One thing air brakes do is they go ON when there is no air, which could be the reason you guys are leaving them open in the winter, to prevent ANY movement of the cars. In the fire department we ALWAYS chocked our vehicles, both in the station and when parked on the road. Some guys DID have to be shown to chock the downhill slope though!! Not many 10 or 15 ton vehicles will roll uphill on their own!!
@Mike maybe they could pay you to 'mow' the daisies once in a while. ;-))
Train brakes are completely different. The air applies the brake and a spring releases it. In the case of regular freight and passenger cars, this is because you need them able to move with no air for switching. On a streetcar, I don't know. Maybe it's the same idea, although the only time it would move not under its own power and braking is if something is wrong with it. But when the air bleeds off, the brakes release. We normally chock the wheels both ways, but the instructions say that if the car/train is on an obvious slope, put both chocks on the downhill side. We generally don't use the hand brakes on anything except diesels; I don't know why.
I forgot one item in the end of day list. (I keep forgetting it when I'm doing it too.) Call it item 4.5: call the dispatcher and report that you're clear of controlled track.
Also, the morning list item 21 and evening list item 4 should include another running brake test because you changed ends again.
[edit]
Also, the forecast for this Saturday is down to 50F with possible showers. I don't think I'm going to be very busy, but I might get some experience with running it on wet rails.
David
Miserable old git
Patiently waiting for the asteroid with my name on it.
Yes draining the tanks of water will make them last longer, but you are also right in your thinking that letting the cooler winter air in could make them rust faster! We drained our air tanks, as a f/f, once a week until the water stopped spitting out. Sometimes we would go thru a couple of tank refills before it would stop! We knew then that the guy who did it before us DIDN'T do it! We had it on a Saturday or Sunday schedule, each station picking their own day, and with rotating shifts it meant every driver got to do it at some point. There is a daily and weekly checklist you go thru for each vehicle at the start of each shift, with ladder trucks of course having a longer list then the fire engines.
One thing air brakes do is they go ON when there is no air, which could be the reason you guys are leaving them open in the winter, to prevent ANY movement of the cars. In the fire department we ALWAYS chocked our vehicles, both in the station and when parked on the road. Some guys DID have to be shown to chock the downhill slope though!! Not many 10 or 15 ton vehicles will roll uphill on their own!!
I've seen different discussions about different vehicles describing what should be the default or 'unpowered' state of the braking system. Hence the varying behaviours with say, loss of air pressure in the lines. The original Westinghouse systems for trains was of fail-safe intent, thus pressure loss caused automatic brake application. That also covered inadvertent disconnection between the cars too, as the brakes then apply and you don't have a runaway unmanned portion.
But you can have it both ways in that air pressure can be used in normal application too, and in that sense it is working on both sides of the actuator arm that puts the brake pad to the wheel. This US Army film shows an interesting setup for their large trucks.
So you can have an air line that holds the brake pad off the wheel by working against the action of a compressed spring, which in turn always acts toward application. However you can add in another air line to aid in the direction of releasing the spring compression and hence toward brake application. To reduce delays over really long vehicles then there are various tricks to 'prime' the containers/lines etc in advance of the actual braking decision. Probably the cleverest idea is the ( lapping ) triple valve which at least tops up the air per car reservoir, drawing flow off the main pipe if the differential is correct. The main pipe in turn is kept pressurised by a main reservoir(s) up at the engine. The engine is of course the source of generation of pressure energies in the system.
Quote:
@Mike maybe they could pay you to 'mow' the daisies once in a while. ;-))
For my sins that day I had to wash the fuselage quite thoroughly of the green splatter, as unfortunately a ride in the sky did not blow much of the impacted grass fragments off ! :-)
Cheers, Mike.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
@Mike they used to tell me, when I was a rookie, that washing the fire engine or truck gave me a chance to 'closely inspect it for damage'. To me it was just a pain in the neck as it was sooo big, as I got more experienced, and found some problems, I began to understand what they meant.
Probably the cleverest idea is the ( lapping ) triple valve which at least tops up the air per car reservoir, drawing flow off the main pipe if the differential is correct. The main pipe in turn is kept pressurised by a main reservoir(s) up at the engine. The engine is of course the source of generation of pressure energies in the system.
Yes, I oversimplified it in my previous post. Once the whole train is up to operating pressure (usually 90 PSI, 110 for passenger trains), the triple valve's spring moves it toward lower pressure in the train line, thus admitting air from the car's reservoir to the cylinder and applying the brake. When pressure in the train line increases, the triple valve goes the other way, which not only recharges the reservoir but also vents the cylinder to atmosphere, releasing the brake.
The forecast for tomorrow is now a high of 46F [edit] and possible snow in that area [/edit]. I wonder if anyone will even show up to make it worthwhile for me to get the car out of the barn.
Note to moderator: I got a friend request from a user named droidgames.com. Seems like a spammer to me.
David
Miserable old git
Patiently waiting for the asteroid with my name on it.
Probably the cleverest idea is the ( lapping ) triple valve which at least tops up the air per car reservoir, drawing flow off the main pipe if the differential is correct. The main pipe in turn is kept pressurised by a main reservoir(s) up at the engine. The engine is of course the source of generation of pressure energies in the system.
Yes, I oversimplified it in my previous post. Once the whole train is up to operating pressure (usually 90 PSI, 110 for passenger trains), the triple valve's spring moves it toward lower pressure in the train line, thus admitting air from the car's reservoir to the cylinder and applying the brake. When pressure in the train line increases, the triple valve goes the other way, which not only recharges the reservoir but also vents the cylinder to atmosphere, releasing the brake.
The forecast for tomorrow is now a high of 46F [edit] and possible snow in that area [/edit]. I wonder if anyone will even show up to make it worthwhile for me to get the car out of the barn.
Note to moderator: I got a friend request from a user named droidgames.com. Seems like a spammer to me.
I don't know where you live, but in early October the mid 40's and SNOW is NOT where I want to be!!! My temps will be in the low to mid 70's for the next week, it's supposed to hit the low 70's today too but it's only 66F right now!
Probably the cleverest idea is the ( lapping ) triple valve which at least tops up the air per car reservoir, drawing flow off the main pipe if the differential is correct. The main pipe in turn is kept pressurised by a main reservoir(s) up at the engine. The engine is of course the source of generation of pressure energies in the system.
Yes, I oversimplified it in my previous post. Once the whole train is up to operating pressure (usually 90 PSI, 110 for passenger trains), the triple valve's spring moves it toward lower pressure in the train line, thus admitting air from the car's reservoir to the cylinder and applying the brake. When pressure in the train line increases, the triple valve goes the other way, which not only recharges the reservoir but also vents the cylinder to atmosphere, releasing the brake.
The forecast for tomorrow is now a high of 46F [edit] and possible snow in that area [/edit]. I wonder if anyone will even show up to make it worthwhile for me to get the car out of the barn.
Note to moderator: I got a friend request from a user named droidgames.com. Seems like a spammer to me.
I don't know where you live, but in early October the mid 40's and SNOW is NOT where I want to be!!! My temps will be in the low to mid 70's for the next week, it's supposed to hit the low 70's today too but it's only 66F right now!
We had a beautiful September, much nicer than normal and finishing with over a week of no rain. Yesterday was in the 70s (and humid, with the rain). Supposed to be back in the 60s next week.
David
Miserable old git
Patiently waiting for the asteroid with my name on it.
Well it's a deep rabbit hole. I found a good site to read on that and other train stuff. I guess it's an issue of how redundant one wants to be in the design.
Quote:
Note to moderator: I got a friend request from a user named droidgames.com. Seems like a spammer to me.
You are dead right. Thank you very much. I'll look into that ! :-)
Spring has well and truly sprung DownUnda. Cracking good weather and much ado in the garden. Buzzy bees and a fabulous dawn chorus from every bird in the neighbourhood that wants to get to know the other gender. Saw that powerful owl flying past transporting possum fragments back to the nest, and there has been a further dip in the rabbit sightings.
Quote:
@Mike they used to tell me, when I was a rookie, that washing the fire engine or truck gave me a chance to 'closely inspect it for damage'. To me it was just a pain in the neck as it was sooo big, as I got more experienced, and found some problems, I began to understand what they meant.
Absolutely right. For the pre-flight walk-around check I was taught to push and pull everything that is supposed to move, not just view control surface responses from the cockpit. The idea was to feel the resistance to movement of say, the ailerons which might indicate an issue. Of special note was testing for the presence, and security, of a nut & bolt that held the vertical rudder shaft in place, plus the split pin through that bolt thread to keep the bolt on. In fact they would particularly fail every student that didn't.
That wasn't the only absolutely-must-do item, but there was a core set that for repeat offenders they would send you home on the day without a flight. You could come back when you had properly memorised and acted upon the check list ! I avoided that. But those that hadn't often complained loudly until they either went away and never came back or went away and did their homework. The guy who ran the school always thought it better to lose a live careless student than a dead one. Interestingly the school was never quiet as it was known for it's thoroughness, which is why I went there, so in the end it never hurt the business to be mildly rude for good reasons.
Cheers, Mike.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
RE: One thing air brakes do
Train brakes are completely different. The air applies the brake and a spring releases it. In the case of regular freight and passenger cars, this is because you need them able to move with no air for switching. On a streetcar, I don't know. Maybe it's the same idea, although the only time it would move not under its own power and braking is if something is wrong with it. But when the air bleeds off, the brakes release. We normally chock the wheels both ways, but the instructions say that if the car/train is on an obvious slope, put both chocks on the downhill side. We generally don't use the hand brakes on anything except diesels; I don't know why.
I forgot one item in the end of day list. (I keep forgetting it when I'm doing it too.) Call it item 4.5: call the dispatcher and report that you're clear of controlled track.
Also, the morning list item 21 and evening list item 4 should include another running brake test because you changed ends again.
[edit]
Also, the forecast for this Saturday is down to 50F with possible showers. I don't think I'm going to be very busy, but I might get some experience with running it on wet rails.
David
Miserable old git
Patiently waiting for the asteroid with my name on it.
RE: Yes draining the tanks
I've seen different discussions about different vehicles describing what should be the default or 'unpowered' state of the braking system. Hence the varying behaviours with say, loss of air pressure in the lines. The original Westinghouse systems for trains was of fail-safe intent, thus pressure loss caused automatic brake application. That also covered inadvertent disconnection between the cars too, as the brakes then apply and you don't have a runaway unmanned portion.
But you can have it both ways in that air pressure can be used in normal application too, and in that sense it is working on both sides of the actuator arm that puts the brake pad to the wheel. This US Army film shows an interesting setup for their large trucks.
So you can have an air line that holds the brake pad off the wheel by working against the action of a compressed spring, which in turn always acts toward application. However you can add in another air line to aid in the direction of releasing the spring compression and hence toward brake application. To reduce delays over really long vehicles then there are various tricks to 'prime' the containers/lines etc in advance of the actual braking decision. Probably the cleverest idea is the ( lapping ) triple valve which at least tops up the air per car reservoir, drawing flow off the main pipe if the differential is correct. The main pipe in turn is kept pressurised by a main reservoir(s) up at the engine. The engine is of course the source of generation of pressure energies in the system.
For my sins that day I had to wash the fuselage quite thoroughly of the green splatter, as unfortunately a ride in the sky did not blow much of the impacted grass fragments off ! :-)
Cheers, Mike.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
WOW lots to learn about
WOW lots to learn about brakes and stuff!
@Mike they used to tell me, when I was a rookie, that washing the fire engine or truck gave me a chance to 'closely inspect it for damage'. To me it was just a pain in the neck as it was sooo big, as I got more experienced, and found some problems, I began to understand what they meant.
RE: Probably the cleverest
Yes, I oversimplified it in my previous post. Once the whole train is up to operating pressure (usually 90 PSI, 110 for passenger trains), the triple valve's spring moves it toward lower pressure in the train line, thus admitting air from the car's reservoir to the cylinder and applying the brake. When pressure in the train line increases, the triple valve goes the other way, which not only recharges the reservoir but also vents the cylinder to atmosphere, releasing the brake.
The forecast for tomorrow is now a high of 46F [edit] and possible snow in that area [/edit]. I wonder if anyone will even show up to make it worthwhile for me to get the car out of the barn.
Note to moderator: I got a friend request from a user named droidgames.com. Seems like a spammer to me.
David
Miserable old git
Patiently waiting for the asteroid with my name on it.
RE: RE: Probably the
I don't know where you live, but in early October the mid 40's and SNOW is NOT where I want to be!!! My temps will be in the low to mid 70's for the next week, it's supposed to hit the low 70's today too but it's only 66F right now!
RE: RE: RE: Probably
We had a beautiful September, much nicer than normal and finishing with over a week of no rain. Yesterday was in the 70s (and humid, with the rain). Supposed to be back in the 60s next week.
David
Miserable old git
Patiently waiting for the asteroid with my name on it.
RE: Yes, I oversimplified
Well it's a deep rabbit hole. I found a good site to read on that and other train stuff. I guess it's an issue of how redundant one wants to be in the design.
You are dead right. Thank you very much. I'll look into that ! :-)
Spring has well and truly sprung DownUnda. Cracking good weather and much ado in the garden. Buzzy bees and a fabulous dawn chorus from every bird in the neighbourhood that wants to get to know the other gender. Saw that powerful owl flying past transporting possum fragments back to the nest, and there has been a further dip in the rabbit sightings.
Absolutely right. For the pre-flight walk-around check I was taught to push and pull everything that is supposed to move, not just view control surface responses from the cockpit. The idea was to feel the resistance to movement of say, the ailerons which might indicate an issue. Of special note was testing for the presence, and security, of a nut & bolt that held the vertical rudder shaft in place, plus the split pin through that bolt thread to keep the bolt on. In fact they would particularly fail every student that didn't.
That wasn't the only absolutely-must-do item, but there was a core set that for repeat offenders they would send you home on the day without a flight. You could come back when you had properly memorised and acted upon the check list ! I avoided that. But those that hadn't often complained loudly until they either went away and never came back or went away and did their homework. The guy who ran the school always thought it better to lose a live careless student than a dead one. Interestingly the school was never quiet as it was known for it's thoroughness, which is why I went there, so in the end it never hurt the business to be mildly rude for good reasons.
Cheers, Mike.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
Good morning everyone.
Good morning everyone. :-)
Happy Saturday to everyone. :-)
TimeLord04
Have TARDIS, will travel...
Come along K-9!
Join SETI Refugees
Howdy ! I was up in Northern
Howdy !
I was up in Northern Wisconsin last week camping
by the shores of Lake Superior ....
Nice up there !
Bill
Looks a good spot Bill! A
Looks a good spot Bill! A dining table with a view. Decent size tent you have. :-)
Cheers, Mike.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal