Pierre Oliver wrote:
I've been reading through a newly acquired copy of Santa Fe Railway Refrigerator Cars and a question has arisen in my mind. Both CNR and CPR had, what I understand, to be great success with an 8 hatch reefer design. The ice bunker extended the full length of the car, generating a more even temperature along the length of the car. Why did none(as far as I can tell)of the US roads copy this design or emulate it in some form?Pierre, I explained this in some detail in Chapter 7 of the PFE book (pages 150-153). Here is a short summary. The overhead-bunker design did provide much more uniform temperature; so did car fans. The latter development was preferred, and widely adopted, in the U.S.
The overhead bunker suffered from a few drawbacks, as PFE found by building experimental cars (so did FGE). The bunkers used crushed or chopped ice, which took more time to fill; the center of gravity of the car was high; damage to bunker floors during loading was common, and thereby dripped water onto loads. The cars were also more expensive to build and maintain. And not least, with an overhead bunker, there was no place to put a heater in cold weather. Canadian cars had permanent ones under the floor, a weight penalty which U.S. operators were reluctant to pay.
Another factor is that the primary use of the Canadian cars was for export meat shipment to ports, in which cars might stand for a time waiting to be unloaded to a ship. Passive temperature uniformity was essential in that situation, and car fans obviously not easily workable. At that time, at least, produce shipment was much less prevalent in Canada (and the cars for it had conventional end bunkers). In the U.S., conventional bunkers and car fans enabled much faster cooling of produce loads which were not pre-cooled; moreover, the type of meat shipment prevalent in Canada was a rather small proportion of the U.S. traffic.
So in brief, yes, U.S. refrigerator operators DID know about and try the overhead bunker, but it was not as suitable for U.S. practice as for Canadian practice. If you would like to read more about this, there are citations to the professional railroad literature in the PFE book.
Tony Thompson Editor, Signature Press, Berkeley, CA
2906 Forest Ave., Berkeley, CA 94705 www.signaturepress.com
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