Page 116 - 39. MRH13-05-May2013

35
35: Next I needed to determine the spacing of the
major ribs. In studying the photo of Erie 72893 ( which
provides a good view of the roof ), I determined one
rib sits in the exact center of the car end-to-end.
Next, I counted rivets ( yes, I’m doing it again ) and
came up with a width of 20” from the edge of the roof
to the edge of the first rib. That dimension also puts
the rib under the running board corner that leads to
the ladder down the side of the car.
All this counting and measuring gave me three
reference points, so I marked these points with a
pencil line. When cementing these ribs in place, I took
extra care to make sure that they were square with the
roof, since the rest of the ribs will be built off of these.
I cemented 1” x 6” strips of styrene at these locations.
Starting in the center, I made sure that I was equal
distance from each edge of the roof to each edge
of the 1” x 6”. I followed up with the outside ribs
working the same methodology. Measuring in from
the end of the roof to the edge of the 1” x 6” and also
between the center rib and the outer rib.
STEP 8A: Adding the Major Ribs
The Erie Railroad Boxcars Part 2 - 5
STEP 8A: Adding the Major Ribs Continued ...
With the ends and the center set, I measured the
distance between the 1” x 6” and found it was 17’-
3”. I divided by 2 to come up with the distance to the
center of the rib which is 8’-8”. I then subtracted 3”
from that dimension which yielded 8’-5” This is the
distance between the edges of the ribs.
Once the mid-point rib bases were placed, there are
two rib bases to be placed in between all of the ribs.
As I cemented the ribs down I used my calipers to
make sure that the distance was equal for the length
of the roof. I found it’s easy to get a piece skewed a
bit, so this is a good check.
I followed the same procedure at the ends, except I
divided the distance by 3 since there are 2 ribs in this
space. This time I needed to subtract 12” from the
distance, the width of 2 ribs, generating a distance of
29” between the rib bases.
Again I used the calipers to make sure that the ribs
were equal distance as I cemented them in place.
When I finished, I had a 29” spacing between all the
rib bases.
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MRH-May 2013