Re: Wheel Howl (Are G scale trains superior?)
Author: HUTCH 7.62
Date: 01-05-2014 - 14:17
OldPoleBurner Wrote:
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> Since I was assigned to work on the property
> (BART) in the days when the first articles were
> delivered, all equipped with standard conical
> wheel treads which were very very quiet (scary
> quiet even) to anybody standing trackside; I have
> come to a theory about all that noise.
>
> After the twelfth car was delivered, they started
> coming with non-standard cylindrical wheel treads,
> which were indeed a lot noisier, even then. This
> was supposedly because the ride (pitch & woo) was
> judged to be unpleasant. Rather than correct the
> dampening ratios, Bechtel came up with this
> solution. Of course, this means that no taper
> exists to help guide the wheels around curves.
> Flanges are all there is - much like a toy train!
>
>
> Worse yet, the extreme rigidity of the trucks, and
> their inadequate dampening, was never fixed.
> Electronic studies of track circuit performance
> even revealed that wheels were routinely lifting
> off the rail by a few thousandths, breaking train
> detection, and probably accelerating corrugation
> effects. To my knowledge, nothing was ever done
> about any of this.
>
> Moreover, even on tangent, both flange fillet
> radii must be in contact with gauge corners of the
> rail at the same time; in order to have any
> finesse control of the wheels. This leads to
> extreme wear on both wheel and rail; and indeed
> could be the cause of premature corrugation. Fact
> is, rail that should last nearly 100 million
> ton-miles (very light cars on heavy rail),
> continues to have a very short lifespan - much
> shorter than the average freight line. BART track
> is thus inordinately expensive to maintain; not
> to mention the systemic train control problems
> caused by wheels that can't keep the rails clean
> of rust. Rust beads were common on rail tops, for
> several years until the wheels were worn-in to a
> natural taper. (caused by the cant of the rail as
> seated in the tie plates).
>
> Sometimes it just doesn't pay to re-invent the
> wheel! Especially, when it was already working
> just fine, and was not the problem. Not that
> anyone at Bechtel knew anything about that - or
> cared. They just ignored us young troglytes with
> any rail experience!
Several days after reading this thread I was picking up one of the many G scale fright cars I own and noticed the steel wheels were conical instead of the non standard cylindrical wheels found on most model trains. Does this make my 40 dollar freight car superior to the wheels on BART:)?