Cantenary lines

[tomikawaTT]

Update on Japanese catenary bridge spacing:

40 meters (2 standard passenger car lengths) seems to have been standard for the 1500VDC system, but some of the higher voltage AC systems went to 50 and even 60 meter spacing, probably because the higher voltage permits using lighter contact and messenger wires.

Where there are two or more parallel tracks under wire, the usual standard calls for hanging the wire under a light truss span supported at both ends. Pre-WWII lines used square cross-section steel truss "poles," while more recent installations usually use circular cross-section concrete poles of the type used for ordinary power distribution. Both types could have one side taller, to carry power and communications lines well above catenary level.

Single track catenary is usually supported by single arms from individual poles. Spacing might be a little closer on single track, since the support system is considerably less robust than the multi-track variety.

Signals were always mounted on their own support structures, usually masts, never on the catenary support bridges.

Since contact wires have to be kept within about 150mm of the track center line, the overhead above complex specialwork gets VERY interesting. There is also a system of weights and anchorages to keep lengths of contact wire tensioned. If done by a rabid rivet counter (which I am most emphatically not,) a catenary system could easily become a Master Model Railroader project.

Possibly the best way to handle the down sides of catenary is to adopt the system used by many Japanese modelers. Install the catenary bridges, substations and so forth. Just don't string the actual wires, and leave plenty of overhead clearance for raised pantographs.

Chuck

[ndbprr]

The distance between supports is a function of gravity and wire size. Gravity makes the wire sag and at a certain point the tension will part the sire before the sag is eliminated. The top wire is the catenary. Vertical wires then hang from the catenary that hold a second wire parallel to the rails. i believe that wire is called the messenger wire. A special clip shaped like an hourglass then holds a contact wore below the messenger wire that is the contact wire for the pantograph shoe. Yes pulloffs may be used on curves and are a necessity on model railroads. I would suggest that scale spacing of cat poles on a model railroad will not look correct but will appear to be too far apart. At least that is my experience. Also plan to leave an area or track for putting equipment on the track where there is no catenary. Trying to rerail something under wires is a bear - again from experience.

[tomikawaTT]

Welcome to the forums, and the wonderful world of modeling Japanese prototype in 1:150 scale (unlike American N scale, which is 1:160.)

After checking a variety of prototype photos, it appears that JR catenary bridges are 40 meters apart on tangent track. On curves, the spacing seems designed to keep the contact wire within about 150mm of the center of the pantograph shoe.

Not immediately obvious, but on tangent track the contact wire isn't exactly on the centerline except at every other catenary bridge. It runs center - offset right (150?mm) - center - offset left - center - ...

Are you planning to model the 1500VDC system, the 60HZ AC system, the 50Hz AC system or equipment which can transition across all of them. Your choice of prototype location and era will determine which to use, which, in turn, will drive your choice of rolling stock. As you probably already know, there is a vast variety of Japanese EMU cars as well as quite a few different electric locos. Since privatization, there is also a whole new crop of color schemes!

I personally model 1964, DC catenary - a combination with which I became intimately familiar "back when." That simplifies my life.

Once again, welcome.

Chuck (who models in HOj, 1:80 scale)

[tgindy]

I am also planning an n-scale traction layout, and know just like you going in, that there will be a lot of scratchbuilding involved for the free-lanced Conemaugh Road & Traction.

NCat has developed highly recommended n-scale traction standards...

NCat Catenary Standards: [1] height above railhead must fall within the limits of 19-22 scale feet; [2] .010" phosphor wire is recommended for the contact wire for best operation & appearance; [3] six inch maximum spacing between poles on straight track, and; [4] closer spacing than six inches as needed on curves.

NCat Pantograph/Trolley Pole Standards: [1] so designed and mounted as to not snap shut above 17 scale feet and shall reach at least 23 scale feet above the railhead, and [2] upward force to be between 5-7 grams.

P.S.: Two of the better n-scale catenary manufacturers include Tomix and Somerfeldt, and; there are others and links available if you look up two of the best n-scale specific traction website references...

Yahoo Group's "nscaletraction" => http://groups.yahoo.com/group/nscaletraction/?yguid=233759921

"NCat Live Catenary" => http://www.teamsavage.com/ncat/ncat.html

nscaletraction has members experienced as n-scale traction scratchbuilders, and; NCat also has four types of manuals for dozens of n-scale projects which they make available for purchase periodically.

There are two PDF editions of "NCat News" => one at NCat and one at nscaletraction for download, and; nscaletraction has many discussions centered around European and Japanese n-scale traction resources.

[DSchmitt]

In thr USA: On tangents the typical pole spacing for direct suspenion wire (trolley wire) is 100 feet. Typical pole spacing for catenary 300 feet. Spacing is, of course, closer on curves.

Source Model Traction Handbook by Paul Mallery and Steven Mallery

[GN-Rick]

Try to contact the member of the forum who calls himself tomikawaTT. He is
also doing JNR modeling. He might have your answers. Hope this helps.

[Anonymous]

i have been looking everywhere google, yahoo and can not find out how far apart cantenary poles are placed also telephone poles i am buiding a japanese electric rail system done know if the disance apart is any different
my layoout will be in n scale but the proto type figures would be fine sincerly Jim