Wire Height and Third Rail Standards for US Traction Routes

[wacampbell]

Its good to see a couple of traction routes under construction - the Riverland Lines and the electrification of the RW&A route. I have a couple of electric routes on my workbench also. It raises the question of standardizing wire height. Since our model trolley poles and pantographs are set at a fixed height, and don't actually follow the height of the wire, we need some standards so the traction locomotives will fit the route wire placement.

I did some research and it appears that RSC has set 5.5 meters ( top of rail to bottom of wire ) as the height for the european routes. The GG1 was initially released at this height.

For the NEC route, they used 6.4 meters. So the NEC stock is at 6.4 meters, and the GG1 was re-released for this height. Richard Scott's CNS&M interurban's are also at 6.4 meters.

What about the prototypes. The AERA/ARA recommendations ( from the 1924 Electric Railway Handbook by Richey ) is:

Trolly Lines - minimum 5.3 meters ( converted from 17' 6" )
Freight Lines - minimum 7.7 meters ( converted from 25' 6" )

The extra height for freight lines provides safety for a brakeman to swing a lantern on the roof of a freight car without touching the wire. A lower 7.2 meters is allowed if rules prohibit brakemen from using lanterns on the car roofs.

So it seems that the NEC height of 6.4 meters would be a compromise for either type of line. I find that passenger trolley's look OK running under 6.4 meters, but my freight locomotives look very squished - the pans are compressed down and its clear that no brakeman could stand on the running boards. I suppose we could introduce a new higher standard height for freight lines, but that would be annoying to have two wire heights in use. That is how we did it in MSTS and it was always a pain to have to release electric locomotives at two wire heights.

Have any of the traction builders given this any thought?

Wayne

Edit - added drawing - and changed thread title to 'Standards'

richey.jpg

[nsl714]

Hello Wayne,

At present it seems that the league of North American Traction construction includes you, me, and Bob (mrbob19). When I started the CNS&M route back in 2012, I was faced with choices on wire models. A unique problem was faced in that the CNS&M used catenary and simple span wire construction. Through experimentation, I found that the wire height for the NEC catenary matched the wire height of a model found with a tram track model for Railsimulator on UKTS (http://www.uktrainsim.com/filelib-info. ... leid=21191). Through manipulation of the track rule I was using (and still am), I was able to assign the catenary to the "fourth rail" category and the simple span to "overhead wire". Then Bob started his Riverland Lines initially with a European wire model at the 5.5 meter height. Richard Scott built the CNS&M car last year and the plan initially was to release it with the CNS&M skins at the 6.4m wire height and the Riverland version at 5.5m. For reasons of simplicity, much like you are suggesting, Bob recently switched to 6.4m wire height.

On standards, I have also read Richey's Handbook. In addition, I have a few CNS&M standard drawings (attached below). Their standard is 22ft/6.7m on simple spans and 22.5ft/6.86m on Catenary. In Milwaukee on street running, the minimum was 18ft/5.5m, but freight trains did not run here. As a matter of common sense, freight crews on the CNS&M did not ride the roofs of cars, instead riding the ladders on the sides of cars.

Then as now, I am not really proficient at modifying physical TS files beyond tweaking a track rule and stumbling through the blueprints of the interurban car. Based on my inexperience at the time and the relative ease to get the catenary and wire in one shot, I considered wire height of 6.4m on the NEC and tram track wire an acceptable compromise, and so it remains today. I do welcome any thoughts/insights you do have on the matter Wayne. Which height is currently installed on the L&PS?

Thanks,
Zach

[wacampbell]

The real L&PS had a nominal contact wire height of 7.0 meters ( 23' 2" ). My Railworks L&PS started out at 6.4 meters, but I didn't like the look so I raised it to 7 meters. Of course at 7 meters I won't be able to run anyone else's locomotives, so I am thinking of putting it back to 6.4 meters. I haven't decided though.

[nsl714]

One other item which has somewhat been shared by myself and Bob is 3rd rail dimensions. UK routes to date have offset it to 1.1 meters, but that is a bit tight for US purposes (primarily the Chicago Elevated and associated interurbans). I have a drawing from that too, and so the 3rd rail beams on the CNS&M car are set at that offset and height, which works to 1.24 meter offset from ceterline of track.

AE&C 3rd Rail.jpg

[wacampbell]

Thanks for sharing the third rail dimensions. Hopefully other builders will find this discussion and make their models compatible.

[nsl714]

Certainly. I can't think of too many other 3rd rail routes potentially being done outside of mine and Bob's, but there they are.

So on the L&PS wire, it was sort of in the middle. I can agree with the wire height looking "wrong". There are a few places where the wire squeezed down on the CNS&M, but for the sake of keeping tall places in the wire tall, they are at a raised height in game. One example is Lake Bluff, where the Mundelein Shuttle goes under the C&NW. It's pretty close to the roofline of the coaches (which is 12' 7" max). [as an aside, freight trains could and did clear this location frequently. It was one of two places to get to the "Shore Line" which ran down the lakefront to Highwood and Highland Park IL. This was the bridge with the greater clearance.]

Lake Bluff After Abandonment 1.jpg

How tall are the L&PS boxcabs over the roofline? The CNS&M's herd of steeplecabs ranged from 12' 1" to 15' 3".

[wacampbell]

How tall are the L&PS boxcabs over the roofline? The CNS&M's herd of steeplecabs ranged from 12' 1" to 15' 3".

The running boards of the L&PS boxcabs were at 13'. The pantographs could operate under wire between 4.6 m ( 15' ) and 7.3m ( 24' ) high.


Its interesting when L&PS bought some cars from the Milwaukee Electric, they had to raise the pans up on platforms to reach the L&PS wire.

[nsl714]

That is an interesting appendage they decided upon. I don't know how much shorter the TM cars were than the L&PS cars, but I wouldn't imagine that it was too much. Perhaps it was just short enough to warrant the extensions.

I've wanted to ask about your methods for catenary as well Wayne. I've noticed in your L&PS screenshots that you managed to get the catenary functioning while keeping simple span wire in the Port Stanley area. How is that? was it a similar method to which I did with the catenary/wire on the CNS&M, or is it a different type of pole which dictates what type of wire to string between them?

[wacampbell]

you managed to get the catenary functioning while keeping simple span wire in the Port Stanley area.

I think I did the same as you. The simple span wire in the yards is just the wire loft that is specified in the track rule. And the catenary is done with proper gantry blueprints for the towers etc. To prevent the simple span wire from appearing in the catenary sections, I set those sections to 'third rail'.

[nsl714]

Ok, that makes sense. Simple enough to get the desired result. Is that a regular gantry (like a telegraph line), or a catenary specific gantry?

Back to the original intent of this thread, it is my opinion that the wire height of 6.4m is a good baseline to standardize. My main argument for that is that it mimics the existing wire height of the DTG NEC routes, which if matched would interchangeability. In my experience I have found that most all pertinent rolling stock fits under this mark (from steam locomotives to era appropriate freight cars to cabeese.....the new Gtrax double stacks have yet to be tested ). And as you said Wayne, 6.4 fits as a happy medium between the AREA specs for streetcar and mainline electrification.

Thoughts?

Zach

(P.S. I seem to recall that the two wire heights in MSTS were 7.2m/23' 7" and 6.2m/20' 4", and everything fit where it was supposed to. Mainline electrics looked great under the 7.2, and the 6.2 was very well suited for the smaller traction. It makes you wonder why/how RSC/DTG came to the conclusion of 6.4m for their NEC wire...)

[wacampbell]

The L&PS catenary was done using Railwork's gantry feature. The towers are actually 'Gantry Blueprints' which define the wire attachment points and for each, the type of wire - ie straight, drooping, or catenary. There is a separate gantry placement blueprint that aids with semi auto placement of the towers and wires along the track. The actual catenary shapes are created procedurally by Railworks to interconnect the towers at whatever spacing you have placed them.

As you can see from the L&PS screenshots, I used a single catenary between each tower and three drooping power wires on the back of the crossarm.

I could also have made wooden poles and specified straight wire connections to simulate a trolley wire installation. The result would be that wherever I placed the wooden poles, for example on a siding, they would be connected with trolley wire, whereas the towers on the mainline would be connected with catenary. Its one of the most flexible and easy to use gantry systems I've seen. RSC did a really good job on it.


As for the wire height question, I would support standardizing on the 6.4m NEC height for both trolley and freight lines. Its a reasonable medium between the two AREA specs.