HANGING SIMPLE OVERHEAD WIRE FOR TROLLEY POLE USE
by George L. Huckaby

January 1996
Rev. January 1998
Rev. May 1999
Rev. Feb 2006

INTRODUCTION

Growing up in Philadelphia, Pennsylvania in the early fifties, I had the pleasure of seeing and riding the Nearside cars,the 1923-1926 Peter Witts (modernized and unmodernized), the double end 1923 cars (modernized and unmodernized), the 1907 Market Street Elevated cars, the 1922 Frankford Elevated cars, the 1940-1942 PCC air cars including 2070 in its striking white, green and orange paint scheme, and even an occasional "Hog Island" car, all at a time when they were somewhat adequately maintained. By 1955, it was obvious to me that most of this would all disappear soon and I wished to maintain my memories by modeling in HO scale. Still a teenager, I bought my first two cars, a Pennsylvania Scale Models (now Bowser) Brill Suburban Car and an all-electric PCC car, each for less than $20.00. I gave them both unprototypical and unprofessional paint jobs and began to find out how to hang overhead trolley wire. My first layout was completed in 1962 and the overhead was atrocious but it worked. After entering the Air Force in 1965, I did not attempt to do this again until 1975, when I constructed a 3' by 6', seven track car barn module. By 1983, my stint with the Air Force was over and I began to build another module. By this time, I had seen enough model trolley overhead wire, read many articles by other traction enthusiasts, and had developed sufficient dexterity in soldering to attempt the "ultimate" in HO trolley wire. I started to put this article together in 1986. When I started conducting workshops in 1996 at the Great American Train Shows in California, I updated the article and what follows is the result of that update after 35 more years of traction modeling. The following article describes the methods currently used by the Southern California Traction Club in constructing operable overhead trolley wire.

PROTOTYPE VERSUS MODEL

There are many areas where we must differ from the prototype because of the differences in scale and practicality. On an actual trolley line, a city curve may have as many as 15 overhead hangers in a 90 degree turn. In fact, the Pacific Electric in some cases used twice that many. In model practice, I limit hangers to no more than one per every 2 inches. This means that for an 8 inch radius curve, the radius of the outer rail is about 8.5 inches and the inner rail is about 7.5 inches. It follows that the radius of the overhead would be about 7.75 inches, if overhead could be made to follow a perfect circle. In reality, the overhead will consist of chords, whose ends touch that imaginary circle. At these points, the hangers are positioned. From geometry comes the rule that the circumference of a circle is equal to the radius multiplied by 44/7. Therefore, with a circumference of 48.71 inches, there would be 24.35 hangers in a complete circle. This would be seven in a 90 degree city turn. Most trolley wiring articles indicate that you can use less and you can. I happen to like this amount. More than that amount makes it more difficult to clean the track and to have access to your cars, and makes it easier to break a wire, doing either one of those tasks. But if you do, having constructed your overhead using this method, you can usually repair it quickly without heating up a soldering gun.

Another difference of models concerns the location of the trolley wire over the track. In the prototype, the contact wire was located as directly over the center of the track as possible. This was critical with the use of trolley wheels. These brass wheels, after some ustended to climb right off the wire on some occasions. Because of the pressure (28 psi) required to keep a brass wheel rolling on the wire, dewirements at speed were sometimes disastrous. Positioning the overhead wire became less critical with the advent of the trolley shoe. Also trolley shoes required much less upward pole pressure. In modeling, some say that it is better to allow the wire to vary a little from the center to keep the contacts clean. In my first module, I must have overdone this, because I caused the grooves in all my collectors to get too wide and this caused excessive dewirements at overhead frogs. I now insist on the wire being located over the center of the track and allow the variations in the wire at the many sharp curves to help keep the contacts clean. A second variation occurs at overhead frogs. To get good operation through overhead frogs, the contact wire must be allowed to wander inward toward the curved or diverging route at the frog location or cars going straight will dewire

PREPARATION & GROUNDWORK

There are several cardinal rules mentioned throughout this article. If you follow them, you will probably avoid a lot of headaches. If you don't, you probably deserve the consequences.

Before getting into the details, it must be acknowledged that many different methods of hanging trolley wire exist. Since I am from Philadelphia and grew up with the Philadelphia Transportation Company and their excellent Wire Department, I chose to hang my trolley wire in that manner. In summary,Philadelphia employed span wire construction, requiring two line poles, used "fan dressings" at most curves, and employed the use of "bridles" on curves. The major purpose of the "bridle" is to maintain the hanger perpendicular to the contact wire. (See Figure l.)

CARDINAL RULE #1

STEP ONE - LINE POLE LOCATION

In my previous attempts at erecting trolley wire, I made every mistake that it is possible to make. Through experience, I have learned to lay out the location of the line poles before actually drilling the holes. I use some round gummed one-half inch diameter labels to mark the proposed locations according to the following guidelines.

Guideline #1

For straight track, line poles are placed no farther than 100 scale feet apart.

Guideline #2

For span wire construction, line poles are placed in such a manner that the span wire will be perpendicular to the contact wire.

Guideline #3

For intersections that will have curves or special work (switches or crossings), a line pole is placed close to each corner of that intersection.

After placing the labels, I examine each pole location to ensure that the pole was not placed in a location that could cause difficulties later on. If, for example, I had placed one pole of a span pair in the middle of a driveway, I would try and move both poles six feet to not violate Guideline #2. This, in turn forced me to relocate the next span pair so as to not violate Guideline #1. I avoid violating the "Guidelines" until operational necessity forces such a violation. Examples of such situations will be discussed later.

STEP TWO - LINE POLE PREPARATION

At the time of the overhead wire construction described in the original version of this article (1985), the span poles formerly marketed by Ed Suydam were no longer available and his successor, California Models, would not commit to production. As of November 1997, Orange Vista Traction Products (OVTP), a division of Alpine Division Scale Models, P.O. Box 611154, West Los Angeles, CA 90064-1154, owned by Michael DeGhetto, a long time traction enthusiast, is marketing the traction line poles formerly sold by Ed Suydam & Co. These poles are basically the original designed Suydam poles with some improvements that the traction fan will find refreshing. The overhead fittings are now available from O'Toole Lines. So I am now using both original Suydam poles and the newer OVTP poles and they work great. Each pole, regardless of the type, -span, single bracket or double bracket-, is constructed of solid brass with a threaded base with two nuts. Because I also have Pacific Electric interurban cars with their high pneumatic trolley pole bases, I desire a high overhead. My overhead is to be 21 scale feet from the top of the railhead. Each span pole has a pre-drilled hole for the span wire. At the time the original article was written, Northeastern Scale Models #068 Eye Pin were available in packages by the gross. We inserted one into the hole after soldering flux had been applied. Shortly after that time, we found that the Northeastern pins were not easy to find, but we found Micro Mark part #60405 to be a great substitute. In fact, they were stronger. We last obtained them in December 2004. They are stronger and have a larger diameter. Some of the holes in the poles have to be enlarged prior to inserting these pins. After ensuring that the eye is perpendicular to the line pole, the eye is soldered to the line pole, making sure that the base of the eye is soldered to the catenary pole to prevent the eye from opening underthe stress of the overhead. For expediency, you can just loop the wire through the hole and around the pole. However, this does not look prototypical to me as this type of attachment was normally seen with wooden poles only. After 10 line poles have been readied in this manner, I carefully clean them of all flux and unwanted solder and prepare them for painting. As a holding tray for the line poles while spraying, I took an 18" length of scrap 2 X 4 lumber. Using an 1/8" drill, I made 2 rows of five holes each 2 inches apart with each row 2 inches apart. For a black finish, I originally used Interior/Exterior Enamel 1601, glossy black, which was available at a local "Do-It-Yourself" store. Later on, I switched to the use of an airbrush and Scalecoat #10 Engine Black. At this time, I am still using my airbrush, but have shifted to Accuflex Weathered Black due to its ability to really stick to metal. Please note that the top horizontal surface of each line pole is not painted at this stage in the process because the line pole may have to be hammered into the module later.

STEP THREE - LINE POLE INSTALLATION

Note: Before entering this subject, we should discuss the layout surface. You will notice that the line poles mentioned in the above paragraph are solid brass rods with threaded bases. Two nuts are provided to secure the pole to the surface using one on top of the surface and one below. This method works well, requiring only the use of scenery tricks to hide the top nut. It can be used with any rigid surface such as plywood but I prefer to use 1/2" thick homosote available in 4' by 8' sheets for about $30.00. I then drill a hole slightly smaller than the diameter of the pole, apply glue and usually hand screw the line pole into the homosote until the pole is at the right height. Poles secured in this manner remain rigid and some have supported trolley wire for over 20 years.

After studying the proposed location of each line pole, I use a 7/32" bit to drill the holes at each location in the homosote. Each hole was drilled at an angle (rake) slightly greater than 90 degrees away from the track. Prototype poles are raked about 5 degrees from the vertical. Note the rake depicted in Figure 2. Wood glue, such as Elmer's Carpenters Glue, is applied to the threaded area of each pole and then the pole is screwed directly into the homosote hammered gently into place until the span wire attachment eye was 21 scale feet from the top of the railhead. At this point, one of the two nuts threaded onto the pole from under the layout until it rests securely against the bottom of the homosote. The second nut will be placed later, when electrical connections are made. After this is completed, the top of the pole was painted black with a brush. The glue must be allowed to dry at least 24 hours before the line pole is used for the hanging of overhead.

STEP FOUR - PREPARATION OF INSULATORS

In this overhead wire hanging method, the span wires are neithter soldered to the poles nor wrapped around them. Simulated wood strain insulators are used. To make these, I got used, scrap telephone wire from Pacific Bell and removed the wire insulation. I then cut the insulation into lengths of 1 scale foot each and put them in a container. For starters, I cut over 100 of these. Preferably, use brown or black insulated wire. This will avoid the need to paint these insulators later.

STEP FIVE - SPAN WIRE INSTALLATION

Next, span wires are hung between all line pole pairs spanning straight track. For all non-contact span wire, I originally used some 30 gauge "magnet wire" which is copper colored with a clear insulating finish. The wire that I used in 1985 was available from Radio Shack, brand name Archer #278-1345. Along with the 30 gauge came some 26 gauge and 22 gauge wire which I have used for line pole anchor wires. Unfortunately, this wire is now available in colors unsuitable for this purpose. So, in 1996, I visited the local electronics store and found some spools of 28 and 30 gauge enameled wire for this purpose and they work fine! For reference, the wire that I found was Consolidated Electronic Wire and Cable 4 oz spools, which cost about $6.00. This wire is currently in use for the Southern California Traction Club's (Torrance, California) traction modules, three of which are in operational status as of July 1996 at All Aboard Model Railroad Emporium, Torrance, CA 90505.

I cut this wire into lengths 2 inches longer than needed and placed two of the "insulators" prepared earlier in the center of this span wire. (See Figure 2.) One end of this wire is looped through the eye on one line pole and the other end looped through the eye in the opposite line pole. Then the wire is pushed back through the "insulator". The "insulator" is then pushed up to the eye while both wires are held with a small pair of pliers or tweezers until snug. Finally the end of the span wire is wrapped around itself. See figure 3 for an illustration of these steps. Place a rubber band around both line poles to create some tension and then perform the same task at the other line pole. Ensure that the span wire is not loose when the loop is made. If done correctly, when the rubber band is removed, the span wire should be at the right tension. Both Suydam S-165, Precision Scale 5316 and O'Toole B-610 straight hangers should be used here. Should you wish to run pantographs also, there are hangers available for that purpose. I do not run pantographs and do not intend to so that subject is not discussed here.

Span wires over curved track are done in a similar manner except that a section of wire 3 inches longer than anticipated is cut initially. This piece of wire is then bisected and each side is fastened to a curve (trolley only) hanger, such as Suydam S-166, Precision Scale 5317 or O'Toole B-615 using the "insulator" approach described in the preceding paragraph. After these are secured, the ends of the original wire are placed in the eyes of the opposing line pole. However, before tightening, ensure that the hanger is in the correct position. Correct position for a curved hanger is somewhere over the point midway between the rails to a point over the inside rail of the curve. The exact position on any layout depends upon the type of cars used on the layout and the respective trolley pole geometry.

Note that for double track curve city span wires, two curved hangers must be spliced into the span wire. The easiest way to accomplish the correct spacing is to measure the distance between the inner rails of both curved tracks and insure that the same distance separates the two curved hangers. Place the hanger over the inner track and the hanger over the outer curved track should automatically be in the correct position.

In doing these span wire tasks,you start to see the the advantage of this type of overhead construction. Since we only solder the actual hanger to the contact wire, all other connections are easily removed and redone when adjustments are needed later (and they will be needed). Please note that the use of the insulated "magnet wire" will allow the poles to be insulated from the wire. This is useful should you want to use prototypical "automatic" and "semi-automatic" turnouts operated by overhead trolley contacts. Nevertheless, some poles will have to be used as feeders. To do this, just remove the insulation in the area of the span wire that will contact the eye before inserting the span wire into the eye. Just before advancing the "insulator" to the eye, solder the span wire to the eye. For identification, I paint the span wire black from the insulator to a point just one scale foot beyond the hanger. Remember, if you choose to locate a feeder wire in a span using a curved hanger, you must remove the insulation in the area that touches the curve hanger and solder before advancing the "insulator" to its final position next to the hanger.

CARDINAL RULE #3

All hangers should be "prepped" before using. Please refer to Step Six prior to using any hanger. This will make the soldering of the hanger to the contact wire much easier later

STEP SIX - HANGER PREPARATION

All hangers, both straight and curved, should be prepared at this point for ease in later soldering. Turn the hanger upside down so that you are looking at the area where the hanger will be soldered to the contact wire. With a triangular file, stroke this area until it is smooth. Take care to leave the area grooved as originally found. You will find it beneficial to prepare at least a dozen at one time.

STEP SEVEN - STRAIGHT HANGER INSTALLATION

Both the Suydam S-165, Precision Scale 5316 and O'Toole B-610 straight hangers are oversize for HO and this is really noticeable in pictures. I have developed my own method when using these hangers to eliminate as much unnecessary bulk as possible. First, I cut these hangers in half as shown in Figure 4. After this, using a saw, cut a groove in the top of the remaining portion of the hanger as shown in the same figure. Since the hanger is to be installed over the center line of the track, I make a center line indicator using an old Pennsylvania Scale Models (Bowser) PCC trailing truck modified as shown in Figure 5. After the insulation is gently scraped from the span wire, the hanger is tinned at the top, placed on the centering jig, and pushed under the span wire. As soon as a hot soldering gun touches the hanger, it is cleanly soldered to the span wire. Please make sure that all insulation is removed from the span wire or you will have much difficulty. The dome of solder created at the junction of the span wire and the hanger is very similar to the "cap & cones" insulated hanger used by many trolley lines. Poles supporting these hangers are excellent locations for feeders to the overhead. First, ensure that the span wire makes good electrical connection with the line pole. If you used the enameled wire, as described here, ensure that the enameled finish has been removed in the vicinity of the eye and solder the span wire to the eye prior to advancing the insulator to that location. Attach the feeder wire to the base of the pole and secure with that second nut. Two separate pole feeders should be installed on each module or every 4 feet.

STEP EIGHT - INSTALLING WIRE

The most fundamental thing to remember when hanging the wire is to make sure that you keep the wire under some tension as you spool it out. This will ensure that the wire is not loose and will avoid getting kinks in your wire that look horrible later and are virtually uncorrectable. Loose wire will make proper frog operation difficult if not unreliable, and make back-poling virtually impossible. I usually start at a line pole located at the end of a siding or a temporary one positioned in the center of the track and, keeping the desired tension, spool out the wire to the first hanger. Place some flux on the top of the contact wire in the area where it will be soldered to the hanger and, using a hot soldering pencil, place a little solder on the wire. Apply a little flux to the underside of the hanger. Keeping the tension by holding the contact wire with one hand, move the contact wire up to touching the base of hanger. Place a hot soldering gun under the hanger and move back and forth about three times under the hanger. Allow the hanger to cool it and then relax the tension. A visual check should confirm a good soldered joint.

STEP NINE - ADDITIONAL PULL-OFFS

Additional pull-offs will be required at curves. First, place the extra pull-offs in the area between the span wires evenly spaced between span or bracket arm line poles. On city curves they should be about 2 to 2.25 inches apart. After the hanger is installed, a wire is normally attached from that hanger directly to the nearest line pole.

STEP TEN - INSTALLING THE "BRIDLE"

To install the bridle, cut a very long section of span wire and loop though the eye of the last line pole in the curve. Install the "insulator" and wrap the end around the span wire at least three times. Keeping tension in the span wire, move to the first hanger. Position the hanger so that the insulator and the hanger are perpendicular to the tangent of the curve of the contact wire at that point. Then wrap the bridle wire around the span wire just once in the area next to the hanger "insulator" and move to the next hanger and perform the same task. Finally, place one more insulator on the wire and insert the end of the bridle wire in the eye of the last line pole in the curve. Ensure the correct tension, advance the insulator and wrap the bridle wire around itself three times. Your bridle should be done. If you don't like it, start over from the beginning. After a couple of tries, you will surprise yourself with the excellent results.

STEP ELEVEN - INSTALLING OVERHEAD FROGS

Almost every trolley modeler considering using operational overhead has read by now that the correct location of an overhead frog is 1/3 of the distance between the end of the turnout point and the frog (See Figure 6.) However, this assumes the use of a Suydam S-172 frog or an O'Toole flat pan type without internal guides. Using the O'Toole B-641 frog or equivalent with internal guides changes this rule to 1/4 of the same distance, especially if your cars use Precision Scale (formerly Kemtron) "trolley shoe" castings on the trolley poles. When placing overhead frogs, pick one of your cars as the standard and ensure that it tracks successfully through every frog both ways, both routes. Ensure that you pick a car with an "advanced" pole position. If you have a lot of one type of car, use one of these as a standard car. I prefer a double-end car with "advanced" pole base position. Be prepared for the fact that if you have different cars with different trolley pole geometries, not every car will give reliable operation through every overhead frog. Long cars with one pole in the center of the car, such as the Pacific Electric 800 class and cars with "retarded" pole position, such as Philadelphia Snow Sweepers, are the most difficult to make reliable unless these are your standard cars. If they are, then cars with "normal" or "advanced" pole base position will normally not give reliable frog operation. This has been a prototypical problem. In Philadelphia, the Kawasaki single end LRV's have a "normal" pole position, while the PCC's which formerly serviced the lines have "advanced" pole position. The LRV's were initially dewiring at certain frogs, positioned in accordance with the long standing Philadelphia practice. Every class of passenger car Philadelphia used in the twentieth century (until these cars) had "advanced" pole base position. Figure 7 illustrates the differences among "retarded","normal" and "advanced" pole base position.

All my cars currently use Precision Scale "trolley shoe" or "trolley wheel" castings on the trolley poles. Wagner B-640 frogs were used in the 1975 module, but the 1983 module went back to Suydam S-172 frogs, and now the O'Toole frogs are used exclusively. One last point for you to remember. If you work with each problem car, eventually, you will find a way to get reliable operation through overhead frogs. Just don't give up.

Several items seem to affect correct frog location. Defining the 1/3 position to be the standard position, several items tend to move this toward the 1/4 or 1/2 positions as shown in figure 6.

1. Use of cars with "advanced" pole position, including long (over 35 scale feet) cars with only one centered trolley pole.

2. Use of Wagner B-640 overhead frogs.

3. Use of Precision Scale "trolley shoe" castings.

Combining more than one of the above conditions exacerbates the problem.

The following items tend to move correct (reliable) frog location toward the 1/2 position:

1. Use of cars with "retarded" pole base position, such as a PRT/PTC double truck sweeper.

2. Use of cars which use the front pole in normal service, such as pole cars, differential dump cars or the Boston Elevated Center Entrance Cars.

3. Use of extremely worn "trolley wheel" castings.

Curved turnouts are particularly troublesome. I have one such turnout on my module 83 and after many experiments, I have concluded that the correct position for the frog here is at the 2/3 position.

This curved turnout has an outer track radius of 9" and the diverging route inner radius of 7". The sharp turn causes the overhead to be very close to the inner rail of the 9" radius curve. Combine this with the extremely long turnout and the 2/3 position becomes the most reliable. One more point. Never allow a frog to be used as a pulloff. See Figure 8 for such a depiction. I have found that this is troublesome.

My standard car is a Bowser Brill, my first car purchased in 1961 when I was 18 years old, which is on its third paint scheme and second motor. Since it has "advanced" pole base position, and most of my city cars seem to share this attribute, only a few cars give me trouble. From my list above, you should note that the use of the O'Toole B-641 frogs forces the optimum frog position to move toward the 1/4 position. In this position, the cars equipped with the Precision Scale "trolley wheel" castings do not give as much reliable operation as those equipped with the "trolley shoe castings". In the 1/2 position, those cars equipped with the "trolley shoe castings" are almost completely unreliable during operation. Therefore, I chose the most reliable location for the standard car and this turned out to be the 1/3 position. This tends to eliminate the O'Toole B-641 (formerly Wagner) frogs and I will probably replace them if I rewire the module completed in 1975. All long double truck cars with one single pole mounted in the center of the car roof, such as some members of the Pacific Electric 800 class, will use "trolley wheel" castings, which allow more variance in overhead frog location. Cars with "advanced" pole base position will normally experience more reliable operation if the length of the pole is reduced. Cars with "retarded" pole base position will operate through frogs more reliably with longer poles, or by installing "trolley shoe" castings. Always change pole length in small increments. Since I insist on using the "Fairfield" style pole which just rests in a brass pivot hole in the roof, I just have several poles with different lengths for testing. When I find the right, that is the length of the pole that the car gets for service. The original length for a trolley pole is always the prototype length. The original prototype collector, trolley wheel or shoe, is always the first choice for the model. Changes are made only to improve operational reliability, and even then, reluctantly.

STEP TWELVE - ADJUSTMENTS

Minor adjustments will be required immediately after finishing the overhead wire for the first time. You will find that some action as far as 6 feet away from an area will result in an overhead frog adjustment, an overhead wire relocation and sometimes a line pole adjustment or relocation. Major adjustments may be forced later. Some events that can force such changes are when a decision in made to add interurbans to a formerly street car layout, to run trains of interurbans or trolley freight trains or to run Pacific Electric "Blimps"or four truck electric locomotives such as those formerly found on the Oregon Electric Railway, Chicago North Shore & Milwaukee, or Illinois Terminal System.

After you have completed everything, you will have two types of problems. The first type is the most important. These are those that cause operational problems. If you used the standard car approach and that works, then the car should be the source of the problem. Remember, this assumes the selection and use of the "right" standard car. Adjustments of pole length or location, changes from wheel casting to shoe casting or vice-versa and/or increasing/decreasing pole base spring pressure should solve your problem - unless the car has weird pole geometry, such as a long double truck car with center pole or extremely "retarded" pole base position. The second type of problem involves things that just don't look right to you. If you followed the Cardinal Rules, you should know what the source of the problem is. If you didn't, that is the problem. Other problems that you will encounter are probably outside of the scope of this guide.

Should you have any problems concerning the hanging of operable overhead wire, please contact Custom Traxx, P.O. Box 641175, West Los Angeles, CA 90064-1175, or E-mail decals@customtraxx.com