Two brake system modeling questions


mjmcguirk@...
 

Hello all,

Hope you all had a wonderful holiday.

I have two (hopefully) quick questions about modeling brake systems:

1. What size wire is appropriate for a train line (specifically the line visible on the side of the hopper) in HO scale?

2. What do you call the small wire extending from the AB triple valve to the side sill of the car on both sides? Is this the release lever? I noticed it on the prototype photo of the CV hopper I'm building -- and can't remember the proper name for it!

Thanks,

Marty


ljack70117@...
 

On the RRs I worked for we called it the bleeder line. It bled off the main air tank.
Thank you
Larry Jackman
Boca Raton FL
ljack70117@...

On Dec 26, 2006, at 10:43 AM, <mjmcguirk@...> wrote:

Hello all,

Hope you all had a wonderful holiday.

I have two (hopefully) quick questions about modeling brake systems:

1. What size wire is appropriate for a train line (specifically the line visible on the side of the hopper) in HO scale?

2. What do you call the small wire extending from the AB triple valve to the side sill of the car on both sides? Is this the release lever? I noticed it on the prototype photo of the CV hopper I'm building -- and can't remember the proper name for it!

Thanks,

Marty



Yahoo! Groups Links



Jeff Coleman
 

The brake pipe(train line)is 11/4" pipe and the release rod is 1/2" rod.
Jeff Coleman

--- In STMFC@..., <mjmcguirk@...> wrote:

Hello all,

Hope you all had a wonderful holiday.

I have two (hopefully) quick questions about modeling brake systems:

1. What size wire is appropriate for a train line (specifically the
line visible on the side of the hopper) in HO scale?

2. What do you call the small wire extending from the AB triple
valve to the side sill of the car on both sides? Is this the release
lever? I noticed it on the prototype photo of the CV hopper I'm
building -- and can't remember the proper name for it!

Thanks,

Marty


Andy Sperandeo <asperandeo@...>
 

Hi Marty,

The train pipe is a nominal 1-1/4" pipe, about 1.66" actual o.d., or .019"
in HO scale. The other element you're asking about is the release (also
called "bleed") rod, used for releasing the pressure in a car's brake
system. It's attached to the release valve stem on the service side of the
AB valve. The release rod is 1/2" in diameter, or .006" in HO. (Info from
Gene Green's Freight Car Underbody Detail clinic book.)

Happy New Year,

Andy

Andy Sperandeo
Executive Editor
Model Railroader magazine
asperandeo@...
262-796-8776, ext. 461
FAX 262-796-1142


MDelvec952
 

In a message dated 12/26/2006 2:52:30 PM Eastern Standard Time,
rfederle@... writes:

Being an engineer I can tell you that all pipe sizes are referencing the
Inside Diameter with the exception of heavier walled pipe such as Schedule 80 or
above. The Brake Pipe size is generally Schedule 40 which is for moderate
pressures generally less than 150 psi.



I was going to chime in after reading all of these, (nice to have a day off
for a change). The Union Tank Car carmen where I work say that schedule 80
is all they're allowed to use for railroad brake pipes, and our mechanics on
the Morristown & Erie feel the same way. Schedule 80 Brake pipe measures just
above 1 1/2".

Release rods, also called bleed rods or bleeders by trainmen, are usually
1/2" and sometimes 3/8". One spotting feature that changed after the scope of
this list is the bend at the end. Steam-era AB rods have a 90-degree bend
with a 4-inch or longer bit of rod for the trainman to hold on to. To bleed off
a car the trainman had to pull (or push) on the rod until the brakes
released, or until the reservoir was empty. Diesel-era ABs of the many versions have
an automatic release feature where the trainman only needs to pull (or push)
on the rod for a second or two until he hears the AB valve click, and then
the AB bleeds itself off. Rods on the automatic release valves have just a
little loop at the end of the rod, providing a quick spotting feature for
trainmen who would work with both types.

That list of measurements is good. When I was more actively modeling I
measured the key rods and piping on older freight cars. After once using my own
hair for a retainer line, I concluded trying to portray the relationships in
thicknesses between the various components was more important than matching
each exact size. Using the 3/4-inch grab irons (.080 wire is perfect once
covered with paint) as a reference, since those are the most numerous and
visible on a model, the vertical brake staffs are about twice as heavy, train lines
and brake rods were between the two, retaining lines are lighter than grab
irons, etc. In an era when you couldn't trust the wire sizes in many kits
and the pre-formed ones were too thick for my tastes, I could stock the basic
stuff and not worry about what came with the kit, reusing it where its size
deemed appropriate. I built a jig and used to make my own ladders with 3/4
rungs, also largely uneeded today.

Mike Del Vecchio


rfederle@...
 

This release valve on some (if not all) cars I've been around have a small (1" or 1 1/2") Stencil above this rod handle stating "RELEASE"

Robert Federle
---- mjmcguirk@... wrote:

Hello all,

Hope you all had a wonderful holiday.

I have two (hopefully) quick questions about modeling brake systems:

1. What size wire is appropriate for a train line (specifically the line visible on the side of the hopper) in HO scale?

2. What do you call the small wire extending from the AB triple valve to the side sill of the car on both sides? Is this the release lever? I noticed it on the prototype photo of the CV hopper I'm building -- and can't remember the proper name for it!

Thanks,

Marty


Schuyler Larrabee
 

The brake pipe(train line)is 1-1/4" pipe . . .
Jeff Coleman

That's ID, right?

SGL


rfederle@...
 

Being an engineer I can tell you that all pipe sizes are referencing the Inside Diameter with the exception of heavier walled pipe such as Schedule 80 or above. The Brake Pipe size is generally Schedule 40 which is for moderate pressures generally less than 150 psi.

Remember that Pipe is measured by inside while Tubing is measured by outside diameters. Also some valves and fittings have cast into them the letters WOG and that stands for Water, Oil or Gas. A number cast near this, such as 6oo would be the working pressures for the WOG materials flowing through it. Since the Brake Pipe and fittings are for Air this would fall into the Gas catagory.

Hope this dont confuse you.

Robert Federle
---- Schuyler Larrabee <schuyler.larrabee@...> wrote:



The brake pipe(train line)is 1-1/4" pipe . . .
Jeff Coleman

That's ID, right?

SGL


rfederle@...
 

Ooops forgot to add this to lengthy commentary. Since the Brake Pipe is 1 1/4" ID the assumption that it is standard Schedule 40 Pipe the wall thickness would be about 1/8" and the outside Pipe Diameter would be
1 1/2" so use a wire diameter accordingly.

Robert Federle
---- Schuyler Larrabee <schuyler.larrabee@...> wrote:



The brake pipe(train line)is 1-1/4" pipe . . .
Jeff Coleman

That's ID, right?

SGL


Bob Karig <karig@...>
 

I measured the outside diameter of several items here at the Railroad
Museum of Pennsylvania.

Here are the results:

Outside
HO Scale
Item Dimension
Equivalent
Train line 1
5/8" .0186"
Pipe from train line to triple valve 1 3/8" .0158"
Pipe from reservoir to brake cylinder 1 1/16" .0122"
Pipe from triple valve to retaining valve 11/16" .0079"
Brake release lever 1/2" .0057"
Brake rods 1 3/16" .0093"
Grab irons 3/4" .0086"
Brake shaft 1 1/2" .0172"

Bob


rfederle@...
 

Thanks Mike for the input.

After I sent that I got to thinking and with the vibration factored in the Schedule 80 would be desired as well as for the pressures involved. Would be less likely to fail. I should have thought of our shipboard air systems which are all Schedule 80.

Sorry if I misled anyone.

Robert Federle
---- MDelvec952@... wrote:


In a message dated 12/26/2006 2:52:30 PM Eastern Standard Time,
rfederle@... writes:

Being an engineer I can tell you that all pipe sizes are referencing the
Inside Diameter with the exception of heavier walled pipe such as Schedule 80 or
above. The Brake Pipe size is generally Schedule 40 which is for moderate
pressures generally less than 150 psi.



I was going to chime in after reading all of these, (nice to have a day off
for a change). The Union Tank Car carmen where I work say that schedule 80
is all they're allowed to use for railroad brake pipes, and our mechanics on
the Morristown & Erie feel the same way. Schedule 80 Brake pipe measures just
above 1 1/2".

Release rods, also called bleed rods or bleeders by trainmen, are usually
1/2" and sometimes 3/8". One spotting feature that changed after the scope of
this list is the bend at the end. Steam-era AB rods have a 90-degree bend
with a 4-inch or longer bit of rod for the trainman to hold on to. To bleed off
a car the trainman had to pull (or push) on the rod until the brakes
released, or until the reservoir was empty. Diesel-era ABs of the many versions have
an automatic release feature where the trainman only needs to pull (or push)
on the rod for a second or two until he hears the AB valve click, and then
the AB bleeds itself off. Rods on the automatic release valves have just a
little loop at the end of the rod, providing a quick spotting feature for
trainmen who would work with both types.

That list of measurements is good. When I was more actively modeling I
measured the key rods and piping on older freight cars. After once using my own
hair for a retainer line, I concluded trying to portray the relationships in
thicknesses between the various components was more important than matching
each exact size. Using the 3/4-inch grab irons (.080 wire is perfect once
covered with paint) as a reference, since those are the most numerous and
visible on a model, the vertical brake staffs are about twice as heavy, train lines
and brake rods were between the two, retaining lines are lighter than grab
irons, etc. In an era when you couldn't trust the wire sizes in many kits
and the pre-formed ones were too thick for my tastes, I could stock the basic
stuff and not worry about what came with the kit, reusing it where its size
deemed appropriate. I built a jig and used to make my own ladders with 3/4
rungs, also largely uneeded today.

Mike Del Vecchio




Jack Mullen
 

--- In STMFC@..., <rfederle@...> wrote:

Thanks Mike for the input.

After I sent that I got to thinking and with the vibration factored
in the Schedule 80 would be desired as well as for the pressures
involved. Would be less likely to fail. I should have thought of our
shipboard air systems which are all Schedule 80.

Sorry if I misled anyone.
Sch.80 is right, but it doesn't matter for modeling, since the OD is
the same for Sch.40 and Sch.80. Sch.80 has a heavier wall, so the
actual ID is somewhat less than for sch.40 of the same nominal size.

1 1/4" pipe OD is 1.66" which would be .019" in HO and .035" in O.

Jack Mullen


Kurt Laughlin <fleeta@...>
 

----- Original Message -----
From: rfederle@...

Being an engineer I can tell you that all pipe sizes are referencing the Inside Diameter with the exception of heavier walled pipe such as Schedule 80 or above. The Brake Pipe size is generally Schedule 40 which is for moderate pressures generally less than 150 psi.

Remember that Pipe is measured by inside while Tubing is measured by outside diameters. Also some valves and fittings have cast into them the letters WOG and that stands for Water, Oil or Gas. A number cast near this, such as 6oo would be the working pressures for the WOG materials flowing through it. Since the Brake Pipe and fittings are for Air this would fall into the Gas catagory.
----- Original Message -----

Nowadays, and for most of the 20th Century, the nominal pipe size really doesn't have anything to do any physical dimensions you might find on the pipe. It's just a label, and A, B, C, or D would be about as meaningful. In the late 1800's when pipe was first standardized, the nominal sizes were chosen based on several factors (including the ID) but as materials, manufacturing, and testing have improved the dimensions have changed and the meaning has been lost. Your best bet when given a pipe size is to look up the OD somewhere.

Tubing can be sized or labeled by any two of the three relevant dimensions: ID, OD, and wall thickness. It really depends on the application and the applicable standards.

Two other points to keep in mind:

1. For a given size of pipe, there may be three to six standard wall thicknesses. However, the OD stays constant. This allows the use of one set of threading tools regardless of the wall thickness involved.

2. Don't confuse pipe with tubing or conduit. Each has their own applicable standards and dimensioning schemes. That's why the proper nomenclature is so important to us engineers.

KL


rfederle@...
 

The attached link should help.

http://www.dlis.dla.mil/fiigdata/A004A/chart15.htm

Robert Federle
---- Kurt Laughlin <fleeta@...> wrote:

----- Original Message -----
From: rfederle@...

Being an engineer I can tell you that all pipe sizes are referencing the
Inside Diameter with the exception of heavier walled pipe such as Schedule
80 or above. The Brake Pipe size is generally Schedule 40 which is for
moderate pressures generally less than 150 psi.

Remember that Pipe is measured by inside while Tubing is measured by outside
diameters. Also some valves and fittings have cast into them the letters WOG
and that stands for Water, Oil or Gas. A number cast near this, such as 6oo
would be the working pressures for the WOG materials flowing through it.
Since the Brake Pipe and fittings are for Air this would fall into the Gas
catagory.
----- Original Message -----

Nowadays, and for most of the 20th Century, the nominal pipe size really
doesn't have anything to do any physical dimensions you might find on the
pipe. It's just a label, and A, B, C, or D would be about as meaningful.
In the late 1800's when pipe was first standardized, the nominal sizes were
chosen based on several factors (including the ID) but as materials,
manufacturing, and testing have improved the dimensions have changed and the
meaning has been lost. Your best bet when given a pipe size is to look up
the OD somewhere.

Tubing can be sized or labeled by any two of the three relevant dimensions:
ID, OD, and wall thickness. It really depends on the application and the
applicable standards.

Two other points to keep in mind:

1. For a given size of pipe, there may be three to six standard wall
thicknesses. However, the OD stays constant. This allows the use of one
set of threading tools regardless of the wall thickness involved.

2. Don't confuse pipe with tubing or conduit. Each has their own applicable
standards and dimensioning schemes. That's why the proper nomenclature is
so important to us engineers.

KL


Kurt Laughlin <fleeta@...>
 

----- Original Message -----
From: rfederle@...

The attached link should help.

http://www.dlis.dla.mil/fiigdata/A004A/chart15.htm
----- Original Message -----

Except that's a chart for tubing, not pipe. (See point #2 of my message. :-) )

http://www.evergreen.edu/biophysics/technotes/fabric/pipe.htm#schedule

The top left table with the heading "PIPE" has the relevant outside diameter vs. nominal size info.

A search of "national pipe size" will pull up a number of sources.

KL


rfederle@...
 

OK

Robert
---- Kurt Laughlin <fleeta@...> wrote:

----- Original Message -----
From: rfederle@...

The attached link should help.

http://www.dlis.dla.mil/fiigdata/A004A/chart15.htm
----- Original Message -----

Except that's a chart for tubing, not pipe. (See point #2 of my message.
:-) )

http://www.evergreen.edu/biophysics/technotes/fabric/pipe.htm#schedule

The top left table with the heading "PIPE" has the relevant outside diameter
vs. nominal size info.

A search of "national pipe size" will pull up a number of sources.

KL


mjmcguirk@...
 

Thanks to all for their answers to my questions about brake systems.

One of the reasons I've enjoyed this group -- in its many iterations over the years -- has been the high signal to noise ratio . . . the answers to my two fairly simple questions bears witness that tradition continues . . . (and I won't even mention Chief Petty Officers)

Marty McGuirk


rfederle@...
 

Isn't it amazing how quickly a fire can start. Not going to touch the CPO.

Robert Federle
---- mjmcguirk@... wrote:

Thanks to all for their answers to my questions about brake systems.

One of the reasons I've enjoyed this group -- in its many iterations over the years -- has been the high signal to noise ratio . . . the answers to my two fairly simple questions bears witness that tradition continues . . . (and I won't even mention Chief Petty Officers)

Marty McGuirk