boxcar design evolution


Robert kirkham
 

A while ago I was able to make a trip into Sandon BC and take photos and measurements of the freight cars there. Now I'm writing a description of two of the cars. They were from the CPR 230000-233499 series composite boxcars - boxcars very much like the USRA design. And as I write about them, I wanted to say that when the cars were built in 1920-21, they were more or less the best boxcar design on the market.

But I wonder if that is really accurate? For example, would the similar cars used on other railways that used Z bracing (rather than the pressed steel shapes on the USRA and CP cars) be considered better or poorer - or was the difference inconsequential from the point of view of boxcar design evolution? Meanwhile, was there anything else on the market yet that was clearly superior?

Rob Kirkham


Anthony Thompson <thompson@...>
 

Rob Kirkham wrote:
But I wonder if that is really accurate? For example, would the similar cars used on other railways that used Z bracing (rather than the pressed steel shapes on the USRA and CP cars) be considered better or poorer - or was the difference inconsequential from the point of view of boxcar design evolution?
I don't know the answer to your question, Rob, but SP and several other railroads which had received USRA single-sheathed cars did not duplicate them in subsequent years but went back to Z bars. At the least, they were unimpressed with the hat-section bracing.

Tony Thompson Editor, Signature Press, Berkeley, CA
2906 Forest Ave., Berkeley, CA 94705 www.signaturepress.com
(510) 540-6538; fax, (510) 540-1937; e-mail, thompson@...
Publishers of books on railroad history


soolinehistory <destorzek@...>
 

--- In STMFC@..., "Rob Kirkham" <rdkirkham@...> wrote:

A while ago I was able to make a trip into Sandon BC and take photos and
measurements of the freight cars there. Now I'm writing a description of
two of the cars. They were from the CPR 230000-233499 series composite
boxcars - boxcars very much like the USRA design. And as I write about
them, I wanted to say that when the cars were built in 1920-21, they were
more or less the best boxcar design on the market.

But I wonder if that is really accurate? For example, would the similar
cars used on other railways that used Z bracing (rather than the pressed
steel shapes on the USRA and CP cars) be considered better or poorer - or
was the difference inconsequential from the point of view of boxcar design
evolution? Meanwhile, was there anything else on the market yet that was
clearly superior?

Rob Kirkham
Where are you saying these fit in the evolutionary chain, Rob? The first steel frame boxcars used stock mill shapes, either Z, C, or L section, while some of the last single sheathed composite cars did likewise. The cars with the pressed framing fit in the middle, a good idea that came... and went.

The argument for purpose designed pressings is they make more efficient use of material, although I don't think the car designs that made use of them were appreciably lighter.

The argument against purpose designed pressings was that they were difficult to repair; the railroad would have to make custom pressing dies to make replacement parts, whereas mill shapes were available off the shelf, so to speak. Late in the cars lives it was found that the pressings trapped water and tended to rust out near the bottom, but I don't think this happened fast enough to really have any impact on the debate; the cars lasted through a reasonable service life without major problems. Anyway, cars with Z section framing also could have problems with cracking of the posts and braces due to repeated stress reversals in the truss members.

It appears that the two design philosophies coexisted for years without either proving to be truly superior.

Dennis


Robert kirkham
 

That is part of what I was wondering about Dennis. I don't know where to slot these cars (or the USRA cars) as of 1920/21.

Regarding the steel used for framing the sides, CP had over 20000 fowler cars on the roster at that time - all with Z bracing. But the CNR was continuing to build similar cars with Z bracing after the CPR 230000 series cars were built. That could mean nothing in terms of design evolution - the CNR was building fowler cars into the early 1920s as well. So it is possible the purpose-built pressed steel framing shape was considered an advance.

At the same time I see your point about repairs being more difficult. I have seen the weld lines where these shapes have cracked and were repaired. My sense of it is the repairs were done after the cars were moved into company service, but I have no data on that subject.

So to sum up what you are saying, the pressed steel braces amount to a difference - not necessarily an advance.

Alternatively, the USRA design cars could be described as an advancement based on size - but I don't know that they were the largest cars around for 1920, or merely a step in that direction. I take it from what I have read that there were not a great many boxcars built to larger specs for some time, but am not sure where exactly to place the USRA design. perhaps just part of a trend, but at least a step forward?

And of course there is the composite construction versus all steel construction. CPR had one all steel car on the roster in 1919 - CP 249000. Must have been an experiment. So the USRA style composite cars are not an advance in comparison to those.

Are there any other considerations one should apply in making that assessment?

Rob Kirkham


--------------------------------------------------
From: "soolinehistory" <destorzek@...>
Sent: Wednesday, April 06, 2011 7:30 AM
To: <STMFC@...>
Subject: [STMFC] Re: boxcar design evolution



--- In STMFC@..., "Rob Kirkham" <rdkirkham@...> wrote:

A while ago I was able to make a trip into Sandon BC and take photos and
measurements of the freight cars there. Now I'm writing a description of
two of the cars. They were from the CPR 230000-233499 series composite
boxcars - boxcars very much like the USRA design. And as I write about
them, I wanted to say that when the cars were built in 1920-21, they were
more or less the best boxcar design on the market.

But I wonder if that is really accurate? For example, would the similar
cars used on other railways that used Z bracing (rather than the pressed
steel shapes on the USRA and CP cars) be considered better or poorer - or
was the difference inconsequential from the point of view of boxcar design
evolution? Meanwhile, was there anything else on the market yet that was
clearly superior?

Rob Kirkham
Where are you saying these fit in the evolutionary chain, Rob? The first steel frame boxcars used stock mill shapes, either Z, C, or L section, while some of the last single sheathed composite cars did likewise. The cars with the pressed framing fit in the middle, a good idea that came... and went.

The argument for purpose designed pressings is they make more efficient use of material, although I don't think the car designs that made use of them were appreciably lighter.

The argument against purpose designed pressings was that they were difficult to repair; the railroad would have to make custom pressing dies to make replacement parts, whereas mill shapes were available off the shelf, so to speak. Late in the cars lives it was found that the pressings trapped water and tended to rust out near the bottom, but I don't think this happened fast enough to really have any impact on the debate; the cars lasted through a reasonable service life without major problems. Anyway, cars with Z section framing also could have problems with cracking of the posts and braces due to repeated stress reversals in the truss members.

It appears that the two design philosophies coexisted for years without either proving to be truly superior.

Dennis



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rwitt_2000
 



Rob Kirkham wrote:

A while ago I was able to make a trip into Sandon BC and take photos
and
measurements of the freight cars there. Now I'm writing a
description of
two of the cars. They were from the CPR 230000-233499 series
composite
boxcars - boxcars very much like the USRA design. And as I write
about
them, I wanted to say that when the cars were built in 1920-21, they
were
more or less the best boxcar design on the market.

But I wonder if that is really accurate? For example, would the
similar
cars used on other railways that used Z bracing (rather than the
pressed
steel shapes on the USRA and CP cars) be considered better or poorer
- or
was the difference inconsequential from the point of view of boxcar
design
evolution? Meanwhile, was there anything else on the market yet
that was
clearly superior?
--- In STMFC@..., "soolinehistory" Dennis Storzek replied:

Where are you saying these fit in the evolutionary chain, Rob? The
first steel frame boxcars used stock mill shapes, either Z, C, or L
section, while some of the last single sheathed composite cars did
likewise. The cars with the pressed framing fit in the middle, a good
idea that came... and went.

The argument for purpose designed pressings is they make more
efficient use of material, although I don't think the car designs that
made use of them were appreciably lighter.

The argument against purpose designed pressings was that they were
difficult to repair; the railroad would have to make custom pressing
dies to make replacement parts, whereas mill shapes were available off
the shelf, so to speak. Late in the cars lives it was found that the
pressings trapped water and tended to rust out near the bottom, but I
don't think this happened fast enough to really have any impact on the
debate; the cars lasted through a reasonable service life without major
problems. Anyway, cars with Z section framing also could have problems
with cracking of the posts and braces due to repeated stress reversals
in the truss members.

It appears that the two design philosophies coexisted for years
without either proving to be truly superior.
==========================

Looking at the the entire North American boxcar fleet we have the
eastern railroads, PRR, NYC and B&O that adopted the all steel designs
and were not large users of single-sheathed designs. So one could ask
the question was the all-steel designs superior to the single-sheathed
designs. Obviously for the mid-western, western and Canadian railroads
the single-sheathed design apparently better met their requirements.

Bob Witt


Pieter Roos
 

It would seem that some 1920's cars were built with the USRA type pressed frame members, but many were not. PRR added reinforcing "boots" on the ends of the framing on many X26 USRA designed cars, and IIRC D&H and some others actually replaced the original framing with 'Z' section material during rebuilding. The WWII "War Emergency" designs also seem to have reverted to standard steel shapes. These events could suggest that the USRA type members were not wholly successful. At least by the 1940's it would appear that standard shapes had won out.

OTOH, hoppers and gondolas, both composite and all steel, continued to use more specialized shapes in their framing. The early PRR single sheathed designs (R7 and X23) also used special pressed members, so USRA was clearly not the first.

The USRA single sheathed design would appear to have been a step forward in height, as the 1920's ARA standard called for scaling the IH back by 6 inches, with the original USRA size as an option.

Pieter Roos
Connecticut

--- In STMFC@..., "soolinehistory" <destorzek@...> wrote:
<SNIP>
Where are you saying these fit in the evolutionary chain, Rob? The first steel frame boxcars used stock mill shapes, either Z, C, or L section, while some of the last single sheathed composite cars did likewise. The cars with the pressed framing fit in the middle, a good idea that came... and went.

The argument for purpose designed pressings is they make more efficient use of material, although I don't think the car designs that made use of them were appreciably lighter.

The argument against purpose designed pressings was that they were difficult to repair; the railroad would have to make custom pressing dies to make replacement parts, whereas mill shapes were available off the shelf, so to speak. Late in the cars lives it was found that the pressings trapped water and tended to rust out near the bottom, but I don't think this happened fast enough to really have any impact on the debate; the cars lasted through a reasonable service life without major problems. Anyway, cars with Z section framing also could have problems with cracking of the posts and braces due to repeated stress reversals in the truss members.

It appears that the two design philosophies coexisted for years without either proving to be truly superior.

Dennis


soolinehistory <destorzek@...>
 

--- In STMFC@..., "Pieter_Roos" <pieter_roos@...> wrote:

OTOH, hoppers and gondolas, both composite and all steel, continued to use more specialized shapes in their framing. The early PRR single sheathed designs (R7 and X23) also used special pressed members, so USRA was clearly not the first.
But then again, the ARA reverted to standard mill shapes for the stakes in MOST of the ARA standard twin, triple, and quad hoppers.


The USRA single sheathed design would appear to have been a step forward in height, as the 1920's ARA standard called for scaling the IH back by 6 inches, with the original USRA size as an option.
There was a reasonable amount of resistance to the 9'-0" IH of the USRA cars as being "too big", wasteful since with most loads the cars would reach their load limit before they cubed out. Indeed, the ARA standard cars of 1923 reverted to the formerly common 8'-7" IH, although they retained the use of purpose designed pressings for posts and diagonals.

The same debate about mill shapes vs. pressings continued in the steel car era; cars built with structural shapes for posts tend to have a single line of rivets on the lap seam of the side sheets; those with double rows have pressed "hat" section posts. Meanwhile, coal hoppers swung back to using pressed posts in the exterior stake designs of the fifties. Ultimately, pressings won out... ALL the modern exterior post cars of recent years have pressed posts, although the fabricating techniques are vastly different from the cars of the teens. It did, however, take a good fifty years for the design features that make pressing superior to all come together. Contrast this with pressed steel ends, or roofs for that matter, which essentially replaced the earlier way of doing things in a brief five or ten years.

Dennis


David
 

--- In STMFC@..., "soolinehistory" <destorzek@...> wrote:
It appears that the two design philosophies coexisted for years without either proving to be truly superior.
Speaking to the USRA in particular, I believe the use of pressed shapes was driven by the cost and demand for rolled shapes during the war. Once the stamping dies were set up for volume production, pressed shapes could be made from small sections of sheet steel which were easier to obtain in a timely manner.

David Thompson


Anthony Thompson <thompson@...>
 

Dennis Storzek wrote:
There was a reasonable amount of resistance to the 9'-0" IH of the USRA cars as being "too big", wasteful since with most loads the cars would reach their load limit before they cubed out. Indeed, the ARA standard cars of 1923 reverted to the formerly common 8'-7" IH, although they retained the use of purpose designed pressings for posts and diagonals.
Not from all railroads. The SP had been building box cars of 9' 0" or more inside height (with Z-bar bracing) before the USRA cars came along, and after the war (when they had received 1000 cars of USRA single-sheath design) returned to Z-bar bracing and not only stayed with 9' 0" height but went beyond, to 9' 3" IH in the B-50-14 class of 1924. Moreover, the SP went on to build two sample cars to the ARA standard box car design of 1924, but then modified both the underframe (with reinforcements) and the height (increased by six inches to 9' 1") to construct two large classes of cars superficially like the ARA standards. Other western railroads also believed in tall box cars, whatever the viewpoint in the east.

Tony Thompson Editor, Signature Press, Berkeley, CA
2906 Forest Ave., Berkeley, CA 94705 www.signaturepress.com
(510) 540-6538; fax, (510) 540-1937; e-mail, thompson@...
Publishers of books on railroad history


Tom Palmer
 

Hi Rob,
The Katy used Z bracing on all of their single sheathed equipment exclusively, both boxcars and cabooses. No pockets to trap debris and hold water causing corrosion.
Best regards,
Tom Palmer

----- Original Message -----
From: Rob Kirkham
To: STMFC@...
Sent: 4/6/2011 1:02:18 AM
Subject: [STMFC] boxcar design evolution



A while ago I was able to make a trip into Sandon BC and take photos and
measurements of the freight cars there. Now I'm writing a description of
two of the cars. They were from the CPR 230000-233499 series composite
boxcars - boxcars very much like the USRA design. And as I write about
them, I wanted to say that when the cars were built in 1920-21, they were
more or less the best boxcar design on the market.

But I wonder if that is really accurate? For example, would the similar
cars used on other railways that used Z bracing (rather than the pressed
steel shapes on the USRA and CP cars) be considered better or poorer - or
was the difference inconsequential from the point of view of boxcar design
evolution? Meanwhile, was there anything else on the market yet that was
clearly superior?

Rob Kirkham




[Non-text portions of this message have been removed]


Richard Hendrickson
 

On Apr 6, 2011, at 11:52 AM, Anthony Thompson wrote:

Dennis Storzek wrote:
There was a reasonable amount of resistance to the 9'-0" IH of the
USRA cars as being "too big", wasteful since with most loads the
cars would reach their load limit before they cubed out. Indeed, the
ARA standard cars of 1923 reverted to the formerly common 8'-7" IH,
although they retained the use of purpose designed pressings for
posts and diagonals.
Not from all railroads. The SP had been building box cars of 9'
0" or more inside height (with Z-bar bracing) before the USRA cars
came along, and after the war (when they had received 1000 cars of
USRA single-sheath design) returned to Z-bar bracing and not only
stayed with 9' 0" height but went beyond, to 9' 3" IH in the B-50-14
class of 1924. Moreover, the SP went on to build two sample cars to
the ARA standard box car design of 1924, but then modified both the
underframe (with reinforcements) and the height (increased by six
inches to 9' 1") to construct two large classes of cars superficially
like the ARA standards. Other western railroads also believed in tall
box cars, whatever the viewpoint in the east.
I will add to this that the Santa Fe and Rock Island did essentially
the same thing, having large numbers of single sheathed box cars
built ca. 1929-'30-'31 which largely followed the ARA standard
design, including pressed steel Pratt truss body framing, but were
considerably taller at 9'6" IH.

With regard to steel vs. composite construction, it is a notable fact
that (with the minor exception of the Chicago Great Western) all of
the 1920s steel-sheathed box cars were built for northeastern
railroads which were close to the steel manufacturing centers and
whose car shops had the costly equipment required to repair all steel
cars. Composite construction remained the rule everywhere west of
the Mississippi River both because composite cars cost less to build
and because wood sheathing could be more easily repaired or replaced,
even in relatively primitive outlying car shops. There were vigorous
debates among railway master mechanics in the 1920s where it was
often argued that steel sheathing would eventually rust out and
require extensive and complicated repair or replacement a view that
certainly proved true on Pennsy X29s, NYC USRA-design steel box cars,
and other similar steel sheathed cars. The Burlington, certainly not
a technologically backward railroad, continued to build single wood
sheathed box cars in its own shops until the late 1930s.

All in all, it is not easy to say where a specific box car design fit
in the historical evolution of 1920s freight car technology because
there was no generally accepted state of the art. The Canadian USRA
clones, like their many cousins south of the border (e.g., C&NW) were
typical of one type of construction that was well regarded at the
time, and certainly not obsolete.

Richard Hendrickson



[Non-text portions of this message have been removed]


Robert kirkham
 

So from what I am reading, I gather:
- the USRA cars were not cutting edge in height - SP (at least) was already there.
- they were not cutting edge in choice of cladding (i.e. still using wood), and
- while the use of pressed steel shapes may (not clearly established here) have been an innovation in WWI, its advantages may have related more to issues of wartime manufacturing; that the purpose-built advantages Dennis has described were off-set in use by disadvantages when repairs were required; that the disadvantages were significant to the point that most/all builders/RRs went back to structural shapes; that only much later (out of era for STMFC) would other manufacturing processes render the pressed steel bracing concept the best choice.

So, the USRA cars were a pragmatic design, shaped by WWI and best suited to a particular traffic niche.

One wonders whether the CPR, which bought only about 2500 (compared to Dominion/Fowler cars on the roster numbering greater than 20000) was able to acquire them more cheaply as war surplus? In any event, as a western & eastern line (and all the way in between), I suspect the load types that justified a larger cube car on the SP were also present on the CPR.

Very interesting info - thanks to all of you who were able to help me put these into a little better context!

Rob Kirkham

--------------------------------------------------
From: "Anthony Thompson" <thompson@...>
Sent: Wednesday, April 06, 2011 11:52 AM
To: <STMFC@...>
Subject: Re: [STMFC] Re: boxcar design evolution

Dennis Storzek wrote:
There was a reasonable amount of resistance to the 9'-0" IH of the
USRA cars as being "too big", wasteful since with most loads the
cars would reach their load limit before they cubed out. Indeed, the
ARA standard cars of 1923 reverted to the formerly common 8'-7" IH,
although they retained the use of purpose designed pressings for
posts and diagonals.
Not from all railroads. The SP had been building box cars of 9'
0" or more inside height (with Z-bar bracing) before the USRA cars
came along, and after the war (when they had received 1000 cars of
USRA single-sheath design) returned to Z-bar bracing and not only
stayed with 9' 0" height but went beyond, to 9' 3" IH in the B-50-14
class of 1924. Moreover, the SP went on to build two sample cars to
the ARA standard box car design of 1924, but then modified both the
underframe (with reinforcements) and the height (increased by six
inches to 9' 1") to construct two large classes of cars superficially
like the ARA standards. Other western railroads also believed in tall
box cars, whatever the viewpoint in the east.

Tony Thompson Editor, Signature Press, Berkeley, CA
2906 Forest Ave., Berkeley, CA 94705 www.signaturepress.com
(510) 540-6538; fax, (510) 540-1937; e-mail, thompson@...
Publishers of books on railroad history



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Anthony Thompson <thompson@...>
 

Rob Kirkham wrote:
So, the USRA cars were a pragmatic design, shaped by WWI and best suited to a particular traffic niche.
I think that's a good summary. Probably it should be restricted to the USRA single-sheath cars, however, as the double-sheath cars were not as progressive (and correspondingly popular with railroad mechanical officers nervous about the 20th century).

Tony Thompson Editor, Signature Press, Berkeley, CA
2906 Forest Ave., Berkeley, CA 94705 www.signaturepress.com
(510) 540-6538; fax, (510) 540-1937; e-mail, thompson@...
Publishers of books on railroad history


Richard Hendrickson
 

On Apr 6, 2011, at 6:24 PM, Rob Kirkham wrote:

One wonders whether the CPR, which bought only about 2500 (compared to
Dominion/Fowler cars on the roster numbering greater than 20000)
was able to
acquire them more cheaply as war surplus?
Definitely not. They were built two years after the USRA cars, had
different ends (7-8 rather than 3-3-3 corrugated), and in other
respects were purpose-built for the CP.


Richard Hendrickson


Robert kirkham
 

sorry - I didn't express myself clearly. My thought was not that left-over USRA composite boxcars were sold to the CPR - as you say, Richard, there is no doubt the cars were built for the CPR new in 1920. My thought was more along the lines of whether, for example, the dies from the USRA era were unused or underused by that point, such that putting them back into production to stamp the side frames resulted in some sort of savings for the CPR. Or some other commitment or deal that made the 2500 cars a good choice. Purely speculative, of course. But I wonder why the CPR made this design choice while the CNR used Z braced cars.

And yes, there were significant differences in the ends and some other features. After messing about Tichy and Westerfield and Accurail, I remain in search of the perfect melding of HO parts. That remains a significant project on my to do list - and part of the reason I had to make time for a visit to the two cars at Sandon BC last year.

Rob Kirkham

--------------------------------------------------
From: "Richard Hendrickson" <rhendrickson@...>
Sent: Wednesday, April 06, 2011 8:24 PM
To: <STMFC@...>
Subject: Re: [STMFC] Re: boxcar design evolution

On Apr 6, 2011, at 6:24 PM, Rob Kirkham wrote:

One wonders whether the CPR, which bought only about 2500 (compared to
Dominion/Fowler cars on the roster numbering greater than 20000)
was able to
acquire them more cheaply as war surplus?
Definitely not. They were built two years after the USRA cars, had
different ends (7-8 rather than 3-3-3 corrugated), and in other
respects were purpose-built for the CP.


Richard Hendrickson






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