Mike,
No, I am not. "Airslide" was a patented construction process of
General Amerian Transportation.
The BN refered to these cars as "Gravity Pneumatic". General
American called them "Dry-Flo". Burlington Bulletin #20
covers these cars very well and even includes a list of recommended
commodities. Generally these were rather free flowing products
and the usual procedure was to use a negative pressure hose and
suck the contents out with the aid of gravity. The enamal or epoxy
lining helped make the bays more slippery. While these cars did
have vibrator brackets it was usually not necessary to use one.
This process is similar to the "Vaculators" that are used for
transloading at derailments.
"Airslide" cars deal with products that have a tendency to cake,
like sugar or flour. If you tried to suck them out about all you
would end up with is a small void and caked product around and
above it. The Airslide system uses tubing with small holes in it
integrated with the slope sheets. Same way that a avalanche happens.
If the snow on a mountain side or the flour in an airslide loses it's
cohesiveness with the surface it is resting on it will all slide at once.
When you unload an airslide you remove the sanitary plate and then
hook the car up to positive air pressure. There is an internal discharge
gate in each outlet that turns with a big wrench that you can use to
regulate the flow. In order to keep the process sanitary they make
boots that can be clamped to a flange where the sanitary cover was
attached with modified vice grips. The boots attach in the same
manner to the leg or auger that is moving the product to a bin.
There is a problem here. If you do not open one of the top hatches
the positive air pressure will cause the sides or roof to bulge out.
I'm sure we have all seen 70 ton airslides with arched roofs. They
make little aluminum chimneys that will allow air to escape at
the top but not allow contamination to come in. Stop by a bakery
when they are unloading flour and there will be one in a top
hatch. Customers have learned about that issue.
Another problem with both types of cars is just attaching the sanitary
plate on one side so it swings around and allows dirt to get in the
car. Most have probably seen that too.
It's been close to twenty years since I had any involvement in this
process. This much, and more, is what I remember. If there are
errors correct them.
The VLBG
ps: Got Volume 1 in your series from someone on the list. The
photographs are beautiful and the layout with timetables and slogans
is just right without being "too busy". The only "nitpick" I saw at
first reading was that the East End wayfreight delivered to the IHB.
That local did not make any deliveries. A great book!
----- Original Message -----
From: "Mike Spoor" <CBQRR@j...>
To: <BRHSlist@yahoogroups.com>
Cc: <BRHSlist@yahoogroups.com>
Sent: Saturday, 05 January, 2002 08:48
Subject: Re: [BRHSlist] Re: Peoria
> VLBG: are you saying "Airslides" when you refer to the 852XX and 853XX
> series cars?
>
> Mike
>
> On Thu, 3 Jan 2002 18:24:40 -0600 "VLBG" <VLBG@s...> writes:
> >Lenny,
> >
> >While I can not answer the particular question at this time I do
> >have another Pabst observation.
> >
> >During the mid 60's through the mid 70's they did load a fair
> >amount of corn grits from their Peoria plant to Milwaukee.
> >This business was routed CB&Q/BN IHB MILW and was
> >usually loaded in CB&Q 852xx or 853xx series cars.
> >
> >TheVLBG
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