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Model Railroading > Time For A Re-weigh


Date: 05/13/19 11:42
Time For A Re-weigh
Author: icancmp193

I was assembling a couple of Bowser Lehigh & New England 70-Ton Covered Hoppers and something struck me odd about the dimensional data. Although the light weight was reasonably accurate at 53,500 lbs, the capacity at 1,540,000 lbs and the load limit of 1,500,000 lbs was a bit over the top, more akin to a small Schnabel car than a little cement hopper. So, with some black Microscale trim film and white dimensional data found in the decal bin, the weights were brought more in line with reality. I checked my other Bowser cars with different road names (LV, E-L, N&B, WM) and they were all OK, so this error seems confined to the L&NE versions.

Next step: These cars need some serious weathering. Those who may recall L&NE (and fellow railroads like the CNJ, LV, E-L, et al) know these hoppers were downright gritty! If I could even come halfway close to some of the Espee hoppers recently done by "Obsessed Foamer", I'd be thrilled.

TJY








Date: 05/13/19 12:45
Re: Time For A Re-weigh
Author: PHall

Question, wouldn't you change the reweigh date too?



Date: 05/13/19 14:29
Re: Time For A Re-weigh
Author: retcsxcfm

PHall Wrote:
-------------------------------------------------------
> Question, wouldn't you change the reweigh date
> too?
I would not think so because he is correcting
what should have done in first place.
Uncle Joe



Date: 05/13/19 14:56
Re: Time For A Re-weigh
Author: icancmp193

retcsxcfm Wrote:
-------------------------------------------------------
> PHall Wrote:
> --------------------------------------------------
> -----
> > Question, wouldn't you change the reweigh date
> > too?
> I would not think so because he is correcting
> what should have done in first place.
> Uncle Joe

Quite honestly, I hadn't thought about it that much.

TJY



Date: 05/13/19 17:13
Re: Time For A Re-weigh - The Rules on Car Weight Markings
Author: CSX602

FYI...  The load limit (LD LMT) and light weight (LT WT) on a 70-ton car should add up to EXACTLY 220,000.  So if the LT WT is "50 700" then the LD LMT should be exactly "169 300".   The "CAPY" could be a rounded off number below that (perhaps 154 000 as that was common, but there was no exact formula or meaning of the CAPY line and that's why the requirement of that line was dropped decades ago).

The load limit on every freight car is the design maximum weight (gross rail load, aka "GRL") minus the empty car weight (light weight).

So called 50-60 ton cars had LT WT + LD LMT = 177 000 (aka 177K) GRL
So called 70-80 ton cars have LT WT + LD LMT = 220 000 (aka 220K) GRL
So called 90-100 ton cars have LT WT + LD LMT = 263 000 (aka 263K) GRL
Modern "286K" or 110-ton freight cars, which were allowed staring in 1995 (I believe), have LT WT + LD LMT = 286 000 GRL (many have 286K markings in a little box on the sides)
(Note there are some 268K cars and 315K cars now but they are relatively uncommon and we don't have any models of those car designs yet)


So every 2-truck 4-axle freight car model you have should likely have the LT WT + LD LMT equal to one of those 4 GRL totals above...  (pre-1995 modelers the top 3, post-1990 modelers the lower 3)

So how does this all work when a car is reweighed? 


If a "70 ton" car (which generally had designs for total rail loading of 220,000 pounds) originally weighed in at 51,000 pounds when new (and thus originally had load limit of 169 000 because 220,000 minus 51,000 equals 169,000) and was later reweighed and found to be 51,176 pounds then that would have been rounded up (to next 100 pounds), the LT WT markings changed to 51 200, and the load limit would have been changed down to 168 800 (because 220,000 minus 51,200 equals 168,800) and the CAPY line likely not changed...    By the 1970s most of the crews doing the reweighing had calculators so errors were rare.  Before that they had tables to help them with the math and subtracting the light car weight from the design weight so they would know the load limit to mark.

A 70-ton airslide hopper with LT WT = 56 700 would have a LD LMT above it of 163 300 (exactly) while a similar car with LT WT = 58 000 would have LD LMT = 162 000 (and both could have had CAPY 154 000).   See page 28 of the Chessie Color Guide to Freight Equipment (by Morning Sun) for two such cars.   Or take a look at any of the freight car color guides.   


Warning...   If you decide to correct your model freight car fleet it could be quite a big effort.  It is unfortunate that some model manufacturers are very sloppy in executing the data on their cars and some even unfamiliar with what the data means or what it should add up to per the freight car data and markings rules.  Once you start looking at the numbers on models you can quickly see who knows the rules, who had good photos, and conversely who was making up numbers or guessing.  And if the last 3 numbers of the LT WT plus the last 3 numbers of the LD LMT don't equal up to either 0 or 1,000 then it's an immediate clue one number is off.  

And if any number has 7 digits...  You know that an extra one got in there somehow...  (and an eraser can come in handy in removing the middle or last one)


In summary here's how the rules end up...
where...
LD LMT = EFG H00
LT WT =     KL M00

H and M will either both be zeros or H+M=10

EFGH + KLM will equal 1770 (50-60 ton car) or 2200 (70-80 ton car) or 2630 (90-100 ton car which generally have 36" wheels) or 2860 (modern 110-ton car)

Every time the LT WT increases/decreases with car reweighing, then the LD LMT decreases/increases by same amount 
(sometimes only H and M numbers are changed, sometimes they redo both entire lines)






 



Edited 2 time(s). Last edit at 05/13/19 18:47 by CSX602.



Date: 05/13/19 18:30
Re: Time For A Re-weigh - The Rules on Car Weight Markings
Author: icancmp193

CSX602 Wrote:
-------------------------------------------------------
> FYI...  The load limit (LD LMT) and light weight
> (LT WT) on a 70-ton car should add up to EXACTLY
> 220,000.  So if the LT WT is "50 700" then the LD
> LMT should be exactly "169 300".   The "CAPY"
> could be a rounded off number below that (perhaps
> 154 000 as that was common, but there was no exact
> formula or meaning of the CAPY line and that's why
> the requirement of that line was dropped decades
> ago).
>
> The load limit on every freight car is the design
> maximum weight (gross rail load, aka "GRL") minus
> the empty car weight (light weight).
> So called 50-60 ton cars had LT WT + LD LMT = 177
> 000 (aka 177K) GRL
> So called 70-80 ton cars have LT WT + LD LMT = 220
> 000 (aka 220K) GRL
> So called 90-100 ton cars have LT WT + LD LMT =
> 263 000 (aka 263K) GRL
> Modern "286K" or 110-ton freight cars, which were
> allowed staring in 1995 (I believe), have LT WT +
> LD LMT = 286 000 GRL (many have 286K markings in a
> little box on the sides)
> (Note there are some 268K cars and 315K cars now
> but they are relatively uncommon and we don't have
> any models of those car designs yet)
>
> So every 2-truck 4-axle freight car model you have
> should likely have the LT WT + LD LMT equal to one
> of those 4 GRL totals above...  (pre-1995
> modelers the top 3, post-1990 modelers the lower
> 3)
>
> So how does this all work when a car is
> reweighed? 
>
> If a "70 ton" car (which generally had designs for
> total rail loading of 220,000 pounds) originally
> weighed in at 51,000 pounds when new (and thus
> originally had load limit of 169 000 because
> 220,000 minus 51,000 equals 169,000) and was later
> reweighed and found to be 51,176 pounds then that
> would have been rounded up (to next 100 pounds),
> the LT WT markings changed to 51 200, and the load
> limit would have been changed down to 168 800
> (because 220,000 minus 51,200 equals 168,800) and
> the CAPY line likely not changed...    By the
> 1970s most of the crews doing the reweighing had
> calculators so errors were rare.  Before that
> they had tables to help them with the math and
> subtracting the light car weight from the design
> weight so they would know the load limit to mark.
>
> A 70-ton airslide hopper with LT WT = 56 700 would
> have a LD LMT above it of 163 300 (exactly) while
> a similar car with LT WT = 58 000 would have LD
> LMT = 162 000 (and both could have had CAPY 154
> 000).   See page 28 of the Chessie Color Guide
> to Freight Equipment (by Morning Sun) for two such
> cars.   Or take a look at any of the freight car
> color guides.   
>
> Warning...   If you decide to correct your model
> freight car fleet it could be quite a big
> effort.  It is unfortunate that some model
> manufacturers are very sloppy in executing the
> data on their cars and some even unfamiliar with
> what the data means or what it should add up to
> per the freight car data and markings rules. 
> Once you start looking at the numbers on models
> you can quickly see who knows the rules, who had
> good photos, and conversely who was making up
> numbers or guessing.  And if the last 3 numbers
> of the LT WT plus the last 3 numbers of the LD LMT
> don't equal up to either 0 or 1,000 then it's an
> immediate clue one number is off.  
>
> And if any number has 7 digits...  You know that
> an extra one got in there somehow...  (and an
> eraser can come in handy in removing the middle
> one)

Oh my! I was just trying to get rid of the outrageous weights that Bowser put on there and I was mildly irritated that they did!
But your information is very enlightening!

TJY
>
>
>
>
>
>
>
>  



Edited 1 time(s). Last edit at 05/13/19 18:39 by icancmp193.



Date: 05/13/19 20:12
Re: Time For A Re-weigh - The Rules on Car Weight Markings
Author: 4745

Great information for those of us that read the data on the model freight cars.
Thanks. Graham.



Date: 05/13/19 20:32
Re: Time For A Re-weigh - The Rules on Car Weight Markings
Author: Hookdragkick

I think the extra weight came from those unsightly grabirons! 1-0 repatching



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