[PRCo] Re: PRCo

[Fred Schneider]

There was, by the way, a study written by Transit Research  
Corporation in 1940 that compared the St. Louis 1500s with spring  
applied shaft or drum brakes with the air cars and the conclusion was  
that spring brakes would not work on all of Pittsburgh's grades.   
They did seem to work satisfactorily on most lines, however.   I can  
assure you that they did not work well on Fineview because I arranged  
to take 1707 up there in 1958 and the shaft brakes were inadequate to  
hold it.   PRC normally rate 1600 air cars on it with boosted air  
pressure.   PAT apparently had some dissatisfaction with 1700s on Old  
Washington Road (Arlington Avenue) on the tunnel bypass although we  
know they ran there all the time and that grade was not as steep as  
roue 8 that had 1700s all the time.



On May 22, 2007, at 2:28 PM, Boris Cefer wrote:

> We have a few grades nearly 6 % in Ostrava and our cars have no  
> problems. I
> am also an expert on this and I can prove that.
> By the way, the manufacturer of TATRA T3 car claims that its shaft  
> brakes
> are capable to hold a fully loaded car (that means 150 passengers!)  
> on a 8
> or 9% grade (I do not have the book by hand and I am not certain which
> figure is correct). What does this say?
>
> I understand your comments
>
> <VBG>
>
> B
>
> ----- Original Message -----
> From: "Fred Schneider" <fwschneider at comcast.net>
> To: <pittsburgh-railways at dementia.org>
> Cc: "Jackson Russ" <rejmhj at netzero.net>
> Sent: Tuesday, May 22, 2007 8:07 PM
> Subject: [PRCo] Re: PRCo
>
>
>> This is impossible Boris.   You know those technically sophisticated
>> Germans tell us that the limits of adhesion for trolleys is about 6
>> percent and beyond that you need a rack.   Even some American
>> engineers today seem to think that you cannot go beyond 6 percent on
>> adhesion.   They command big bucks so they must be correct.
>>
>> This data must all be fabricated.   And if you try to prove it, I'll
>> bet all the U. S. Geologic Society maps are all lies.   The contour
>> lines are all figments of someone's imagination.
>>
>> <BG>
>>
>> The only thing that makes me believe the values are correct is that I
>> climbed those hills when I was a young man of 12, 13, 14, 15, and on
>> into my early 20s long before heart disease, overweight and arthritis
>> was a problem and they were still damn steep.
>>
>> f3
>>
>> On May 22, 2007, at 1:00 PM, Boris Cefer wrote:
>>
>>> Content-Type: text/plain;
>>> charset="iso-8859-2"
>>> Content-Transfer-Encoding: quoted-printable
>>>
>>>
>>> It seems the subject of the jerky operation of 1711 somewhat =
>>> evaporated...
>>>
>>> But there is an interesting chart which I got from Russ Jackson.
>>>
>>> Boris
>>>
>>>
>>> -- Attached file removed by Ecartis and put at URL below --
>>> -- Type: image/jpeg
>>> -- Size: 800k (819994 bytes)
>>> -- URL : http://lists.dementia.org/files/pittsburgh-railways/Pgh%
>>> 20Grades.jpg
>>>
>>>
>>>
>>
>>
>>
>> __________ Informace od NOD32 2285 (20070522) __________
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>> Tato zprava byla proverena antivirovym systemem NOD32.
>> http://www.nod32.cz
>>
>>
>
>