Modeling open ice hatches on refrigerator cars

Many prototype photos of freight trains or freight yards reveal some refrigerator cars with ice hatches latched open. This represents what the Protective Services Tariff called “ventilation service,” and it meant that ice was not placed in the bunkers, but the cooling of outside air was considered sufficient for the perishable cargo. A frequent case was onions, which are preferably shipped at temperatures well above refrigeration temperature, and so will travel all right under vent service.

     in this connection, I can’t resist mentioning that contrary to modeling legend, cars with hatches latched open are not “empties being dried out,” but are loaded cars with cargoes in vent service instead of iced. In fact, three different retired PFE people I interviewed all said they had never even heard of cars being “dried out” that way. Some railfan photographers have also been guilty of this belief, and have captioned photos of cars in vent service as “empties.”

     That said, you may need a few cars exhibiting vent service, if you model a somewhat cooler part of the year (spring or fall), or model perishable traffic which falls into the frequent use of vent service. A longer discussion of this situation is in the PFE book (Pacific Fruit Express, 2nd edition, by Thompson, Church and Jones, Signature Press, 2000), but a brief summary was presented in a previous blog post, discussing packing house and shipping practices. I included the U.S. Dept. of Agriculture shipping temperature table (you can see it at: http://modelingthesp.blogspot.com/2011/08/few-words-on-packing-houses-and-produce.html ).

     So let’s assume you would like to roster a few reefers, whether PFE or not, which are visibly in vent service. There are two keys to modeling open ice hatches to make them look right. First, the hatch plugs should be evident on the underside of the hatch cover, whether it is wood or steel. The steel ice hatches in Red Caboose kits have a hatch plug molded underneath, which only has to be touched up with a canvas or light gray color (more on this below). Second, though only a glimpse of the car interior is possible, it is still necessary to install a view block to represent the bunker bulkhead (I tried to omit this on a previous model and was not happy with the result), and the bunker interior walls need to be gray (they were usually galvanized steel, which oxidizes light gray).

     Here are a few photos to show the prototype, all PFE photos from my collection. First, the interior of an ice bunker, sheathed with galvanized sheet. This is from a steel car, but wood-sheathed cars had ice bunkers like this too. The openings at the top are the external ice hatches. The racks at the bottom are for stage icing; they can be moved up to half height so as to use less ice (many PFE cars after 1940 were equipped for stage icing).

     Next, here is a view from inside the car during rebuilding, with the “bunker sheet” of steel in place, with air circulation vents top and bottom, but without the “pad,” the wood bulkhead with insulation and sheathing, which forms the inside bunker wall. The perforated steel sheet you see here is galvanized. When completed, this will be a “convertible” bulkhead, which can be rotated to one side to permit use of the entire car interior for loads in ventilation service, or for non-perishable backhaul loads. The photo was taken at Roseville on March 25, 1944, during rebuilding of Class R-30-19.

     When the hatches were latched open for “vent” (ventilation) service, they were not open very far. This photo shows a Class R-30-19 car, with the latch extended as high as it can go. Plugs are visible underneath the hatch cover, as are the hooks which permit locking the hatch from inside. Some modelers make the mistake of setting the hatches at 45 degrees or steeper, which clearly is not prototypical.

     Any number of refrigerator car kits down through the years have mentioned modeling the ice hatches open. I did that with a Tichy kit for a PFE Class R-40-4 car, and it looks all right, though to me has been a headache because the very thin hatch cover latch bars are fragile, and in ordinary layout operation, sooner or later some of them break off.

Seen in profile (below), the foreground Tichy latch is full length and looks great, but at the moment is the only surviving full-length one on the model. The angle here is about right, and thus the latch bar really is too long. Note plugs underneath.

     Another way to do this is to use something much stronger than thin styrene for latch bars. I used flat brass wire in modeling open hatches on an Athearn reefer. If anything, these are probably too steeply open.

And, as the next photo of the same car shows, I also added styrene blocks underneath the hatch covers to represent the plugs. The locking hooks were not modeled on this car, and again, the latch bars are too long.

Seen in profile, the angle of the open hatch is a little too steep.

     I mentioned the Red Caboose cars with steel ice hatch covers earlier in this post. I assembled a kit for one of these cars, a process in which there is nothing out of the ordinary, except that I chose to model ice hatches open in vent service. I will show how I did that. 

     I think that modeling the internal bulkhead is most easily done with a sheet of styrene, made as a slip fit into the car interior. Ice bunkers were about 3-1/2 feet long. I used 0.015-inch thickness sheet, with a corner reinforcement at the bottom. The photo below shows these bulkheads inside the car, notched to clear the roof, and already painted acrylic Neutral Gray. Also visible are my usual car weights, a pair of 5/8-inch steel nuts, which weigh about an ounce each, attached with canopy cement. (If you’re not familiar with this adhesive, you might like to read my discussion and explanation about it, which is at: http://modelingthesp.blogspot.com/2013/05/a-few-words-in-praise-of-canopy-glue.html .)

     As I mentioned, the Red Caboose steel hatches have plugs molded underneath. I simply painted these light gray while still on the sprue. To me, these are pretty thin and offer marginal realism, but at least they are there.

    I carefully built the roof subassembly with hatches open to the top notch on the latch bar. Again, this is probably too steep and I will adjust in future models.

Also evident in this view is the minimal thickness of the plugs, but again, they are okay to give the impression that something is under there. Next time, though, I will also thicken the plug area
     Probably the ultimate in this topic is hatch covers which are not even attached. Why model them that way? So I can show hatches entirely open, as for icing, or simply set them in place for closed hatches. This photo shows an Athearn car with the hatches closed at one end, open for icing at the other. All four hatches, as I said, are unattached to the car. You may wish to click on the image to see the locking hooks on the open hatch covers.

     This brings me to the end of what I wanted to say on these interrelated topics about ice hatches, when modeled in the open position. I enjoy having a few cars that way, though they normally wouldn’t be spotted as empties to be loaded (the hatches usually would be latched open after the car is loaded). In most cases, I stage them onto the layout, to serve as loaded cars to be picked up, or operate them in mainline trains only. But they definitely offer a nice variation in the reefer fleet.
Tony Thompson