# CSX, one ton of freight, 436 miles, one gallon of fuel. Huh? **URL:** \ **Category:** Factual Questions\ **Created:** [May 19, 2009, 12:20pm UTC](https://boards.straightdope.com/t/csx-one-ton-of-freight-436-miles-one-gallon-of-fuel-huh/496953 "2009-05-19T12:20:52Z")\ **Posts on this page:** 9\ **Page:** 2
**Author:** ![IAmNotSpartacus](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@IAmNotSpartacus](https://boards.straightdope.com/u/IAmNotSpartacus)\ **Post date:** [May 19, 2009, 8:29pm UTC](https://boards.straightdope.com/t/csx-one-ton-of-freight-436-miles-one-gallon-of-fuel-huh/496953/21 "2009-05-19T20:29:07Z")
> [@Xema](#): > > From your link: Yet you managed to leave out the rest of the paragraph, leaving it out of context. > [@](#): > > This method, however, dissipates all the energy as heat in the motor itself and so cannot be used in anything other than low-power intermittent applications due to cooling limitations. It is not suitable for traction applications. ---
**Author:** ![IAmNotSpartacus](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@IAmNotSpartacus](https://boards.straightdope.com/u/IAmNotSpartacus)\ **Post date:** [May 19, 2009, 8:31pm UTC](https://boards.straightdope.com/t/csx-one-ton-of-freight-436-miles-one-gallon-of-fuel-huh/496953/22 "2009-05-19T20:31:53Z")
> [@Xema](#): > > From your link: Yet you managed to leave out the rest of the paragraph, leaving it out of context. > [@](#): > > This method, however, dissipates all the energy as heat in the motor itself and so cannot be used in anything other than low-power intermittent applications due to cooling limitations. It is not suitable for traction applications. Edit: You also missed the part about blended braking, in conjunction with the air brakes on the train. From further on in the article: > [@](#): > > One locomotive manufacturer, EMD, estimates that dynamic braking provides between 50% to 70% of the braking force during blended braking. ---
**Author:** ![IAmNotSpartacus](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@IAmNotSpartacus](https://boards.straightdope.com/u/IAmNotSpartacus)\ **Post date:** [May 19, 2009, 8:35pm UTC](https://boards.straightdope.com/t/csx-one-ton-of-freight-436-miles-one-gallon-of-fuel-huh/496953/23 "2009-05-19T20:35:50Z")
However there are [switchers](http://www.railpower.com/products_hl_ggseries.html) which use resistive braking to power battery banks and also have on-board diesel generators that will power up the battery bank when the engine is idling. ---
**Author:** ![Markxxx](https://avatars.discourse-cdn.com/v4/letter/m/5daacb/32.png) [@Markxxx](https://boards.straightdope.com/u/Markxxx)\ **Post date:** [May 19, 2009, 9:07pm UTC](https://boards.straightdope.com/t/csx-one-ton-of-freight-436-miles-one-gallon-of-fuel-huh/496953/24 "2009-05-19T21:07:17Z")
The one mile is all downhill 🙂 ---
**Author:** ![Dag\_Otto](https://avatars.discourse-cdn.com/v4/letter/d/439d5e/32.png) [@Dag\_Otto](https://boards.straightdope.com/u/Dag_Otto)\ **Post date:** [May 19, 2009, 9:24pm UTC](https://boards.straightdope.com/t/csx-one-ton-of-freight-436-miles-one-gallon-of-fuel-huh/496953/25 "2009-05-19T21:24:51Z")
I’ve often wondered how effective this sort of public relation advertising is. Certainly, I don’t expect BNSF or Union Pacific to start advertising that they get 447 ton-miles per gallon (take that, CSX!), and I don’t think that CSX wants you to specify ‘Rail’ as the shipping option for your next Amazon order. Maybe they want you to forgive them the next time they derail in your town. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [May 19, 2009, 10:20pm UTC](https://boards.straightdope.com/t/csx-one-ton-of-freight-436-miles-one-gallon-of-fuel-huh/496953/26 "2009-05-19T22:20:11Z")
> [@IAmNotSpartacus](#): > > Yet you managed to leave out the rest of the paragraph, leaving it out of context. > “This method, however, dissipates all the energy as heat in the motor itself and so cannot be used in anything other than low-power intermittent applications due to cooling limitations. It is not suitable for traction applications.” This is a very strange post. You state correctly that I didn’t quote the entire paragraph. But it is not correct that this takes what I quoted out of context. You then appear to supply what I omitted - but what you supply is from another paragraph, and is _definitely_ taken out of context. The post that started this was your response to JoeFF, in which you dispute his contention that big freight trains employ electro-resistive braking - you argue that what’s used is dynamic braking. Now let’s have the full paragraphs - first mine, with what I quoted in bold: > [@](#): > > **Dynamic braking is the use of the electric traction motors of a railroad vehicle as generators when slowing the vehicle. It is termed rheostatic if the generated electrical power is dissipated as heat in brake grid resistors** and regenerative if the power is returned to the supply line. Dynamic braking lowers the wear of friction braking components and additionally regeneration can also lower energy consumption. Note how this makes clear that dynamic braking includes what JoeFF was saying is used. And how regenerative braking isn’t germane. Next your paragraph, with your quote in bold: > [@](#): > > For permanent magnet motors, dynamic braking is easily achieved by shorting the motor terminals, thus bringing the motor to a fast abrupt stop. **This method, however, dissipates all the energy as heat in the motor itself and so cannot be used in anything other than low-power intermittent applications due to cooling limitations. It is not suitable for traction applications.** Note how this makes it clear it isn’t what JoeFF was talking about: dissipating heat in separate, fan-cooled resistors. > [@](#): > > You also missed the part about blended braking, in conjunction with the air brakes on the train. I didn’t miss it - I simply didn’t find it relevant to the point I was making. ---
**Author:** ![Driver8](https://avatars.discourse-cdn.com/v4/letter/d/b5a626/32.png) [@Driver8](https://boards.straightdope.com/u/Driver8)\ **Post date:** [May 19, 2009, 10:58pm UTC](https://boards.straightdope.com/t/csx-one-ton-of-freight-436-miles-one-gallon-of-fuel-huh/496953/27 "2009-05-19T22:58:46Z")
> [@Dag\_Otto](#): > > I’ve often wondered how effective this sort of public relation advertising is. Certainly, I don’t expect BNSF or Union Pacific to start advertising that they get 447 ton-miles per gallon (take that, CSX!), and I don’t think that CSX wants you to specify ‘Rail’ as the shipping option for your next Amazon order. > > Maybe they want you to forgive them the next time they derail in your town. I guess people making the decisions at large companies that have to ship tons of stuff watch TV and listen to the radio too! 🙂 Actually, I’ve always understood this sort of PR exercise to be of an indirect influential style. Sure, 99.9% of the people seeing your advertising aren’t going to directly use your services, but it may be helpful when lobbying a representative to be able to point out that 80% of their constituents think you are totally awesome. It is like when Boeing advertises their new 777: it isn’t like I whip out my credit card and buy one, but if Boeing can point out to American Airways that the public associates their plane with comfort and luxury it must influence purchasing decisions … ---
**Author:** ![troub](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/troub/32/14802_2.png) [@troub](https://boards.straightdope.com/u/troub)\ **Post date:** [May 20, 2009, 12:38am UTC](https://boards.straightdope.com/t/csx-one-ton-of-freight-436-miles-one-gallon-of-fuel-huh/496953/28 "2009-05-20T00:38:20Z")
And to add to **Driver8** ’s post, there’s a reason you only see these ads on NPR and during Meet the Press, Face the Nation, etc. Investors. While I certainly don’t have any use for calling up CSX and buying the services of a railcar, I might think “Why, that’s a business that’s going to be more in demand due to high fuel prices, etc… I think I’ll add them to my portfolio.” Same thing with all the ads for ADM, BASF, Boeing, etc. Investors. Also, I find the dynamic braking subthread here bizarre as well. **Joe Frickin Friday** had it basically right–electric locos and cars can perform regen. braking, and diesel-electrics (your typical freight “diesel” locomotive) just applies a resistive load across the traction motors and dissipates the heat through the resistor bank (with large fans) on top of the locomotive. “Shorting” the motor is not relevant at all. My understanding (from simulation and light railfanning/modelling) is that dynamic braking is most often used either to assist air braking or to maintain control (keep from accelerating too much) on long grades where heat buildup from friction braking (the air brakes on the cars) is a concern. Primarily midwestern railroads like the Illinois Central tended to have relatively few locomotives outfitted with dynamic brakes because of the flat terrain. ---
**Author:** ![Category5](https://avatars.discourse-cdn.com/v4/letter/c/85f322/32.png) [@Category5](https://boards.straightdope.com/u/Category5)\ **Post date:** [May 20, 2009, 1:35am UTC](https://boards.straightdope.com/t/csx-one-ton-of-freight-436-miles-one-gallon-of-fuel-huh/496953/29 "2009-05-20T01:35:58Z")
I think they are also trying to create some kind of greener-than-thou image to get mileage in Washington DC and the press corps. [Previous page](https://boards.straightdope.com/t/csx-one-ton-of-freight-436-miles-one-gallon-of-fuel-huh/496953.md?page=1)