Seems to me she was upgraded so she could handle the new 5 inch dual purpose guns, 40mm Bofors, 20mm and radar and communications. Her WWI minded builders design had to place in the new type of warfare that was unleashed during the bombing of Pearl Harbor.

Mark

What was done is understandable, the questions is the timing and the why.
The Nevada was seriously damaged at Pearl Harbor, so the updated superstructure & armament was understandable.
But if you look at what was done to the other "Standard" battleships at the time, the New Mexico class (USS New Mexico, USS Mississippi, and USS Idaho), the Tennessee Class (USS Tennessee), and the Colorado Class (USS Colorado, USS Maryland,) that suffered little or no damage from Pearl Harbor, none of them received the amount of rebuilding that the USS Pennsylvania had until much later in the war. In fact, some never received the twin 5" guns or radar upgrades. Only the USS California and the USS West Virginia received the complete rebuild with the "South Carolina" style superstructure and later model radar systems.

Bottom line - there seems to be no reason for the level of rebuilding that the USS Pennsylvania received given that it sustained little damage. None of the later class ships were needed more then she was yet they were not upgraded as much. Several of my books on US Navy battleships remark on the lack of upgrading the later ships, particularly the New Mexico and Tennessee classes received. But I have never read anything about the decisions made as to which ships were rebuilt.

I've always thought the USS West Virginia was rebuilt, not because she was needed - practical thought would have been to scrap her - but because she was a symbol. She was rebuilt and she took part in the surrender of Japanese forces. Also, because she had the latest radar, at the Battle of Surigao Strait, she apparently hit the battleship Yamashiro with her first salvo.

Pennsylvania sustained very little damage. Nothing to fix before rebuilding, making for a potentially quicker turnaround. Sister to the Arizona, so that might have been a motivator. Politics maybe involved? Lots of Naval yards in Pennsylvania. Once the first few were done and so many ships were being built they may have figured that it wasn't necessary to rebuild everything. Carriers were doing the fighting and by 1943 battleships were offshore artillery, a job that cruisers and 8" guns seemed to do better at. All of this is conjecture on my part.

This seemed like an intriguing question which peaked my interest so I went down to the dungeon and sifted through my tomes of ancient knowledge and came up with Norman Friedman's "U.S. Battleships, An Illustrated Design History". A review of Friedman seems to indicate that actually very little was done to Pennsylvania in the months shortly after Pearl Harbor. On page 357, for anyone with a copy of this hefty reference, there is a very good close-up shot dated 2 March 1942 of the bridge portion of the ship (starboard side) that shows the addition of splinter shields for the single mount 5"/25s and a tub w/ 1.1" AA abaft of the no 2 main turret. The only other change seems to be an enclosed Mark 19 director and numerous single mount 20mm guns placed on any available deck space. She still retains the 5"/51 single purpose casement guns at deck level in this shot. On page 372 there is a photo dated 1 August 1943 that shows Pennsylvania after a major refit (probably 1st half of 1943) with the addition of twin mount 5"/38 duel purpose guns and the removal of much top hamper to clear AA firing arcs and save weight for all the additional AA. She seems to have had a final refit in the first half of 1945 to update radar and add even more AA. Sorry for not including some photo examples, but ever since the Photobucket debacle I been remorse in keeping up with events at Kit Maker and haven't figured out how to work around the problem. Hope this sheds some more light on the issue.

Why is it so hard to accept that the former fleet flagship, with it expansive flag bridges and plots, added comms gear, etc., had value as an amphibious flagship and bombardment gunship?

Secondly, your Pennsylvania post-Pearl Harbor "major overhaul" contention doesn't hold water. The Pennsylvania's war time improvements were made in a series of opportunistic small upgrades none of which came anywhere near her 21 month major modernization of 1929 - 1931. These included:

1. A short 11 day stay at Hunter's Point, 1/1/1942 to 1/12/1942 just to repair damage from the Pearl Harbor attack.

2. An approximately 6 month Mare Island refit, added AA, forward tripod removed and replaced with deck house. Stripped of turret top catapults, large boat cranes, and conning tower. This was the largest post-Pearl Harbor refit.

3. Many small "renew and refresh" maintenance periods - like a week in the floating drydock ABSD2 at Seeadler Harbor, Manus.

4. A 4 month March to June 1945 Hunters Point upgrade - replaced worn out main and secondary armament, add more AA, radar, etc.

I contend that the short #2 and #4 refits in no way constitute the "major rebuild" that is at the heart of your contention. I list below what was done in the 1929 - 1931 major modernization as a basis for comparison.

And why wouldn't you use the same extended deck house as Nevada when the 5"/38 twins we added? Gave better firing arcs and you worked from a common design set of drawings - saves time, less mistakes. There would be no value, especially under the pressure of war, to re-invent the wheel and create a unique design if a common design fit!

1929 - 1931 refit
- Increase deck and turret roof armor
- Added anti-torpedo bulges
- Added additional inner bottom under boiler rooms
- Added additional 30 lb anti-torpedo bulkhead outboard boiler rooms
- Replaced Turbine Generators with new TGs
- Installed new steam turbines
- Installed new small tube boilers boilers (replaced large tube
- Increase main battery elevation
- Reduced 5"/51 battery - all hull guns removed, 10 remounted in deck house,2 on top
- Replaced 3" AA with 8 x 5"/25
- Removed underwater torpedo tubes
- Removed cage masts and replaced with tripod masts
- Enlarged bridges and flag facilities
- Installed two catapults
- Accommodation substantially increased to 2037