in the wake.--------------------- With fully skirted rear wheels I think this" box" configuration will offer the absolute lowest drag for a single add-on structure.---------------- I'm pretty jazzed about it every time I look at it.------------- I would would estimate a 32% drag reduction by itself without the bellypan.Won't know 'til completed.------------- Off the top of my head that's all I can think of.I think you'd really enjoy this sort of technology.I think it's the future.

[jamesqf]

Originally Posted by Big Dave

Mountain passes are the first places to electrify but by no means the only ones.

Sure. I was just thinking of mountain passes as the place to start, where you'd get most "bang for buck". Then maybe the next step would be short distances out of rail yards, so the trains could get up to speed on electric power. Then build out until you get complete runs done...

You realize this technology could be made to work on the Interstate for Class 8 trucks. Hang catenaries on the right lane...

And in cities, too. Where I lived in Europe, the city buses were mostly electric (except for some longer routes out to more suburban areas). Build it here, with some sort of cost-accounting method to allow delivery trucks to use the same system. You'd have some sort of hybrid, that'd charge off the catenary on main roads, then run on battery into neighborhoods...