Going back to the smoke cylinders on the aft galleries of Essex class ships, I have been doing a little research. Thank the lord for HNSA where I found information about "smoke" generators.
It seems that the smoke generators for DD and cruisers, the Mk1, four cylinder configuration and the Mark4, four cylinder configuration, had "smoke" tanks that were less than 70" in length and less than 16" in diameter. My nombers are not precise as the dimensions were given for the entire units, rather than the tanks. The reference publication does not list usage on any ships larger than cruisers.
However, the Ordnance Pamphlet does list the aircraft smoke generator tank. This is shown as being 67" in length/height and 19" in diameter. This would seem to be what we are seing in the photos.
Now, you may wonder why those tanks are stored/stowed on the gallery, rather than with the rest of the aircraft munitions. The answer lies in what those tanks contained. It develps that smoke generators Mk 1, 2, 4, and aircraft Mk 5, did not contain "smoke" but, rather liquid chemicals called FS.
http://www.hnsa.org/doc/smoke/index.htm#pg15Now, the tanks could leak, which was why all the ship and boat mounted generators had quick release levers so the units could be jettisoned. After use, the tanks were refilled from 55 Gal drums of the mixture. The smoke was corrosive enough that the generators had to be placed at least 24" from depth charges.
FS was a mixture of Sulphurtrioxide in Chlorosulfonic acid. The liquid was dispersed from the tanks by connection to the ship's high pressure air supply, in the case of the Mk 1 generator, or by a CO2 cylinder attached to the fluid tanks. When this chemical combination was sprayed from the holding tank, it reacted with water vapor in the outside air. This created the "smoke" and to quote, "In contact with the air it reacts with the moisture present to form a mixture of sulfuric and hydrochloric acid mist." In perhaps an understatement, it goes on, "Not only the smoke mixture, but also the smoke, is corrosive."