So I am making a Museum exhibit about overhead power collection. Now I can find a lot of information on trolley wheels and some on paragraphs, but very little on trolley shoes. When and why did trolley shoes come into play.

23 route in Philadelphis had 1947 GE all-electric PCC cars with field taps. Going up Negley's Hill wheels would arc behind wheel-wire angle. This was with 0000 round wire and conventional hangers. When they switched to shoes with carbon inserts and grooved wire, the arcing disappeared. The carbons did not like rainy weather though.

Sweepers still carried icebreaker wheels.

Phil Mulligan

These are pages from a from a late 1940's BICC Tramway and Trolleybus overhead equipment catalogue...


The first paragraph sums up the advantages nicely - though they were known as carbon slipper trolley heads here in the UK.

Trolley wheels were limited in the amount of current they could handle. The high performance interurban cars went to cast iron shoes, maybe as early as the 1910s.
North Shore, Sacramento Northern, CRANDIC, C and L E, PE and probably many others used iron or bronze shoes. The objection to iron shoes was wire wear. Some companies greased the wire to reduce wear. However, the interurbans were running a train every few hours, not every few minutes like the street railways, so some wear was tolerable.

The pantograph was developed by the Key Route, in Oakland, CA, to address this same issue in 1906. The design was licensed to Nuttal, who built them for both General Electric and Westinghouse. The pantograph was heavy, expensive, and required a different style of overhead trolley design. It was almost universally adopted by suburban and main line electrifications, the notable exception was NYC along the Hudson River. Some interurbans also used pantographs. In higher voltage operations, handling of the trolley pole by the operator with a rope was not practical. Freight switching could be done with poles, but pantographs have a clear advantage.

Thanks. I believe the arcing behind the trolley wheel was amps that couldn't be carried by the contact between wheel and wire. The cars accelerated to 40 mph on that grade as shown on my speedometer. No TDH-5106 could do that.

Some of the Germantown 2700's are being rebuilt as PCC III's for further service on Girard Ave's 15 route. They're currently 76 years old. They're renumbered into the 2300's and you can't tell the players without a scorecard. As things currently go they are planned with poles rather than pans, but the consultants are having apoplexy.

I don't think a trolley wheel could carry enough amps to power a 30-ton air conditioned SEPTA Kawasaki Car.

Phil Mulligan

what does an ice breaker wheel look like?

From my 1950's Ohio Brass catalogue.....

The wheel in the upper left is what was in the sweepers. It's about 20% bigger than the regular wheels the cars used and the running surface was like a ladder with big slots for the ice to fall through.

Phil Mulligan

In Toronto, trolley coaches were re-introduced on a number of lines around 1948 and the new coaches were equipped with Ohio Brass, G-6 slider shoes with replaceable carbon inserts. After a few years of successful operation, TTC had by 1952 decided to equip the entire streetcar fleet (excepting a few soon-to-be retired trailer shunters) with OB, J-6 carbon insert slider shoes.
There were a number of advantages:
-noticeably less contact wire wear $$$
-simplified maintenance and repair $$$; less moving parts ; wheels, axles, bushings, bronze side shunts, etc.
-the entire slider shoe assembly could be changed off within minutes with only one machine screw securing the assembly or the carbon insert alone could be changed out quickly

One stated disadvantage was less predictable pole tracking with sliders when backpoling but this was not a big issue at the TTC as overhead maintenance was very good and backing was done with an employee holding the rope should the pole dewire.
In TTC practice, carbons were changed every other night as the cars came into the carhouses, even numbered cars one night, odd numbered cars the next.

There were two additional types of winter shoe that were used in cases of sleet and ice getting on the contact wire, both types attached the same way as the regular shoe; the sleet cutter was solid cast iron, the ice cutter had open sections between the contact surface with fairly sharp edges to knock ice off the wire.

In the later CLRV years, TTC devised a new shoe with a slightly wider and longer carbon with a flatter radius to handle more current but still interchangeable with the J-6. With the higher current demand of the present low floor fleet, the shoe was again redesigned. The system has recently converted to 100% pantograph operation but poles are retained but are not normally used.

As a matter of interest, the last use of trolley wheels in Canada on a commercial, non-museum, non-mine, railway operation was on the locomotives and work equipment of the Cornwall St. Ry. Light & Power Co. in October of 1971.

At high speeds, the rotating trolley wheel is very problematic. Just a slight imbalance, for example from a "Zorch", can create high frequency vibrations. Combined with the natural swaying of the car it creates little waves in the trolley wire. That contact surface between the rotating wheel and the vibrating wire becomes extremely shoddy, creating constant arcing which quickly eats up the smooth surface of the wheel, and also damages the running surface of the wire.

the Como-Harriet museum line in Minneapolis run its streetcars with trolley wheels, including the PCCs. This is because there are not turning facilities at either end of the line and all the cars are singled ended, so they must run in reverse for half of the trip. That half is done by back poling with the trailing pole rather than by putting poles on both ends of the cars and taking away from the historic looks. The wheels lessen the chances of dewirements at frogs or snagging in general.

Yes, backpoling with slider shoes can be an issue in some cases.
At the Halton County Radial Ry., we ran single-end cars backpoling primarily with slider shoes from about 1972 through 1985 when our loops went into service. There were few incidents on the main line which is catenary and had no facing overhead frogs at the time. Our only operational PCC in the early years (TTC air-electric 4000) had an opening back window as did all our single-end service cars so all backpoling movements had a crew member holding the rope in case of issues.
We had slightly more problems with poles jumping when backing into yards and especially carhouses and I have had my share of straightening bent poles over the past 51 years. Straightening a pole by bending it over the axle of a de-motored truck is a handy dandy, quick fix, by the way.
Over the last decade, our OCS guys have really focused on upgrading problem areas so pole tracking problems have been minimal. Don't ask me about pantograph repairs on our L&PS interurban, though!
Gord.

At Branford, we also do not have a loop at the end. When we have to operate single-pole equipment, we swing the pole around the center of the car and either there is a second catcher bracket on the side of the car near the mid-point, or we just tie off the rope to something solid inside the car. This way we are not back-poling for over a mile, including through an 1800 foot long reverse curve with an approximate 350' radius.

We limit our speed during back-poling to 10MPH in our rulebook.

Back-poling with sliders is very hard on the carbon inserts. Especially with traditional round wire where there is a little bump at the peen-over ears.

The Western Railway Museum runs with a mix of trolley wheels, carbon shoes, cast iron shoes, copper pantograph sliders and carbon pantograph sliders. The Museum tries to keep the current collector correct to the car from when it was in service. Many of the cars run on a five mile line at a maximum speed of 30 mph. Most of the trolley wheels are 6” diameter with oiled, graphite filled bronze bearings, or the OB wheels with graphite plugs for lubricant. The non OB wheels are purchased from Electric Materials. They come with a brass bearing and no provisions for lubricate. I assume they are intended for mine operation. In order to get these wheels to run without a continuous arc (as seen at night) the bearings are pressed out and replaced with the graphite filled bronze bearings, an oil hole is drilled and tapped into the oil reservoir and a screw plug is added, the bottom of the groove is turned true to the bore within less than 0.001’ run out, and then the wheels are balanced to within 1 oz “. Wheels modified this way run black at night and last for years. The modified Electric Material wheels outlast the OB wheels 3 to 1. Part of the museums success with current collectors is probably attributable to the pantograph operation. On the pans, between the copper runners, the area is filled with paint on graphite. This area is repainted every year. The result of this is the wire is so slick that sometimes there is not enough friction to get a trolley wheel to turn, but the wheels never develop flat spots. These practices have developed over the 55 years that WRM has been running trolleys on overhead wire.

Is the "oil reservoir" a cored cavity in the wheel, or does this refer to the small volume inherent in the passage that you drilled through?