Sunday, November 13, 2005

Do the math

One simple change to semi-trailers can reduce total fuel consumption of the rig by 10%. If we could save 10% of US diesel consumption, that would be approximately 277,000 barrels/day or 101 million barrels/year. This is just one simple change which could be retrofitted; it's only the beginning of possible improvements.

Oil production from Alaska averaged 908,000 bbl/day last year (down 55% from its 1988 peak of 2.02 million bbl/day). ANWR reserves are estimated at 6.4 billion barrels. In short, if we started trying to produce ANWR oil today and it first hit the pipeline in 2015, semi-truck boattails could have saved 1/6 of the total oil in the reserve before the first barrel got to a refinery (and probably at a much smaller cost). Improvements which cut consumption by 30% are likely both possible and inexpensive, and would save a full ANWR-worth in the next 20 years.

The US Senate has wisely removed ANWR drilling from the bill to cut the budget. If our Senators are wiser, they should also insert a provision over-riding state truck length limits for boat-tail extensions and other drag-reducing devices.

¶ 11/13/2005 11:24:00 PM

Comments:

Every time you post something like this I scratch my head and think, "Why haven't we been doing this all along?" A 10% decrease in transport expenses must look attractive to companies, even in good times.

# posted by

Ryos : 11/13/2005 11:43 PM

One reason this hasn't happened is state length restrictions on trucks. You could build a trailer with a boat-tail, but if it was a cargo area it would make it harder to load and unload and prevent anything above a certain size from being loaded through rear doors. An empty boat-tail would cut the cargo capacity of the trailer.

This sort of thing really needs federal action to override the patchwork of state regulations. Should I start writing sample letters to legislators?

# posted by

Engineer-Poet : 11/13/2005 11:59 PM

It's just a pity that it buggers up one of my favourite pieces of engineering, the Moffatt Mounty, a three-wheeled forklift that climbs onto the back of the truck using its forks and folds up, so whereever you roam, you have a fork lift to load and unload. Be hard to fit the thing on there with the boat tail.

# posted by

Alex : 11/14/2005 10:45 AM

Looks like the Moffet Mounty is aimed more at flatbeds than box trailers. Boxes tend to be loaded and unloaded at loading docks, which usually have their own fork trucks. Flatbeds don't have the square aft ends suitable for boat-tails anyway.

The Mounty isn't full-width past a certain height, so it looks like a fairing could still fit around the top sections; it just wouldn't be quite as
effective.

# posted by

Engineer-Poet : 11/14/2005 11:00 AM

Also, if the boat tail can be folded out of the way, which from the photo appears to be part of the design, then it shouldn't behave differently than a non-boat tailed trailer.

# posted by

Karl Hallowell : 11/14/2005 11:29 AM

"Should I start writing sample letters to legislators?"

Yes! You've got the numbers to do it. I'll sign it if you circulate an email or petition.

Parlty inspired by the math you've shown on your blog, I've been talking about the potential gains from efficiency in comparison to gains from drilling in ANWR at various blogs for the past few weeks. When you start to actually do the numbers, the claims that ANWR has anything to do with energy independence and not greater profits for Exxon is rediculous. We could do so much more with fuel efficiency improvements.

# posted by

Jesse Jenkins : 11/15/2005 6:05 PM

Okay, you've just given me some fodder for a whole new family of blog posts: fact lists for letters.

Every fact will come with a cite, of course.

# posted by

Engineer-Poet : 11/15/2005 10:49 PM

I wonder if the boat-tail would interfere with the stacking of trailers on railcars or on ships.

# posted by

David Foster : 11/16/2005 11:49 AM

If a boat-tail can fold back to allow normal access to a loading dock, stacking should be impaired slightly if at all.

Standard cargo containers probably wouldn't have boat-tails; those would be part of the trailer they ride on.

# posted by

Engineer-Poet : 11/16/2005 12:18 PM

I tend to go by a simple rule with ideas like this. Trucking firms know a lot more about these things than I do, and they're much more highly motivated than I am, therefore I assume that if they haven't done this, it doesn't pay.

But hey, write to big trucking firms. Let me suggest JB Hunt, Yellow Freight, and UPS.

# posted by

J Bowen : 11/28/2005 2:01 AM

Do the math

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