[PRCo] Re: Brakes on Pittsburgh PCCs

[Fred Schneider]

You don't know, however, how costly it was to make the change to  
extended dynamic braking.   Some day we may get everything moved into  
a new facility and have the prints conserved and then you can look at  
the drawings and you'll know how difficult it was to make the change  
from the original drawings for the 1200s to those shown on dwg. 7D-7720.
On Jul 10, 2006, at 3:35 AM, prcopcc at p-r-co.com wrote:

>> Fred Schneider writes:
>
>> I found a rather unique document in my files that lists brake
>> apparatus on Pittsburgh PCCs as of 6 December 1955.
>
>> 1230  --  1500 type trucks, 1500 type Westinghouse Motors.
>> ...Extended dynamic braking and motor mounted drum brakes.
>> ...Wiring changes see Drwg. No. 7D-7490.
>
>> 1224 to 1274 incl.
>> ...Extended dynamic braking and Westingthouse Air Brake Co.,
>> ......pinion mounted drum brakes.   (except car 1230).
>> ...For wiring changes see Drwg. 77-7720 except
>> ...cars 1225 and 1250   see Drwg. 7D-7445.
>
>> 1278  --  1600 type trucks, 1600 type G. E motors.
>> ...Extended dynamic braking to 2 M/hr.
>
> While we don't know the dates of actual conversion from this  
> listing  (to
> extended range dynamics)  I questioned the change of the 1200s to  
> same on an
> economic basis  --  but it Does Make Sense on a practical basis.   
> 12s had
> spring applied friction brakes which, in early years, were not as  
> reliable,
> especially as drums, so extra help from EDB may be beneficial!!!
>
> Also interesting is that the EDB on 1278 is 2-mph.  Depending upon  
> source
> information, dynamics faded at just less than 3.0-mph on Air-Cars and
> 0.75-mph on All-Electrics  --  with All-Electrics being described  
> as having
> EDB when built!!   PRCo 1601s also had EDB when built!
>
>
>> 1505  --  1600 type trucks, 1600 type Westinghouse motors.
>> ...Extended dynamic braking and Clark motor mounted drum brakes.
>
> This car was actually delivered as 1547 on 19450803 and the number  
> switched
> with 1505 in 1947 to keep all drum brake equipment together as  
> 1500--1505,
> this delivery of 1547 almost 6-months after 1564 on 19450219.  As  
> we know
> the original 1547 was diverted to Twin Cities so the second 1547  
> was built
> with and actually delivered with 1601s and after 1602 of 19450802!!
>
>
> What is interesting is that a number of the entries show that the  
> vehicles
> have truck styles common to other PCC groups;;  this begs the  
> question of
> how the basic B2 is distinguished between the series?!?!
>
>
>
>
> Jim__Holland
>
> I....Like....IKE__---__And....PCCs!
>
> down...with...pantographs.......
>
> UP___WITH___TROLLEYPOLES!!!
>
>