To paraphrase Vane Jones, "Knowledge is of little value until shared with others."

Monday, March 3, 2014

Trolley Pole Primer - Part 1 The Basics and the Base

The one item which makes a trolley model unique is the trolley pole! While this comment may seem obvious to us trolley modelers, it is the part of the model which draws the attention of the average non-trolley modeler and brings the question, "Does the model pick-up electricity from the wire?" 

Steam and diesel models don't have anything as odd or unique as a trolley pole!
My idea was to write everything in just one post. As my brain kicked into gear the realization set in, this was going to be one of those subjects requiring more than just a quickie writing.

We will start from the bottom of the trolley pole up in describing the differences between the trolley poles and their manufacturers. There are 4 different designs of trolley poles available based upon the trolley's base available in O scale. 

A trolley base is "an iron base attached to the roof of the car and having a swiveling socket for the bottom end of the trolley pole. The socket and pole are normally held in an upright position by one or more stiff coil springs which are compressed when the pole is pulled down on an angle." 1911 Electric Railway Dictionary

From the description the trolley base includes the object attached to the trolley boards on the roof of the car plus the spring holders and a pivot which allows the pole to move up and down.

For the part attached to the trolley boards on the roof on the car, many modelers use a soft metal casing available from Current Line Models or Q-Car. If a soft metal casting isn't used something which was included on the model, if it came already built-up, or we build our own.

Various prototype manufacturers produced trolley poles over the years trolleys were in use. These included:
     Ohio Brass,
     Union Standard made by R. D. Nuttall Company,
     National Ball and Rolling Bearing,
     Bayonet Roller-Ball made by Bayonet Trolley Harp Company,
     Sterling Roller-Bearing Trolley Base by Sterling-Meaker Company,
     Holland Ball-Bearing by Holland Trolley Supply Company, and

Each manufacturer supplied a number of different trolley pole bases. Some of the trolley pole base designs were unique to the company while other bases looked similar to other companies' bases.

We are lucky as there are 4 sources of trolley poles in O scale. In alphabetical order the manufacturers of O scale trolley poles are:

  • Current Line Models (originally Wagner Car Company)
  • Midcco Models - Jim Osborn
  • Precision Scale Models (PSC)
  • Q-Car Company
You can look up Current Line, PSC, and Q-Car trolley products on the web. Jim Osborn sells poles by word of mouth and at trolley meets. Here is one of his flyers.

Note the date on the flyer, prices may have changed so contact Jim Osborn 1st before sanding any money. 

You can buy direct from the manufacturers or from the several trolley model suppliers. Check the right side and bottom of this web page.

The underlined part of the following descriptions were given by the Wagner Car Company to their trolley poles. For the most part the descriptions are the ones used by trolley modelers.

1. Four Spring Horizontal Forward - the Ohio Brass name is Ohio Brass Form 20
   Probably the most common of all the different styles of trolley pole bases.
Trying to find a photo of this style of base was hard. Everyone takes photos of the entire car (model) while few concentrate on just the trolley pole and its base.

2. Two Spring Vertical Forward or 4 Spring Vertical Forward  - the Ohio Brass name is either
    Ohio Brass Form 10 or 11 depending upon the number of springs. Apparently these trolley poles could be obtained for just streetcars or for heavier duty.
The 3 photos above were supplied by Carl Lantz.
The above photo shows the bearings required to support the pole upon which it rotates 360 degrees. The page goes into the amount of weight the bearings can support.

3. Four Spring Horizontal Back - the Ohio Brass name is Ohio Brass Form 1
Please excuse the quality of the photo. The photo was taken from an early issue of Trolley Talk. The photo was taken before the entire trolley pole was blackened making the parts of the base easier to see..

4. PE air pneumatic (spring powered) available from Jim Osborn
    The in depth reason for the PE to develop and use the air pneumatic trolley pole is lost on me. PE developed and used the air pneumatic trolley pole base to keep the trolley pole from flying up in the air after a dewirement and destroying the span and associated wires suspending the trolley wire. Apparently the PE had not heard of or believed in the trolley retriever.

The air pneumatic part of the trolley pole base was used to lower the trolley pole in case it went too far up into the air. A lever was tripped as the trolley pole went up causing compressed air to be released into the cylinder. A piston in the cylinder pushed the pole down.
Suydam O scale brass model of a PE car with air pneumatic trolley poles.

I do not know if a trolley railway could specify a particular pole base or if the railway had to take what the builder of the car had. If a series of photos of PCC cars are examined, all of the PCC's came equipped with the vertical spring trolley base.

All of the CA&E cars were equipped with the horizontal spring base, except #20 the line car; until the St. Louis Car Co. delivered the 450 series of cars with vertical spring bases.

The North Shore Line had all 3 of the common trolley bases - springs horizontal, vertical, and backward in use at the same time.  The NSL kept the same type of trolley base on a car for the life of the car. As a car was shopped and some made into Silverliners, it emerged with the same trolley bases.

If the trolley base includes a "plate" attached to the trolley boards on the roof of the car plus the spring and pivot which allows the pole to move up and down plus a swiveling socket for the bottom end of the trolley pole. The swiveling socket has to be the 2-56 screw or something like it or the pole would not rotate in a 360 degree arc.

So how is a model trolley pole attached to a trolley model? There are 2 different way. Both ways have as many pluses and minuses. You'll have to decide which method is best for you. Furthermore, the descriptions below and installation instructions can vary depending upon the model and the modeler.

The 1st method, which I call the "screw mount", is to mount the 2-56 screw through the roof pointing up. The key is to have enough material in the roof to support the trolley pole. The drawing shows the best way to mount the screw in a brass roof. The 2-56 screw has to be insulated from the roof and the balance of the model to prevent short circuits.

The primary reason for having enough material under the brass roof is to protect the 2-56 screw plus the brass roof material from damage should the 2-56 screw receive a sharp blow from the side. The screw can be bent or dislodged and the brass roof severely bent out of shape.

The other method of mounting a trolley pole on a model is the "insert mount". First, either a 2-56 screw has to be screwed into the trolley base and cut short with out its head. Or, piece of 0.090" diameter brass has to be threaded 2-56 with enough threads to just screw into the trolley base. The balance of the 0.090" brass rod is cut so enough will fit into the insert in the roof of the model.
To prepare the model find out what size styrene tubing is required to accept a piece of brass tubing into which the either the 2-56 screw of the 0.090" rod will fit. Glue the piece of styrene to a piece of 0.020" thick styrene sheet to make the insulation for the trolley boards and the roof of the model. A soft metal casting of the piece of trolley base can be glued on top of the piece of 0.020" styrene sheet.
Glue a piece of plastic or other non-conductive material inside the roof to be used as a vertical support of the insert. Drill a hole for the styrene insulation tube into the trolley boards through the roof and vertical support piece.
A piece of wire has to be soldered to the piece of brass tubing into which the 2-56 screw or 0.090" brass rod will fit.  The wire is used to bring the trolley wire current into the model. The piece of brass rod can be glued into the styrene insulating tube.
For both of the methods of mounting the trolley base, my explanation was kept brief. You should discuss the pro and cons plus how to mount the base with another modeler who has used both methods.
One more piece of detail before we move on. The 4-Spring Horizontal Backward Base, due to the swing of the trolley harp as the pole moved up and down, can "cut" into the trolley base attached to the roof boards. This can happen with either the screw or insert mount. Due to the small size of the parts, the action of the trolley harp has to be seen to appreciate what is happening.
If you are not too confused we'll go onto the pole and the items at the top of the pole in the next post. There still are many areas to cover regarding trolley poles.

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