PCC and *Light* Rail Vehicles -- Weights

[Jim Holland]

Greetings!

	The weight of a standard PCC could easily be rounded to 36,000 pounds.

	The weight of a Boeing LRV could easily be rounded to 72,000 pounds.

	For the PCC that is 9,000 pounds / axle.

	For the Boeing LRV that is 12,000 pounds / axle.

	The Boeing LRV is 33% heavier / axle than the standard PCC.

	This is an  *e-x-t-r-e-m-e-l-y  v-a-l-i-d  c-o-m-p-a-r-i-s-o-n.*  The
reason is that the truck centers are very similar - the Boeing LRV had
to negotiate standard street turns like the standard streetcars so the
distance between trucks is almost identical making the overall car very
similar to the PCC in total size or mass.

	This comparison between the PCC and the Siemens, Bombardier, or other
vehicle used on systems built from scratch where cars are considerably
longer but still have only 6 axles would not be a fair comparison - the
weight could be greatly increased with the extra length.

	Comparison on weight per seat would be more favorable. But the LRVs of
today have far more doors which eat up seat space so this would not be
fair, either, but it would be better than a per-axle comparison of
weights.  What would be more fair would be to assume the LRV is single
ended like the PCC and then assign seats to the doors on one side as
well as the operators compartment on one end.  Then a comparison between
a PCC and most any LRV on a *weight-
per-seat* basis would be very good.

	An interesting observation:::  ---  Here in San Francisco, the N JUDAH
is the heaviest streetcar line.  Base service with PCCs was 6 minutes
all day, more frequent in rush hour.  Base service with LRVs was 10
minutes with two car trains.  Assuming a time frame of 20 hours, that is
7,200,000 pounds of PCC plying the rails vs 17,280,000 pounds of LRVs!! 
Quite a difference.  In 15 years the sharp turns on city streets at 9th
and Irving, the "S" from Carl to Irving, and the turn from the street to
the Sunset tunnel have totally worn out and been replaced!  It would
take 36 years of wear from a PCC before the turns would be worn out 
I-F  the wear from a PCC is the same.

James B. Holland
------- -- ---------
        Pittsburgh Railways Company (PRCo), June of 1949 -- June of 1953
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