> -----Original Message----- > From: piclist-bounces@mit.edu > [mailto:piclist-bounces@mit.edu] On Behalf Of James Newton, Host > Sent: Monday, December 18, 2006 6:13 PM > To: 'Microcontroller discussion list - Public.' > Subject: RE: [EE]:: Bimota centre hub steering > > > Not currently in the US, it isn't. Automotive diesels in > the US are > > dirty, and heavy/industrial diesels are unbelievably dirty. > So dirty > > that you can't put enough people on a bus or a commuter > train to make > > them pollution competitive to all of those people driving a single > > passenger Suburban. > > I would very much like to see any study or figures that backs > up that statement. You can start here: http://www.epa.gov/otaq/crttst.htm That's the OTAQ WWW page I referred to previously. There are links to 2007 and previous year certification data in tab delimited format. The file is straightforward, although you may have to do some reading to understand the acronyms they use. That file makes it easy to compare cars and trucks. Heavy duty diesels are different. These engines are rated on one or more SAE schedules that contain various load points (ie idle, max torque, max power, etc.). These load points are combined together to obtain a single rating in grams/hp-hr for the various pollutants. The schedule is chosen to mimic the expected use of the engine. A stationary generator would use a schedule of something like 90% full throttle max power and 10% idle. An engine for a bus would use something like 30% idle, 30% full throttle, 40% part throttle, etc. So a diesel engine rated at 4 grams/hp-hr would take some massaging to turn it into grams/mile, how cars are rated. You can find the heavy duty diesel certifications here: http://www.epa.gov/otaq/certdata.htm. To use this you'll have to get the certification ID number off the diesel engine in question. Then look that up in the certification data to find the pollution. Here's an article I wrote about buses: http://www.lewrockwell.com/orig6/ravet1.html And here's something I wrote about trains: ------------------------------------------------------ It's difficult to form a detailed opposition to the rail plan because Capital Metro hasn't released any details. But, the EPA has emissions requirements for trains starting in 2007 that can be used as a starting point. The Colorado Railcar company has a DMU that will meet these EPA requirements now. You can find their brochure here: http://www.coloradorailcar.com/dmubro.pdf Page 21 compares the railcar NOx emissions to the federal standard. It emits 4.1 grams of NOx per horsepower-hour (bhp-hr). That's really dirty, it takes a lot of passengers to get that to an acceptable level per passenger mile. The following numbers are a _best_case_ example for the railcar here in Austin: 1) each train is 1 bi-level DMU plus 2 bi-level coaches, completely full with 550 passengers. 2) Since the route is fairly level, the train averages 800 bhp (of the available 1200 bhp) over the trip 3) The route is 32 miles, and takes an hour (per Capital Metro). This scenario of full trains would result in 6600 passenger trips per day. Capital Metro is only predicting 2000 passenger trips per day. With that we have: 4.1 g | 800 bhp | 1 hr ------------------------------------ 1 bhp-hr | 32 mi | 550 passengers Multiplying that out and cancelling units gives .186 grams of NOx per passenger mile. Compare this to 2005 model year emissions data from the EPA: Toyota Prius: .01 grams/mile Honda Accord: .03 grams/mile Dodge Caravan: .08 grams/mile Dodge Viper: .1 grams/mile Chevy Corvette: .1 grams/mile Chevy K1500 4WD Suburban: .15 grams/mile Chevy H2 .75 grams/mile These numbers can be found here: http://www.epa.gov/otaq/crttst.htm The result of this analysis is that Central Texas would be better off pollution-wise if Cap Metro just bought each of their initial 1000 riders a Suburban and scrapped the train. 1000 Suburbans would only cost about $35M, less than half of what Cap Metro will spend on the train. A more likely scenario is that each train is a single DMU with a coach, at something less than capacity. This more typical scenario gives an NOx number of .83g/passenger mile. This is terrible, more pollution than the H2 Hummer. And it will only get worse as Capital Metro adds spurs. It also doesn't include the increased car pollution caused by cars waiting for the train to pass, or waiting for the circulator busses which will be able to pre-empt lights at intersections. --------------------------------- If you've gotten this far I'll just add one more thing, for 2006 Chevrolet recertified the Hummer so that it's now comparable to the Suburban and other light duty trucks. --steve -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist