[ARC5] Locomotives

[J. Forster]

Nope.

The coefficient of static friction (your 0.25) limits the horizontal force
the loco can apply to the train.

A loco can pull far, far more than that.

The limit is set by train weight and steepest grade. The force required to
pull a train uphill is:

train weight x sin(grade angle) + rolling friction force on level track.

If the track is horizontal, the sin term is zero

-John

============


>
> Added weight on the rails for any locomotive means
> that heavier train weights can be moved.  Friction
> coefficient of steel wheels on steel rails has been
> stated as .25.  This means that the maximum weight
> that can be moved (including locomotive weight) on
> level, clean track is 25% of the weight of the loco.
>
> * * * * * * * * * * *
> * 73 - Mac, K2GKK/5 *
> * (Since 30 Nov 53) *
> * k2gkk at hotmail.com *
> * Oklahoma City, OK *
> * USAF & FAA (Ret.) *
> * * * * * * * * * * *
>
>
>
>
>
>
>> From: releazer at earthlink.net
>> To: arc5 at mailman.qth.net
>> Date: Wed, 19 Dec 2012 19:04:55 -0500
>> Subject: [ARC5] Locomotives
>>
>> Read a few years ago that they are building "hybrid" locomotives, hybrid
>> in the same sense that a Prius is hybrid.
>>
>> They replace switching engines in the yards and in fact use the running
>> gear and frame from the old switch engines. They use a whole bunch of
>> batteries and a diesel engine such as would come in a large pickup
>> truck. The engine keeps the batteries charged, only starting when
>> required. The batteries run the locomotive. A disadvantage of
>> conventional diesel electric locomotives for switch engines is that they
>> don't have to move long distances but have to run pretty much all day
>> and night so to be handy as required. The hybrid locomotive's engine
>> only has to run as needed and I guess this not only reduces fuel costs
>> but helps satisfy local air pollution requirements. The hybrids actually
>> weigh more than conventional diesel electric locomotives but this is
>> seen as an advantage when assembling trains because it gives them more
>> momentum.
>>
>> They are going to start using hybrid locomotives for some long distance
>> routes; I would guess these are for routes where the braking can be used
>> to charge the batteries.
>>
>> I have always thought it strange that the first major commercial user of
>> GPS, using it even before the system was fully deployed, was the
>> railroads. While it is quite hard to get lost in a train, it turns out
>> that knowing exactly where you are on a route helps a great deal, since
>> you can apply or reduce power to handle changes in grade based on solid
>> data rather than "This Looks About Right." Thus, fuel and maintenance
>> costs are reduced significantly.
>>
>> Finally, I was told that in 1955 the old steam locomotives were
>> surplused and sold for $500 each, and that included free use of the RR
>> network to get it to your destination. Don't ya'll all wish you had
>> bought one?
>>
>> Of course, in 1955 the USN's F8F Bearcats were surplused and sold for
>> $500 each. And I would rather have one of those!
>>
>> Wayne
>
> ______________________________________________________________
> ARC5 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/arc5
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:ARC5 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>