Bad train pictures

[Anonymous]

PBX means "Private Business Exchange" It's an old Bell System term for an in-house private telephone exchange system.

[Anonymous]

PBX means "Private Business Exchange" It's an old Bell System term for an in-house private telephone exchange system.

[Mikeygaw]

i was looking at some railroad radio frequencies, and noticed that some have PBX listed as what their use for. What does PBX stand for?

[Mikeygaw]

i was looking at some railroad radio frequencies, and noticed that some have PBX listed as what their use for. What does PBX stand for?

[edblysard]

Yeah, but just when you think your through with that one, another one comes in from out in the weeds...

Ed

[edblysard]

Yeah, but just when you think your through with that one, another one comes in from out in the weeds...

Ed

[wabash1]

QUOTE: Originally posted by edblysard

Now thats a smart idea, a built in jumper cable plug.
Down here, our shop guys have 30' jumper cables, home made from welding cables, I think.
We have to jump off a lot of the older locomotives left here by foreign crews, the old Santa Fe units even more than most, because they are told to shut them down when they tie up.

And yeah, you'd think having close to 500 gallons on board would be enough....
(hey, you through stepping in Doggy doo for a while?)

Ed

Doggy doo???? I had to look that up, not use to technical terms..

answer is yes and have been for sometime. I dont have the patients for that stuff anymore. if i wanted to here fighting and bickering i go into the living room and sit with the wife. it usually takes about 5 min for her to come up with something to start a fight over. takes the wind from your sail real quick. i bypass any subject that i see that he starts and bypass all responses he makes. life is easier that way.

[wabash1]

QUOTE: Originally posted by edblysard

Now thats a smart idea, a built in jumper cable plug.
Down here, our shop guys have 30' jumper cables, home made from welding cables, I think.
We have to jump off a lot of the older locomotives left here by foreign crews, the old Santa Fe units even more than most, because they are told to shut them down when they tie up.

And yeah, you'd think having close to 500 gallons on board would be enough....
(hey, you through stepping in Doggy doo for a while?)

Ed

Doggy doo???? I had to look that up, not use to technical terms..

answer is yes and have been for sometime. I dont have the patients for that stuff anymore. if i wanted to here fighting and bickering i go into the living room and sit with the wife. it usually takes about 5 min for her to come up with something to start a fight over. takes the wind from your sail real quick. i bypass any subject that i see that he starts and bypass all responses he makes. life is easier that way.

[M636C]

Tom,

The usual reason for excess power is "balancing", getting a locomotive from one location to another where it is needed, and running it attached to a train to avoid using a extra crew for a non revenue movement.

Has there been a pattern to the operation of two units, mainly in one direction, or varying in a regular pattern between northbound and southbound?

If there was a busy train in one direction, it might be convenient to combine the cars from two trains in the opposite direction, and run the locomotive back on an earlier or later train.

A different reason could be testing of units recently out of workshops. If AEM-7s are being upgraded in some respect, or just falling due for a periodic repair, it might be considered prudent to give them a couple of runs with another reliable unit to check for any break-in failures without risking a delay to a passenger train.

I hope this isn't too simplified an explanation, but those are the main reasons for such workings.

As an aside, in Australia, there were some short distance coal train workings which were often delayed by higher priority trains, and these were worked by double Beyer-Garratt articulated steam locomotives. When the locomotives ran out of coal, they ran back to the locomotive facility to re-coal, and were often replaced by a similar pair. This allowed fans to see pairs of these huge locomotives, working light without trains, passing eachother in opposite directions!

This is an extreme example of wasteful working, and is what Amtrak, running extra locomotives attached to normal trains, as you describe, is trying to avoid!

Peter

[M636C]

Tom,

The usual reason for excess power is "balancing", getting a locomotive from one location to another where it is needed, and running it attached to a train to avoid using a extra crew for a non revenue movement.

Has there been a pattern to the operation of two units, mainly in one direction, or varying in a regular pattern between northbound and southbound?

If there was a busy train in one direction, it might be convenient to combine the cars from two trains in the opposite direction, and run the locomotive back on an earlier or later train.

A different reason could be testing of units recently out of workshops. If AEM-7s are being upgraded in some respect, or just falling due for a periodic repair, it might be considered prudent to give them a couple of runs with another reliable unit to check for any break-in failures without risking a delay to a passenger train.

I hope this isn't too simplified an explanation, but those are the main reasons for such workings.

As an aside, in Australia, there were some short distance coal train workings which were often delayed by higher priority trains, and these were worked by double Beyer-Garratt articulated steam locomotives. When the locomotives ran out of coal, they ran back to the locomotive facility to re-coal, and were often replaced by a similar pair. This allowed fans to see pairs of these huge locomotives, working light without trains, passing eachother in opposite directions!

This is an extreme example of wasteful working, and is what Amtrak, running extra locomotives attached to normal trains, as you describe, is trying to avoid!

Peter

[Anonymous]

I have a stupid question. Why does Amtrak need 2 AEM7's to pull 5 coaches when I regularly see a single AEM7 pulling 7-8 coaches?

I have seen this configuration several times over the past month.

[Anonymous]

I have a stupid question. Why does Amtrak need 2 AEM7's to pull 5 coaches when I regularly see a single AEM7 pulling 7-8 coaches?

I have seen this configuration several times over the past month.

[edblysard]

Now thats a smart idea, a built in jumper cable plug.
Down here, our shop guys have 30' jumper cables, home made from welding cables, I think.
We have to jump off a lot of the older locomotives left here by foreign crews, the old Santa Fe units even more than most, because they are told to shut them down when they tie up.

And yeah, you'd think having close to 500 gallons on board would be enough....
(hey, you through stepping in Doggy doo for a while?)

Ed

[edblysard]

Now thats a smart idea, a built in jumper cable plug.
Down here, our shop guys have 30' jumper cables, home made from welding cables, I think.
We have to jump off a lot of the older locomotives left here by foreign crews, the old Santa Fe units even more than most, because they are told to shut them down when they tie up.

And yeah, you'd think having close to 500 gallons on board would be enough....
(hey, you through stepping in Doggy doo for a while?)

Ed

[wabash1]

Ed

A few commints on what you have said. next time you get a NS engine ( all emd and a few GE) have this . Look where the mu cables go in. there is one marked dummy and the other is hot. right below these and on some beside these toward outer edge there is a little recepticle with 2 pins in a offset connector, if you have a dead engine with week batteries all you need is another engine bring it in couple into the dead one and plug in your cable. this is a jumping port connected like jumping cars only this is for engines. plug it in wait a few minutes then start your dead engine. the gage cable used is just a few steps higher than regular jumper cables. it dont matter which engine you use they all work the same for jumping. One of the better things ive seen in decades for engines.

As far as the cooling system goes I dont agree with some things you said but that will be another days arguement. And after holding 480 gals of water you wouldnt think a engine wouldnt need a reserve tank. but they have them and if you look at the radiator fin just before the fin on engineers side at the top there is a little door. this is the filler tube for the reserve tank. ( or at least this is what i have been told by the shop) On a emd i dont know never had to work on them .

[wabash1]

Ed

A few commints on what you have said. next time you get a NS engine ( all emd and a few GE) have this . Look where the mu cables go in. there is one marked dummy and the other is hot. right below these and on some beside these toward outer edge there is a little recepticle with 2 pins in a offset connector, if you have a dead engine with week batteries all you need is another engine bring it in couple into the dead one and plug in your cable. this is a jumping port connected like jumping cars only this is for engines. plug it in wait a few minutes then start your dead engine. the gage cable used is just a few steps higher than regular jumper cables. it dont matter which engine you use they all work the same for jumping. One of the better things ive seen in decades for engines.

As far as the cooling system goes I dont agree with some things you said but that will be another days arguement. And after holding 480 gals of water you wouldnt think a engine wouldnt need a reserve tank. but they have them and if you look at the radiator fin just before the fin on engineers side at the top there is a little door. this is the filler tube for the reserve tank. ( or at least this is what i have been told by the shop) On a emd i dont know never had to work on them .

[Modelcar]

...Peter: Unusual data.....and "Wisconsin Central operation" in Australia....Didn't imagine there would be such an operation down under. Thanks for the input. Ed and I had the cooling discussion going pretty good.
HAPPY EASTER TO ALL THERE IN DOWN UNDER COUNTRY.

[Modelcar]

...Peter: Unusual data.....and "Wisconsin Central operation" in Australia....Didn't imagine there would be such an operation down under. Thanks for the input. Ed and I had the cooling discussion going pretty good.
HAPPY EASTER TO ALL THERE IN DOWN UNDER COUNTRY.

[Allen Jenkins]

So long as you peckerwoods don't call slugs, the twenty-five SCL MATE(Motors for Additional Tractive Effort) units, which were built new, and ran Blomberg trucks, albiet with the GE752 traction motor, on a new U-boat frame, along with auto re-fuel technology, way back in 1973, only capable of being run with the fifty U36B engines up to twenty-eight miles per. I'll be happy with the junked out slugs you talk about! Just Kidding, Enjoy Your Hobby! ACJ.

[Allen Jenkins]

So long as you peckerwoods don't call slugs, the twenty-five SCL MATE(Motors for Additional Tractive Effort) units, which were built new, and ran Blomberg trucks, albiet with the GE752 traction motor, on a new U-boat frame, along with auto re-fuel technology, way back in 1973, only capable of being run with the fifty U36B engines up to twenty-eight miles per. I'll be happy with the junked out slugs you talk about! Just Kidding, Enjoy Your Hobby! ACJ.

[edblysard]

Cool....
I knew some had a reserve tank, just didnt know where in the long hood it was.
Next chance I get, I will nose through the long hood on a Dash 9, and see where GE stashes it.
Ed

[edblysard]

Cool....
I knew some had a reserve tank, just didnt know where in the long hood it was.
Next chance I get, I will nose through the long hood on a Dash 9, and see where GE stashes it.
Ed

[M636C]

Quentin, Ed,

I thought I should mention something I saw some weeks ago. There was one standard gauge grain train run by the former Wisconsin Central operation in Australia, which was called "Australian Transport Network". The train consisted of about forty grain wagons, new cars built in China (prototypes for all those HO models?), but they used some fairly old locomotives. There were two Clyde/EMD GT26Cs, 251 and 270 (export versions of the original SD40), and a 1000 HP Alco. 251 was in fact the first turbocharged EMD to operate in Australia, in 1967, and has had a hard life since then.

Anyway, this loaded train stopped in the passenger station at Goulburn, next to the passenger building, the crew opened the hood doors just at the front of the radiator section on both sides, and passed the garden hose used to water potted plants on the platform through the hood and filled a water tank on the left side of 251, the leading unit. This took several minutes, then the train moved forward to place 270 in that location, and the same was done to that. The Alco didn't need water!

I hadn't seen a train stop for water since steam days! These units were obviously losing water far too quickly, and on their next operation two days later, the train failed on a steep grade some forty miles South of that location, locomotives shut down due to lack of water!

Since then, that operation has passed to our biggest private operator, Pacific National, and we assume that ATN was cutting costs waiting for the takeover (and a supply of more modern, better maintained units).

But presumably, most EMD units would have a coolant tank in that location near the radiators to provide some reserve for the radiators.

Peter

[M636C]

Quentin, Ed,

I thought I should mention something I saw some weeks ago. There was one standard gauge grain train run by the former Wisconsin Central operation in Australia, which was called "Australian Transport Network". The train consisted of about forty grain wagons, new cars built in China (prototypes for all those HO models?), but they used some fairly old locomotives. There were two Clyde/EMD GT26Cs, 251 and 270 (export versions of the original SD40), and a 1000 HP Alco. 251 was in fact the first turbocharged EMD to operate in Australia, in 1967, and has had a hard life since then.

Anyway, this loaded train stopped in the passenger station at Goulburn, next to the passenger building, the crew opened the hood doors just at the front of the radiator section on both sides, and passed the garden hose used to water potted plants on the platform through the hood and filled a water tank on the left side of 251, the leading unit. This took several minutes, then the train moved forward to place 270 in that location, and the same was done to that. The Alco didn't need water!

I hadn't seen a train stop for water since steam days! These units were obviously losing water far too quickly, and on their next operation two days later, the train failed on a steep grade some forty miles South of that location, locomotives shut down due to lack of water!

Since then, that operation has passed to our biggest private operator, Pacific National, and we assume that ATN was cutting costs waiting for the takeover (and a supply of more modern, better maintained units).

But presumably, most EMD units would have a coolant tank in that location near the radiators to provide some reserve for the radiators.

Peter

[edblysard]

Quentin,
Had a 1950 Ford Four Door, V8 flathead, with two water pumps and two thermostats, and the pressure cap was just like you described, a 7lbs cap.

As for knowledge on how the system on a locomotive decides what temp to turn the fans on, well, I just gave you about all I know, anything else is guessing on my part.
But, I am friends with the head wrench turner in our shop, so I will ask him for you.
Keep waiting for Mark H to jump in here, he turned wrenches on locomotives for a while, and would have a detailed knowledge of the parts involved, and how they work.

My guess would be they have a simple bi-metal probe in the rad, wired to the fans.

And in a way, they have solved the problem of the extra care in cold temps, sorta.
When the locomotives water temp drops, the locomotive starts up, to keep it warm.
Well, it isnt fancy, but it works...

Ed

[edblysard]

Quentin,
Had a 1950 Ford Four Door, V8 flathead, with two water pumps and two thermostats, and the pressure cap was just like you described, a 7lbs cap.

As for knowledge on how the system on a locomotive decides what temp to turn the fans on, well, I just gave you about all I know, anything else is guessing on my part.
But, I am friends with the head wrench turner in our shop, so I will ask him for you.
Keep waiting for Mark H to jump in here, he turned wrenches on locomotives for a while, and would have a detailed knowledge of the parts involved, and how they work.

My guess would be they have a simple bi-metal probe in the rad, wired to the fans.

And in a way, they have solved the problem of the extra care in cold temps, sorta.
When the locomotives water temp drops, the locomotive starts up, to keep it warm.
Well, it isnt fancy, but it works...

Ed

[Modelcar]

...The Kiss principle....Ed you have me on that one. Can't it have just a few moving parts under that system...[kidding].

Your point of trying to repair the thing in the middle if kansas is well taken....and I understand where you are coming from on needing reliability on the equipment. I have heard of the need to drain cooling systems on this equipment for so long..that is, when not in use, etc...that I simply wondered why design and engineering of the age we live in now couldn't take care of that problem.

Back to the auto for a moment.....I guess I really shouldn't have used the term "closed" as it may have led the discussion in the wrong direction....I simply meant, a self controlling system that didn't need special care when temps. were a threat to it to cause the engine to have to be left running or drained, etc....

And by the way Ed, again using the auto in our discussion....and using GM again....The "pressure system" wasn't used wide spread in autos before 1950...! The 1949 [and previous], Chevrolet did not use a pressure cap to maintain any pressure in the cooling system...The pressure cap was then addapted in 1950 and I believe at that time started out at about 7 psi....Somewhat less than our typical 15 lb. units almost common now.

And if one removes the fan belt from the water pump on your auto....you won't get far as it will heat up in nothing flat....It must have circulation and the water pump is critical in doing so.......I know years ago, and I believe I'm correct on this...Model T's didn't employ a water pump...they were designed to simply circulate via hot ver. cold water movement...But that was a simple system allowing that to occur.

Fully understand about the fan not being used much in an auto cooling system except at traffic conditions where no air movement through the radiator is possible by forward motion, etc....And on oil cooling, our auto does have an oil cooler for engine oil and I'm sure that really helps control some of the temp.

By the way....where is the reserve coolant supply on a railroad engine....and how is it fed into the system when needed...? And is there a thermostat system on the cooling fans of the engine cooling system...? Such as being controlled by the temp of the air going through it, etc....or do they run uncontrolled all the time the engine is operating....?
Surely not...

HAPPY EASTER TO ALL.... [8D]

[Modelcar]

...The Kiss principle....Ed you have me on that one. Can't it have just a few moving parts under that system...[kidding].

Your point of trying to repair the thing in the middle if kansas is well taken....and I understand where you are coming from on needing reliability on the equipment. I have heard of the need to drain cooling systems on this equipment for so long..that is, when not in use, etc...that I simply wondered why design and engineering of the age we live in now couldn't take care of that problem.

Back to the auto for a moment.....I guess I really shouldn't have used the term "closed" as it may have led the discussion in the wrong direction....I simply meant, a self controlling system that didn't need special care when temps. were a threat to it to cause the engine to have to be left running or drained, etc....

And by the way Ed, again using the auto in our discussion....and using GM again....The "pressure system" wasn't used wide spread in autos before 1950...! The 1949 [and previous], Chevrolet did not use a pressure cap to maintain any pressure in the cooling system...The pressure cap was then addapted in 1950 and I believe at that time started out at about 7 psi....Somewhat less than our typical 15 lb. units almost common now.

And if one removes the fan belt from the water pump on your auto....you won't get far as it will heat up in nothing flat....It must have circulation and the water pump is critical in doing so.......I know years ago, and I believe I'm correct on this...Model T's didn't employ a water pump...they were designed to simply circulate via hot ver. cold water movement...But that was a simple system allowing that to occur.

Fully understand about the fan not being used much in an auto cooling system except at traffic conditions where no air movement through the radiator is possible by forward motion, etc....And on oil cooling, our auto does have an oil cooler for engine oil and I'm sure that really helps control some of the temp.

By the way....where is the reserve coolant supply on a railroad engine....and how is it fed into the system when needed...? And is there a thermostat system on the cooling fans of the engine cooling system...? Such as being controlled by the temp of the air going through it, etc....or do they run uncontrolled all the time the engine is operating....?
Surely not...

HAPPY EASTER TO ALL.... [8D]

[edblysard]

Quentin,
A closed cooling system with antifreeze would require a themostat and a presurized system.

You understand that the water pump in your car isnt a pump, but presure device, an impeller, to keep a constant pressure (appox 14 psi) on the block, or hot side of the system?
Water under pressure boils at a highter tempature.
Water under pressure with coolant/antifreeze even higher.
Your closed system uses convection and the pressure from the water pump to cause a partial exchange of the cool water in the radiator with the hot water in the block when the thermostat opens, usually about 195 degrees for most GM V8 engines.
This temp keeps the engine running at the most efficent temp, too cool and oil dosnt flow enough, too hot, oils burns and thickens.
The thermostat in your car is the "sensor" that decides when the enging is too hot, and allows cooler water from the radiator, to flow into the block, or too cold, and restricts the flow of cool water.
By the way, this isnt to remove the heat of the combustion, most of that heat is blown out the tailpipe, it is to keep the lubricating oil at the correct temp to allow it to do its job, prevent wear.
(Volkswagon had a very successful air cooled motor, with a oil cooler.
Add a oil cooler to your car, and watch the efficency and gas milage increase.)

This exchange is almost a complete exchange at first, but as the water temp rises, the thermostat begins to open and close quickly, several times every few minutes, until a balance is established, and the termostat remains partially open all the time, allowing a small amount of cooler water from the radiator to enter the block all the time, keeping the engine at the required temp for efficent performance.
Speed up, and the process changes, the thermostat closes even more, because the air blowing through the radiator removes even more heat quicker, so the water becomes cooler, and less of this cooler/colder water is needed to maintain the correct engine temp.
Slow down, the amount of air blowing through the radiator decreases, the heat exchange process between the radiator and the outside air lessens, so a fan is needed to pull cooler air through the radiator, and the thermostat opens wider, because more of this warmer, or less cool water is needed to kept the engine temp correct..
At highway speed, a fan clutch cuts out the radiator fan completly, it freewheels, because enough air is blowing across the radiator to remove the excess heat.
Closed systems are designed for short, constant speed use, where cooling efficency is a requirement, due to space limitations.
All of that to get to this.

Locomotives require a long term, constant use system, moderatly efficent, and having no real space limitatons. (you can use as big a radiator as you need to)
Locomotive water pumps are just that, pumps that move water in GPM rates.
Because it is a open, or non pressurized system, evaporation will occure, but leaks of any kind are, for the most part, small.
In your closed system, a pin hole in a radiator hose will empty most of the system, because it is under pressure.
A pin hole in a locomotive dosnt empty the system.
You car, and a closed, pressurized system, requires quite a few complicated parts, a locomotive dosnt.
Your car operates at a almost constant speed, and part of that speed is used to cool the engine, a locomotive operates at several different throttle setting constantly, and, unless you mount the radiator on the nose, air flow over the radiator due to the speed of the equipment is nill, it has to be created by a fan.

A closed system requires a precise mixture of water and coolant/antifreeze, with a fixed amount of water, change any of those, and you change the efficency of the system.
Closed systems are pressurized, any leak is massive.

Open systems require water, pumps, cooling fan ,a simple temp probe in the radiator, and something a closed system cant use, a reserve supply of water.
Leaks, unless they are into the crankcase/oil system, are not a problem, and are usualy slow and small, and you have a reserve supply of water.

Again, size and location play/use a large role.

You car blows a radiator hose, you tow it to a shop, or home, and fix it with relatively simple tools.

Lose a thermostat or a hose on a locomotive in the middle of Kansas, and
your stuck, real stuck, because now you not only have to find a way to move the locomotive, but the train it is attached to.

The simpler a system is, both in design and maintaiance, is the key for locomotives.
These things run from Canada to Brownsville, there isnt too many places where the crew can pull in and get it fixed.

The kiss principle applies here, the less moving parts or complicated systems and subsystems, the less likely the system will fail.

All of that said, yes, you could design a closed system, but it wouldnt survive long without heavy maintainance, and maintainance cost are a big part of railroading.

Ed

[edblysard]

Quentin,
A closed cooling system with antifreeze would require a themostat and a presurized system.

You understand that the water pump in your car isnt a pump, but presure device, an impeller, to keep a constant pressure (appox 14 psi) on the block, or hot side of the system?
Water under pressure boils at a highter tempature.
Water under pressure with coolant/antifreeze even higher.
Your closed system uses convection and the pressure from the water pump to cause a partial exchange of the cool water in the radiator with the hot water in the block when the thermostat opens, usually about 195 degrees for most GM V8 engines.
This temp keeps the engine running at the most efficent temp, too cool and oil dosnt flow enough, too hot, oils burns and thickens.
The thermostat in your car is the "sensor" that decides when the enging is too hot, and allows cooler water from the radiator, to flow into the block, or too cold, and restricts the flow of cool water.
By the way, this isnt to remove the heat of the combustion, most of that heat is blown out the tailpipe, it is to keep the lubricating oil at the correct temp to allow it to do its job, prevent wear.
(Volkswagon had a very successful air cooled motor, with a oil cooler.
Add a oil cooler to your car, and watch the efficency and gas milage increase.)

This exchange is almost a complete exchange at first, but as the water temp rises, the thermostat begins to open and close quickly, several times every few minutes, until a balance is established, and the termostat remains partially open all the time, allowing a small amount of cooler water from the radiator to enter the block all the time, keeping the engine at the required temp for efficent performance.
Speed up, and the process changes, the thermostat closes even more, because the air blowing through the radiator removes even more heat quicker, so the water becomes cooler, and less of this cooler/colder water is needed to maintain the correct engine temp.
Slow down, the amount of air blowing through the radiator decreases, the heat exchange process between the radiator and the outside air lessens, so a fan is needed to pull cooler air through the radiator, and the thermostat opens wider, because more of this warmer, or less cool water is needed to kept the engine temp correct..
At highway speed, a fan clutch cuts out the radiator fan completly, it freewheels, because enough air is blowing across the radiator to remove the excess heat.
Closed systems are designed for short, constant speed use, where cooling efficency is a requirement, due to space limitations.
All of that to get to this.

Locomotives require a long term, constant use system, moderatly efficent, and having no real space limitatons. (you can use as big a radiator as you need to)
Locomotive water pumps are just that, pumps that move water in GPM rates.
Because it is a open, or non pressurized system, evaporation will occure, but leaks of any kind are, for the most part, small.
In your closed system, a pin hole in a radiator hose will empty most of the system, because it is under pressure.
A pin hole in a locomotive dosnt empty the system.
You car, and a closed, pressurized system, requires quite a few complicated parts, a locomotive dosnt.
Your car operates at a almost constant speed, and part of that speed is used to cool the engine, a locomotive operates at several different throttle setting constantly, and, unless you mount the radiator on the nose, air flow over the radiator due to the speed of the equipment is nill, it has to be created by a fan.

A closed system requires a precise mixture of water and coolant/antifreeze, with a fixed amount of water, change any of those, and you change the efficency of the system.
Closed systems are pressurized, any leak is massive.

Open systems require water, pumps, cooling fan ,a simple temp probe in the radiator, and something a closed system cant use, a reserve supply of water.
Leaks, unless they are into the crankcase/oil system, are not a problem, and are usualy slow and small, and you have a reserve supply of water.

Again, size and location play/use a large role.

You car blows a radiator hose, you tow it to a shop, or home, and fix it with relatively simple tools.

Lose a thermostat or a hose on a locomotive in the middle of Kansas, and
your stuck, real stuck, because now you not only have to find a way to move the locomotive, but the train it is attached to.

The simpler a system is, both in design and maintaiance, is the key for locomotives.
These things run from Canada to Brownsville, there isnt too many places where the crew can pull in and get it fixed.

The kiss principle applies here, the less moving parts or complicated systems and subsystems, the less likely the system will fail.

All of that said, yes, you could design a closed system, but it wouldnt survive long without heavy maintainance, and maintainance cost are a big part of railroading.

Ed