Date   

Re: AIR BRAKES 101.... was Re: RGS #20. Was: [HOn3] Division Point K-27 question

Climax@...
 


What do you mean "have the hand brakes tied down"?  Do  you use a rope or a chain or something or is it just a slang term for setting the brakes?
Mule

-----Original Message-----
From: Mark Lewis
Sent: Oct 10, 2020 12:59 PM
To: HOn3@groups.io
Subject: Re: AIR BRAKES 101.... was Re: RGS #20. Was: [HOn3] Division Point K-27 question

Johnny,

😱🚂💥

Mark Lewis

On Sat, Oct 10, 2020 at 12:41 PM johnny graybeal <johnnyg@...> wrote:

The best way to think about it is to see a balanced beam on a fulcrum. Pressure goes one way and then another, in releases and charges. The triple valve controls the balance and is the fulcrum. It is a constant moving back and forth with each move of the brake valve.
One thing not mentioned so far is when a car is parked on a siding, you can turn the valve on each end and keep the air in the pipe under the car. In theory, that would allow the car to stay parked with the air in the line, but in reality there is always a leak somewhere. Thus the line left alone, will lose pressure one ounce of pressure at a time until it all hits 0. At that point there is no break pressure and the brakes release, actually before when it drops to a certain point. That is why all cars have to have the hand brakes tied down. The brakes will NEVER hold it over time. 

Reading the old books on this can be very confusing, but less so than talking about how a check valve lets water of less pressure go into a boiler of higher pressure. That still gives me headaches.
Johnny Graybeal


Re: We be injections (was AIR BRAKES 101.... was Re: RGS #20. Was: [HOn3] Division Point K-27 question)

John Stutz
 

Many thanks for the reference Mike

I was not previously aware of http://www.railway-technical.com/
It is a remarkably informative website.

John Stutz

On October 10, 2020 at 10:45 AM Mike Conder <vulturenest1@...> wrote:

BTW, great description of the triple valve is here:


Mike Conder

On Sat, Oct 10, 2020 at 11:41 AM Mike Conder < vulturenest1@...> wrote:
Sort of, I think.  The injector uses internal venturis powered by steam.  The venturis create a high velocity and low pressure (via conservation of energy) and then the mix is going fast enough and is now dense enough to get into the boiler.  Seems like magic, but it's just brilliant mechanical engineering! (and the triple valve is ALSO brilliant mechanical engineering!)

Mike Conder, mechanical engineer

On Sat, Oct 10, 2020 at 10:54 AM Nolan Hinshaw via groups.io <cearnog= yahoo.com@groups.io> wrote:
On Oct 10, 2020, at 09:41, johnny graybeal < johnnyg@...> wrote:

> Reading the old books on this can be very confusing, but less so than talking about how a check valve lets water of less pressure go into a boiler of higher pressure. That still gives me headaches.

What forces water from an injector through a check valve is impulse, not pressure, It's the energy water (density higher than steam's) gets passing through an injector and gaining velocity (momentum is mass times the square of velocity, wherefrom impulse, which depends on compressing that momentum into very small intervals of time,...). Simple Newtonian mechanics at work - nothing to see here - move along...

From a pump, there's the force multiplier between the steam cylinder(s) and the water cylinder(s) that produces a positive pressure differential at the check.





 


Re: We be injections (was AIR BRAKES 101.... was Re: RGS #20. Was: [HOn3] Division Point K-27 question)

Mike Conder
 

BTW, great description of the triple valve is here:


Mike Conder

On Sat, Oct 10, 2020 at 11:41 AM Mike Conder <vulturenest1@...> wrote:
Sort of, I think.  The injector uses internal venturis powered by steam.  The venturis create a high velocity and low pressure (via conservation of energy) and then the mix is going fast enough and is now dense enough to get into the boiler.  Seems like magic, but it's just brilliant mechanical engineering! (and the triple valve is ALSO brilliant mechanical engineering!)

Mike Conder, mechanical engineer

On Sat, Oct 10, 2020 at 10:54 AM Nolan Hinshaw via groups.io <cearnog=yahoo.com@groups.io> wrote:
On Oct 10, 2020, at 09:41, johnny graybeal <johnnyg@...> wrote:

> Reading the old books on this can be very confusing, but less so than talking about how a check valve lets water of less pressure go into a boiler of higher pressure. That still gives me headaches.

What forces water from an injector through a check valve is impulse, not pressure, It's the energy water (density higher than steam's) gets passing through an injector and gaining velocity (momentum is mass times the square of velocity, wherefrom impulse, which depends on compressing that momentum into very small intervals of time,...). Simple Newtonian mechanics at work - nothing to see here - move along...

From a pump, there's the force multiplier between the steam cylinder(s) and the water cylinder(s) that produces a positive pressure differential at the check.





Re: We be injections (was AIR BRAKES 101.... was Re: RGS #20. Was: [HOn3] Division Point K-27 question)

Mike Conder
 

Sort of, I think.  The injector uses internal venturis powered by steam.  The venturis create a high velocity and low pressure (via conservation of energy) and then the mix is going fast enough and is now dense enough to get into the boiler.  Seems like magic, but it's just brilliant mechanical engineering! (and the triple valve is ALSO brilliant mechanical engineering!)

Mike Conder, mechanical engineer

On Sat, Oct 10, 2020 at 10:54 AM Nolan Hinshaw via groups.io <cearnog=yahoo.com@groups.io> wrote:
On Oct 10, 2020, at 09:41, johnny graybeal <johnnyg@...> wrote:

> Reading the old books on this can be very confusing, but less so than talking about how a check valve lets water of less pressure go into a boiler of higher pressure. That still gives me headaches.

What forces water from an injector through a check valve is impulse, not pressure, It's the energy water (density higher than steam's) gets passing through an injector and gaining velocity (momentum is mass times the square of velocity, wherefrom impulse, which depends on compressing that momentum into very small intervals of time,...). Simple Newtonian mechanics at work - nothing to see here - move along...

From a pump, there's the force multiplier between the steam cylinder(s) and the water cylinder(s) that produces a positive pressure differential at the check.





Re: AIR BRAKES 101.... was Re: RGS #20. Was: [HOn3] Division Point K-27 question

Mark Lewis
 

Johnny,

😱🚂💥

Mark Lewis


On Sat, Oct 10, 2020 at 12:41 PM johnny graybeal <johnnyg@...> wrote:

The best way to think about it is to see a balanced beam on a fulcrum. Pressure goes one way and then another, in releases and charges. The triple valve controls the balance and is the fulcrum. It is a constant moving back and forth with each move of the brake valve.
One thing not mentioned so far is when a car is parked on a siding, you can turn the valve on each end and keep the air in the pipe under the car. In theory, that would allow the car to stay parked with the air in the line, but in reality there is always a leak somewhere. Thus the line left alone, will lose pressure one ounce of pressure at a time until it all hits 0. At that point there is no break pressure and the brakes release, actually before when it drops to a certain point. That is why all cars have to have the hand brakes tied down. The brakes will NEVER hold it over time. 

Reading the old books on this can be very confusing, but less so than talking about how a check valve lets water of less pressure go into a boiler of higher pressure. That still gives me headaches.
Johnny Graybeal


We be injections (was AIR BRAKES 101.... was Re: RGS #20. Was: [HOn3] Division Point K-27 question)

Nolan Hinshaw
 

On Oct 10, 2020, at 09:41, johnny graybeal <johnnyg@boone.net> wrote:

Reading the old books on this can be very confusing, but less so than talking about how a check valve lets water of less pressure go into a boiler of higher pressure. That still gives me headaches.
What forces water from an injector through a check valve is impulse, not pressure, It's the energy water (density higher than steam's) gets passing through an injector and gaining velocity (momentum is mass times the square of velocity, wherefrom impulse, which depends on compressing that momentum into very small intervals of time,...). Simple Newtonian mechanics at work - nothing to see here - move along...

From a pump, there's the force multiplier between the steam cylinder(s) and the water cylinder(s) that produces a positive pressure differential at the check.


Re: AIR BRAKES 101.... was Re: RGS #20. Was: [HOn3] Division Point K-27 question

johnny graybeal
 

The best way to think about it is to see a balanced beam on a fulcrum. Pressure goes one way and then another, in releases and charges. The triple valve controls the balance and is the fulcrum. It is a constant moving back and forth with each move of the brake valve.
One thing not mentioned so far is when a car is parked on a siding, you can turn the valve on each end and keep the air in the pipe under the car. In theory, that would allow the car to stay parked with the air in the line, but in reality there is always a leak somewhere. Thus the line left alone, will lose pressure one ounce of pressure at a time until it all hits 0. At that point there is no break pressure and the brakes release, actually before when it drops to a certain point. That is why all cars have to have the hand brakes tied down. The brakes will NEVER hold it over time. 

Reading the old books on this can be very confusing, but less so than talking about how a check valve lets water of less pressure go into a boiler of higher pressure. That still gives me headaches.
Johnny Graybeal


Re: AIR BRAKES 101.... was Re: RGS #20. Was: [HOn3] Division Point K-27 question

Mike Smith
 

At the end of my career, the handbrake instructions were to tie the handbrakes with the engines attached, Then release the train air and the engine brakes.  If the handbrakes held the train with the engines attached, you were good to cut off and go.  If the thing moved, you had to go back and tie more handbrakes.  So if you had a lot of engines, you tied a lot of extra brakes.  You couldn't get away with not following the instructions, because it all showed up on the event recorder. (Black Box) 

Mike Smith
Tucson 

Glad to be retired and playing with trains when the sun is up!

On Friday, October 9, 2020, 05:03:06 PM MST, Earl Knoob <earlk489@...> wrote:


The railroads were, and still are,  quite vague in the number of handbrakes to be set when setting out cars.  Generally, the rule stated "a sufficient number of handbrakes must be set to prevent movement."  So, the company left it up the employee's judgement as to the number of handbrakes that needed to be set.

A quote from the Cumbres & Toltec Scenic RR Rulebook , dated about 1993:  

"101. When cars are left standing on any track a sufficient number of handbrakes must be set to prevent movement.  Cars left on grades must also have a sufficient number of wheels blocked to prevent movement when the engine is detached."

I can't find my D&S rulebook, but they took it further by requiring, the hand brake applied, then the air brakes bled off, so that the hand brake was to sole method of braking applied.  You then pulled away from the car to see if it stayed put.  Other places I have worked had special instructions for tying down trains at certain locations.  At the last place I worked before retirement - the Copper Basin Ry - when you tied the ore train down at the end of the day, you set all the locomotive hand brakes (3 units), plus the first 5 cars of the train. 


From: HOn3@groups.io <HOn3@groups.io> on behalf of John Stutz <john.stutz@...>
Sent: Thursday, October 8, 2020 8:01 PM
To: HOn3@groups.io <HOn3@groups.io>
Subject: Re: AIR BRAKES 101.... was Re: RGS #20. Was: [HOn3] Division Point K-27 question
 
Dave

I speculate that official rules called for tying down all hand brake on set out cars, but that crews often did less, and relied on the air brakes with cars that were only temporarily set out.  Check published or online rule books for operation of trains.  My knowledge comes mostly from air brake instruction manuals, which tend to focus on ideal rather than actual operating practices.

John
On October 8, 2020 at 5:52 PM Climax@... wrote:

Since I model the 1900 to 1927 era this is important to me.  If, as you say, a train set a few cars on a siding did all the hand brakes need to be cinched down or would they only do one car?  Dave

-----Original Message-----
From: John Stutz
Sent: Oct 8, 2020 5:04 PM
To: HOn3@groups.io
Subject: Re: AIR BRAKES 101.... was Re: RGS #20. Was: [HOn3] Division Point K-27 question

Dave

Circa 1900 brake cylinders used leather gaskets to seal the brake cylinder, and they usually leaked off slowly.  This is why set out cars are supposed to always have the hand brake set.

The air and hand brake act independently, through the foundation brake gear, the set of rods and levers that carry braking force to the brake shoes.  The air brake cylinder piston has a hollow stem holding a push rod.  When the air brake is activated, this rod pushes on the connected lever.  The hand brake is connected to the same lever, usually through a chain.  When the hand brake is wound up. the chain pulls on the lever, and pulls the push rod partially out of the brake piston's stem. 

The triple valve is the heart of the automatic air brake, and some version has been used from the first automatic system of circa 1870.  The triple has undergone frequent revision ever since, to adapt it to evolving RR demands for better control of longer, heaver and faster trains.  But all versions have essentially operated in the manner that Earl described.  The KC or KD brake is simply the standard freight car apparatus of circa 1890-1940, fitted with the type K triple valve of circa 1902, and arranged  in the Combined or Detached format.  The principle improvement of the AB valve is the provision of separate service and emergency valves, with separate air reservoirs, so that full emergency power is always available.

John Stutz
On October 8, 2020 at 1:20 PM Climax@... wrote:

Lets say a box car was left on a siding with a grade.  Now there is either a very slow leak or can someone come along and pull the bleed off rod and would that result in the brakes being applied through springs to not let the car roll, or would the brakes release and let the car roll?  If it did roll, and you jumped on the car to get to the Brake wheel, does that apply or release brake pressure. 
The triple valve is on an AB system while a K system did not have that feature of  triple valve?
Dave

 


Re: "Gramps " decals

Mick Moignard
 

I would not trust MDC accuracy over Thinfilm, or indeed Blackstone, whose Gramps lettering is the same size as Thinfilm.  Both also match photos of the real thing.

Mick

________________________________
Mick Moignard
m: +44 7774 652504
Skype: mickmoignard

The week may start M,T but it always ends WTF.


Re: AIR BRAKES 101.... was Re: RGS #20. Was: [HOn3] Division Point K-27 question

Earl Knoob
 

The railroads were, and still are,  quite vague in the number of handbrakes to be set when setting out cars.  Generally, the rule stated "a sufficient number of handbrakes must be set to prevent movement."  So, the company left it up the employee's judgement as to the number of handbrakes that needed to be set.

A quote from the Cumbres & Toltec Scenic RR Rulebook , dated about 1993:  

"101. When cars are left standing on any track a sufficient number of handbrakes must be set to prevent movement.  Cars left on grades must also have a sufficient number of wheels blocked to prevent movement when the engine is detached."

I can't find my D&S rulebook, but they took it further by requiring, the hand brake applied, then the air brakes bled off, so that the hand brake was to sole method of braking applied.  You then pulled away from the car to see if it stayed put.  Other places I have worked had special instructions for tying down trains at certain locations.  At the last place I worked before retirement - the Copper Basin Ry - when you tied the ore train down at the end of the day, you set all the locomotive hand brakes (3 units), plus the first 5 cars of the train. 


From: HOn3@groups.io <HOn3@groups.io> on behalf of John Stutz <john.stutz@...>
Sent: Thursday, October 8, 2020 8:01 PM
To: HOn3@groups.io <HOn3@groups.io>
Subject: Re: AIR BRAKES 101.... was Re: RGS #20. Was: [HOn3] Division Point K-27 question
 
Dave

I speculate that official rules called for tying down all hand brake on set out cars, but that crews often did less, and relied on the air brakes with cars that were only temporarily set out.  Check published or online rule books for operation of trains.  My knowledge comes mostly from air brake instruction manuals, which tend to focus on ideal rather than actual operating practices.

John
On October 8, 2020 at 5:52 PM Climax@... wrote:

Since I model the 1900 to 1927 era this is important to me.  If, as you say, a train set a few cars on a siding did all the hand brakes need to be cinched down or would they only do one car?  Dave

-----Original Message-----
From: John Stutz
Sent: Oct 8, 2020 5:04 PM
To: HOn3@groups.io
Subject: Re: AIR BRAKES 101.... was Re: RGS #20. Was: [HOn3] Division Point K-27 question

Dave

Circa 1900 brake cylinders used leather gaskets to seal the brake cylinder, and they usually leaked off slowly.  This is why set out cars are supposed to always have the hand brake set.

The air and hand brake act independently, through the foundation brake gear, the set of rods and levers that carry braking force to the brake shoes.  The air brake cylinder piston has a hollow stem holding a push rod.  When the air brake is activated, this rod pushes on the connected lever.  The hand brake is connected to the same lever, usually through a chain.  When the hand brake is wound up. the chain pulls on the lever, and pulls the push rod partially out of the brake piston's stem. 

The triple valve is the heart of the automatic air brake, and some version has been used from the first automatic system of circa 1870.  The triple has undergone frequent revision ever since, to adapt it to evolving RR demands for better control of longer, heaver and faster trains.  But all versions have essentially operated in the manner that Earl described.  The KC or KD brake is simply the standard freight car apparatus of circa 1890-1940, fitted with the type K triple valve of circa 1902, and arranged  in the Combined or Detached format.  The principle improvement of the AB valve is the provision of separate service and emergency valves, with separate air reservoirs, so that full emergency power is always available.

John Stutz
On October 8, 2020 at 1:20 PM Climax@... wrote:

Lets say a box car was left on a siding with a grade.  Now there is either a very slow leak or can someone come along and pull the bleed off rod and would that result in the brakes being applied through springs to not let the car roll, or would the brakes release and let the car roll?  If it did roll, and you jumped on the car to get to the Brake wheel, does that apply or release brake pressure. 
The triple valve is on an AB system while a K system did not have that feature of  triple valve?
Dave

 


Thinfilm Gramps" decals

Robert Veefkind
 

page 298 of Sloans book shows Thin film decals are correct. I should have done my homework first
 


Re: "Gramps " decals

John Stutz
 

Note that PSC offers the body bolster from their frameless tank car kit as a separate styrene part.  This may fit the MDC tank shell.   The dome, handrail brackets, and some other parts, are also available.  The domes and detail parts for Tichy's tank cars are also available separately.

John Stutz

On October 9, 2020 at 9:55 AM Randy Hees <randyhees@...> wrote:

The MDC tank was more "representational" than carefully accurate, and was offered as a standard gauge car. with a frame..  Gramps was applied to the Van Dyke (frameless cars).. But noting that tank cars seem to have been more standardized than other cars, and the narrow gauge UTLX cars were all older standard gauge cars converted to narrow gauge.  I would trust Thinfilm rather than MDC...   But it is also possible that the Gramps lettering had variations...   The Narrow gauge pictorial, Vol IV, covers the tank cars.  Sloan's Century + also covers them.

Randy Hees

On Fri, Oct 9, 2020 at 8:53 AM Robert Veefkind via groups.io <snookdust= aol.com@groups.io> wrote:
Another snag ?   Hello gang I was applying the Thinfilm hon decal to one of the old MDC tankers when I noticed it took up 15 feet of the tank. The MDC  Gramps lettering is 10 feet long. Any thoughts?   Bob V.


Re: "Gramps " decals

Randy Hees
 

The MDC tank was more "representational" than carefully accurate, and was offered as a standard gauge car. with a frame..  Gramps was applied to the Van Dyke (frameless cars).. But noting that tank cars seem to have been more standardized than other cars, and the narrow gauge UTLX cars were all older standard gauge cars converted to narrow gauge.  I would trust Thinfilm rather than MDC...   But it is also possible that the Gramps lettering had variations...   The Narrow gauge pictorial, Vol IV, covers the tank cars.  Sloan's Century + also covers them.

Randy Hees

On Fri, Oct 9, 2020 at 8:53 AM Robert Veefkind via groups.io <snookdust=aol.com@groups.io> wrote:
Another snag ?   Hello gang I was applying the Thinfilm hon decal to one of the old MDC tankers when I noticed it took up 15 feet of the tank. The MDC  Gramps lettering is 10 feet long. Any thoughts?   Bob V.


Re: "Gramps " decals

cmdrwmriker
 

If the air brake system for the car does not actually function, then no one will notice the decal being slightly out of scale.

----- Original Message -----
From: Robert Veefkind via groups.io <snookdust@...>
To: hon3@groups.io
Sent: Fri, 09 Oct 2020 11:53:49 -0400 (EDT)
Subject: [HOn3] "Gramps " decals

Another snag ?   Hello gang I was applying the Thinfilm hon decal to one of the old MDC tankers when I noticed it took up 15 feet of the tank. The MDC  Gramps lettering is 10 feet long. Any thoughts?   Bob V.




"Gramps " decals

Robert Veefkind
 

Another snag ?   Hello gang I was applying the Thinfilm hon decal to one of the old MDC tankers when I noticed it took up 15 feet of the tank. The MDC  Gramps lettering is 10 feet long. Any thoughts?   Bob V.


Re: AIR BRAKES 101.... was Re: RGS #20. Was: [HOn3] Division Point K-27 question

Mike Conder
 

Perfectly clear now, great explanation of something that I didn't understand before.  Thanks!

Mike Conder

On Thu, Oct 8, 2020 at 1:28 PM Earl Knoob <earlk489@...> wrote:
When the brakes are initially charged up, 90 lbs of air pressure is sent down the brake pipe.  This air not only fills the brake pipe, but it charges up the auxiliary reservoir in each car.  There is a valve called the "triple valve" which connects the brake pipe, the brake cylinder and the aux. reservoir together.

Once the aux reservoir and brake pipe are fully charged, the brakes are functional.  To make a controlled "service application". The engineer releases air from the brake line.  This causes a pressure imbalance between the aux air res pressure (still at 90 psi) and the brake pipe (now something less).  The triple valve then sends air from the aux. reservoir to the brake cylinder.  Once the pressures equalize, the triple valve "laps" and stops the flow of air.  If more braking is need, more air is released from the brake pipe, again causing a pressure imbalance, letting the aux. res. to put more air into the brake cylinder.

To release the brakes, the brake pipe pressure is restored, the triple valve again recharges the aux. res. and the brake cylinder pressure is exhausted to atmosphere.  The retainer valve is placed in the brake cylinder exhaust line.  It is simply an either spring loaded valve or a dead weight valve, that holds air in the brake cylinders while the brake pipe and auxiliary reservoir pressure is restored.  Holding the air in the brake cylinders allow the brake to drag while recovering the pressures.

If an air hose breaks, all the air is lost from the brake pipe.  This creates a massive pressure imbalance between the aux res and the brake pipe.  The triple valve then dumps all the aux res air into the brake cylinder at once as an "emergency application".

In theory, the brakes would remain set until the brake pipe pressure is restored.  Or you can go to each car and pull the bleed off rod, which releases the air out of the aux res.  As the triple valve is in emergancy position, the aux res it is connected to the brake cylinder through the valve, so when the aux res air is drained out, so is the brake cylinder air.

Clear as mud, right?


From: HOn3@groups.io <HOn3@groups.io> on behalf of Climax@... <Climax@...>
Sent: Thursday, October 8, 2020 12:19 PM
To: HOn3@groups.io <HOn3@groups.io>
Subject: Re: RGS #20. Was: [HOn3] Division Point K-27 question
 

I always thought that the lack of air pressure set the brakes.  If a line rupture they cylinders would empty and as it did the brakes came on slowly.  Am I wrong?  If a car is set on a siding and some nitwit came along and released the air the brakes should set no matter what, unless someone is smart enough to burn the brake wheel to release them or does that only set them?
Dave
-----Original Message-----
From: John Stutz
Sent: Oct 8, 2020 2:07 PM
To: HOn3@groups.io
Subject: Re: RGS #20. Was: [HOn3] Division Point K-27 question

Thanks Earl

You are quite correct, on both counts, although one only needs to close the angle cocks to uncouple and switch cars wile the brake reservoir is charged.

John
On October 7, 2020 at 7:22 PM Earl Knoob <earlk489@...> wrote:

The semi-official term for releasing the air from the aux reservoir under the car is called "bleeding the car off".  It is used when a car with the brakes charged is uncoupled and the brake hoses part, setting the brakes.  In order to release the brakes without hooking the hoses back up (switching without air brakes is pretty common), you have to pull on the "bleed off rod" to release the remaining air out of the aux reservoir and brake cylinder. 
 


From: HOn3@groups.io <HOn3@groups.io> on behalf of John Stutz <john.stutz@...>
Sent: Tuesday, October 6, 2020 1:46 PM
To: HOn3@groups.io <HOn3@groups.io>
Subject: Re: RGS #20. Was: [HOn3] Division Point K-27 question
 
Mark

This use of dump is new to me.  In North America, dumping the air on a car means to release air form the car's air reservoir.  Dumping the air on a train means to release essentially all air from the train line, which immediately triggers emergency braking. 

From your description, dumping air to release the brakes, the Wolsztyn line is using a straight air brake. 

John
On October 5, 2020 a t 11:12 PM Mark Kasprowicz <mark@...> wrote:

A few years back I drove steam trains on the Wolsztyn line in Poland. Each of the locomotives had a brake dump operated by a wire inside the cab. It was situated by the cab side on the drivers side. It was used to release the train brake when it was slow to release.

Mark K
Oxon England

 


Re: AIR BRAKES 101.... was Re: RGS #20. Was: [HOn3] Division Point K-27 question

Climax@...
 


Thanks John

-----Original Message-----
From: John Stutz
Sent: Oct 8, 2020 10:01 PM
To: HOn3@groups.io
Subject: Re: AIR BRAKES 101.... was Re: RGS #20. Was: [HOn3] Division Point K-27 question

Dave

I speculate that official rules called for tying down all hand brake on set out cars, but that crews often did less, and relied on the air brakes with cars that were only temporarily set out.  Check published or online rule books for operation of trains.  My knowledge comes mostly from air brake instruction manuals, which tend to focus on ideal rather than actual operating practices.

John
On October 8, 2020 at 5:52 PM Climax@... wrote:

Since I model the 1900 to 1927 era this is important to me.  If, as you say, a train set a few cars on a siding did all the hand brakes need to be cinched down or would they only do one car?  Dave

-----Original Message-----
From: John Stutz
Sent: Oct 8, 2020 5:04 PM
To: HOn3@groups.io
Subject: Re: AIR BRAKES 101.... was Re: RGS #20. Was: [HOn3] Division Point K-27 question

Dave

Circa 1900 brake cylinders used leather gaskets to seal the brake cylinder, and they usually leaked off slowly.  This is why set out cars are supposed to always have the hand brake set.

The air and hand brake act independently, through the foundation brake gear, the set of rods and levers that carry braking force to the brake shoes.  The air brake cylinder piston has a hollow stem holding a push rod.  When the air brake is activated, this rod pushes on the connected lever.  The hand brake is connected to the same lever, usually through a chain.  When the hand brake is wound up. the chain pulls on the lever, and pulls the push rod partially out of the brake piston's stem. 

The triple valve is the heart of the automatic air brake, and some version has been used from the first automatic system of circa 1870.  The triple has undergone frequent revision ever since, to adapt it to evolving RR demands for better control of longer, heaver and faster trains.  But all versions have essentially operated in the manner that Earl described.  The KC or KD brake is simply the standard freight car apparatus of circa 1890-1940, fitted with the type K triple valve of circa 1902, and arranged  in the Combined or Detached format.  The principle improvement of the AB valve is the provision of separate service and emergency valves, with separate air reservoirs, so that full emergency power is always available.

John Stutz
On October 8, 2020 at 1:20 PM Climax@... wrote:

Lets say a box car was left on a siding with a grade.  Now there is either a very slow leak or can someone come along and pull the bleed off rod and would that result in the brakes being applied through springs to not let the car roll, or would the brakes release and let the car roll?  If it did roll, and you jumped on the car to get to the Brake wheel, does that apply or release brake pressure. 
The triple valve is on an AB system while a K system did not have that feature of  triple valve?
Dave

 


Re: AIR BRAKES 101.... was Re: RGS #20. Was: [HOn3] Division Point K-27 question

John Stutz
 

Dave

I speculate that official rules called for tying down all hand brake on set out cars, but that crews often did less, and relied on the air brakes with cars that were only temporarily set out.  Check published or online rule books for operation of trains.  My knowledge comes mostly from air brake instruction manuals, which tend to focus on ideal rather than actual operating practices.

John

On October 8, 2020 at 5:52 PM Climax@... wrote:

Since I model the 1900 to 1927 era this is important to me.  If, as you say, a train set a few cars on a siding did all the hand brakes need to be cinched down or would they only do one car?  Dave

-----Original Message-----
From: John Stutz
Sent: Oct 8, 2020 5:04 PM
To: HOn3@groups.io
Subject: Re: AIR BRAKES 101.... was Re: RGS #20. Was: [HOn3] Division Point K-27 question

Dave

Circa 1900 brake cylinders used leather gaskets to seal the brake cylinder, and they usually leaked off slowly.  This is why set out cars are supposed to always have the hand brake set.

The air and hand brake act independently, through the foundation brake gear, the set of rods and levers that carry braking force to the brake shoes.  The air brake cylinder piston has a hollow stem holding a push rod.  When the air brake is activated, this rod pushes on the connected lever.  The hand brake is connected to the same lever, usually through a chain.  When the hand brake is wound up. the chain pulls on the lever, and pulls the push rod partially out of the brake piston's stem. 

The triple valve is the heart of the automatic air brake, and some version has been used from the first automatic system of circa 1870.  The triple has undergone frequent revision ever since, to adapt it to evolving RR demands for better control of longer, heaver and faster trains.  But all versions have essentially operated in the manner that Earl described.  The KC or KD brake is simply the standard freight car apparatus of circa 1890-1940, fitted with the type K triple valve of circa 1902, and arranged  in the Combined or Detached format.  The principle improvement of the AB valve is the provision of separate service and emergency valves, with separate air reservoirs, so that full emergency power is always available.

John Stutz
On October 8, 2020 at 1:20 PM Climax@... wrote:

Lets say a box car was left on a siding with a grade.  Now there is either a very slow leak or can someone come along and pull the bleed off rod and would that result in the brakes being applied through springs to not let the car roll, or would the brakes release and let the car roll?  If it did roll, and you jumped on the car to get to the Brake wheel, does that apply or release brake pressure. 
The triple valve is on an AB system while a K system did not have that feature of  triple valve?
Dave

 


Re: AIR BRAKES 101.... was Re: RGS #20. Was: [HOn3] Division Point K-27 question

Climax@...
 

Since I model the 1900 to 1927 era this is important to me.  If, as you say, a train set a few cars on a siding did all the hand brakes need to be cinched down or would they only do one car?  Dave

-----Original Message-----
From: John Stutz
Sent: Oct 8, 2020 5:04 PM
To: HOn3@groups.io
Subject: Re: AIR BRAKES 101.... was Re: RGS #20. Was: [HOn3] Division Point K-27 question

Dave

Circa 1900 brake cylinders used leather gaskets to seal the brake cylinder, and they usually leaked off slowly.  This is why set out cars are supposed to always have the hand brake set.

The air and hand brake act independently, through the foundation brake gear, the set of rods and levers that carry braking force to the brake shoes.  The air brake cylinder piston has a hollow stem holding a push rod.  When the air brake is activated, this rod pushes on the connected lever.  The hand brake is connected to the same lever, usually through a chain.  When the hand brake is wound up. the chain pulls on the lever, and pulls the push rod partially out of the brake piston's stem. 

The triple valve is the heart of the automatic air brake, and some version has been used from the first automatic system of circa 1870.  The triple has undergone frequent revision ever since, to adapt it to evolving RR demands for better control of longer, heaver and faster trains.  But all versions have essentially operated in the manner that Earl described.  The KC or KD brake is simply the standard freight car apparatus of circa 1890-1940, fitted with the type K triple valve of circa 1902, and arranged  in the Combined or Detached format.  The principle improvement of the AB valve is the provision of separate service and emergency valves, with separate air reservoirs, so that full emergency power is always available.

John Stutz
On October 8, 2020 at 1:20 PM Climax@... wrote:

Lets say a box car was left on a siding with a grade.  Now there is either a very slow leak or can someone come along and pull the bleed off rod and would that result in the brakes being applied through springs to not let the car roll, or would the brakes release and let the car roll?  If it did roll, and you jumped on the car to get to the Brake wheel, does that apply or release brake pressure. 
The triple valve is on an AB system while a K system did not have that feature of  triple valve?
Dave


Re: AIR BRAKES 101.... was Re: RGS #20. Was: [HOn3] Division Point K-27 question

Russ Norris
 

I use a straight pin on the grade.


On Thu, Oct 8, 2020, 5:50 PM <Climax@...> wrote:
Wow, now I know why the cars I spot on my siding with a grade always seem to roll away.  Not really, I put the fishing line trick in place and now they stay put.

-----Original Message-----
From: John Stutz
Sent: Oct 8, 2020 5:04 PM
To: HOn3@groups.io
Subject: Re: AIR BRAKES 101.... was Re: RGS #20. Was: [HOn3] Division Point K-27 question

Dave

Circa 1900 brake cylinders used leather gaskets to seal the brake cylinder, and they usually leaked off slowly.  This is why set out cars are supposed to always have the hand brake set.

The air and hand brake act independently, through the foundation brake gear, the set of rods and levers that carry braking force to the brake shoes.  The air brake cylinder piston has a hollow stem holding a push rod.  When the air brake is activated, this rod pushes on the connected lever.  The hand brake is connected to the same lever, usually through a chain.  When the hand brake is wound up. the chain pulls on the lever, and pulls the push rod partially out of the brake piston's stem. 

The triple valve is the heart of the automatic air brake, and some version has been used from the first automatic system of circa 1870.  The triple has undergone frequent revision ever since, to adapt it to evolving RR demands for better control of longer, heaver and faster trains.  But all versions have essentially operated in the manner that Earl described.  The KC or KD brake is simply the standard freight car apparatus of circa 1890-1940, fitted with the type K triple valve of circa 1902, and arranged  in the Combined or Detached format.  The principle improvement of the AB valve is the provision of separate service and emergency valves, with separate air reservoirs, so that full emergency power is always available.

John Stutz
On October 8, 2020 at 1:20 PM Climax@... wrote:

Lets say a box car was left on a siding with a grade.  Now there is either a very slow leak or can someone come along and pull the bleed off rod and would that result in the brakes being applied through springs to not let the car roll, or would the brakes release and let the car roll?  If it did roll, and you jumped on the car to get to the Brake wheel, does that apply or release brake pressure. 
The triple valve is on an AB system while a K system did not have that feature of  triple valve?
Dave


--
Russ Norris, MMR
Cape Cod, Massachusetts
http://blacklogvalleyrailroad.blogspot.com/

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