70 ton triple bay hopper

70 ton triple bay hopper

Postby scaro » Sun Jan 13, 2013 6:29 pm

a manufacturer on shapeways is thinking about a 70 ton triple open hopper like this:

http://appalachianrailroadmodeling.com/ ... u72663.jpg

apparently lengths for these vary, the atlas trainman one in HO represents a longer type and he's thinking of one about 1'6" shorter.

it is to be similar to the AAR one and would be correct for many eastern and midwestern RRs. i know very little about these, a start can be made by looking at Rail Model Journal, June 1995 edition, where there's an article about release of an MDC version of the design for HO. it is termed a '9-panel' hopper so i assume that doesn't include the end sections.

ben
Last edited by scaro on Sun Jan 13, 2013 9:00 pm, edited 1 time in total.
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Re: 70 ton triple bay hopper

Postby scaro » Sun Jan 13, 2013 8:42 pm

RRs who used the design include RDG, WM, B&O, C&O, C&EI, SOU, CofG, SCL (rebuilt from offset 3-bays) MP/T&P, M&StL, CB&Q and later BN, D&RGW and others.
scaro
 

Re: 70 ton triple bay hopper

Postby Richard-B » Mon Jan 14, 2013 9:30 pm

scaro wrote:RRs who used the design ...

Careful... the term "the design" can be open to quite loose interpretation...

Do you mean 9-panel 3-bay hoppers in general... or this exact configuration... or something else???

Here are three "similar"... but not necessarily exact.
Note differences in rivet patterns, end sheets, and proportions.
Would they do as stand-ins? YMMV.

CofG
CofG-22126 HM-3bay_TheRightWay_builders_ACF-Aug1957_cSWydeck.jpg
CofG 9-panel 3-bay


M&StL
M&StL-66743 HM-3bay_builders_ACF-May1957_cSWydeck2.jpg
M&StL 9-panel 3-bay


WM
WM-70506 HT-3bay_BSC-bSep1956_cJKinkaid.jpg
WM 9-panel 3-bay
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Re: 70 ton triple bay hopper

Postby scaro » Tue Jan 15, 2013 5:54 am

i've been looking into this but cannot say i understand the variations yet. not at all. there was apparently a discussion on STMFC when atlas re-released older hoppers under their 'trainman' range in HO. it's more accurate to say 'designs'. for now anyway.

they would be based on SCL H3s which were converted from offset hoppers ... i don't have the data to say what they'd be most exact for. i take from the discussions that there are some that are too long for AAR length, by about one-and-a-half feet, and the SCL one is closer to the AAR length. but shoot me down on this anytime, i don't know the detail and don't have the tools at my disposal to better inform myself, RPCYCs not being awful cheap or available in the UK.

being a late rebuild - 1969 - an H3 may have idiosyncrasies of its own; i simply can't say. i am told they are close to something southern had, as well, though the hopper slope sheets look steeper on the SCL H3. there is one pic on the ACL-SAL-SCL modelling group that i can find, and it appears close to the MStL hopper at first glance. they do look like a fairly generic 9 panel 70 ton triple hopper. i have asked for permission to post that image here.

on the ACL-SAL-SCL modelling group the release of the trainman model (too long for the SCL ones) was greeted with a deal of enthusiasm, with the feeling being that removal of cast on detail and addition of grab irons in the right places would produce something close to the SCL one, despite the extra 1'6" length.
scaro
 

Re: 70 ton triple bay hopper

Postby railtwister » Tue Jan 15, 2013 10:55 am

Hi Ben,

What's "STMFC"?

I think given the state of available US prototype models in TT scale today some leeway must be given regarding dead-on accurate dimensions for a particular prototype in most cases. This is not to say that a model of an odd or obscure prototype such as a B&O wagon-top boxcar, covered hopper, or caboose shouldn't be as close to accurate as possible, but such rivet counting concerning more generic prototypes simply isn't practical. As for hopper cars, if the number hoppers and panels is correct and the height to length ratio isn't way off visibly, that should be good enough, at least for now. Leave the complaining about accuracy not within a protypical fraction of an inch to the other scales.

Bill in FtL
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Re: 70 ton triple bay hopper

Postby scaro » Tue Jan 15, 2013 4:08 pm

hi bill, it's the STeaM era Freight Car list. it's a yahoo list. it deals with prior to 1960. there's the complementary MFCL or modern freight car list for cars post-1960.

i think there's a balancing act here.

the producer tells me he's going to research 2 and 3 bay hoppers a bit and may offer different options, but this will be in a few months.

presumably he's taking time to think about what might appeal to a broad market. this is a car with broad appeal. there need not be too many fudges to come up with a car that is approximately right for many lines.

at the same time, i'd try to follow a prototype, or at least make the differences easy to fix!

in terms of how and why TT exists, i'd hope that even if we only have a few cars, that they are ones that appeal to the person who wants to do something that's a bit more prototypical and is prepared to take time to get things accurate.

hasn't happened a lot in TT, especially compared to N scale, but getting a car which isn't accurate for anything is kind of a waste, i'd say.

i've only seen one photo of an H3. it looks pretty generic to me anyway. i may be wrong, but i think it could be dressed up, with rivet decals, heap extenders and grab irons for any of the three hoppers richard showed.

if you go onto STMFC there will be nits picked all over the shop, because that's what they are there for. but as long as everyone knows the necessary compromises, then that's fine. i would go on STMFC to learn, and to take note of those criticisms, but if i were a manufacturer i wouldn't consider myself restricted by such things.

95% of people don't care, and there are different ways of capturing the prototype feel other than worrying about the placement of rivets.
scaro
 

Re: 70 ton triple bay hopper

Postby Richard-B » Tue Jan 15, 2013 4:29 pm

railtwister wrote:I think given the state of available US prototype models in TT scale today some leeway must be given regarding dead-on accurate dimensions for a particular prototype in most cases.


No problem with your point...
but given many prototype cars that are quite similar (albeit with detail differences) and one prototype that is different, let's build for the many... and let it stand-in for the one-off; NOT the other way around.

A prototype which was modified in-service
scaro wrote: which were converted from offset hoppers
is necessarily going to be right for exactly one car type... and dead wrong for everything else. This limits the addressable TT market.

Full disclosure: I have no skin in this particular 3-bay hopper game... since the number of this type 70t 3-bay cars native to the West Coast is asymptotic to ZERO.
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Re: 70 ton triple bay hopper

Postby scaro » Tue Jan 15, 2013 7:18 pm

i will reserve my opinion until i see what eventuates.
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