AB Air Reservoir Orientation Question


Nelson Moyer
 

I posted this to the resinfreightcarbuilders group but haven’t gotten an answer yet, so I’m expanding the pool of expertise by posting my question here.

 

I’m working on the 2018 Chicagoland FGE mini-kit, and I’ve noticed an anomaly in the instructions and photos. RCW and all of the modeler posts about the AB brake component mounting for this car have the Auxiliary end of the air reservoir (1 mounting lug) pointed toward the B end, while most prototype diagrams I’ve seen, Ted Culotta’s treatise on freight car brakes, and most kit instructions have the Emergency end of the air reservoir pointing toward the B end. Exceptions to that orientation are in diagrams published by Mainline Modeler and  repeated in the Tichy AB brake mounting instructions.  I’ve always mounted the air reservoir with two lugs facing the B end.

 

The question is this, did this FGE car deviate from the norm (Emergency end toward B end), or are the instructions and photos in error? Do I mount the air reservoir with one lug or two lugs toward the B end of a FGE series 14000 reefer?

 

Nelson Moyer

 


Nelson Moyer
 

Since posting my AB air reservoir question, I've reread Gene Green's paper on freight car brakes. A study of the photos and diagrams in this paper suggest that the  AB air reservoir has an up and down side, with the 'fat' side hanging down from the floor mounts, and it is usually mounted on the opposite side of the the center sill from the brake cylinder with two lugs facing the B end (direction to which the brake cylinder points).

 

 

Applying that convention, when the air reservoir is mounted on the opposite side of the center sill from the brake cylinder, two lugs face the B end. When the air reservoir is mounted on the same side of the center sill as the brake cylinder, one lug faces the B end. Cars converted from KC to AB brakes frequently have the AB air reservoir on the same side of the center sill as the brake cylinder hence the FGE car has one lug facing the B end. I think that pretty well sums up the answer to my initial question.

Nelson Moyer


John Sykes III
 

Also, but not necessarily in your case, many builder diagrams show the brake system (and other underbody details) as though you are looking down, through the floor of the freight car, not looking up.  That is how all the early Athearn blue-box kits ended up with their brake systems on the wrong side of the underframe.

-- John


Nelson Moyer
 

Athearn isn’t the only victim of misreading engineering drawings. I’ve encountered current models from two companies who shall remain nameless with erroneous underbody brake diagrams in their instructions. The best way to check instructions is to look at original engineering drawings, but lacking that, look at photo graphs of both sides of the car under construction whenever possible. I’ve adopted the dictum, trust but verify. Then there is the Intermountain PFE reefer brake disaster……….

 

Nelson Moyer

 

From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> On Behalf Of John Sykes III via groups.io
Sent: Monday, May 24, 2021 9:15 AM
To: main@RealSTMFC.groups.io
Subject: Re: [RealSTMFC] AB Air Reservoir Orientation Question

 

Also, but not necessarily in your case, many builder diagrams show the brake system (and other underbody details) as though you are looking down, through the floor of the freight car, not looking up.  That is how all the early Athearn blue-box kits ended up with their brake systems on the wrong side of the underframe.

-- John

 


John Sykes III
 

Luckily, the Intermountain PFE brake details are so poorly cemented on, that I can easily pop them off and add brass wire for the correct arrangement.

-- John


irv_thomae
 

Nelson,
   Thanks for a very clear explanation!

   You've mentioned Ted Culotta's "treatise on freight car brakes" and Gene Greene's "paper on freight car brakes."   Can you remind us where to find them on line?

   (And then there are the railroads that mounted air reservoirs with their long axis perpendicular to the car centerline, such as CN and the T&P.  Are there any consistent rules that apply to them?)

Thanks!


Steve SANDIFER
 

Santa Fe also had many cars with perpendicular air reservoirs.

 

 

J. Stephen Sandifer

 

From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> On Behalf Of irv_thomae
Sent: Monday, May 24, 2021 12:28 PM
To: main@RealSTMFC.groups.io
Subject: Re: [RealSTMFC] AB Air Reservoir Orientation Question

 

Nelson,
   Thanks for a very clear explanation!

   You've mentioned Ted Culotta's "treatise on freight car brakes" and Gene Greene's "paper on freight car brakes."   Can you remind us where to find them on line?

   (And then there are the railroads that mounted air reservoirs with their long axis perpendicular to the car centerline, such as CN and the T&P  Are there any consistent rules that apply to them?)

Thanks!


Nelson Moyer
 

I attached Gene Green’s paper to my last email to the resinfreight car builders io Group, so you can get it there or search the web for “Freight Car Underbody Detail.pdf”. Search “Modeling AB Brakes on Freight Cars.pdf” for Ted’s paper, which also covers KC brakes.

 

These papers should be in the files of the RealSTMC, resinfreightcarbuilders, plasticfreightcarbuilders, and proto-layouts io groups. If they aren’t, somebody needs to upload them.

 

As I said before, I leave transverse mounted air reservoirs to modelers of the PRR, ATSF, and perhaps other roads.

 

Nelson Moyer

 

From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> On Behalf Of Steve SANDIFER
Sent: Monday, May 24, 2021 7:31 PM
To: main@RealSTMFC.groups.io
Subject: Re: [RealSTMFC] AB Air Reservoir Orientation Question

 

Santa Fe also had many cars with perpendicular air reservoirs.

 

 

J. Stephen Sandifer

 

From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> On Behalf Of irv_thomae
Sent: Monday, May 24, 2021 12:28 PM
To: main@RealSTMFC.groups.io
Subject: Re: [RealSTMFC] AB Air Reservoir Orientation Question

 

Nelson,
   Thanks for a very clear explanation!

   You've mentioned Ted Culotta's "treatise on freight car brakes" and Gene Greene's "paper on freight car brakes."   Can you remind us where to find them on line?

   (And then there are the railroads that mounted air reservoirs with their long axis perpendicular to the car centerline, such as CN and the T&P  Are there any consistent rules that apply to them?)

Thanks!


Gatwood, Elden J SAD
 

Group;

 

The PRR had at least two groups of cars in classes X29 and X31 with transversely-mounted reservoirs.

 

I don’t have the complete details, but know some car numbers that had them, and have furnished some details to folks on the PRR list and Society.

 

If you are interested, I can expand.

 

Elden Gatwood

 

 

From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> On Behalf Of Nelson Moyer
Sent: Monday, May 24, 2021 10:19 PM
To: main@RealSTMFC.groups.io
Subject: [Non-DoD Source] Re: [RealSTMFC] AB Air Reservoir Orientation Question

 

I attached Gene Green’s paper to my last email to the resinfreight car builders io Group, so you can get it there or search the web for “Freight Car Underbody Detail.pdf”. Search “Modeling AB Brakes on Freight Cars.pdf” for Ted’s paper, which also covers KC brakes.

 

These papers should be in the files of the RealSTMC, resinfreightcarbuilders, plasticfreightcarbuilders, and proto-layouts io groups. If they aren’t, somebody needs to upload them.

 

As I said before, I leave transverse mounted air reservoirs to modelers of the PRR, ATSF, and perhaps other roads.

 

Nelson Moyer

 

From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> On Behalf Of Steve SANDIFER
Sent: Monday, May 24, 2021 7:31 PM
To: main@RealSTMFC.groups.io
Subject: Re: [RealSTMFC] AB Air Reservoir Orientation Question

 

Santa Fe also had many cars with perpendicular air reservoirs.

 

 

J. Stephen Sandifer

 

From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> On Behalf Of irv_thomae
Sent: Monday, May 24, 2021 12:28 PM
To: main@RealSTMFC.groups.io
Subject: Re: [RealSTMFC] AB Air Reservoir Orientation Question

 

Nelson,
   Thanks for a very clear explanation!

   You've mentioned Ted Culotta's "treatise on freight car brakes" and Gene Greene's "paper on freight car brakes."   Can you remind us where to find them on line?

   (And then there are the railroads that mounted air reservoirs with their long axis perpendicular to the car centerline, such as CN and the T&P  Are there any consistent rules that apply to them?)

Thanks!


Benjamin Hom
 

Elden Gatwood wrote:
"The PRR had at least two groups of cars in classes X29 and X31 with transversely-mounted reservoirs."

Regarding Class X29, only Dreadnaught end cars built 1932-1934 had transversely-mounted reservoirs.  All other cars retrofitted with AB brakes had reservoirs mounted parallel to the center sill.  This is a glaring error on all Red Caboose X29 models (except for the Dreadnaught end models).


Ben Hom


Benjamin Hom
 

Irv Thomae asked:
"You've mentioned Ted Culotta's "treatise on freight car brakes" and Gene Greene's [sic] "paper on freight car brakes."   Can you remind us where to find them on line?"

Ted Culotta's "treatise on freight car brakes" appeared as sidebars in the RMC Essential Freight Car series, AB brakes in the August 2003 issue, KC brakes in the September 2003 issue.


Ben Hom


al_brown03
 

Gene Green's paper on freight car brakes, whose title is "Freight Car Underbody Detail", is in the Files section of this group.

Al Brown, Melbourne, Fla.


Nelson Moyer
 

Correct, and they were combined into a single pdf which was circulating some years ago. If it’s not in the archives, I will upload it.

 

Nelson Moyer

 

From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> On Behalf Of Benjamin Hom
Sent: Tuesday, May 25, 2021 6:14 AM
To: main@RealSTMFC.groups.io
Subject: Re: [RealSTMFC] AB Air Reservoir Orientation Question

 

Irv Thomae asked:

"You've mentioned Ted Culotta's "treatise on freight car brakes" and Gene Greene's [sic] "paper on freight car brakes."   Can you remind us where to find them on line?"

 

Ted Culotta's "treatise on freight car brakes" appeared as sidebars in the RMC Essential Freight Car series, AB brakes in the August 2003 issue, KC brakes in the September 2003 issue.

 

 

Ben Hom

_._,_._,_

 


Dennis Storzek
 

Nelson, here is the URL: https://realstmfc.groups.io/g/main/files/Freight%20Car%20UnderbodyDetail.pdf

You are correct that the reservoir had a defined top and bottom, they were always mounted with the mounting lugs above center line.
In addition, the mounting brackets were almost always arranged to support the lugs from below. With the brackets below the lugs, in the event of a loose or broken bolt, the reservoir is still supported. Not so if it were hung from the bolts.

The secret to mounting orientation is revealed in Fig.7 on page four. Note that the air lines from the emergency and auxiliary reservoirs do not cross. Fig.s 12 & 13 on page six show the locations of the different connections on the control valve pipe bracket. The connections are not interchangeable, therefore the reservoir was always positioned in such a way that each pipe had a straight shot between it and the control valve, to make pipe fitting and maintenance easier.

Dennis Storzek


Nelson Moyer
 

Yes, that was my eureka moment.

 

Nelson Moyer

 

From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> On Behalf Of Dennis Storzek
Sent: Tuesday, May 25, 2021 8:55 AM
To: main@RealSTMFC.groups.io
Subject: Re: [RealSTMFC] AB Air Reservoir Orientation Question

 

Nelson, here is the URL: https://realstmfc.groups.io/g/main/files/Freight%20Car%20UnderbodyDetail.pdf

You are correct that the reservoir had a defined top and bottom, they were always mounted with the mounting lugs above center line.
In addition, the mounting brackets were almost always arranged to support the lugs from below. With the brackets below the lugs, in the event of a loose or broken bolt, the reservoir is still supported. Not so if it were hung from the bolts.

The secret to mounting orientation is revealed in Fig.7 on page four. Note that the air lines from the emergency and auxiliary reservoirs do not cross. Fig.s 12 & 13 on page six show the locations of the different connections on the control valve pipe bracket. The connections are not interchangeable, therefore the reservoir was always positioned in such a way that each pipe had a straight shot between it and the control valve, to make pipe fitting and maintenance easier.

Dennis Storzek


Paul R Greenwald
 

Nelson -

Tried your suggested search for Ted's paper  with no luck.  Any other suggestions?

TIA
--
Paul R Greenwald 
PRRT&HS #1802
NMRA #129229


Nelson Moyer
 

I’ll upload the file to the file section.

 

Nelson Moyer

 

From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> On Behalf Of Paul R Greenwald
Sent: Tuesday, May 25, 2021 10:10 PM
To: main@RealSTMFC.groups.io
Subject: Re: [RealSTMFC] AB Air Reservoir Orientation Question

 

Nelson -

Tried your suggested search for Ted's paper  with no luck.  Any other suggestions?

TIA
--
Paul R Greenwald 
PRRT&HS #1802
NMRA #129229