yard trusses

[cteno4]

interesting to see some of the trusses have bird wire all over them, guess those were just attractive to some birds that were either pooping too much or getting fried.

 

jeff

[gmat]

More bits and pieces.

 

 

 

 

 

 

 

Best wishes,

Grant

[gmat]

Last two. Taken north of Ueno Station.

 

 

Best wishes,

Grant

[KenS]

Those are great detail photos.  I'd never seen trusses with "bird wire" before in any photo. I wonder if this is a new development.  They seem to be all on main lines, as opposed to storage tracks, which is a bit odd.  Perhaps it's to discourage birds from roosting where they might fly into trains moving at speed?

 

Were all of those "bird wire" shots on the Keihin-Tohoku (or is that the Tokaido Main south of Tokyo and the Tohoku north of it, I've never been clear on that)? Could it be simply to keep trains through the tourist-heavy city center cleaner?

[gmat]

I'll look at some other lines for older trusses to see if others have the bird wire. I think that only older trusses have the bird wire, and they are being progressively replaced with trusses on concrete poles. The last two photos were of the parking area for the Takasaki line and Utsunomiya line special trains at Ueno Station. This is at the north edge of the station. The other two photos with the bird wire are west of Tokyo. I don't travel on that line so I don't know if it is a feature of the Keihin Tohoku line. The rusted condition of those trusses west of Tokyo would indicate that they are an older model, which being wider, may have needed the bird wire.  The newer trusses mounted on poles seem thinner and may have been designed so that they would not need the wire screen.

Best wishes,

Grant

[cteno4]

maybe they have little spikes on the top to poke their little feet! LOL

 

the new bird guard now is the spike strips which look as ugly as the mesh does!

 

im guessing if they dont give a good flat horizontal surface on the new ones for them to roost on that helps a lot. most of the new ones below have an upside down T or round stock at the bottom, where as the bird meshed ones have big flat horizontal stock to roost on comfortably! but then some of those trusses have nice big flat plates on the top of them, so maybe the mesh is not for birds?

 

in looking at the photos i am starting to think another option might be to build longer trusses out of styrene strip stock. if you make a jib and most of the parts are uniform length then pretty easy to cut up and lay into a jig for gluing up. with the V cross section design it should be pretty sturdy. probably a lot cheaper than doing a custom etch and maybe even less time in the long run as setting up the drawing and testing, etc is going to take some time.

 

cheers

 

jeff

[gmat]

Trusses at the Yamanote Depot next to Oimachi Station.

 

Sorry, have to shoot it through trees.

 

 

 

 

 

 

 

Best wishes,

Grant

[cteno4]

gezes Grant, you da man! great shots.

 

really interesting high truss with the walkway that connects to the yard building wonder what that is, just an overhead walkway to the office thru the yard?! looks like it does lighting as well.

 

thanks again for all these shots!

 

cheers

jeff

[gmat]

The Shinkansen line has bird wire covering their truss pylons. This is the section next to Osaki Station, where the Shinkansen has separated from the Yamanote line.

 

I believe that Japan used heavier truss pylons because of typhoons and perhaps earthquakes. The bird wire on the older box shaped horizontal trusses may be to prevent crows from building nests in the trusses. The later triangular shaped with the single bar on the bottom does not have enough area for a nest and the upper part would be exposed to the elements. That is why there is no anti-roosting spikes on current horizontal support bars for the catenary lines. Anyone who can help me with the proper terminology?

 

Views of the top of a horizontal truss. These were taken on the Meguro line where it emerges from  tunnel south of Meguro Station.

 

Not the best, but you can see the pattern of bolts on top.

 

 

Close up of the top.

 

 

 

So again, I think that the bird wire was to discourage nest building rather than pigeon droppings. Another possibility might be to prevent rats from gnawing the cables. I have seen anti-rat circular plates on support cables for truss pylons.

 

Best wishes,

Grant

[gmat]

Thank you cten04,

 

I didn't being a meter stick and couldn't measure the width/diameter of the truss pylon or poles, but used my backpack to give some clue.

First, the two types of pylons. Taken on the Tokaido line next to Oimachi Station. South crossing.

 

The new pylon, perhaps heavier, seems to be a bit lower than the older one.

 

Notice the use or outriggers to hold the cabling. This one has outriggers on one side.

 

You can see how the black conduit for the cables has been rerouted from the old truss pylon to the newer concrete pylon.

 

Concrete pylon.

 

Truss pylon.

 

The extra dark line near centerline is a conduit for cables, but I don't think that it is currently used.

 

Best wishes,

Grant

[KenS]

Great photos. That's a pretty substantial concrete pylon. Next to your backpack it looks close to a foot (30 cm) across.

[gmat]

Thank you, KenS,

This is one seen with outriggers on both sides. Sorry, I was in error is describing a dpouble outrigger. That statement has been deleted.

Taken on the north side of the vehicular overpass NE of Osaki station, Yamanote Line.

 

 

 

Notice anti-rat shield on wire.

 

More later.

Best wishes,

Grant

[Bernard]

Grant - great photos and highly detailed, thanks for posting. There are some large telephone poles near a wildlife park in Upstate NY, and some eagles have made nests on them. They are huge!

[inobu]

Thanks again Grant,

 

Jeff, I think this will be your best bet in the yard trusses.

 

 

It is pretty straight forward, you can use Kato's catenary for the height reference. The tubular design of the horizontal support makes it easy to build and extend from 4 to a 6 rail track width.

 

 

Inobu

[inobu]

Configuring it like this.

 

 

Inobu

[cteno4]

Inobu,

 

yes that was my thought of using metal or concrete round cross section uprights instead of the X braced columns you usually see in the large yards where the trusses span like 6 or ore track at a crack.

 

the horizontal trusses belowwere the ones i was thinking would be the easy etch with a simple V brace patter and they would just be folded over double to stiffen them.

 

also still thinking of trying these out of styrene stock. i did a truss test last year out of styrene strip stock glued together for a tower crane idea and it came out quite sturdy. once you make the template on the computer and then just pin it all down its not so hard to make them. kind of like building balsa wood airplane wings!

 

cheers

 

jeff

[inobu]

I'm trying the concrete method first we will see what happens.

 

Inobu

[cteno4]

inobu,

 

what are you using for your horizontal trusses?

 

my though on the etching was to just do long, continuous V braced truss, then make some larger V braces with a pole attachment (could be removed for attaching to vertical truss config) so that for the ends you could just snip out the last V and bend down the bottom rail at an angle for the pole attachment and glue in the larger V brace.

 

cheers

 

jeff

[inobu]

Looks like plastic is the most versatile

 

Kato's catenary design is the most practical 23-061. Their v braces are solid and tapered giving a visual illusion of being opened brackets.  

 

 

[smg id=1024]

 

 

Inobu  

[cteno4]

Inobu,

 

if you use a piece of T stock for the top strip then you could easily do the two sided bracing and just join at the bottom. making those V x section pieces would not be fun! you could create you own T stock with a flat strip and a small square piece.

 

once the drawing is done the etching is then done for like $40 to make a number of these. problem is if you screw up the etching you are out your $ and need to start over! i worry about learning the details of what works and what doesnt at $40 a pop. thinking if i go this route i will try a bunch of ideas and tests on one run then do a production run of what works, but will cost some $$$!

 

styrene is pretty cheap, but takes some time an patience to put together. also not sure how solid it will be once done with this thin of styrene to be close to prototypical.

 

cheers

 

jeff

[inobu]

Jeff,

 

I'm finding out that one needs to do a lot of planning and calculations.

 

The span of the truss is based on the turn outs used to create the yards track centers. #4 has 33mm centers and #6 has 48 and 49.5mm center spacing. Most tight yards use #4's

but the "yard variation kit" that people have are #6's.This created a issue on the spacing. Most yards are 12 to 20 tracks wide so that disparity adds up. 4 sets of 48mm is 194 mm verses 132 for the 33 mm.

 

I am basing my dimensions on Kato's catenarys because they work for the most part but the base/span width can make or break it.

 

Not sure if you saw that, I sure didn't

 

Redoing my number. 

 

Inobu

 

[cteno4]

Inobu,

 

Yes i have been thinking about this some. I was planning on trying to do the V braces in an integral number per 48mm (ie maybe 6 Vs per 48mm) and then do the trick of snipping the last couple off and adding the special angle ones to take up the slack for the pole. in the basic yard ladder its only the beginning track that has the 49.5 and the rest are then 48s so those extra can be made up with a tad extra at the pole ends. this way i could etch longer strips and cut them to 3 - 6 track widths as needed. also could easily etch on insulator connectors every 48mm then snip off ones not needed. these could get glued on later also at the exact track spacing as i doubt they would get much stress.

 

i have some of the tomix 3 and 4 track girders and they look ok, but limited to 4 track max and spacing is off for unitrak.

 

im going to see what the minimum cost is on the etching to try a dry run to experiment some. also hoping i could put a bunch of odd little things onto the girder run like ladders, railing, benches, etc that would be easy to draft out and fill the odd areas.

 

cheers

 

jeff

[cteno4]

ok i just got the prohobby truss set. turns out its tiny. only about 23mm underside clearance and 46mm in width. the girder sections (both horizontal and vertical) have material along both long sides (with V bracing in between) and 3 small connecting tabs between the sides that are the bending points so very easy to bend the 4 corners around. they do give two sections of uprights that are connected together so you could pop the height up to about 46mm clearance underneath, but its still only wide enough for a single track. you get two sets, one is about 2mm wide and the other 3mm.

 

im not quire sure what these little guys are made to be used for. not useful for a yard truss at all, too short for uprights even.

 

cheers

 

jeff

[maxa1]

Jeff, can you upload a picture of those trusses? Can they be soldered together to make a mast or two? Is the etching of brass or stainless steel?

 

Cheers

 

Max

[cteno4]

Doh i thought i had posted this! sorry bright shiny object syndrome here.

 

cheers

 

jeff