Wednesday, March 9, 2022

Empty reefers with car fans

I introduced the topic of managing empty refrigerator cars in a previous post, inspired in part by Mike Jordan’s layout operations, as I described in that post. If you’d like to read some of that background material, it is at this link: https://modelingthesp.blogspot.com/2021/12/distributing-ice-reefers.html

One of Mike’s layout procedures is to make sure that fan-equipped reefers are delivered to the shippers that need them. Cars with fans could maintain much more uniform temperature within the loaded car interior, obviously avoiding damage to produce in the warmest car areas (upper center of the car). There were two kinds of crops where this uniformity was especially important: dense produce, like melons or fruit; and leafy vegetables, such as cabbage or celery. 

Let me repeat below a drawing from Preco (Pacific Railway Equipment Company), showing fan installation with their equipment. It was included in the PFE book on page 175. (Pacific Fruit Express, 2nd edition, Thompson, Church and Jones, Signature Press, 2000). Air circulation is emphasized in the upper drawing, details of fan and heater installation in the four small drawings at bottom. (You can click on the image to enlarge it if you wish.)

As mentioned in the previous post (link in top paragraph, above), for more than 10 years, PFE painted fan shafts on the car side black, and when fan shafts were no longer needed (their use is shown at bottom left in the drawing above), and electric fans were installed, a round plate, the size of a fan shaft mounting, was added to the car side and painted black. The photo below, a Pullman photo of a Class R-40-23 car built in April 1947, illustrates how evident these black circles were.

What are the PFE cars that were built with fans? The first class of new cars with fans was Class R-40-23, built in 1946-47 (such as the one above), followed by all the subsequent steel ice cars. The first rebuilt cars that received fans were classes R-40-21 and -24. But matters are complicated by the fact that PFE retrofitted fans to cars of several early c lasses, including R-40-10 and R-40-20, from 1950 onward.

In peak harvest season, usually in September and October, even PFE’s immense fleet of over 40,000 cars (in this era) was not enough, and foreign cars were borrowed, either informally or under contract (one such contract was with BAR). 

One frequent source of borrowed cars was ART, which had declining traffic in the 1950s. It is interesting, though, that in the late 1950s, PFE did not want any foreigns unless they had fans. They supplied instructional photos to various junction yards so that yardmen would be able to recognize the “right” cars. Here is an example.

The topic of car fans overlaps with that of pre-cooling of loads. Shippers should ideally pre-cool their produce to shipping temperature themselves, as they then had control of the process and could cool quickly. For dense produce, chilling the individual fruit in a running stream of refrigerated water was fast and effective. For leafy vegetables, either storage in a cold room (slower) or vacuum-exposure of the produce after misting with water (causing rapid evaporation and cooling, thus quicker) was practiced. 

The shipper would of course order fan cars from the local agent, if those were needed, and the Car Distributor filling the order would ordinarily comply. But then what?

 [Some years back, I included part of the transcript of my interview with Pete Holst, long-time PFE Assistant General Manager for Car Service (meaning management of the car fleet). It gives a great many insights into PFE operations. You can read it here: https://modelingthesp.blogspot.com/2012/09/pfe-operations-from-pete-holst.html .]

For reefer operations on my layout, I have separated my outgoing waybills for produce loads, so that fan cars are preferentially used for the kinds of loads that would require fans. But that doesn’t help with inbound empties, because Empty Car Bills don’t specify the industry to which the car(s) may be destined. 

One possibility for directing spotting of fan cars is an agent’s message (see: https://modelingthesp.blogspot.com/2015/06/operating-with-agent-messages.html ) to deal with empty car spots, for example, “spot fan cars at Guadalupe Fruit,” and let the switch crew select out those cars. But the agent knows the incoming empty car numbers (the Car Distributor will have notified him), so this is an artificial arrangement. I am continuing to think about ways to do this better.

Tony Thompson

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