Classic Trains - Frisco 4300's

Discussion in '4300 Class Mountains' started by meteor910, Nov 3, 2010.

  1. meteor910

    meteor910 2009 Engineer of the Year Staff Member Frisco.org Supporter

    Check out the story by Frederick Clem in the current issue (Winter, 2010 - just received) of Classic Trains, page 80-81, regarding the substitution of a 4300 for a sick 1500 on the KC-FS in 1946 at Ft. Scott. Neat!

    Ken
     
  2. tmfrisco

    tmfrisco Member Frisco.org Supporter

    Thanks for the heads up, Ken. I have been trying to get all my yard work ready before my hip replacement surgery later this month, and I have not been able to stay awake long enough to read through that issue. That is a great shot of the engine. It looks very clean considering the extremely heavy war time usage. Terry
     
  3. DanHyde

    DanHyde Member

    Best of luck on your surgery, Terry. I had my left hip replaced 2 years ago. If it wasn't for that, my current issue with the broken right leg would not be as managable as it has been. It's great to be in NO pain!!:):):)
    Dan
     
  4. tmfrisco

    tmfrisco Member Frisco.org Supporter

    Thanks, Dan. I am looking forward to having no pain. I may have to relearn how to walk, though, as I have developed a distinct limp. I am looking forward to starting my layout this winter:) and need to be able to carry the supplies into the house and up the stairs. I think my grandson doesn't believe me anymore when I tell him we are going to have a real:cool: layout. He and a friend of his from church love to play with the trains I can run on the simple track running around the room, so having some variety of routes will be more fun, plus being able to run trains in different directions. Terry
     
  5. DanHyde

    DanHyde Member

    It's like riding a bicycle - a quick return I am sure.:) At least, mine was.
    Dan
     
  6. frisco1522

    frisco1522 Staff Member Staff Member

    My Dad always thought the 4300s were excellent engines.
     
  7. yardmaster

    yardmaster Administrator Staff Member Administrator Frisco.org Supporter

    Don, that's interesting to hear. I'm finding myself with an increasing fascination with the 4300s, considering that they were Frisco-built.

    Did your dad have any recollections on how they compared with the 4400s? Knowing that the latter were thoroughly reclaimed from the 2-10-2s, I'd suspect that they performed quite differently.

    Best Regards,
     
  8. TAG1014

    TAG1014 Frisco.org Supporter Frisco.org Supporter

    Too bad the Classic Trains' 4300 article was so short and the picture so small! Can't believe Kalmbach couldn't find a bigger and better photo. Nice little remembrance though...

    Tom
     
    Last edited by a moderator: Nov 30, 2010
  9. Brad Slone

    Brad Slone Member Frisco.org Supporter

    Need to keep an eye out for the January issue of the NMRA Scalerails, there's a little bit of Frisco coverage coming up.

    Brad
     
  10. Rick McClellan

    Rick McClellan 2009 Engineer of the Year

    Wow, I wonder who the author is . . . . . . . .
     
  11. Brad Slone

    Brad Slone Member Frisco.org Supporter


    Well, despite whoever the author might be, the editor did a pretty good job, and the pictures tell the story anyway!

    Brad
     
  12. Frisco1515

    Frisco1515 Frisco1515

    Joe Collias' book, FRISCO POWER, lists the horsepower of the 4300s as 4800, and the 4400s as 4400. The 4300s had boiler pressure of 250 and the 4400s at 210, which would probably account for a difference in hp. Glad you liked my article in Classic Trains. Frederick Clem
     
  13. yardmaster

    yardmaster Administrator Staff Member Administrator Frisco.org Supporter

    So, I've searched the various threads regarding the 4300s and 4400s thinking this may have been a question that others have posed, but I cannot locate it hereabouts.

    Naturally, the heavier weight of the 2-10-2 locomtives-turned-4400-class Mountains explains the difference in tractive effort; a subject that tends to elude my pitiful brain.

    However, if both the 4300s and 4400s were equipped with identical Franklin C-2 trailing truck boosters, as noted in "Frisco Power, " I'm puzzled as to why the boosters added 8,450 lbs of additional tractive effort on the 4300s, while the same appliance added 8,750 additional lbs on the 4400s.

    I presume it still comes down to the weight of the locomotive itself?

    Best Regards,
     
    Last edited by a moderator: Aug 29, 2013
  14. meteor910

    meteor910 2009 Engineer of the Year Staff Member Frisco.org Supporter

    Yes, most likely due to the trailing truck/booster on the 4400's bearing more weight on the rails than the same booster on the trailing truck on the lighter 4300's. More weight = more tractive effort, as long as you have enough power to turn the wheels.

    Ken
     
  15. TE doesn't consider the weight on drivers - weight and hence adhesion affects the drawbar pull but not the TE

    TE on a two cylinder engine is calculated by a simple formula, D²xSxPxF/d, where D is cylinder diameter in inches, S is the stroke and P is the boiler pressure in psi, F is a factor which varies according to who is doing the calculation) and d is the driver diameter. The variability of F is due it being something of a fudge factor to allow for losses in the steam path between the boiler and pistons. Typically in US practice it would be around 85% and which is a useful estimate for low speed work.

    Now you'll see that weight on drivers hasn't entered yet; TE is simply a measure of the force delivered at the outside face of the wheel.

    Where weight matters is in adhesion - too high a TE for a given weight on drivers and you get powerful machine that can't start a train because it slips badly on starting. Typically designers worked around an adhesion ratio of about 4 - that is the total weight on drivers should be about 4 times the tractive effort. A significantly lower figure makes for a slippery engine - the TE is still calculated the same way, but the maximum pull at the drawbar has gone down because of lack of adhesion. Note the number of drivers doesn't affect the calculation - only the total weight on drivers.
     
  16. meteor910

    meteor910 2009 Engineer of the Year Staff Member Frisco.org Supporter

    Thanks. Shows what happens when a diesel guy starts explaining steam issues.

    Ken
     
  17. yardmaster

    yardmaster Administrator Staff Member Administrator Frisco.org Supporter

    Either way, I appreciate the insight. Sometimes I feel like Sam Clemens learning the art of reading the Mississippi River in his apprenticeship with Horace Bixby. If I ever manage to learn and remember all of this stuff, I'll need crutches to help carry my brains around.

    Thanks Ken and Mad Dan...
     
  18. Karl

    Karl 2008 Engineer of the Year Frisco.org Supporter

    Aidrian rightly notes that frictional forces (adhesion) is independent of the number of drivers. As counter-intuitive as it may seem, friction has nothing to do with surface area. Only the coefficient of friction of the materials in contact with each other and the pressure between the two materials enter into the equation.
     
  19. yardmaster

    yardmaster Administrator Staff Member Administrator Frisco.org Supporter

    The more I try to absorb this, the more fun it becomes!

    Regarding Aidrian's formula of D[SUP]2[/SUP]xSxPxF/d, then where does the trailing truck booster fit into the equation?

    Best Regards,
     
  20. Karl

    Karl 2008 Engineer of the Year Frisco.org Supporter

    The booster engine is just a second, two cylinder, steam engine, and Cole's formula would be used calculate its TE. The power was transmitted to the axle via a set of gears, and the gear ratio would have to factored into the calculation.
     

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