An article I was reading on reefers mentioned "half-stage" and "full- stage" icing but didn't define those terms. It sounded like some ice bunkers could be set up to receive only half a load vs. full load. Is it that simple? Why the need for a special rack, if that's what it is? Why wouldn't ice bunkers be loaded full -- shorter trip, less cooling, or??
Just a guess - perhaps a difference between keeping meat fresh and not freezing lettuce?
I would guess the special rack for a half load of ice is to keep the ice close to the roof. Cold air falls, so having the ice close to the roof would make for better cooling.
It might be the type of icing done as in a half stage being a short term icing to get the car to a major yard with a full icing facility ? In many cases ice had to be brought to a shipper or packing house in reefer cars where there was no ice plant. I would guess that in these cases they would only ice enough to get to the main icing plant.
Years ago an old man came to one of the open houses and struck up a conversation with one of our members. When the member found out he worked for the railroad as an icing platform supervisor, he was brought to me. I picked his brain for about two hours and listened to his stories for another hour of so. I wished I had a tape recorder and because of this I keep one at the club at all times. The older I get, the less older guys are around. I was dumbstruck when he explained all the different types of ice and different salt combos that went into each train.
This is one of the finest articles / explainations of icing that I have ever read.
Enjoy.
Refrigerator cars with "stage icing" have adjustable ice grates in the end ice bunkers. The ice grates can be set up:
1) near the bottom of the bunker in the "full stage position" to allow a maximum load of ice for maximum cooling of the load, 2) near the middle of the bunker in the "half stage position" to allow a smaller load of ice for reduced cooling of the load, or 3) can be left folded up when the car is used as a ventilator car for shipments in cool weather that don't require lower temperatures. PFE had stage icing on several classes of reefers, and noted it with small lettering "stage icing" near the car ends. Geezer
Hey, thanks! Great cite.
It is of more than passing interest that the brine dripping from these cars did harm to metal bridges, causing considerable expense... and that the salt water could interfere with signal operations as well. Mechanical refrigeration was a great cost-saving measure.
On Tue, 15 Aug 2006 07:23:48 -0400, Geezer posted in article ...
Many thanks for the details. It sounds like some reasonable form of temperature control could be achieved through appropriate combinations of mechanical air circulation fans, amount of salt, amount of ice, ice placement, and open/closed roof hatches. I suppose with the grates folded up, the car also could be used to haul other forms of clean lading, not just produce and meat.
This prompted me to order Thompson's PFE book.
Thanks also to the other responders.
Indeed. Guess it's time to install an ice dock and produce warehouse to generate some complexity.
Don't know about the impact on signaling, but I doubt brine releases from ice reefers would have a significant effect on bridges -- just not enough volume of brine from infrequent passage of reefer trains. Bridges along coastal areas with constant salt spray would be another matter.
Speaking of railroad bridge damage, I found this oops while tracking down info on creosote facilities:
Dripping brine meltwater was a no-no, which is why so many reefers were fitted with brine retention tanks.
and Maintenance Cyclopedia, page 671 "Floor systems in particular are subject to serious damage from corrosion resulting from the collection of brine drippings, coal particles, and cinders on their horizontal surfaces." It goes on to exhort inspectors to pay careful attention to areas where loss of metal would affect the carying capacity of the span.
In a signal maintainer's biography of his life spent working on Donner Summit he recounts how the passage of produce trains in the summer left a coating of salt on the ties and ballast. With the arrival of the winter rains, the rails would be shunted by the resulting brine and the signals would give false indications, sending him out on goose chases. I am sorry that I cannot now find the precise reference.
On 16 Aug 2006 09:47:02 -0700, video guy -
Thanks. Makes sense in conjunction with S leached from coal and cinders.
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