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doctorwayne
| Posted by doctorwayne on Friday, February 18, 2011 11:01 AM The roundhouse probably eats more space than the turntable, but you should consider whether or not you need either of them. Many prototype locations had turntables but no roundhouse - some nothing but the turntable at the end of the line. Others may have had an enginehouse but no need to turn their locos. My layout is a point-to-point-to-point design, (the third "point" is yet to be built) with a means to turn the locos (steam) necessary at each end. One uses a turntable, but I turned what was once a Vollmer three stall roundhouse into a shop building. It takes up less room, and its main purpose is as a scenic feature. It still uses a lot of space, but it's space that wouldn't be of much use operationally.
The second "point" uses a wye. These can also be space eaters, but I placed mine in a corner of the layout room, using what would otherwise be waste space.
The as-yet-unbuilt- third point will use a turntable and roundhouse, with either 5 or seven stalls. It will also be located in a corner of the room, with only the front of the roundhouse fully modelled. One side will be unseen and shortened severely, the other (along the aisle) will be more fully represented, but shortened as necessary. The stalls will be almost totally unuseable, with the structure not much more than a scenic backdrop. A friend who has an around-the-room type layout uses most of one wall as an engine terminal, with a large turntable, two roundhouses, and a couple of shop buildings. He's not too interested in operation, but enjoys photographing his large locomotive collection, and this area provides a perfect setting. Wayne
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tomikawaTT
| Posted by tomikawaTT on Friday, February 18, 2011 9:30 PM In my version of Central Japan there will be two turntables, because I absolutely have to be able to turn locomotives and cars end-for-end at those two places. Neither will have a traditional roundhouse - those weren't common in Japan. One won't have any kind of maintenance facilities, the other will be close to a rectangular shop building just big enough to get the welder and pipefitters out of the rain. My longer turntable will be 250mm long, standard JNR 20 (scale) meter size - plenty adequate to turn my 'big' steam (2-8-2s with short tenders.) The turntable at the far end of the branch will be 200mm long, the length of the absolutely longest anything that can ever reach it. Since I don't run Big Boys or PRR locos with Lines West tenders I have no need for a 135 foot HO turntable. Bottom line - include what you need to handle the operations you plan to run. If you need a yard and don't need a roundhouse, so be it. Chuc (Modeling Central Japan in September, 1964)
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doctorwayne
| Posted by doctorwayne on Sunday, February 20, 2011 12:07 PM Thanks for the kind words, Larry. The turntable is mostly scratchbuilt, although the bridge girders were cut and spliced from a pair of used (cheap) Atlas through girder bridges. These were cemented to a block of wood. The track is a section of Atlas code 83 flex. I removed all of the webs joining the ties, then re-spaced them to allow insertion of longer basswood ties, which support the planked deck. This maintains the track gauge with no additional spiking required. The decking is basswood planks, which I also had on-hand. I was going to throw away all of the basswood, as I much prefer working with styrene, but this was a good way to use it up. If I had used styrene, the total cost of the installed turntable would've been under $10.00. The pit was cut in a section of 3/4" plywood installed for this purpose (most of the layout is open grid, with plaster-on-screen landforms), then the cut-out piece was used to form the pit bottom. The centre bearing pedestal and the ring rail foundation were cut from good-quality 1/4" plywood, and the pit wall is a piece of 1/8" Masonite.
The control shack was built from scraps of Evergreen styrene siding, and the handrails were built-up using modified metal stanchions (from old-style Athearn diesel handrails), some brass tubing, bits of styrene and some piano wire. Yet to be built and added is a power arch. The ring rail is cut from another piece of Atlas flex, with the ties shortened using a utility knife. While it's not totally prototypical, it works well and looks passable. The bridge pivots on a beater shaft from a hand-held mixer, turning in a bearing made from a brass washer and some brass tubing. My original plan was to use the mixer mechanism, driven by a fascia-mount handcrank, for turning the bridge, but mounting the mixer proved difficult. Since the layout here is only 30" deep (and the pit less than 3" from the aisle) I opted for a full "Armstrong-type" bridge, powered by a well-placed single digit from my trusty 0-5-0 switcher. The other bridge rail is powered from the ring rail. I used a pair of slightly-modified freight trucks for current collection, with one wheel completely removed from each axle. The other wheels were replaced with metal wheels from an Athearn passenger car, two per axle and install face-to-face on the outer ends of the axles. These overly-wide double-flanged wheels easily accommodate any irregularities in the ring rail, and axle wipers transmit the power to the other bridge rail. I also added a rail wiper, which both picks up current and keeps the ring rail clean.
While my layout is DC controlled, I'm guessing that your connections for DCC would be similar, as this is the equivalent of a turning loop. Power pick-up is from an adjacent live track, and is routed through a dpdt centre-off switch mounted on the layout fascia. The various table and shop tracks are controlled through a separate rotary switch, a feature you wouldn't require for DCC. Because of the very limited space here, my nominal 90' turntable scales-out to an actual 89-footer. Wayne
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There are wipers beneath the pit which rub on the shaft, supplying current to one of the bridge rails. 
The weeds in the bottom (many tables used dirt bottoms, with solid supports only for the bearing points of the bridge) are an alternative to concrete or brick. They are sprayed regularly, but keep coming back. |
gandydancer19
| Posted by gandydancer19 on Sunday, February 20, 2011 1:05 PM
Thanks. The turntable and pit are scratch built. The pit was made with "speaker rings" and a Luan bottom. I forgot where I ordered them from but you can do a search for them. They are a wood composite product. The turntable is a length of wood, (Poplar). The pivot is a quarter inch phone plug with a metal cord cover. The plug is glued into a hole in the Poplar (you need a drill press to get the hole right), and the jack is mounted in the pit (Luan). The electrical connections are made from the track to the phone plug. Then from the phone jack to an auto reverser. The rest is jut detailing. The ring track / rail is a section of N scale flextrack cut down the center lengthwise. The track for the turntable is a section of code 83 Atlas snap-track. That makes the table nine inches long. You move it by hand. I guess its time to take some pictures of it. To me, simple is best. Elmer. The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961. (Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.
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