Bad train pictures

[Anonymous]

The "sensor" is known as a track circuit. They run a low current through the rails, and this holds a relay open, allowing current to flow through the green light. When a train shunts the circuit through its metal axles, the relay drops (no current!) and the current flows to the red light. (This is a fail-safe feature; that way, if any component fails or the system loses track circuit power, it drops to red. You need a flow of energy to keep it green, not the other way around.)

The yellow light means the next signal is red, and the engineer must proceed prepared to stop. (Usually a speed restriction is attached to this - 30 or 40 MPH, depending on the road. This is an extra safety feature; that way the engineer is required to do something the moment he sees the yellow signal. It's a psychological thing, rather than risk letting him/her just pass by it and forget about the warning.) The yellow light is activated by another relay -

There's a second relay in the signal that switches between green and yellow; I believe this relay is held open (to the green light) when there's current flowing through the NEXT track circuit; when that circuit is shunted - and so the next signal red - the relay loses power and drops, and the signal shows yellow.

There's no timer that controls the transition from red to yellow. (Remember, the fundamental cornerstone of block systems since the end of the early days has been separation by some distance, not by time!)

[Anonymous]

The "sensor" is known as a track circuit. They run a low current through the rails, and this holds a relay open, allowing current to flow through the green light. When a train shunts the circuit through its metal axles, the relay drops (no current!) and the current flows to the red light. (This is a fail-safe feature; that way, if any component fails or the system loses track circuit power, it drops to red. You need a flow of energy to keep it green, not the other way around.)

The yellow light means the next signal is red, and the engineer must proceed prepared to stop. (Usually a speed restriction is attached to this - 30 or 40 MPH, depending on the road. This is an extra safety feature; that way the engineer is required to do something the moment he sees the yellow signal. It's a psychological thing, rather than risk letting him/her just pass by it and forget about the warning.) The yellow light is activated by another relay -

There's a second relay in the signal that switches between green and yellow; I believe this relay is held open (to the green light) when there's current flowing through the NEXT track circuit; when that circuit is shunted - and so the next signal red - the relay loses power and drops, and the signal shows yellow.

There's no timer that controls the transition from red to yellow. (Remember, the fundamental cornerstone of block systems since the end of the early days has been separation by some distance, not by time!)

[edblysard]

Wow,
I think Nora started something!
Bet on what you saw being a slug, a old locomotive, with out a diesel engine, having had the cab removed and the hood cut down to improve visability over the top.
These are often home made affairs, made in that railroads shops out of older junked locomotives.
There are B units, cabless locomotives, but they look like their counterparts, sans a cab.
A slug's fuel tank is filled with sand or cement, and 55 gallon drums of cement or sand are put in the hood where the diesel was, to increase the weight.
The traction motors draw current from the lead locomotive, which ever one is the controling unit.

EMD made a cow and calf set, called a TR5, basicly a SW9 switcher with a cabless SW9 unit semi permantly coupled to it, both had diesel engines, the calf, or cabless unit had a simple set of hoslter controls to allow it to be moved around by itself if needed.
These have been gone for years.

You see slugs in hump yard service, and on occasion, in yard to yard transfer service, they provice additional tractive effort without using fuel.

As for the 8 or 9 locomotives, most likley a power move.
If you live between two yards, or near where there are a few yards, you will see this often.
Locomotives seem to bunch up in one yard or another for some reason, and when there is a shortage in one yard, and a excess in another, they move the power to where it is needed most.
Most likley, only the head two, or leading locomotives were on line, the rest were being towed, no need for that much horsepower.

Note that when you see only two locomotives, they are usually coupled rear end to rear end, one each facing away from the other.
When a crew completes their run, and needs to return, or a new crew needs to take a train back in the direction the locomotives came from, there is no need to turn them around, with one facing each way, all you have to do is swap the controls from one to the other, either one can be the lead unit.
With a diesel electric locomotive, it makes no difference which way it faces, it runs just as fast and just as well in reverse as forward

Signals, in ABS, the system is designed to keep a minimun of three blocks between trains, so when you enter a block, the signal that is four blocks ahead of you, facing opposing traffic, will go red, the one after that, 5 away from you, will show yellow, so forth and so on.
As you proceed, the signals for any opposing traffic will keep pace ahead of you, the signals behind you will also change, in reverse order, so any following traffic will allways be three blocks behind you.
By the way, that is a very simplified example, there is enough to fill a small book!
In CTC, the dispatcher can overide the system for any special movement, and can flag you through a red if needed.
If the power fails, most systems will show red on all signals, they have back up batteries.
If for some reason, all power, battries included, fail, then the signal will go dark.
The rules state any signal that is dark or not functioning, should be treated as a absolute red, you must stop and contact the dispatcher to receive permission to proceed.

By the way, Nora, the only silly question is the one not asked!
No one single person here has all the answers, even the trainmasters dont know it all, (although they would never admit to it), but there are enough railroaders and sharp fans here to answer almost anything you need or want to know.
Some even go out of their way to research a answer for others.
Jenny, aka Mookie, should be able to run a locomotive, or do a conductors job, based soley on the questions she askes!
And she askes some tough one, real doozies!
Stay Frosty,
Stay nosey!
Ed[8D]

[edblysard]

Wow,
I think Nora started something!
Bet on what you saw being a slug, a old locomotive, with out a diesel engine, having had the cab removed and the hood cut down to improve visability over the top.
These are often home made affairs, made in that railroads shops out of older junked locomotives.
There are B units, cabless locomotives, but they look like their counterparts, sans a cab.
A slug's fuel tank is filled with sand or cement, and 55 gallon drums of cement or sand are put in the hood where the diesel was, to increase the weight.
The traction motors draw current from the lead locomotive, which ever one is the controling unit.

EMD made a cow and calf set, called a TR5, basicly a SW9 switcher with a cabless SW9 unit semi permantly coupled to it, both had diesel engines, the calf, or cabless unit had a simple set of hoslter controls to allow it to be moved around by itself if needed.
These have been gone for years.

You see slugs in hump yard service, and on occasion, in yard to yard transfer service, they provice additional tractive effort without using fuel.

As for the 8 or 9 locomotives, most likley a power move.
If you live between two yards, or near where there are a few yards, you will see this often.
Locomotives seem to bunch up in one yard or another for some reason, and when there is a shortage in one yard, and a excess in another, they move the power to where it is needed most.
Most likley, only the head two, or leading locomotives were on line, the rest were being towed, no need for that much horsepower.

Note that when you see only two locomotives, they are usually coupled rear end to rear end, one each facing away from the other.
When a crew completes their run, and needs to return, or a new crew needs to take a train back in the direction the locomotives came from, there is no need to turn them around, with one facing each way, all you have to do is swap the controls from one to the other, either one can be the lead unit.
With a diesel electric locomotive, it makes no difference which way it faces, it runs just as fast and just as well in reverse as forward

Signals, in ABS, the system is designed to keep a minimun of three blocks between trains, so when you enter a block, the signal that is four blocks ahead of you, facing opposing traffic, will go red, the one after that, 5 away from you, will show yellow, so forth and so on.
As you proceed, the signals for any opposing traffic will keep pace ahead of you, the signals behind you will also change, in reverse order, so any following traffic will allways be three blocks behind you.
By the way, that is a very simplified example, there is enough to fill a small book!
In CTC, the dispatcher can overide the system for any special movement, and can flag you through a red if needed.
If the power fails, most systems will show red on all signals, they have back up batteries.
If for some reason, all power, battries included, fail, then the signal will go dark.
The rules state any signal that is dark or not functioning, should be treated as a absolute red, you must stop and contact the dispatcher to receive permission to proceed.

By the way, Nora, the only silly question is the one not asked!
No one single person here has all the answers, even the trainmasters dont know it all, (although they would never admit to it), but there are enough railroaders and sharp fans here to answer almost anything you need or want to know.
Some even go out of their way to research a answer for others.
Jenny, aka Mookie, should be able to run a locomotive, or do a conductors job, based soley on the questions she askes!
And she askes some tough one, real doozies!
Stay Frosty,
Stay nosey!
Ed[8D]

[Anonymous]

ED, I'm hurt [|)] I'm broken-hearted [:(] You didn't answer my question. I'm still in the "blind" [;)] What is a feller to do? [:0]

My question may be to archaic for our "young" members such as myself [;)] By the way I still have that swamp land in Arizona for sale--price reduced to $2,499 an acre. Any takers? [:D]

Stay safe, and Look, Listen, and LIVE

Don't forget the troops

That ok ED, I'll still vote for you. [:)]

[Anonymous]

ED, I'm hurt [|)] I'm broken-hearted [:(] You didn't answer my question. I'm still in the "blind" [;)] What is a feller to do? [:0]

My question may be to archaic for our "young" members such as myself [;)] By the way I still have that swamp land in Arizona for sale--price reduced to $2,499 an acre. Any takers? [:D]

Stay safe, and Look, Listen, and LIVE

Don't forget the troops

That ok ED, I'll still vote for you. [:)]

[edblysard]

My deepest, most humble appoligies.
But I have no idea what "in the blind" means[.
But after reading your guess, I think you got it allready.
Edquote]Originally posted by jhhtrainsplanes

ED, I'm hurt [|)] I'm broken-hearted [:(] You didn't answer my question. I'm still in the "blind" [;)] What is a feller to do? [:0]

My question may be to archaic for our "young" members such as myself [;)] By the way I still have that swamp land in Arizona for sale--price reduced to $2,499 an acre. Any takers? [:D]

Stay safe, and Look, Listen, and LIVE

Don't forget the troops

That ok ED, I'll still vote for you. [:)]

[edblysard]

My deepest, most humble appoligies.
But I have no idea what "in the blind" means[.
But after reading your guess, I think you got it allready.
Edquote]Originally posted by jhhtrainsplanes

ED, I'm hurt [|)] I'm broken-hearted [:(] You didn't answer my question. I'm still in the "blind" [;)] What is a feller to do? [:0]

My question may be to archaic for our "young" members such as myself [;)] By the way I still have that swamp land in Arizona for sale--price reduced to $2,499 an acre. Any takers? [:D]

Stay safe, and Look, Listen, and LIVE

Don't forget the troops

That ok ED, I'll still vote for you. [:)]