Choosing a model car fleet-3: stock cars

I have been devising what I call “car plans” by car type. Each plan lists the cars I already have of that type, including unbuilt models, and lists what may be needed as to road names or other additions. This helps identify models that should be sold or modified, as well as unfilled needs.
     In this post, I’ll talk about stock cars. It’s well known that stock could not be confined in a railroad car for more than 28 hours (36 hours if so requested in advance by the shipper) without being fed, watered and rested. [I have space on my livestock waybills to indicate whether the 36-hour rule was invoked.] “Rest” meant letting the animals out of the car, unless they had room to lie down in the car and could also receive feed and water in the car. The minimum time for rest was 5 hours. All this was federal law.
     These regulations meant that stock traffic was handled as expeditiously as possible, usually in the hottest manifest trains. But when animals were unloaded for rest, it was common to send any empty foreign cars homeward and reload into the home road’s cars. Of course if a home road car was not available, this could not be done. It was permissible to reload animals into the same cars, but fresh cars had to have fresh bedding, as did the cars spotted for initial loading. Cars were normally steam cleaned between runs, and shippers had the right to reject for loading any car which in their judgement was not clean.
     These background facts mean that on a railroad the size of the SP, foreign stock cars would not be common except for direct connections. Study of SP photographs in southern and central California has shown me the following foreign cars on line: ATSF, CB&Q, D&RGW, MKT, NP, T&NO, T&P, and UP. Of course T&NO is only formally a foreign road and its cars would be expected to be freely mixed with SP stock cars.
     My current stock car plan provides for one each ATSF, D&RGW, NP and T&P cars, along with three T&NO and three UP cars. I already have six SP cars and will add an NWP car. Stock cars in the 1950s were sometimes in surplus, and as observed in the “Equipment Instructions” document (described in my post “Modeling freight traffic: Coast Line, 1953-Part 4”, available at: http://modelingthesp.blogspot.com/2011/01/modeling-freight-traffic-coast-line_30.html), divisions were instructed to store surplus cars. I need to have an adequate stock track to accommodate a couple of cars stored there even if no inbound or outbound loads are in prospect. Here’s a photo of one of my SP cars, a Red Caboose Class S-40-5 car:

     Stock traffic on the Coast Line by the 1950s was not extensive, but did include both animals being moved to slaughterhouses, and inbound breeding stock. There was only limited traffic in animals being moved between seasonal pastures.
     A stock pen should have some size relation to expected shipments. Ordinarily about 25 cattle (typically weighing around 1000 pounds each) were loaded in a car, or 75 hogs in a single-deck car, or 240 sheep in a double-deck car. Needed pen capacity for these sizes of car loads is about 850 square feet per car. I am doubling the size of the pens in the old A.H.M stock pen kit to provide pens of this size. It’s easy to modify or scratchbuild pens with stripwood or styrene.
     Anyone interested in typical stock pen sizes and designs, with detail drawings of loading chutes and other details, may wish to look at Chapter 13 in John A. Droege’s book (Freight Terminals and Trains, McGraw-Hill, 1925; NMRA reprint, 1998). The chapter also contains detailed comments about stock handling by railroads.
Tony Thompson