Hope everyone is enjoying the holiday weekend. I have copied the link to
a c.1906 photo from Shorpy,
<http://www.shorpy.com/node/8252?size=_original> , showing a siding full
of new Merchants Despatch reefers. All of them look new with a *distinct
hump , floor to roof line*. Is this typical for this type of
construction? The older reefers down the track appear to have flat floor
lines. Thanks.
Art Kuperstein
M&PRR c.1949
Langhorne, Pa.

The builder adjusted the tension in the truss rods to over compensate for the eventual sag which will come with age and use. Surmising from all of the new cars with identical "arch", I would say that the builder already knows how much "pre-tension" he needs to install.

We see similar considerations in modern flat bed trailers on the highways. Many of these trailers have an arch built in and when a heavy load, such as steel plates, is applied, the bed goes flat.
-Andy Carlson



All of them look new with a *distinct
hump , floor to roof line*. Is this typical for this type of
construction? The older reefers down the track appear to have flat floor
lines.

over-tightened truss rods.      Tom W.

The bow almost seems exagerated in that photo; there's another builder's photo of a car from the same series on the Wikipedia articlel for MDT which I beleive is also from the Detroit Publishing collection. I've never noticed such a bow before , but if I stare at it there does seem to be one. Side shots of cars from the same lot in service do not exhibit bow; and very old cars exhibit a bow but the other way. My guess is the truss rods may have been a bit overtightened to compensate for settling of the hardware under road and loading conditions. Just a guess. I also suspect some of the bowing is due to the angle of the shot.


Roger Hinman
On May 30, 2010, at 10:13 AM, Arthur Kuperstein wrote:

Hope everyone is enjoying the holiday weekend. I have copied the link to
a c.1906 photo from Shorpy,
<http://www.shorpy.com/node/8252?size=_original> , showing a siding full
of new Merchants Despatch reefers. All of them look new with a *distinct
hump , floor to roof line*. Is this typical for this type of
construction? The older reefers down the track appear to have flat floor
lines. Thanks.
Art Kuperstein
M&PRR c.1949
Langhorne, Pa.

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

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

I think most rolling stock has some amount of camber that can be
seen best when the cars are empty. I recall a few years ago when
Walthers produced some correctly bowed Amtrak passenger cars (there's
something like 3"-4" of camber over the 85' length of the cars) that
modelers thought they were defective! But I imagine it's not easy to
cut molds that reproduce the slight camber for freight cars. Door
tracks, doors, roofs would all be affected!

Tim O'Connor

--- In STMFC@..., Roger Hinman <rhinman@...> wrote:

The bow almost seems exaggerated in that photo; there's another builder's photo of a car from the same series on the Wikipedia article for MDT which I believe is also from the Detroit Publishing collection...

It appears that the focal length of the lens was what could be considered a mild telephoto; all the cars are foreshortened and that accentuates the bow.

What is more interesting to me is the color separation on the needle beams, they appear to be hand painted without the aid of any masking. They also end at different places; on the nearest beam the white ends just above the inner bolt on the queenpost casting, while on the next beam it extends several inches further. I guess this is what you do when the customer wants the needle beams white but not the whole underframe.

Dennis

The needlebeam support is wood whereas everything in the under-frame by this time was iron or steel, hence painting it a different color made some sense. It was very common on 19th century cars to paint the iron work black. As far as the color separations, this is an interesting observation. My assumption has been the entire wood beam was painted white whereas this photo makes it appear the white is a highlight painted on the ends.
I have a good side shot of a car in this series after years of service and the demarcation between light and dark is a straight triangular line which I take to be a shadow. So one theory is the dark is shadow, the other would be it's a highlight and if that is the case, there is certainly a lot of variation.

FYI, the customer for these cars was the company that built them.


Roger Hinman
On May 31, 2010, at 12:54 PM, soolinehistory wrote:

--- In STMFC@..., Roger Hinman <rhinman@...> wrote:

The bow almost seems exaggerated in that photo; there's another builder's photo of a car from the same series on the Wikipedia article for MDT which I believe is also from the Detroit Publishing collection...

It appears that the focal length of the lens was what could be considered a mild telephoto; all the cars are foreshortened and that accentuates the bow.

What is more interesting to me is the color separation on the needle beams, they appear to be hand painted without the aid of any masking. They also end at different places; on the nearest beam the white ends just above the inner bolt on the queenpost casting, while on the next beam it extends several inches further. I guess this is what you do when the customer wants the needle beams white but not the whole underframe.

Dennis

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

--- In STMFC@..., Roger Hinman <rhinman@...> wrote:

The needlebeam support is wood whereas everything in the under-frame by this time was iron or steel, hence painting it a different color made some sense...

Iron or steel? Hardly. Look at the end of the draft sill where it shows next to the coupler; you can see the annual rings of the wood!

http://www.shorpy.com/node/8252?size=_original

Since draft sills were some of the first parts of the underframe to be converted to metal (those and body bolsters, which are metal on these cars) the sills above them are undoubtedly wood also. The construction with the iron faced wood buffer block with a iron strap dropping below the sills to both tie them together and support the coupler shank is also very typical of an all wood underframe. The 1904 date of the photo is just a couple years too early for major amounts of steel in underframe construction.

Dennis

In my response I considered the sills as part of the body structure The underframe being the bolsters and the needle beam. I'm in 100% agreement with you on the break in dates of steel. Once steel is introduced the whole idea of what's in the underframe begins to change.

--- In STMFC@..., Roger Hinman <rhinman@...> wrote:

In my response I considered the sills as part of the body structure The underframe being the bolsters and the needle beam. I'm in 100% agreement with you on the break in dates of steel. Once steel is introduced the whole idea of what's in the underframe begins to change.

Yeah, I've always considered the center sills and draft sills (back in those days a separate sub sill from the bolster outward), the side sills as part of the body framing, and the intermediate sills as, well, who knows? :-) But one could also consider all the sills as part of the underframe, as the function of the end sills was to distribute the buffing forces to all of them, a design concept that was to change by WWI.

A related question, that perhaps Tony can answer off the top of his head, is when was wrought iron no longer used in freightcar construction? Did it last to the end of wood construction, or was it totally replaced by steel at some point either before or after the general change away from wood framing?

A number of years ago, I was involved in scrapping some wooden Chicago elevated cars for parts, cars that dated to between 1900 and 1906. Admittedly, these weren't freight cars (some commuters would disagree, I'm sure) but were typical of the carbuilders' art of the time, with wooden bodies on channel sill underframes reinforced with truss rods. In cutting the frames, there were some minor members that simply wouldn't burn correctly, and the only explanation we could come up with was that they were iron rather than steel. I've always wondered how long wrought iron plate and bar were produced after steel structural sections were introduced.

Dennis

Dennis S. wrote:

A related question, that perhaps Tony can answer off the top of his head, is when was wrought iron no longer used in freightcar construction? Did it last to the end of wood construction, or was it totally replaced by steel at some point either before or after the general change away from wood framing?

Wrought iron did continue to be used as small parts in car bodies, and in truss rods, for some time after steel replaced iron in virtually all large-scale applications. When steel suddenly became much cheaper than wrought iron in big sizes (once the Bessemer process reduced production costs to a fraction of previous costs), wrought iron continued to be well liked for its easy workability. So new bridge construction went quite rapidly went from iron to steel in just a few years in the 1880s. But car body construction may have continued to use some wrought iron later. I think wrought iron bar stock was readily available and in use as late as WW I.

A number of years ago, I was involved in scrapping some wooden Chicago elevated cars for parts . . . I've always wondered how long wrought iron plate and bar were produced after steel structural sections were introduced.

After about 1890, very little if any plate or large-section wrought iron would have been available. But small parts and tension rods may have been used in significant amounts for another decade or two.

Tony Thompson Editor, Signature Press, Berkeley, CA
2906 Forest Ave., Berkeley, CA 94705 www.signaturepress.com
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