Denver, South Park and Pacific Railroad
The Double-Board Roof
John Maxwell's plans for some DSP&P house cars have the notation
"double-board roof" so it appeaars likely that most were built
with this kind of roof. Early cars may have had a single-board
roof at first. All of Ron Rudnick's drawings of DSP&P
house cars show wood-board roofs.
Since the large scale commercial models lettered for DSP&P have
a form of metal (Murphy) roof, I wanted to backdate the roofs on
my cars to represent the 1885 era, well before metal roofs were
in common use. The first Murohy metal roofs didn't appear
until 1906 and photos of C&S era cars show no evidence that
these or similar roofs were ever applied.
Below is the reasearch that I could find on the Internet on the
subject of wooden roofs, followed by my solution to retrofit
wood roofs to large scale models.
Some
Board-Roof Definitions
Four general
styles of roof construction were used in the 1880's on boxcars
and refrigerator cars:
1: the double-board roof
2: the single board roof covered with tin or other sheet
metal
3: the sheet metal roof protected by a single layer of
roughly matched boards
4: a double roof consisting of an inside roof covered with
felt, tar paper or asphalted canvas and
an outside roof built over it to
protect the roofing material from injury.
Ridge pole -- runs the
length of the car along the centerline, under the roof, forming
support for the
peak of the roof.
Purlins or purlines -- beams that run the length of the car,
spaced between the ridge pole and the
exterior wall of the car to support roof boards.
Carlines or carlings -- beams that run from the car side wall to
the ridge beam, acting like rafters, to
support the purlins, which in turn support the roof boards.
Double board roof -- two layers of dressed 1x6 lumber, with
grooves to shed water, running from the
ridge pole to the car sides, painted before installation and
overlapped so that joints are offset from one
layer to the neaxt.
Single board roof -- a single layer of boards as above but
covered externally by tarred canvas or
sheet metal, or with sheet metal underneath with or
without tar paper or tarred felt between.
NOTE: on a self-supporting
metal roof, such as the Murphy patent roof, the carlines are
outside the roof, not underneath, and act as both support for
the roof and as a water-tight seal at each panel joint. There
are no interior caelines or purlins, thus giving an unobstructed
interior to the car. Panels and carlines were galvanized to
resist corrosion. The panel joimts and carlines were riveted,
and later welded, to form a "uni-body" roof.
Research
Results - Double Board Roof
The double-board roof was the most common,
well into the 1900's, but had disappeared on new construction in favour of all metal roofs by the early to mid 1920's.
As quoted on the
Pacific NG website "In the
construction of this roof only the best seasoned white pine
boards should be used. A common practice is to use boards
dressed on both sides and edges to a uniform size of about 7/8 x
5 1/8 inches and have two semi-circular grooves of 5/8 inch
diameter on one side, near each edge. (running the length of the
board). The purpose of these grooves in the top course of boards
is to catch and carry off as much of the water as possible,
keeping it out of the joints; these same grooves in the under
course catch and carry off such of the water as penetrates the
joints of the top course. As the grooves in the under course are
apt to become clogged with dirt sometimes the two courses are
placed in contact so as to increase the size of the channel for
carrying off the water. The boards of both courses are nailed to
the plates, purlines, and ridge pole. The edges and faces
of the boards are always heavily coated with paint before they
are laid. The pitch of the roof varies from 1 ¼ to 2 inches rise
per foot. The steeper the pitch the better the protective
qualities of the roof but the more dangerous to trainmen who
have to pass over it."
Cross-section of the two styles of double-board roof. It is not
known which was used on DSP&P cars. Only the version shown at
the top of the image is given in the Car Builder's Dictionary of
1879 and 1888. Note that the grooves are not at
the edge of the boards, as they are on V-groove
tongue-and-groove siding.
I used Bachmann simulated wood roofs to replace the Murphy style metal
roofs on my large scale DSP&P house cars, as shown later on
this page.
Another drawing of the double board roof, an out-take from
Robert Stears drawing of D&RG reefer #119.
Research
Results - Single Board Roof
The single-board roof became more common in the late 1880's and
early 1900's. It typically used wooden roof strips over each
joint in the boards and had metal inner roof to keep out the
water. There were many variations on the theme as car builders
progressed toward the self supporting metal roof.
The single-board roof was made of T&G 1" x 6" boards without V-groove
edges. Some had metal above the boards, some had metal below,
some had roof-strips covering each joint. Cross-section above
from the 1887 Car Builder's Dictionary shows 1.
roof strip, 2 metal sheet underneath boards, 3. roof ridge pole,
4. purlin parallel to roof ridge, 5. car side-wall sill, 6. roof
boards. I have never seen anyone model roof strips and most
models show V-groove boards.
Example
of the Double Board Roof
This is UPD&G boxcar 25192 on the ground near DSP&P tracks at St
Elmo near Aloine Tunnel in 1948 after more than 50 yeasr of
weathering and modification as a shed. The sawed-out roof area
shows construction details including the near-side purlin
rumming legthwise halfway between the car wall and ridge pole.
Photo from "Narrie Gauge Pictorial" Vol VIII.
<==
Closeup of the roof hints at the double board construction along
the lengthwise saw cut near the roof ridge. A carline is also
visible under the purlin, and the interior roofing below that.
A Double Board Roof Solution for Large
Scale Models
The Murphy patented "outside" metal roof didn't arrrive until
1905 so no DSP&P car could have carried one until well along in
C&S service.
Converting the poorly rendered Murphy roof on the LGB,
Delton, and USA Trains reefers and boxcars to a simulated wood
roof makes a huge difference. The cure is to purchase some well
used Bachman 933xx series boxcars at auction and snap off the
roof - it is simulated wood, and the only one available in
large scale. It needs to be shortened a bit in a miter saw to
replace the Delton and USA Trains roof, and shortened even more
for the LGB cars, then it just snaps into place. A little glue
makes it semi-permanent. LGB boxcars have the top door track
molded into the roof, so you will need to steal door tracks as
well as the roof, and glue them in place before installing the
roof.
After you steal the roofs from the Bachmann boxcars, what do you
do with the leftovers? Remove the trucks, underframes, steps,
grab irons (both sides and ends), and the doors and door tracks
(one side only). Glue two cars side-to-side, add a platform,
stairs, freight, barrels, people, signage, and (of course) a new
roof. Here I used three of the LGB roofs to make the two needed
replacements. You could use simulated corrugated iron or shakes,
depending on your taste. The trucks, or at least the wheels,
from the Bachmann cars are probably better than some on your
older rolling stock, so use these spare parts to upgrade, or for
another kitbashing project.
