blue streak 1 ...... So a AC-64 = 6400kw + 1000 KW HEP =7400 /12 KV = ~~ 62 amps max.
...... So a AC-64 = 6400kw + 1000 KW HEP =7400 /12 KV = ~~ 62 amps max.
!!! 6,400 kW + 1,000 kW = 7,400 kW / 12 kV = 616.67A !!!
from the Far East of the Sunset Route
(In the shadow of the Huey P Long bridge)
It's quite possible CTA is the last user of gravity shoes. Except for a hundred or so 6000 series PCC cars and the 150 cars in the 2200 series, just about all CTA cars including the recently-delivered 5000 series have gravity shoes. Both series that used spring shoes required rework shortly after delivery, though neither got gravity shoes.
IS NOT CTA THE ONLY REMAINING PROPERTY USING GRAVITY THIRD RAIL SHOES?
NYCITY STOPPED USING THEM WHEN THE LOWER PORTION OF THE MYRTLE AVENUE ELEVATED CEASED IN BROOKLYN.
The Illinois Central and South Shore have used 1500 VDC catenary since 1926. MILW and Lackawanna used 3000 VDC catenary.
Speculation but pickup shoes have a large Amps load due to third rail's 600 - 750 maximum voltage. As well pans that contact same voltage CAT will also have high amp loads. Now the CN IC and south shore's 1500 volt will have a much small amp load. Then we get to Amtrak's 12 Kv ( PRR and New Haven routes ) or Amtrak's 25Kv New Haven BOS route which will have very low amp loads. ( note also same for many countries' 25 KV systems )
Wear on shoes will be fairly great especially any time loss of power to car shoes occurr. We have all seen the welding type flames from the shoes arcing.
To decrease wear on CAT pans most modern overhead CAT will not be in a straight line but goes side to side from each CAT pole. So as pan goes along wire sweeps back and forth over approximately 2/3 of the pan there fore not putting a grove in the pan pickup shoe. Curves are somewhat different. Would be interesting the mileage each type and voltage of these pick ups get between replacements.
So a AC-64 = 6400kw + 1000 KW HEP =7400 /12 KV = ~~ 62 amps max.
Without giving a specific answer, since I don't have one, I'll fall back on an aircraft maintenance term:
Inspect, and repair (or replace) as necessary.
I can see a lot of variables in the equation, from the effects of weather (ice causes arcing, and pitting) to the effects of misadventure. There probably isn't one simple answer, just a range of possibilities. So, if in doubt, look - and fix if the wear limits have been exceeded.
Chuck
So the answer to "how long do electric pickup shoes last is..." it depends. Keep in mind that all of my descriptions below are generalized.
Third rail systems use either overrunning (shoe rides on top) or underrunning (shoe touches bottom).
Underrunning third Rail systems use paddle type shoes that are pulled up by spring pressure. Depending on the current load carried they could be expected to last anywhere from a few days to several months.
Overrunning third rail systems use either spring-loaded paddle type shoes or "gravity" shoes which are fairly heavy castings that - you guessed it - ride on top of the third rail by gravity. Gravity shoes can last a very long time, but they are regularly checked to make sure that they wear evenly.
Trolley cars originally used wheels on the ends of the poles, which tended to wear out on their axles, which is where the current from the wire entered the pole. By the 1910s various types of sliding shoes were in use, usually with carbon inserts. Carbon inserts also made it less necessary to grease the overhead wire, since they left a graphite trail. A carbon shoe is usually good for a couple hundred miles depending on operating characteristics. For a car operating on a long line like Western Avenue in Chicago, it might mean the shoes get changed every third or fourth day.
Pantograph shoes are either bronze or some other copper alloy, or are equipped with carbon inserts. Most low voltage DC systems prefer carbon shoes since they are not as hard on the overhead wire.
Bob Riggs (2-11):
Hi, Bob, and welcome to the forum!
I am not that familiar with the terminology you used, but it would seem “pickup shoe” would have reference to third rail. If you are referring to a pantograph system …
…that would have its own meaning, at least to me. I’ve often wonder about the life cycle of both types of electrical contact systems. Sorry more definitive information isn’t conveyed outside of a mere clarification.
About the above photos, they were shot on Los Angeles Metro’s ‘south side’ Gold Line on October 3, 2015 at Indiana Street and East 3rd Street in Los Angeles, CA.
https://www.google.com/maps/@34.0333456,-118.1922197,199m/data=!3m1!1e3
For your amusement, I suppose, is a photo closer to downtown Los Angeles of a light rail movement going into a dark, long tunnel on the line. A cemetery looks down at that going into the tunnel movement, which is a strange addition to a commuter ride.
It is hoped all this gives a little pizazz to an unspecific answer to your inquiry.
Take care,
K.P.
----------------------------------------------------------------------------------------------------------------------------------- K.P.’s absolute “theorem” from early, early childhood that he has seen over and over and over again: Those that CAUSE a problem in the first place will act the most violently if questioned or exposed.
I have looked at numerous transit article and have seen photos of the NYC subway/Chicago transit cars and have wondered about the maintenance required to keep the pickup shoe in srvice..,Any information would be helpfil.Thank Bob Riggs
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