[PRCo] Re: Pittsburgh Overhead
James B. Holland
PRCoPCC at P-R-Co.com
Fri Mar 18 16:41:23 EST 2005
Sensitive -- Yes and No! A hanger missing on overhead strung for
trolley pole ((Please See URL at Very End of this Email)) will
Most Always allow the trolley pole to pass without problem, even at
normal speed for that section! HowSomeEver....... a broken
// missing hanger on a curve built for pans-only will Guarantee a
dewirement of the pan. I-F the trolley pole dewires -- Just
Put It Back On The Overhead. If a pan dewires, well.......
hope it remains on the vehicle but it can't be put back on the overhead
without a shop call!
THE Single Biggest Reason for trolley pole dewirements is poor
spring tension -- remember, even the North Shore traveled in excess
of 80-mph Regularly and kept the poles on the overhead. Mostly
Tangent track but also remember, with only 25-30--pounds pressure
(nominal wire height of 18-feet) there is MUCH pounding from span to
span with wire droop in between and at North Shore speeds the pole is
passing 2.1734-spans a *second* ((117.34-feet/second at 80-mph)) with
spans 100-feet apart and it won't take much to knock the pole off the
overhead.
Pans can have poor spring tension as well and they will skip and bounce
along the overhead thus losing contact momentarily and make for an
unsmooth ride.
Too much speed on a sharp curve *may* cause a trolley pole to dewire
but then the speed is probably uncomfortable for passengers if not
unsafe period!
Shallow turnouts, spiral easements are most problematic for a trolley
pole following at a turnout. On a standard radius turnout the
trolleycar has completed its turning away from the tangent as much as
15-20--feet before the trolley pole hits the frog which forces the pole
to follow the correct wire -- Please Note that in such a turn, the
trolley pole Does NOT swing away from the car to the inside of the
curve -- the Trolley*Car* actually turns underneath the pole -- the
pole is on tangent wire still even when the whole trolleycar is on the
curve -- In Reality, there is Very Little side to side movement of the
trolley pole -- The Most movement is coming out of the turn when the
trolleycar is on tangent and the pole is still on the curve and it is
necessary for the pole to swing back over the center of the car.
On a spiral easement the trolleycar is still in the processing of
turning from the tangent into the nominal radius even up to the track
frog so the pole is not trailing properly when the car is still in the
process of turning. This was most noticeable inbound at the north
end of the Smithfield bridge after trackage rebuilt when B&O station was
moved. 01.>-- Only experienced one dewirement here on an
interurban, but I knew the potential was there.
The following are *PRCo* trolley pole dewirements in 20++ years of
personal riding, railfanning, Sunday Pass riding from 6-AM to midnight,
18hours/day, etc.:::::::
02.>-- Outbound 88-line on Penn first curve past Butler.
03.>-- Trailing turnout frog Stanwix / Fort Duquesne -- ONLY
1000-series cars. Waited here for 4-hours watching every passing
car and only 1000-series cars dewired, two cars, 2-dewirements!
04.>-- Dawn Jct. OB, 42 - shallow turnout -- 1-dewirement, car 1454.
05.>-- North Side passing under RR viaduct.
06.>-- 4-dewirements on Interurban (sometimes remained on Interurban
ALL day on Sunday pass.)
07.>-- 3-dewirements in South Hills Jct. area which includes ALL prw
through the yard, on the 40-line, 44,47,48, interurbans, 38,39,42 -- 2
a broken hanger whose ear then obstructed the overhead on the 38, 39, 42
tracks just north of Palm Garden Jct. and one a car entering track-4 of
the yard.
A total of 13-dewirements in 20++years on *PRCo* -- probably others
but not many others. This was Not a Frequent occurrence on *PRCo.*
NEVER A Dewirement in the vicinity of the SHJ Admin building nor
within 400-feet any direction.
NEVER A Dewirement on the 87-Ardmore.
NEVER A Dewirement on the 56-McKeesport.
If I didn't ride interurbans All Day then a ride on the two above was a
MUST.
NEVER A Dewirement on 88-Frankstown.
NEVER A Dewirement on 40-line
NEVER A Dewirement on 44-line
NEVER A Dewirement on 48-line
NEVER A Dewirement on 53-line
NEVER A Dewirement on 38-Mt.Lebanon.
NEVER A Dewirement on 39-Brookline.
NEVER A Dewirement on 50-Carson.
NEVER A Dewirement on Fifth Avenue routes.
NEVER A Dewirement on Forbes Avenue routes.
NEVER A Dewirement on Second Avenue Routes.
NEVER A Dewirement on West End Routes -- but I never rode them,
either!
NEVER A Dewirement on Charters.
Jim__Holland
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
I--Like__Ike.......AND__PCCs__AND___TrolleyPoles
Solly, Cholly -- Had To Say This // That!
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Boris Cefer wrote:
> But the pole is more sensitive on any inequality. And the pantograph
> simply can't follow wrong path on a trolley branch, which is possible
> with the pole. I know that it does not happen often, but it is possible.
>
> B
>
> ----- Original Message -----
> From: "James B. Holland" <PRCoPCC at P-R-Co.com>
> To: <pittsburgh-railways at dementia.org>
> Sent: Thursday, March 17, 2005 10:06 PM
> Subject: [PRCo] Re: Pittsburgh Overhead
>
>
>> Neither Do Trolley Poles!!!!!!! :-D
>>
>> J
>>
>>
>> Boris Cefer wrote:
>>
>>> That's all correct. I meant that pantographs do not "dewire" on
>>> trolley which is OK.
>>>
>>> B
>>>
>>> ----- Original Message -----
>>> From: "James B. Holland" <PRCoPCC at P-R-Co.com>
>>> To: <pittsburgh-railways at dementia.org>
>>> Sent: Wednesday, March 16, 2005 10:58 PM
>>> Subject: [PRCo] Re: Pittsburgh Overhead
>>>
>>>> Broken hanger / span ((on curve strung only for pans)) not noticed
>>>> by operator will *probably* cause dewirement of pan -- with pan
>>>> being ripped off the roof of the trolleycar!!!!!!!D> Can We Really
>>>> Call them *TrolleyCars* If They Have Pans??!!:D>
>>>>
>>>>
>>>> Pan *Requires* overhead in Far Better Condition than that required
>>>> for trolley pole -- pan is very slow to react to changes in wire
>>>> height or other conditions -- pan will resist wire suddenly
>>>> dropping lower which could potentially dmage pan, and will skip off
>>>> the wire that rises too fast -- LOTS of bounce on pans here in SF
>>>> at grade changes.
>>>>
>>>> Jim
>>>>
>>>>
>>>> Boris Cefer wrote:
>>>>
>>>>> Ugly is the correct word.
>>>>> And there is no chance to dewire with pantographs.
>>>>>
>>>>> Boris
>>>>
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