Re: [Non-DoD Source] Re: [PRR] PRR X31A facts you want to know

Gatwood, Elden J SAD


From correspondence I have read, they were trying to maximize capacity within the as-then clearance diagram dimensions, and tunnels, and accommodated that by several means: the grab above the side ladders and below the lateral had a depression for fingers beneath the grab. So, the grab didn't enter the "forbidden" space. The roof shape and r/b fit nicely within clearances, while pushing the envelope above the dimensions of X28, etc.

It is not lost on me that the shape of the X31/32/33 resembles a tunnel bore, which PRR had in numbers, of restricting size/dimension, on the Panhandle in particular (some later "day-lighted"), which plays into the "why wasn't it rectangular" question. I have not seen the mention of which specific tunnels, although it must've been a discussion. Other roads had similar restrictions.

It appears that automobiles were certainly a consideration for all railroads, like PRR, Wabash, NYC, and others wanting to ship autos, but loading them horizontally, on the floor, was inefficient and costly.

I am certainly no expert on auto racks, but when Evans started coming out with their racks, PRR noticed.

Depending on the racks, it could be under/over, or diagonally under/over, and that depended on what type of vehicle. The limited number I have seen are HIGHLY varied.

The X31/32/33 were a success.

PRR kept pushing the envelope. The most interesting from my point of view, is the experiment that became the X37/37A/37B, and X38/38A/etc cars, where a "Mansard"-looking eave/juncture between roof and side was created, that totally pushed the envelope. Those cars varied height by sub-class, and could be refused based on height, if for instance, they were routed onto the B&O, or other lower height-able roads.

Bruce is going to educate us all on the larger story....

Elden Gatwood

-----Original Message-----
From: <> On Behalf Of Douglas Nelson
Sent: Saturday, June 13, 2020 11:52 AM
Subject: [Non-DoD Source] Re: [PRR] PRR X31A facts you want to know

Was the round roof used to provide extra interior height for automobile loading? Was there a rack system for over-under loading?

Also, did railroad clearance need to be increased before these cars entered service?

Doug Nelson.
On Jun 13, 2020, at 8:09 AM, Gatwood, Elden J SAD <> wrote:

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