[PRCo] Re: Nosing

[Boris Cefer]

No no no! The B-2 is softer vertically (=> bouncing), while the B-3 is in
vertical direction stiffer and thus better for prw with rail joints in poor
condition (but relatively straight vertically).
The B-2 does not transmit lateral irregularities of the track to the body as
much as the B-3.
As for the B-2b, the truck bolster was laid on the truck frame somewhat
higher than on standard B-2, from which I deduce that the riding quality on
B-2bs was a transition fbetween B-2 and B-3, but closer to B-2.

Boris

----- Original Message -----
From: "James B. Holland" <PRCoPCC at P-R-Co.com>
To: <pittsburgh-railways at dementia.org>
Sent: Thursday, January 27, 2005 7:16 PM
Subject: [PRCo] Re: Nosing


> You Say It So Nicely!
>
> So in theory, the B2 would provide a better ride on open prw than the
> B3  --  yet theoretically the B3 was designed Just For That kind of
> operation!!!!!!!
>
>
> Jim__Holland
>
>
>
> Boris Cefer wrote:
>
> > The problem of B-3 is obvious.       The main (coil) springs are
> > higher on B-3 than on B-2, which means that the B-2 truck is laterally
> > stiffer than B-3.       In addition to that, on B-3 trucks the car
> > body rests on the truck frame at higher point than on B-2s.       The
> > B-2 truck bolster design is selfcentering and the weight of the car
> > body drives it to its lowest position (the result is automatical
> > dampening).       Also the tapered tread plus inadequate gauge
> > clearance (bad track) provides very good excitation for lateral
> > motions of the truck and whole the car body.
> >
> > Boris
> >
> > ----- Original Message -----
> > From: "James B. Holland" <PRCoPCC at P-R-Co.com>
> > To: <pittsburgh-railways at dementia.org>
> > Sent: Thursday, January 27, 2005 6:41 AM
> > Subject: [PRCo] Re: Nosing
> >
> >
> >> Can be a variety of things.
> >>
> >> [[Snip]]
> >>
> >> It needs to be recognized that all  *hunting__is__Not__hunting*  --
> >> the differences in design between the B2 and B3 make for different
> >> performance on the same track. There was a portion on Church Street
> >> here in SF outbound between 17th and 18th downhill that was quite
> >> rough -- a B3 equipped car slammed back and forth sideways while a B2
> >> passed through with barely a disturbance. The Swing link possibly
> >> saved sideways motion on the car on a B2 truck as the truck itself
> >> moved back and forth on the uneven track -- the bad track was short
> >> enough that the motion was not transferred to the body. But the
> >> framing of the B3 truck would even get the spring pots moving from
> >> side to side which then transferred this motion to the body. The
> >> motion ceased when the car passed this brief section of bad track --
> >> that would not happen with hunting -- hunting seems to intensify once
> >> begun until measures like purposely slowing are taken to alleviate
same.
> >>
> >> This same type of situation is pointed out in the PCC books about
> >> Chicago B2s and B3s on rough track -- considerably sideways action to
> >> the B3 whereas it is hardly noticeable on the B2.
> >>
> >> Yes, the B3 was developed for open track but have said before that
> >> the B2 did just fine from a ride standpoint -- don't know if it was
> >> more problematic for maintenance. Would Dearly Like To Know what a
> >> ride on the interurban would be like with the *Original__B2Bs* ---- A
> >> Truly Superb Ride And The ONLY equipment I have ever ridden that
> >> aptly fit the description of *Riding__On__A__Cloud!*
> >>
> >>
> >> Jim__Holland
> >
>
>