From: Edgewater, MD
Good catch, Buck. In the game, the older USN CAs (excl. New Orleans) and the Brooklyns get the tower armor reduced to 0 in later upgrades.
I have checked a couple of books about cruisers and googled as well, but find only references about changes to masts, adding open bridges, landing a catapult etc. but no removal or changes to conning towers / pilot houses.
Don't know the why's or wherefor's but...
From Matt's link -
Note on WWII modifications: All ships in service through WWII were
extensively modified. Modifications generally consisted of additions of
new weapons, radars and open bridges, and corresponding reductions as
weight compensation. Large numbers of 20 and 40 mm AA guns were added,
replacing .50 cal and 1.1 inch weapons. Superstrucutures were cut down to
open sky arcs for AA weapons and as weight compensation, new open bridges
were added, and masts were cut down or removed. Many ships lost one of two
seaplanes and catapults; boats and boat cranes were removed. Conning
towers and splinter protection were reduced as weight savings; new gun
directors were fitted, turret rangefinders were removed. Flammable
material was removed wherever possible. Modifications were generally done
after major battle damage or during major overhauls, and were done in
stages. Thus, a few ships were not fully modernized, and the details of
modernization varied from ship to ship. Omaha class modernizations were
kept to a minimum, as the ships were totally obsolete, they were
decommissioned immediately after the war ended. Most of the other ships
were decommissioned in 1946, with the last going to reserve in early 1947.
All of these ships were dramatically overweight by 1945.
Here's a link to: Treespider's Grand Campaign of DBB
"It is not the critic who counts, .... The credit belongs to the man who is actually in the arena..." T. Roosevelt, Paris, 1910