The Ju-52 was used as a bomber in the Spanish Civil war, and in Polish campaign. Did it have a bomb bay, bomb racks, bombs thrown out the door , or something else?
I wish the historyofwar.org site the mlees found had a bit more support.
I was unable to find any other site that described the actual way that bombs were carried. However, two (inconclusive) points make me tend to doubt the bomb bay claim.
The weaker of the two is that several sites mentioning the use of Tante Ju in Spain seem to imply that the same planes were used both as bombers and transports. A genuine bomb bay, with internal vertical racks and the hardware to open and close belly doors would have been a pretty nasty restriction to put on a transport. “Modular” construction (providing for the racks to be inserted and removed with a minimum of hassle were not common design features in the 1930s. (As I say, that is the weaker protest.)
The stronger of the two are photos of the actual plane in service. In this photo of a Ju-52 releasing a bomb, there is no evidence of bomb bay doors opened beneath the fuselage. On the other hand, just visible to the right of the starboard wheel, is what appears to be the “cage” support for the “dustbin” ventral defensive gunner position that was lowered from the fuselage to provide protection beneath the plane. The same sort of gun tub may be seen in this photo, just aft the wheels. Unfortunately for a bomb bay design, the gunner is sitting below the plane at exactly the best location in which to place a bomb bay, balanced at the center of gravity and structural support where the wings intersect the fuselage. With a gunner in that location, a bomb bay would have to be moved farther aft, jeopardizing the plane’s center of gravity when the bombs were released.
Now, my evidence is not conclusive. In the photo of the plane dropping the bomb, it might have been dropping a secondary bomb from a rack (so that the bomb bay doors did not need to be opened) or the Ju-52 might have had some sort of rack-and-pinion door gears that snapped them shut the instant a bomb was released.
Similarly, the gun tub might appear to be in the “wrong” place due to odd perspectives in old, grainy photos.
Still, I am guessing that external bomb racks, (which, I confess, I cannot make out in either photo), still seems more likely.