Christopher Brimley updated September 8, 2011


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  • A simple-to-Build Scratchbuilt On30 Engine Shed

    by Tom Houle

    Photos and drawings by the author

    Model Railroading - July 2005 - Page 28

    When I launch a scratchbuilding project, I typically search all the prototype books, magazines and Internet references I can access for drawings and photos. I spotted this project in an excellent book I purchased from the Chicago and North Western Historical Society, C&NW and CStPM&O Locomotive Facilities/Engine Terminals Book I by A. Joseph Follmar. The drawings and photo I used are on pages 14-15. Since I needed an early 20th century engine shed for my C&NW and Soo Line branchline, the single clear photo and original C&NW framing drawings were all I needed to get started. This particular shed was built in 1887 in Redwood Falls, MN, and sited adjacent to an "armstrong" turntable. In my grade school years I spent many happy hours prowling the Redwood Falls C&NW railyard. I recall the armstrong turntable being turned by engine crews, but I dont recall the structure. By the 1940s, the shed had probably been torn down.

    This sort of structure is perfectly suited to house a standard or narrow gauge 2-8-0. Since I putter with On30, Randy suggested I do the project in On30, and so it was. For those of On30 ilk who prefer to mimic a prototype, the C&NW at the turn of the century, did operate a 3' gauge line from Minnesota into Iowa. The entire roster consisted of a couple of coaches, a few boxcars, and a pair of diminutive 2-6-0s. Passengers who rode the narrow gauge affectionately termed it the dinky. My project closely follows the C&NW Redwood Falls prototype. Its footprint is 20' x 65' (5" x 16.5") in O scale.

    The model is built of Northeastern Scale Lumber basswood sheet and strip stock with 1 /32" ply cores for the shed doors. You could just as well frame, clad and roof it in styrene.

    This is the first structure Ive built with exposed scale framing. It required more fiddly work, but I think the results warrant the extra effort. One thing Id do differently next time is pre-stain the framing strips before cutting and assembly. Joe Piersen of the C&NW Historical Society said the interior shed walls typically were not painted. Since I didn't pre-stain (an oversight), I had to paint the shed interior walls a light gray to hide the glue evidence. On my next exposed framing project, Ill age the bare strips and interior siding with a product I discovered at Walthers A.I.M. Products Quick Age. I recommend it for imparting the look of an unpainted smoke and soot stained engine shed interior. It comes in 16oz. bottles and can be brushed or sprayed. It reminds me of the traditional india ink and alcohol formulation. I tried spraying and brushing it onto bare basswood with equally excellent results. A 16-oz. bottle goes a long way.

    Model Railroading - July 2005 - Page 29

    Sidewall Construction

    I began shed construction by cutting the studs and horizontal fillers for the sidewalls. If you want unfinished studs, prestain the basswood strips before you cut them. The horizontal filler strips were inserted on the prototype to brace the relatively long studs and also served as nailing surfaces for the board-and-batten siding butt joints. I used 1/16" x 1/8" basswood strips for my studs. In O scale these scale out to 3" x 6". Close enough to replicate rough-sawn 2" x 6" studs. If you're modeling in HO, I believe you can buy correctly sized studs. You'll need to cut a lot of studs and fillers for this structure. My NWSL Chopper turned this tedious task into a simple chore. I used a stop block on the Chopper to cut the studs and fillers to a uniform length. If you're doing any scratchbuilding, life is better with the Chopper.

    I launched actual wall construction by laying waxed paper and a copy of the sidewall drawing over a 20" piece of acoustic ceiling tile. You'll need a tin of straight pins to hold the studs in place for gluing. I assembled the walls dry, i. e., no glue until the walls were completely assembled over the plans.

    First, I pinned down the lower plate, then the studs, followed by the upper plate. The horizontal spacers go in last. The upper and lower spacers are held in place by their adjoining studs. If the spacers wander up or down as you go, thats okay. They did the same thing on the prototype. There are 46 studs in each sidewall. Take your time. Id do 10-15 studs and then take a break. Its just like building real stud walls; tedious work but at the same time kind of fun to play O-scale carpenter man. When all the studs and spacers were in place and aligned to my satisfaction, I carefully wicked slow-setting cyanoacrylate (CA) glue into all the joints. A bit of kicker speeds up this process. The waxed paper peels easily from the finished stud walls.

    If you're concerned about the strength of these open-framed walls, consider this: I block sanded my walls with 150-grit paper with no problems before I added the basswood siding. The CA glue is quite strong and leaves virtually no glue filleting.

    End Wall Construction

    The two end walls are built in the same way. I cut all the angled studs to a common angle on my NWSL Chopper. The door end is built entirely of 1/8" square timbers. This follows the prototype, which was framed with 6" x 6" lumber. Depending on your layout and loco service trackage, you could build this shed with doors at one or both ends. Either way it follows the C&NW prototype. When the four walls were done, I erected and dry-fitted the walls to ensure everything lined up. The structure looked pretty neat in its skeletal state. Note that the end walls fit between the two sidewalls. Overlapped siding and right angle corner trims will effectively hide those corner joints.

    When the four walls were done, they were erected and dry-fit to ensure everything was in alignment.
    Model Railroading - July 2005 - Page 30


    I considered using 1/32" basswood siding, but I wanted board-and-batten siding to replicate the prototype, and Northeastern Scale Lumber board-and-batten siding is only available in 1/16" thickness, which does add considerable strength. When the structure is done, the added wall thickness is not apparent until you remove the roof. I added 5 /32" of height to the siding above the top plates to allow it to extend upward between the rafters. These siding extensions will be notched to clear the rafter ends. I butt-glued the siding to match the overall sidewall length before I applied the siding to the framing. It may be just as easy to separately glue each piece to the framing.

    The end walls are sided just like the sidewalls. I centered a batten on the peak of each end. The end wall siding is extended 3 /16" beyond the framing to overlap the sidewall ends. Use glue sparingly when attaching the siding. You dont need much. Any excess will ooze into the interior framing where it will be impossible to remove. After the four walls were sided, I noted a tendency for the sidewalls to bow slightly. To correct this, I weighted down the sidewalls on a flat surface and kept them that way until the four walls were joined.

    Exterior view of unfinished sidewall with siding and windows in place.
    Model Railroading - July 2005 - Page 31

    Shed Doors

    The shed doors were done next. To maintain some semblance of scale door thickness I considered using styrene, but ultimately decided to stay with basswood to ensure the finished door paint would match the siding paint. I built my doors using Northeastern Scale Lumber. Each door has a 1/32" plywood core faced on both sides with Northeasterns 1 /32" thick 1/8"-scribed basswood. The door thickness without the inside bracing is 3/32" or a scale 41/2". Thats not too bad. And this door construction wont warp at least mine havent. Dont forget to cut the mandoor into the right hand door.

    Its uncharacteristic as engine doors go, but these doors are only braced on their inside faces. Its a unique look that I liked plus I didn't have to bother with bracing on the exterior faces. On the inside faces, I used 1/32" x 3/16" basswood strip bracing. The prototype plans showed a pair of 9-pane windows cut into the doors. The Redwood Falls, MN, prototype had no windows in its doors so I left them off. Curiously, the sidewalls on the Redwood Falls structure had only two windows per sidewall. The drawing showed three per side. I chose to follow the Redwood Falls structure window arrangement. It must have been kind of dark inside the shed on those short snowy Minnesota winter days.

    The doors are hinged with Grandt Line working hinges (#3524). To ensure the door hinges were aligned with their respective hinge posts, I alternately threaded three fulllength hinge straps and three more hinges with their straps cut off (to serve as the hinge posts) onto a length of .020 brass wire about 8" long. Make two of these - one per door - and be sure each hinge post is located under its corresponding hinge strap.

    Next, I taped both doors into the doorframe with masking tape. I applied the masking tape to the inside faces of both doors and then laid the end wall on a flat surface with the exterior facing up. Then I carefully taped the two brass hinge wires in place, ensuring the wires ran vertically and parallel to the doorframe.

    I glued the brass wires into the hinge posts with minute applications of CA. Do not glue the hinge straps. Take care to keep those hinge straps away from the hinge posts when you glue the wire to the hinge posts. When the glue had cured, I slid each hinge strap into place directly above its respective hinge post and glued the hinges to the doors with minute applications of CA. Satisfied that no glue had wicked into the hinges, I cut the brass wire about 1/16" above each hinge so that the wire projected just enough to hold the working hinges. This loosely termed hinge jig ensures your doors will open and close. With both doors attached, I added a length of 1/ 16" square basswood strip to the inside top of the door opening. The stop prevents the doors from swinging inward.


    I painted the interior sides of the walls before I assembled them. The interior color of these sheds is anybodys guess. I checked with the C&NW Historical Society and no one could recall for sure if the interior walls were even painted much less suggest a color. I tested several shades of gray on scrap basswood, before I settled on Floquil SP Lark Light Gray. I lightly airbrushed the paint, trying to avoid uniform or solid coverage.

    The C&NW shed drawing showed a brick chimney on the inside of the structure that ran straight up and through the roof. It didnt show a potbelly stove. I assumed a stove was used and that it used the chimney as a flue. In O scale, the chimney scales out to 9/32" square. I made mine from basswood and covered it with styrene brick sheet. Its attached directly to the studs, and its top is angled to match the roof angle.

    A view of the interior after painting. Note placement of chimney.
    Model Railroading - July 2005 - Page 32

    Rafters and Roof

    The rafter trusses were built next. I fashioned mine from 1/ 16" x 1/ 8" strips. Youll need to make 25 of these trusses. To speed up construction, I made a bunch of photocopies of the rafter truss plan so I could build several trusses in a single sitting. I precut the rafter components on my NWSL Chopper. This ensures the angles will be consistent from truss to truss. I built my trusses just like the walls, on a piece of ceiling tile that accepted straight pins. Waxed paper is laid over the drawing. When the trusses are done, set them aside and cut out the roof panels.

    There are two roof panels, which I cut 3 13/32" wide x 171/4" long from 1/32" Northeastern Scale Lumber birch plywood. I laid out the locations of the trusses on the underside faces of the two roof panels. Tape the two panels together when you do this layout. The truss locations should be aligned with the wall stud locations. I built up a simple 1/8" x 1/2" strip angle jig to ensure the two roof panels were joined at the correct angle. That done, I taped the outside faces of the two roof halves together and laid the roof into the jig. I ran a thin bead of CA down the inside roof ridge seam and then hit the seam with a shot of kicker. Presto! I had a correctly angled roof. I left the roof in the jig and then glued the trusses one by one into the roof. The trusses added quite a bit of strength to the roof.

    In retrospect, it might be simpler to glue all the trusses to one roof panel and then glue the other roof panel onto the trusses. Either way, its sort of tedious work, so work slowly. A bit of patience and a couple of coffee breaks will reward you with a nifty looking roof and exposed rafter ends. All thats left on the roof are the smoke jack, brick chimney and roll roofing.

    Exterior view showing placement of smoke jack and chimney.
    Model Railroading - July 2005 - Page 33

    I made my smoke jack from Grandt Line parts, 7/16" OD styrene tube and 3/8" birch dowel. If you prefer not to build your own jack, you can buy a complete smoke jack kit from Grandt Line (#3512). My drawing shows the C&NW jack layout. Note the stack tapers inward from bottom to top; that feature I didn't copy. Before I attached the smoke jack to the roof, I drilled a pair of .025 holes at right angles through the top of the smoke jack pipe. After the stack is installed, .005 brass guy wires are threaded through these holes and then secured to the underside of the finished roof.

    With the smoke jack assembled and ready to install, I cut a hole through the roof, inserted the jack, sans the interior smoke collector, into the opening. I then attached a Grandt Line #3512 smoke collector. The jack is glued at the roof ridge and the smoke collector is glued at those points where it contacts the roof trusses. On the prototype the smoke jack can be raised or lowered onto the loco stack by means of chains and weights. (Something I didn't know until I built this shed.) I set my smoke collector about a scale 6" (1/8") below the rafter cross ties. Did you know that early engine sheds had the smoke jack installed at the far end from the doors? Later the jack was located at the end nearest the doors, and the locomotives were backed in. Yes, this took extra work on the turntable, but it eliminated having the loco stack run the interior length of the shed, which must have filled the shed with smoke and flue gases. Lack of a turntable might also have forced the locos to enter front end first. I positioned my smoke jack as if there were a turntable...its the least I can do for my O-scale crews. I painted the smoke jack flat black.

    I added the brick chimney next - a Grandt Line #3509. I tapered the bottom of the chimney to match the slope of the roof and located the chimney so it was aligned with the chimney section below the roof. The Grandt chimney is painted oxide red with add-on acrylic mortar lines.

    The C&NW photo didn't show the roofing, so I chose to use what I thought was likely - asphalt roll roofing. You could also use asphalt tabbed shingles or cedar shakes. However, the shop foreman might raise his eyebrows at those cedar shakes and maybe make you buy him a ladder to set alongside the shed in case those shakes catch fire...and he's got to get some water up on the roof. Roll roofing comes in a standard 36" width. I laid out corresponding reference lines that ran the length of the roof. In O scale, the first line is drawn 3/4" up from the eave. From there, the remaining lines are spaced 5/8" apart to allow a 1/8" roofing overlap.

    Some people use 3/4"-wide masking tape to simulate roll roofing. Ive tried it, but I dont care for the look of the masking tape at the overlaps. The tape is too thin to suit me, and the overlaps tend to be too apparent. For this job I cut 220-grit waterproof sandpaper (color isn't important) into 3/4"wide strips 11" long. I attached the strips with Aleenes Original Tacky Glue. White or yellow glue will work as well, but I hesitate using these glues on large thin plywood surfaces. My experience has been thin ply or basswood will warp while these glues are setting. Aleenes doesn't seem to create this problem. It works well for wood to paper joints, dries clear, and is available in most craft stores.

    As you apply each strip of sandpaper, the sandpaper will tend to curl slightly. I correct this by adding strips of masking tape to hold down the applied rows of roofing. The tape prevents curling while the glue cures, and it readily pulls away from the sandpaper when the glue has cured. I capped the ridge with a 1 /2" wide strip of sandpaper folded into a V-shape. I let the roof sit for a day to ensure the glue had thoroughly cured. I masked off the painted smoke jack and chimney and then sprayed the raw sandpaper roof with a spray can of Testors Red Oxide Primer. It took three light coats to achieve solid coverage. I airbrushed the underside of the roof with Floquil SP Lark Light Gray to match the interior walls. As on the interior walls, I sprayed just enough paint to get a light seethrough coverage. An overspray of Floquil Grimy Black will be applied later down the center of the trusses to simulate stack soot and ash build-up.

    Interior details were added.
    Model Railroading - July 2005 - Page 34

    The Grandt Line #3714 windows were addressed next. I sprayed them with a can of red oxide primer from Ace Hardware. I like to keep a can of Ace brand flat black, red oxide and gray primer on hand. These paints are an excellent and inexpensive way to spray finish coats onto basswood and styrene structures, roofs, windows, and even certain rolling stock. I can decal right over these paints and they readily accept Testors Dullcote.

    I hate glazing windows. Accurately cutting those clear plastic upper and lower sash panes is difficult at best. And in the loco shed they had to fit perfectly because the interior sashes of the Grandt windows are exposed to viewing. I wondered if there was a better way. I posed my concern to Chris and Randy at Model Railroading. They suggested I look into laser-cut Grandt Line window glazing from Stevens Creek Models. Id never heard of those folks. When I visited their website at I discovered a cool line of HO and O scale Grandt Line window glazing sets. And their prices are right very reasonable. I had my glazing kits within a week of my mail order. The panes fit perfectly. I held mine in place with dots of Aleenes Original Tacky Glue, which dries clear. R/C airplane canopy glue also works well. I believe its called RC 56.

    Before installing the five windows into the shed walls, I brush-painted the exterior walls with Delta Ceramcoat acrylic paint. This paint comes in a huge array of suitable railroad colors, and its available in most craft stores. Right from the bottle it flows out nicely on bare or primed basswood. I use a lot of it on my basswood structures. I dont recommend brushing it onto styrene because it doesn't cover well and tends to build up. Someday Im going to try thinning it with rubbing alcohol and airbrushing it onto styrene. I used Brown Iron Oxide on my shed. Let it sit overnight to adequately cure.

    Wall assembly is next. I used Aleenes Original Tacky Glue for final assembly. CA glue would be faster, but the risk of getting corners that arent 90 is much higher as the CA sets so fast. Aleenes give you time to accurately position the corners. I used scraps of square-cut basswood to ensure the corners were at right angles. Masking tape held the sides together until the glue cured. The corner joints were hidden by adding 3/ 32" Northeastern basswood angle strips. I painted these strips Brown Iron Oxide.

    The prototype used exposed poured concrete footings, which I simulated with 1/4" wide x 3/8" high basswood strips. The 3/8" footing height I used works well with 3/32" thick ties and code 100 rail. It will afford adequate interior stack and cab clearance for most O and On30 locos. However, its a good idea to make sure before you set your footing height. I brushpainted the footings with Delta Ceramcoat Mudstone before I cut them to fit. They are glued to the bottom edges of all four walls except beneath the doors. The footings are set in 1/32" from the board-and-batten siding.

    Adding glazed Grandt Line windows completed the walls. I thought the windows painted red on both sides was enough detail for the interior windows. With exposed studs I dont think there would have been interior window trim.

    I didn't add an inspection pit. On my road, the shed is used only for light maintenance and keeping my steamers out of the inclement Wisconsin weather. If you do choose to add a pit, it would be 3 ' to 4' deep and the width of the inside of the rails. The pit would typically run threefourths the length of the shed. The rails would run on timber or concrete supports. My C&NW drawing showed poured concrete walls and floor for the pit. There were no steps into the pit. I guess a guy just had to hop in and out of the pit or use a ladder.

    I detailed my shed interior with an assortment of shovels, oil drums, car jacks, kerosene lanterns, oil cans, bench grinder and a potbelly stove. These came from Berkshire Valley, Evergreen Hill and Sequoia Scale Models. I scratchbuilt an oil drum rack, a pair of workbenches, and concrete and wooden platform flooring. I didnt add a floor as the C&NW structures were built right on the dirt, then the floor was strewn with cinders. Much more detail could be added and will be at a later date when the shed is finally installed on my layout.

    I posted a note to the Yahoo O Trains Group requesting information on the interior detailing of a typical engine shed. Ed Bommer, a great O scale modeler and rail historian, shared his thoughts, which I found useful and thought you might also. Heres what Ed had to say:

    "For a shed to simply store an engine between service runs, it would be built right over a stub-ended track. The shed might be constructed of brick, stone or wood, but wood of course was prone to catching fire. At the turn of the century when many of these sheds, including mine, were built, steam locos still had a lot of wood in their superstructures. A shed sheltered these locos from the weather. Rails were on ties or length-wise timbers if there was a pit. The ties were buried in the dirt and covered with cinders to assure good drainage of water that inevitably dripped from the loco. The smoke jack could be lowered over the loco stack with a pulley and weight arrangement to route smoke up and out of the shed. The smoke jack would be located where the loco stack would be when it was laid up in the shed.

    "Depending on the shed size, there could be a small corner office-room with a stove. There was no need for a stove in the engine bay, as the engine itself would warm the shed. The tiny office would have a roll-top desk with pigeonholes and a chair. The railroads kept a lot of records on paper. Somebody would likely be there, day and night. There would also be a privy out back and not too far from the engine house - probably a one-holer.

    Model Railroading - July 2005 - Page 35

    "There would be workbenches and tools; large wrenches would be hung on the walls to cover ongoing valve train adjustment, rod bushing replacement, etc. Steam locos were like Italian sports cars they - needed lots of tinkering and care.

    "An inspection pit was needed to work on inside-hung Stephenson valve gear. Driven by cams on the driver axle, this valve gear had to be reset from time to time. The pit also enabled other work to be done on the running gear, equalizers, springs, etc. And dont forget there should be a minimum of six heavy-duty screw jacks in the shed. (Mine only has four.) The pit might have a brick floor and masonry walls upon which the rails were set. Poured concrete could be used as well.

    "If a loco had to have its drivers turned, a drop pit would be used. This type of pit had a small piece of track on an elevator in the pit. Once the driver set had been disconnected from the loco, it was dropped below track level, slid out from under the loco, and elevated to floor level where it was rolled by hand to the wheel shop. An alternative would be an overhead crane capable of lifting the loco off its drivers. The crane would lift one end of the loco high enough for a driver set to be taken out sideways. 12" x 12" timber cribbing would support the loco frame until the driver set was reinstalled. The drivers still in place would remain on the track.

    "For this sort of operation, long workbenches would be located along both side- walls of the shed. There would be more tools, too; large wrenches, sledge hammers, small jack-cranes for carrying drive rods, plus an assortment of machinist gauges and squares.

    "If rod bushings were cast in the shed, youd find a small foundry in a corner, containing a blacksmiths hearth, crucibles with long handles for melting and pouring the brass along with a heavy workbench and clamps to hold the mold patterns while the bearings were poured. These old bearing foundries typically occupied about 12 square feet of space."


    Id like to thank Ed Bommer for his shed interior input along with Joe Follmar for his excellent book and Joe Piersen who provided additional information about C&NW prototype engine structure practices. With their help and expertise I feel pretty sure my engine shed is a reasonable replica of the real thing.

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