I wrote

The two SP prototype classes of 12-panel box cars DID have the thin top stiffener. I hope IM did not remove that stiffener in order to model the SP cars <g>.

Tim O'Connor replied:

Tony, this one doesn't.

http://www.speedwitch.com/Images/models/sp21622.jpg

Perhaps we are descending into the Swamp of Definitions. I would agree that the some of the P-S cars built for SP have more of a thin, straight rib, instead of a tapered thin rib like those between the major corrugations. (Let's not call it a "riblet" lest I think excessively of BBQ.) See the relevant pages in my SP Freight Cars Vol. 4 for additional photos. The contrast, if I understood the discussion correctly, had to do with whether there was ANY small rib above the highest major corrugation.

Tony Thompson Editor, Signature Press, Berkeley, CA
2906 Forest Ave., Berkeley, CA 94705 www.signaturepress.com
(510) 540-6538; fax, (510) 540-1937; e-mail, thompson@signaturepress.com
Publishers of books on railroad history

[ Take Four ]

Tony Thompson wrote

The contrast, if I understood the discussion correctly, had to do with
whether there was ANY small rib above the highest major corrugation.

Not my understanding. The small stiffener was well above the major
and minor corrugations, and is clearly present on most GN cars and
the SP B-50-27/28 classes, and absent from the B-50-25/26 and some
GN cars... as we have discussed up to this point.

But as Ed pointed out clearly, no one (including Sunshine) makes the
end with the small stiffener correctly, because the topmost major "rib"
(corrugation) has a flattened bottom edge.

Intermountain's end without the stiffener (which I believe is the second
or later version in the IRC timeline) is the only correct end for SP 12 panel
cars, some GN 12 panel cars, and is incorrect for SP 10 panel cars.

Tim

--- In STMFC@yahoogroups.com, Anthony Thompson <thompson@...> wrote:

I wrote

The two SP prototype classes of 12-panel box cars DID have the thin
top stiffener. I hope IM did not remove that stiffener in order to
model the SP cars <g>.

Tim O'Connor replied:

Tony, this one doesn't.

http://www.speedwitch.com/Images/models/sp21622.jpg

Perhaps we are descending into the Swamp of Definitions.....

Hey, I am just relieved to find out I am not the only one confused by
this conversation! I'm in good company this time...;-)

Chris Frissell
Polson, MT
(*sitting here wondering there the GN-built SP&S 12-panels fit in,
having heard at least two conflicting accounts on their ends from
other sources...but perhaps now is not quite time to ask*)