I was able to take a little time yesterday to photograph the steam A/C details under former Southern Railway coach 817. This car is now in private ownership and is undergoing restoration in Oak Ridge, TN. I have attempted to identify the components
based on the Safety Car diagram that George Eichleberger posted from the SRHA archives. I’m no expert on steam A/C, but I believe most of my assumptions are reasonable. If anyone has any corrections, please feel free to make them.
I’m using the mechanical standard that when you stand in the gauge facing the car on the B end (vestibule end in this case)the left is on your left and the right is on your right to refer to locations of items. Descriptions are below pictures.
This photo has been cropped and blacked out to show The overall layout of the underbody details to be covered. In this picture, the descriptions will move from right to left.
As you walk along the left side of the car, the first item you come to is this box. I expect it originally had a cover. Who knows when it was removed. Inside the box, moving from right to left, I believe the cylinder shaped object is the flash tank. The
item to the left appears to be a pressure reducing valve. And outside and to the left of the box is what I believe to be the motor operated valve.
The next item on the left side is a very large box. This box is missing the cover which seals roughly 1/3 of the front. Based on the top photo this may have been a screen cover. Moving right to left, the steam line comes in at the top of the box and enters
the steam ejector and evaporator. It can be seen wrapped in foam insulation. The motor mounted on the bottom of the box turns a pulley to run the condenser fan which is on the left.
The next part of the box (roughly 2/3 of the total length) still has a cover. I didn’t take it off, but I’m pretty certain it contains the refrigerating unit and condenser. Air blows from the condenser fan on the right and is ducted through here into
our next box below.
This box appears to be complete and is the last of the items easily visible on the left side. This is the exhaust for the condenser fan. You can see it is connected to but not part of the large box partially visible to the right.
This photo is looking underneath this large box. At the back of it under the refrigerating unit and condenser is a sump tank. It’s shown on the diagram but not labeled.
Now we’ll take a stroll down the right side of the car. It should be noted that all of the equipment is on the left side of the center will, but items behind the large boxes are visible from the right side.
There are two pumps in this system. The condenser water spray pump is shown on the right. It’s located behind the big box and is connected to the sump on the condenser. Partially visible on the left is the cold water pump.
This is the cold water pump. The two pumps appear to be identical although they are mounted differently. This one has the motor mounted to the right and the condenser water spray pump is mounted with the motor on the left. Just to the left is a rusty item
that appears to be the float valve along with its paraphernalia.
Funny crop, but this shows the Items visible on the backside of the boxes. Right to left we see the end of the water tank shroud. Next two steam traps or regulators or whatever you want to call them are seen pointing straight down. The end of the sump
is visible with a drain plug. On the back of the sump is the condenser spray pump, then the cold water pump. Visible just beyond them are two more steam traps.
One of the steam traps. This type was very common in lightweight equipment. Superfluous details were marked out for clarity.
So there it is. The visible steam A/C parts on a Southern Budd coach. I think the important thing to note here is that the schematic shows how the system worked and how items were arranged in relationship as to how the steam, water, and air flowed. However
I think we see here that items were assembled in order to fit the area given and the schematic is for reference not physical location info. I’ll also point out that the layout could differ not only between types (coach vs dining car vs coach/lounge) but also
between cars of the same type. Always check photos of a particular car to ensure correct placement.
The SRHA archives is full of information about Southern’s passenger equipment along with diagrams and photos. I would encourage everyone to at least make a small donation to the organization to help preserve this info for future generations.