R143 & R160 questioin

Discussion relating to the past and present operations of the NYC Subway, PATH, and Staten Island Railway (SIRT).

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frankie
Posts: 253
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Location: St. Peters, Missouri

R143 & R160 questioin

Post by frankie »

I'm new here on this fourm, so bare with me. I was recently looking at clips on Youtube of L line trains emerging and entering the tunnel at Broadway Junction. On both the R143 and R160A-1 cars, I'm curious to why half the axle tips on the trucks are painted yellow. All the axles look like little whirligigs when view from the side!

Also, on the R160A-1 cars, why do the circular outline of the route indicator rotate?

Frankie
Mineola, NY is my real home, however I live 60 miles from Mineola, MO. No LIRR here!

Kamen Rider
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Re: R143 & R160 questioin

Post by Kamen Rider »

The ends of the axles are painted so you can tell they are moving.

the end signs don't rotate, the lights switch on and off in rapid succesion; too fast for the eye to see, but slow enough for the camera to catch.
仮面ライダー / Kamen Rider
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frankie
Posts: 253
Joined: Fri Sep 28, 2007 11:54 pm
Location: St. Peters, Missouri

Re: R143 & R160 questioin

Post by frankie »

As for the end sign rotation, check out this clip at 3:00 and you'll see what I mean. All the trains from this point on shows this.

http://www.youtube.com/watch?v=4jv-Y3vLYN0

Frankie
Mineola, NY is my real home, however I live 60 miles from Mineola, MO. No LIRR here!

Kamen Rider
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Re: R143 & R160 questioin

Post by Kamen Rider »

the sign is not rotating. it's "refreshing".
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frankie
Posts: 253
Joined: Fri Sep 28, 2007 11:54 pm
Location: St. Peters, Missouri

Re: R143 & R160 questioin

Post by frankie »

Well okay, then why does it refresh on some trains and not on others?

Also with regards to the half axle yellow paint, has there ever been a problem in the past where the wheels don't turn while the train is in motion? I don't see the logic behind it.

Frankie
Mineola, NY is my real home, however I live 60 miles from Mineola, MO. No LIRR here!

Kamen Rider
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Joined: Mon Mar 17, 2008 11:34 pm
Location: NYC

Re: R143 & R160 questioin

Post by Kamen Rider »

frankie wrote:Well okay, then why does it refresh on some trains and not on others?
they all do it, it's just that the 160s rate is slower.
Also with regards to the half axle yellow paint, has there ever been a problem in the past where the wheels don't turn while the train is in motion? I don't see the logic behind it.
Motor fails or an axle sticks and the wheel gets draged, or conversly, shows wheel slip, the wheel spinning when the train is standing still.
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JoshKarpoff
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Re: R143 & R160 questioin

Post by JoshKarpoff »

High Intensity LEDs are frequently cycled on and off to save energy and to reduce heat build up (which is one of the main killers of LEDs) and thus lengthen the operating life. As the human eye has difficulties seeing things flashing at rates above 16Hz, why waste energy on having the LEDs illuminated all of the time?
http://en.wikipedia.org/wiki/Flicker_fusion_threshold

As this is all a matter of perception, a camera can potentially capture the flicker. For example, when a video camera is pointed at a computer screen and catches the refresh.
---Electrical Engineer---
5th generation from Harmon (Croton-on-Hudson, NY), home of the MTA MNRR Harmon Shops.
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frankie
Posts: 253
Joined: Fri Sep 28, 2007 11:54 pm
Location: St. Peters, Missouri

Re: R143 & R160 questioin

Post by frankie »

Thanks Josh. In other words, the rotation we see on video (as in the clip that I uploaded), doesn't really exist in real life. So the person taking that video doesn't see the rotation that his video captured. WOW! Very interesting.

Thanks for the input!

Frankie
Mineola, NY is my real home, however I live 60 miles from Mineola, MO. No LIRR here!

Kamen Rider
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Joined: Mon Mar 17, 2008 11:34 pm
Location: NYC

Re: R143 & R160 questioin

Post by Kamen Rider »

it exists, but it's too fast for the eye to comprehend unaided as a camera doesn't work the same way an eye does. You camera operates on a frame rate, meaning it takes multiple pictures a second laced togther to form an image. the eye works on a constant flow of light in, information out.

Every electronic screen refreshes itself. The slowest examples are the LCD side signs on th 142s, which have to switch off before showing something else. Your TV does it at apromimtly 30 frames a second. every second 30 complete pictures are show on the screen, replaced fast enough that the brain comprehnds the images as moving.

It is physicly possible to photograph the front of a 160 and get the full circle by lengthing the exposure.
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UpperHarlemLine4ever
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Re: R143 & R160 questioin

Post by UpperHarlemLine4ever »

Is the refresh rate different for the 143's as it doesn't seem to appear on them?

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