The brazilian meter gauge BB+BB diesels

Pedro Rezende Dec 21, 2005

  1. Flash Blackman

    Flash Blackman Staff Member TrainBoard Supporter

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    Darren: Thanks. Pedro's album is just wonderful! We are going to see some really great pictures here! [​IMG]
     
  2. Stourbridge Lion

    Stourbridge Lion TrainBoard Supporter

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    His site is now listed on the RailSeek.com - Newest Additions found on the Bottom of the TrainBoard pages as it is now listed within RailSeek.com

    [​IMG] [​IMG] [​IMG] [​IMG] [​IMG]
     
  3. William Cowie

    William Cowie TrainBoard Member

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    Maybe I missed it, but has anyone explained what the logic would be to get BB + BB trucks? Is it to run on lighter rail? Get more traction?
     
  4. Gats

    Gats Staff Member TrainBoard Supporter

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    Combination of both, William. Since it's running 3' 6" the weight of the rail will probably be less than that used on heavy duty standard gauge so the axle load it can handle would be less as well. By increasing the number of axles bearing the load the axle loading is less per axle than with a three axle truck.
    With four axles you would expect an increase in traction of 33% (over an equivalent three-axle truck) using the same diameter wheels but the reduced wheel diameter used would reduce that gain a little.
    Using a BB truck arrangement also gives greater flexibility assuming using three pivot points (one bolster-body and two bolster-truck points), as opposed to a solid D truck with one pivot point, reducing the rail and flange wear.
     
  5. Mark4

    Mark4 TrainBoard Member

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    US locomotives are typically set up for about a 30 ton axle load. This is determined by the track, bridges etc. By spreading the same weight (more or less) over 8 axles rather than 6 the axle load drops to 22.5 tons and this is more typical railways outside North America.

    The 2 extra traction motors won't add anything to the maximum tractive effort if the weight of the locomotive is not increased (so i can't really agree with you on that one Gary!). They should, however, be relatively unstressed and cool-running. A good wheelslip-control system would be important in locos like this.

    I am guessing that the smaller wheels are to keep the overall height of the loco within limits.

    Narrow gauge loco design has always been more of a challenge for loco builders than the standard gauge equivalents. Generally it is not the track gauge that is the big issue - it's the lower permissable axle load and the loading gauge; the profile through which the loco must fit. To keep the weight down EMD and GE export models typically offer lighter frames, smaller fuel tanks and turbo-charged 12 cylinder engines rather than 16. On 3'6" and meter gauge systems C truck road locos have been the rule for decades. With lower permissable axle loads and power in excess of 3000 hp wheelslip control becomes a big issue for mountain operation.
     
  6. Pedro Rezende

    Pedro Rezende TrainBoard Member

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  7. Pedro Rezende

    Pedro Rezende TrainBoard Member

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  8. Flash Blackman

    Flash Blackman Staff Member TrainBoard Supporter

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    That got it! What a beautiful shot!! [​IMG]

    You know, I think that track in the foreground is dual guage??
     
  9. Pedro Rezende

    Pedro Rezende TrainBoard Member

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  10. Pedro Rezende

    Pedro Rezende TrainBoard Member

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    Yes, most of lines here are dual gauge: 1,600 and 1,000 mm.
    Please, tell me why these links are differents: The firts one was post by a friend of us. I copied the same pictures and tried to post it again, but I couldnĀ“t. Why his link has that %5c before the road numbers? the link I copy appears just the _ between them.

    pictures%5C3812%5C746%201203_3313_eldorado_12jun2005.jpg[/IMG]


    pictures_3812_746 1203_3313_eldorado_12jun2005
     
  11. Pedro Rezende

    Pedro Rezende TrainBoard Member

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    Hi friends!

    Sorry for the long time absent, but I was on vacation.
    I got wondefull pictures in my trips. I hope a can post then here. [​IMG]


    pedro
     
  12. Pedro Rezende

    Pedro Rezende TrainBoard Member

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    Hi friends!

    Sorry for the long time absent, but I was on vacation.
    I got wondefull pictures in my trips. I hope I can post then here. [​IMG]


    pedro
     

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