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Increasing slope sheet angle on hoppers


spsalso
 

In 1955, GN changed the slope sheet angle on some of their 73000-73199 hopper cars:


http://www.accurail.com/accurail/art/2300/2301.jpg


from about 30 degrees to 55 degrees, and renumbered them into the 73700-73764 series.  The cubic capacity dropped from 1622 to 1253.

I've asked after this matter on the GN group.  Nobody knows why.

So I'll bring the subject up here.  

What load would GN have modified these cars for?

I'm interested in factual knowledge, and also informed speculation, since I have doubts anyone knows specifics on this matter.

My suspicion is that it was for "ore", or what most civilians would call "dirt".

I will also speculate that if the "ore" were no longer being transported, they'd be prized as hopper cars that would dump just about anything.



Ed

Edward Sutorik


mark_landgraf
 

Is there a listing of on line shippers for GN?
Or any conductors switch lists or yard lists or junction interchange lists for GN available?

Maybe these documents could assist in identifying the commodity. 

Mark Landgraf
Albany NY


On Thu, Dec 17, 2020 at 12:23 PM, spsalso via groups.io
<Edwardsutorik@...> wrote:
In 1955, GN changed the slope sheet angle on some of their 73000-73199 hopper cars:


http://www.accurail.com/accurail/art/2300/2301.jpg


from about 30 degrees to 55 degrees, and renumbered them into the 73700-73764 series.  The cubic capacity dropped from 1622 to 1253.

I've asked after this matter on the GN group.  Nobody knows why.

So I'll bring the subject up here.  

What load would GN have modified these cars for?

I'm interested in factual knowledge, and also informed speculation, since I have doubts anyone knows specifics on this matter.

My suspicion is that it was for "ore", or what most civilians would call "dirt".

I will also speculate that if the "ore" were no longer being transported, they'd be prized as hopper cars that would dump just about anything.



Ed

Edward Sutorik


Tony Thompson
 

Mark_Landgraf wrote:

Is there a listing of on line shippers for GN?
Or any conductors switch lists or yard lists or junction interchange lists for GN available?

  You want the GN Shippers Guide, available from Rails Unlimited. They are at this link:  http://railsunlimited.ribbonrail.com/  and click on Books.

Tony Thompson




Schuyler Larrabee
 

The Lackawanna did this too. Unfortunately, I do not remember exactly why.  It might surface after a while.  You could ID the cars that had this done after they were de-converted by a line of empty rivet holes in the sides.

 

Schuyler

 

From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> On Behalf Of mark_landgraf via groups.io
Sent: Thursday, December 17, 2020 4:58 PM
To: main@RealSTMFC.groups.io; spsalso via groups.io <Edwardsutorik@...>
Subject: Re: [RealSTMFC] Increasing slope sheet angle on hoppers

 

Is there a listing of on line shippers for GN?

Or any conductors switch lists or yard lists or junction interchange lists for GN available?

 

Maybe these documents could assist in identifying the commodity. 

 

Mark Landgraf

Albany NY

 

On Thu, Dec 17, 2020 at 12:23 PM, spsalso via groups.io

In 1955, GN changed the slope sheet angle on some of their 73000-73199 hopper cars:


http://www.accurail.com/accurail/art/2300/2301.jpg


from about 30 degrees to 55 degrees, and renumbered them into the 73700-73764 series.  The cubic capacity dropped from 1622 to 1253.

I've asked after this matter on the GN group.  Nobody knows why.

So I'll bring the subject up here.  

What load would GN have modified these cars for?

I'm interested in factual knowledge, and also informed speculation, since I have doubts anyone knows specifics on this matter.

My suspicion is that it was for "ore", or what most civilians would call "dirt".

I will also speculate that if the "ore" were no longer being transported, they'd be prized as hopper cars that would dump just about anything.



Ed

Edward Sutorik


Jack Mullen
 

Could be something as basic as sand, gravel, or crushed stone, although most railroads using old hoppers in such service didn't bother with alterations to suit the material. A relatively steep slope sheet helps discharge aggregates that can be reluctant, and the reduced cubic capacity works for a material with bulk density around 100 pcf.

Jack Mullen


Schuyler Larrabee
 

Yep, as I said, the reason the Lackawanna altered hoppers with steeper slope sheets came back to me.  It was so they could be used for cement service.  That accomplished both of the issues you mention, Jack, the better to discharge the lading, and also to reduce the cubic volume so as not to over load the trucks.

 

Schuyler

 

From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> On Behalf Of Jack Mullen
Sent: Friday, December 18, 2020 1:29 AM
To: main@RealSTMFC.groups.io
Subject: Re: [RealSTMFC] Increasing slope sheet angle on hoppers

 

Could be something as basic as sand, gravel, or crushed stone, although most railroads using old hoppers in such service didn't bother with alterations to suit the material. A relatively steep slope sheet helps discharge aggregates that can be reluctant, and the reduced cubic capacity works for a material with bulk density around 100 pcf.

Jack Mullen


Tim O'Connor
 


They were coal hoppers. I suppose some grades of coal required steeper slope sheets. There were
lignite coal deposits in GN territory and I think that type of coal is "brown dirt" rather than hard coal.


On 12/17/2020 12:23 PM, spsalso via groups.io wrote:
In 1955, GN changed the slope sheet angle on some of their 73000-73199 hopper cars:


http://www.accurail.com/accurail/art/2300/2301.jpg


--
Tim O'Connor
Sterling, Massachusetts


spsalso
 

Thanks all for your thoughts!

I will mention that there are two photos of these cars in Scott R. Thompson's "Great Northern Equipment Color Pictorial Book Two".  One photo shows one of the cars in 1959 at Okanagon WA, at what looks like it might be an aggregate facility.  There are piles of stuff, and a bin and a sort of conveyor belt showing.  The other shows a car at Wenatchee, but it's not helpful.

I am kind of surprised that such stuff would need such a steep slope to dump.  But this article:

https://en.wikipedia.org/wiki/Angle_of_repose#:~:text=The%20angle%20of%20repose%20can%20range%20from%200°,can%20also%20be%20affected%20by%20additions%20of%20solvents.

has gravel and wet sand at an angle of repose of 45 degrees.  Which is a lot steeper than the 30-ish degrees of the original slope sheets.

OMI made models of both the original and the modified hoppers, and I've got both and have been wondering what I will do with them.



Ed

Edward Sutorik