From: romeo@niagara.Tymnet.COM (Michael Stimac)
Newsgroups: rec.railroad
Subject: Re: Water scoops
Date: 16 Oct 92 17:46:05 GMT
Organization: BT North America (Tymnet)

Doug Jones has given some good info regarding track pans for scooping
water at speed. I'm giving some additional material.

In article <1992Oct16.135840.28152@news.uiowa.edu> jones@pyrite.cs.uiowa.edu (Douglas W. Jones,201H MLH,3193350740,3193382879) writes:
>From article <1992Oct16.030619.9198@pasteur.Berkeley.EDU>,
>by zephyr@cory.Berkeley.EDU (COIFMAN):
>> 
>>  I am curious about the mechanics involved with these water scoops. e.g.
>> where was the the water held (between the rails or outside)?
>
>There were long pans between the rails, probably 3 feet wide and a foot
>deep.
>

The depth of the pan was determined by the height of the rails,
of course. You'd want the pan to be as deep as possible, but not
provide interference with the rolling stock. The pans rested upon
the cross ties.

>> How long of a run did it talke to fill a tender or how much water could
>> they take on?
>
>If you figure a 6 inch safety margin all around, your scoop will skim
>a 6 inch by 2 foot slab of water out of the 1 foot by 3 foot pan.  That
>means it gets a cubic foot of water for every foot traveled down the pan.
>
>That means that 1/2 mile pans ought to do well.
>
At least on the Pennsylvania RR, pans typically varied from 1 mile
to 1 1/2 mile in length. Many PRR tenders carried circa 24,000 gals.

>> Were they successful?
>
>Yes, at least during the era when fast non-stop passenger service was a big
>status issue with the railroads.
>
>> Was there a lot of damage associated with their use?
>
>I assume a stupid fireman could rip the scoop off, but the pans had ramps
>at each end to prevent the scoop from trying to scoop up ballast or ties.
>

There was a low signal placed to mark the track pans. These were
similar in appearance to switch stand lamps. One signal was placed
at the beginning of the pan, one at the center, and one at the end.
These informed the enginemen where to drop the scoop, warned them
when they were halfway through, and marked the point to raise the
scoop.

>There are spectacular photos of trains taking on water with a scoop.  The
>splash is tremendous.  Think of the rate at which a scoop takes on water.
>All you have to do is translate miles per hour to feet per second, and then
>think of one cubic foot of water per foot of travel.  When the tender fills
>to overflowing with the scoop down, you get close to 100 gallons per second
>of overflow!

The overflow must be accommodated. Pennsy engines had vents in the
tender top deck which allowed excess water an exit. These vents were
also necessary to allow displaced air to escape. The New York Central
had at least 8 (maybe 12) overflow pipes installed which lead the
excess water and air back down to trackside. These pipes are easily
visible in photos of NYC centipede tenders. I've heard rumors that
before such overflow pipes were installed, there was at least one
instance of a tender "exploding" from the high pressure of the
inrushing water.

The trackage around the track pans was built-up with brick or
cobblestone to provide excellent drainage of excess water away
from the track structure. 

Nearby to the pans was a boiler house, providing steam heat to
keep the water liquid through winter. Yes, the entire thing
was heated. If you think about the enormous cost of keeping
this system working, you can begin to realize how important it
was to keep a fast schedule for competitive reasons. The
huge number of trains helped keep the cost per train at a
reasonable level, but still the capital expense was significant.

I know that the arch-competitors Pennsy and NYC used track
pans, but I don't know of any other rrs that used them.

Another point. Once the track pan system was in place, it was
a very small incremental cost to add scoops to freight engines
as well. Many PRR freight engines also had scoops.

The Pennsy had many track pan installations which were on
all four of its main tracks.

Michael Stimac
-- 
Michael Stimac
(415) 355-8889
romeo@tymnet.com
These opinions are not necessarily anyone's but my own.