Re: Re: Melbourne, Christchurch

Thanks for the input, Andrew.

I've been on that PCC site since they started. I sign there as RT Murphy
because that is what everyone called me when I worked for the Muni in the
60s and early 70s, including several stints on PCCs.

There were big differences between ride quality on the two main bogie types
under PCCs. And in San Francisco most of us hot rod types preferred the one
with the ride a bit like a meatwagon which was accentuated by the fact that
we usually drove them faster than the railfan types who generally preferred
the B-3 truck. Both trucks had coil springs but the B-3s had big ones and
did ride very well vertically but could slam from side to side in a most
alarming manner at certain speeds on certain track. The B-2 were a bit
rougher vertically but did not slam from side to side and thus did not alarm
the passengers so much when the tram was on the pace.

I find rail suspension increasingly interesting because I have been involved
in a fair bit of research on "road-friendly" truck suspensions which can
lengthen road pavement life by limiting dynamic peak loads.

Some rail research has been done into "rail-friendly" suspensions/truck
design which reduces dynamic peak loads both vertically and horizontally
(compared with road vehicle suspension which only has to work vertically).

There are bigtime implications for extending rail life or allowing heavier
locomotives (in the case of heavy rail) to use existing lines.

Hence my interest.

I think the Z cars in Melbourne ride like meat wagons and though they have
been improved since then, the M&MTB once did an inquiry into Z car
suspension and came to the conclusion that they offered "Unacceptable levels
of vertical and lateral oscillation under acceleration, steady state or
deceleration, even on straight good track", I remain unimpressed.

The M&MTB engineers were forced to take that design on price even though
they pushed strongly for DuWag monomotor bogies. There was just too much of
a price disparity.


Cheers,

Bob Murphy
----- Original Message -----
From: <[email protected]>
To: <[email protected]>
Sent: Monday, August 27, 2001 3:22 PM
Subject: [TramsDownUnder] Re: Melbourne, Christchurch

--- In TramsDownUnder@y..., "IS Edit" <isedit@g...> wrote:

Cripes!

You trying for a PhD on old tram trucks, Andrew?

The M&T 588 sounds like a useful design.

When they transport revolution is here and we need thousands and

thousands

of single truck trams we'll know what to go for.:)

Has there ever been a successful (in this case that means good

riding) tram

with metalastik suspension in your estimation? (Don't even think

about

nominating Melbourne's Z-1s). The lack of metal on metal contact and
implications for almost maintenance free operation make the idea
interesting.

Cheers,

Bob Murphy

No, no Phd, just been fascinated by tramcar trucks since I were nobbut
a lad. I don't know how to answer the metalastik question given the
constraints you impose, as my brief acquaintance with the Z-1
suggested nothing that would imply it (or any of the other modern
cars) didn't produce a perfectly acceptable ride quality.

Not being an engineer, I don't know the virtues or otherwise of
metalastik bonding over what the PCCs used, but I would point you in
the direction of the PCC trolley group at Yahoo which very recently
has been having a heated debate over why all our US LRVs don't give as
smooth and untroubled a ride as PCCs, even with their technological
sophistication. (And I may say I don't really agree with that
assessment, although it may be that there are engineering problems
etc. which tell against the metalastik susoension either in
maintenance, ride, design, you name it. The engineers will know and
that group has some of the best in its cadre of correspondents.

Not that those who claim the PCC gives a better ride are suggesting
its ride was 100% perfect, far from it.

But anyway, I urge you to join that group, read what they have to say
and then give all of us your opinion because I suspect it's my
ignorance of modern truck technlogy that prevents me from giving a
credible answer to your question.

Andrew D. Young

----- Original Message -----
From: "David Young" <dayoung007@h...>
To: <Tramsdownunder@y...>
Sent: Monday, August 27, 2001 4:54 AM
Subject: [TramsDownUnder] Melbourne, Christchurch

Thanks for the replies to my questions, guys.

Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

------------------------ Yahoo! Groups Sponsor ---------------------~-->
FREE COLLEGE MONEY
CLICK HERE to search
600,000 scholarships!
http://us.click.yahoo.com/zoU8wD/4m7CAA/ySSFAA/DiTxlB/TM
---------------------------------------------------------------------~->



Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/