[PRCo] Re: Nosing

[Fred Schneider]

Great description Boris.

Back in the late 40s or early 50s the New Haven Railroad bought a group of Mack
diesel buses on B2 trucks.  Dave Gaul (the last paid employee of Transit
Research) told me they rode as smooth as glass on the railroad, and then he
added, "But in those days, anything would have given a smooth ride on New Haven
tracks."  The implication was that they still had first rate track maintenance.
I've seen track so bad that the springing on a B2 actually lifted the body off
the truck and slammed it back down with a thud ... the implication here is of
course that the restraining bolts on the king pin were not tightened.  It
happened at several places on Baltimore Transit's Sparrows Point line in 1958,
just a week or so before the line was abandoned and dismantled.  It should be
obvious that there was no maintenance being done to either the cars or the track
that was not absolutely necessary to get cars over the line.  There a couple of
low spots on the Baltimore Streetcar Museum track where I am uncomfortable
running the PCC over 20 miles per hour because of the bouncing.

Boris Cefer wrote:

> 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
> > >
> >
> >