I’m always for energy saving ideas when they payback the effort. Here’s one that would be an advantage for our long haul American Interstate trucking companies. This semi has both side wings and a boat tail to decrease wind drag.
It is pretty simple really:
‘Boat tail’ decreases fuel consumption for trucks by 7.5 percent
From a Delft Technical University press release
A boat tail, a tapering protrusion mounted on the rear of a truck, leads to fuel savings of 7.5 percent. This is due to dramatically-improved aerodynamics, as shown by road tests conducted by the PART (Platform for Aerodynamic Road Transport) public-private partnership platform.
Here are the other places wind resistance on a semi-truck can be addressed for fuel savings:
Public highways
A boat tail is a tapering protrusion about two metres in length mounted on the rear of a truck. The boat tail had already proved itself during wind tunnel experiments and computer simulations, both conducted at TU Delft, in theory and using small-scale models. Now an articulated lorry fitted with a boat tail has also undergone extensive testing on public highways.
Emissions
An articulated lorry was driven for a period of one year with a boat tail (of varying length) and one year without a boat tail. The improved aerodynamics, depending on the length of the boat tail, resulted in reduced fuel consumption (and emissions!) of up to 7.5 percent. The optimum boat tail length proved to be two metres.
PART
The tests were conducted by PART. This is a platform in which academics, road transport manufacturers, transport companies and shippers work together. The platform aims to reduce fuel consumption in the road transport industry by improving aerodynamics. PARTs ambition is to achieve a 20 percent reduction in fuel consumption and CO2 emissions in the road transport industry by 2020. TU Delft acts as secretary of PART. PART has previously conducted road tests on a new generation of aerodynamic sideskirts, which are to make their commercial debut later this year.
More information
More on PART: www.part20.eu
More about the side wings: www.ephicas.eu
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damn, damn, damn, damn! There goes my free fuel ride down the interstate!
Dang! I could have thought of that! Oh well, it’s not the time to be concerned about money with the banking cartel and other dragons to slay. Now about that Princess …
If they would use the railways more efficiently and just use local distribution from the railway system, they would not only make the whole moving of good more efficient but also make the highways safer. The big rigs are a real mortal danger to us little car drivers.
Drafting improves mileage quite a bit. Who knows, maybe this will make it even better 🙂
Pamela,
I was thinking the same thing, except I don’t have the (insert body part here) to drive that close to a simi. I want to die in bed – or anywhere else besides on the highway. I’m with Anthony, discoveries like this can save fuel, dollars, and lots of bad stuff from going into the air (soot, CO, the terrible GHG H2O, nitrogen compounds and so on) Work like magic, cost very little to install, and have a return on investment that is tangible.
What a concept.
Mike
These are also impractical and add weight to the vehicle. The truck driver must stop, remove the boat tail, then back into the loading dock. After leaving the loading dock, the boat tail must then be re-installed. Each operation requires time, and time is money to a trucking company.
There are also overall length limitations in the U.S. – the aerodynamic improvement device cannot extend more than 5 feet beyond the trailer. (23 CFR 658.16(b)(6)) Those that are 2 meters are just a bit too long.
I see that everyone else beat me to the “drafting” issue. Ray (21:05:29) : is also partly correct about rail…. back in the 60’s I was a railroader and my favorite job assignments were to freight or switching (I also worked the commuter runs from Stamford to NYC and decided I HATED commuters)… but building a spur to a factory is expensive and trucking allowed you to build your factory/warehouse/distribution site anywhere the land values and taxes were cheaper. The completion of the Interstate System in the 70’s drove the last nail into heavy-rail freight. Pity.
Ray (21:05:29) :
If they would use the railways more efficiently and just use local distribution from the railway system, they would not only make the whole moving of good more efficient but also make the highways safer. The big rigs are a real mortal danger to us little car drivers.
This also would have the added benefit of putting all interstate shipping in the hands of the unions.
By the way, most rail lines which are government subsidized lose about $35 per passenger.
I’m with Ray. Railways for heavy goods. Trains can be made very aerodynamic too, especially with top & side sheets between the cars.
Aerodynamics tends to ruin slipstreaming, (draughting/drafting).
DaveE.
The stickers plus the box total 28.7% gas savings. Sounds too good to be true. Notice the “up to” that has been left out in the first three paragraphs, then slipped in towards the end as an afterthought. My BS detector has gone nuts.
It would reduce the efficiency of drafting behind a big rig…….but probably only very slightly. This sort of addition to big rigs will be difficult to implement in practice…..there are very very strict length limitations for the various types of axle combinations in North America. Also, a huge part of trucking in general is to be able to easily back up to a loading dock, quicklly & repeatedly throughout a typical day.
This modification would appear to impede that somewhat & it would have to be detachable, which is further inconvenience drivers don’t need or want. If you actually built it into the shape of the trailer the rear doors would be too small to be functional. It’s a tough design problem.
They could put a screen back in there and project “An Inconvenient Truth” in an endless cycle. You know, to educate the driving public. Just and idea.
This is why I like this site – there’s always something interesting going up.
Ray said:
“If they would use the railways more efficiently and just use local distribution from the railway system, they would not only make the whole moving of good more efficient but also make the highways safer. The big rigs are a real mortal danger to us little car drivers.”
If it were cheaper to move goods as you say, then the distribution companies would do so. One can’t just second-guess hundreds and thousands of folks whose livelihood in on the line.
Regarding the trucks being a danger . . . well, that’s why I like larger cars.
Craig
You could do much the same with a canvas boat tail that would self-inflate with speed, and wouldn’t damage anyone who rear ended it.
Those small spoiler wings that station wagons use to keep the dust off the rear window would reduce drag, too, though not as much as a full boat tail.
Why is this a good idea? Because it saves money.
The B-triple road trains in Australia always fascinated me. I guess those must be highly efficient. One tractor pulling 3 loads.
http://static.panoramio.com/photos/original/16126974.jpg
Imagine that rig in snow, ice, side winds, or getting max cargo under the length regulations. I’ve got a half million miles long haul driving and I can tell you that rig is a looser.
This is old news. I remember reading about a rubberized fabric boat tail inflated by the tractor air system when the rig was on the road.
All of these have the same problem. State law sets limits on maximum rig length. Adding a 2 meter boat tail under current laws requires eliminatig 2 meters of trailer. The loss in cargo capacity costs more than the fuel saved,
Look at this 29-trailer road train!!!
http://outbacktowing.tripod.com/sitebuildercontent/sitebuilderpictures/29_rt2.jpg
Oh I can just see it now. The boattails will be getting ripped off while maneuvering at truck stops, shippers and receivers and rest areas. Likely many front tractor hoods will taken off as well. Can you see one of those things trying to turn hard in a Wal~Mart parking lot and taking the top half of your vehicle off. Its just nuts, and the fairings are as well… try putting snow chains on one of those puppies with all those fairings and stuff. Now a good engine design and gearing on a truck with good nose configuration can meet or likely exceed the efficiency without all the bodywork in the shop.
Freight rates regulated to where companies can afford to install new air filters, more frequent oil changes, new tires, (not recaps) and improved maintenance & inspection would do far more to reduce fuel usage than this silly idea.
The other advantage of railways is lower rolling resistance, though with modern high pressure tyres, (tires), I’m not sure how much of an advantage this would be.
Perhaps an efficient rail network isn’t practicable in a country as large as the U.S.A. whereas in the U.K., it’s just not practiced 😉
DaveE.
Oh I can just see it now. The boat tails will be getting ripped off while maneuvering at truck stops, shippers and receivers and rest areas. Likely many front tractor hoods will taken off as well. Can you see one of those things trying to turn hard in a Wal~Mart parking lot and taking the top half of your vehicle off. Its just nuts, and the fairings are as well… try putting snow chains on one of those puppies with all those fairings and stuff. Now a good engine design and gearing on a truck with good nose configuration can meet or likely exceed the efficiency without all the bodywork in the shop.
Freight rates regulated to where companies can afford to install new air filters, more frequent oil changes, new tires, (not recaps) and improved maintenance & inspection would do far more to reduce fuel usage than this silly idea.
Do you folks have any idea how much freight is moved in this country? If railroads could move it all, believe me they would be doing it. But rail is lacking in capacity and slow… manufacturing and retail/wholesale demands ‘just in time’ delivery for the most part, so that they do not have the expenditure of vast warehouse storage. Fresh fruits and vegetables as well as most meats cannot take a long time to move from point A to point B.
Even if rail had the capacity you will still see the same numbers of trucks, they just won’t be doing the long haul. Go check out how many warehouses have rail docks yet get the majority of product through the truck docks. There is a reason for this… just in time, triple screamer hot loads. Companies often do a poor job of ordering product because they run down-sized on staff and fail to spot shortages effectively.
Doug (22:10:11) :
A few years back, I was hitch hiking & got a lift in a 40 ton curtain side from Kings Lynn in Norfolk, (U.K), East Anglia is flat & largely below sea level. Winds were gusting to 70 – 80mph & the lorry only had 4 tons on board.
It was an exciting ride LOL
DaveE.
Ray (21:05:29) :
Which is why George Soros put his money in the railroad. He knows where the top efficiency in land transportation lies.
DaveE (22:17:11) :
Oh, but rail is very practicable in the US, especially given the distances involved.
Before the advent of cheap fuel, rail was already king of overland efficiency.
Now that cheap fuel is fast becoming a distant memory, rail is commanding attention.