Stock Car Shipments

There's been an interesting discussion on the STMFC group about stock car shipments and the group has been reporting a lot of data.  So I thought I would chip in a bit with some statistics from the 1% Carload Waybill Survey.  Unless otherwise mentioned, the totals for carloads are those reported in the survey, and should be multiplied by 100 to obtain an estimate for the yearly totals.

I decided to use statistics from 1953 for this post, as that seems to be a popular modeling year.  It should be noted that there was a steady decline in the number of stock car shipments during the 1950s, which I have commented on in earlier posts, and that the commodity flows related to stock car shipments changed a lot during the decade.

In 1953 the 1% sample contained 4558 shipments that were made in cars with AAR mechanical designation S.  They break down this way:

Products of Agriculture:             49
Animals and Their Products:  4337
Products of Mines:                     18
Products of Forests:                  109
Manufactures and Misc.             45


Its interesting to note that about 5% of the shipments in the sample that were made in stock cars were not shipments of animals.  So there's probably some justification for sparingly running a particularly interesting model of a stock car carrying a non-animal commodity, but the vast majority of the stock car shipments (and the remainder of this post) will be devoted to the commodity flows associated with Animals and Their Products.

Out of the 4337 stock car shipments of animals, the breakdown in terms of commodity classes looks like this:

201 - Horses Mules and Ponies:                   56
203 - Cattle and Calves, Single Deck:      2760
205 - Calves, Double Deck:                         12
207 - Sheep and Goats, Single Deck:         150
209 - Sheep and Goats, Double Deck:       422
211 - Swine, Single Deck:                          397
213:  Swine, Double Deck:                        540

So you can see that the stock car shipments will be influenced by a variety of commodity flows; primarily cattle shipments, but hogs, and to a smaller extent, sheep and goats, will be important as well.  (As I have remarked earlier, one of the nice things about the 1% Carload Waybill Survey is that it gives us a feel for the relative frequencies of use of single-deck and double-deck cars, which I think are quite different visually on a layout - we should be able to use this to advantage in developing our setting and era.)

 I looked at the state to state data, and tabulated all the flows that were present in the sample at a frequency greater than 10.  My feeling was that the smaller numbers were just not reliable (over 30% uncertain).  So this next part of the discussion considers about 110 state-to-state flows that make up the most significant part of the stock car shipments.  It is not comprehensive - it is trying to focus on the most significant.

These are the most significant originators of stock car shipments by state (remember that the carloads tallied are the carloads in the sample):

From:	Carloads
Ill.	491
Neb.	304
Tex.	266
Iowa	230
Mont.	201
Col.	184
Kan.	170
Mo.	133
Ind.	114
Wy.	95
Minn.	80
S.D.	76
N.M.	65
Ida.	56
Okla.	51
Utah	49
Ariz.	37
N.D.	37
Wis.	30
Nev.	20
Ohio	10

and these are the most significant terminators of stock car shipments by state:

From:	Carloads
Ill.	432
Cal.	424
Iowa	275
N.Y.	194
N.J.	166
Mo.	148
Kan.	138
Pa.	125
Col.	123
Neb.	120
Minn.	118
Mich.	80
Ohio	80
Tex.	65
Wash.	47
Ariz.	31
Wis.	30
Md.	29
Mont.	18
Utah	16
Ida.	10
Mass.	10
S.D.	10
Tenn.	10

The state to state flows and the summary of stock cars by AAR MD from the Jan 1958 ORER are in the Data Appendix at the end of this post.

Points to Ponder:

• When we, as prototype modelers, are talking about stock cars, it seems to be useful to make the distinction between single deck and double deck cars.  This aspect of stock car modeling seems to me to be as important as getting box car heights correct.  They look different on the layout and they moved differently in real life.  
• It also seems to be important to make the distinctions among the commodity shipped when considering stock car movements.  The state to state patterns of cows, pigs, and sheep are all significant components of the stock car patterns.  And they are all different.  So rather than making generalizations about stock car movements, I think its useful to think about the specifics of what facility we are trying to model and what cars it takes to service it.   
• I've focused on the most significant commodity flows in this post.  About 110 state-to-state flows account for about 60% of the commodity movement.  There's about 40% of the movement in less frequent, "noisier", flows.  There's a lot of room for minor variation around these national statistics to fit individual layout situations. 

Charles Hostetler
Goshen, IN


Data Appendix:

This long table lists the most significant commodity flows that resulted in stock car shipments in 1953.  The carloads tabulated are those in the sample - estimate the total carloads per year by multiplying the provided numbers by 100.  The rows colored green are ICC Commodity Class 203, Cattle and Calves, Single Deck.  The rows colored gray are ICC Commodity Class 209, Sheep and Goats, Double Deck.  the rows colored bright red are ICC Commodity Class 213, Swine, Single Deck, and the rows colored orange are ICC Commodity Class 211, Swine, Double Deck.

From:	To:	Carloads
Ill.	N.Y.	97
Ill.	N.J.	72
Ill.	Pa.	63
Neb.	Ill.	63
Tex.	Kan.	60
Tex.	Cal.	58
Kan.	Mo.	48
Ill.	Ohio	45
Neb.	Iowa	44
Mont.	Cal.	43
Tex.	Tex.	43
Mo.	Ill.	41
Neb.	Cal.	40
Iowa	Ill.	38
Ill.	Ill.	38
Ida.	Cal.	38
Minn.	Minn.	38
Iowa	Iowa	37
Col.	Cal.	37
Neb.	Mo.	35
Iowa	Iowa	35
Kan.	Ill.	34
Col.	Ill.	33
Utah	Cal.	33
Wy.	Neb.	33
Ind.	N.J.	32
Mont.	Ill.	31
Kan.	Kan.	30
Mont.	Iowa	29
Tex.	Ill.	29
Ill.	N.Y.	29
Tex.	Col.	28
Ind.	Pa.	28
Col.	Col.	27
Ill.	N.J.	27
Ind.	N.Y.	27
Ill.	Mich.	26
Mont.	Minn.	25
Mont.	Wash.	25
Mo.	Ohio	25
Neb.	N.J.	25
N.M.	Cal.	25
N.D.	Minn.	25
Ill.	Ill.	25
Ariz.	Cal.	24
Ill.	Pa.	24
Neb.	Cal.	23
Okla.	Ill.	22
Mo.	Mich.	21
Wy.	Iowa	21
Iowa	Cal.	21
Mont.	Neb.	20
Iowa	Mich.	20
Neb.	Neb.	20
Nev.	Cal.	20
Minn.	Minn.	19
Neb.	Kan.	19
S.D.	Iowa	19
Ill.	N.Y.	19
Mont.	Mont.	18
Mo.	Mo.	18
Col.	Kan.	18
Okla.	Mo.	18
Tex.	Ariz.	18
Tex.	Mo.	18
Col.	Col.	18
Ida.	Cal.	18
Wis.	Wis.	18
Iowa	Cal.	18
Iowa	Iowa	18
Mo.	Iowa	17
Wy.	Neb.	17
Ind.	Md.	17
Kan.	Iowa	16
N.M.	Ill.	16
Utah	Utah	16
Kan.	Col.	15
Kan.	Neb.	15
Col.	Iowa	15
Col.	Neb.	15
Neb.	Cal.	14
Ill.	Ill.	14
Ariz.	Ariz.	13
S.D.	Ill.	13
S.D.	Mich.	13
Wy.	Col.	13
Iowa	Ill.	13
N.M.	Col.	12
N.M.	Tex.	12
N.D.	Iowa	12
Tex.	Iowa	12
Wisc.	Wisc.	12
Kan.	Cal.	12
Minn.	Wash.	12
Ill.	Md.	12
Minn.	Ill.	11
Col.	Mo.	11
Neb.	N.Y.	11
Okla.	Kan.	11
S.D.	Minn.	11
Wy.	Ill.	11
Mo.	N.Y.	11
Mont.	Ida.	10
Iowa	Tenn.	10
Ind.	Ohio	10
Neb.	Col.	10
Col.	N.J.	10
S.D.	S.D.	10
Iowa	Tex.	10
Iowa	Mass.	10
Ohio	Pa.	10
S.D.	Wash	10

These are the totals for the stock cars listed in the Jan, 1958 ORER:

SM	27103
SA	1660
SC	8698
SD	1536
SH	39
SF	3216
Total S	42252