Shelf Oddity 1/700 USN 1.1”/75cal “Chicago Piano” AA Guns 

by Dan Kaplan 
This U.S. Navy close-range anti-aircraft weapon was designed in the mid-1930s as a replacement for the M2 .50cal Browning machine gun.  It was meant to engage enemy aircraft at a longer ranger than possible for the Browning. It mounted 4 barrels, each with a bore of 1.1inches and a barrel caliber of 75 (82.5inches). The four barrels were required to duplicate the rate of fire of the Browning weapon.

Development was a lengthy process, and the weapon remained problematic even after placed into service in 1936. It was prone to jamming, and clearing a jam was both difficult and time-consuming. Plus, the multiple loaders had to work in very close proximity to each other, often hampering reloading. Production was slow, and the gun did not appear in quantity for fleet wide distribution until 1940. 

Nonetheless, approximately 1000 units were produced and distributed in small quantities to individual ships throughout the fleet. Its deficiencies were recognized almost immediately, and these guns were replaced by more dependable, powerful, and more easily produced 20mm Oerlikon and 40mm Bofors mounts as soon as these units became available in quantity in 1942—43. 

Review Item
There are but a handful of 1/700 photoetch and 3D printed versions of this mount available as aftermarket items from various manufacturers. Shelf Oddity of Poland happens to offer an extremely well-defined 3D printed version of this mount in this scale. SO1-1A
SO1-1B SO1-1C SO1-1D SO1-1E SO1-1F

A medium grey resin wafer holds twelve sets each of the barrel assemblies and the mounting carriages.  Both the barrel assemblies and carriages are very finely scaled and detailed. There are top loaded reload clips mounted into the rear end of each barrel, and the bases included both seats for the gunners and what may be foot pedals. 

The set arrives packaged with the resin wafer sitting within a clear plastic tube. Care must be taken when removing the parts from the wafer as they are very fragile. It appears that the mount can be posed at different elevations. While there are no instructions provided, one merely has to go to the Shelf Oddity website and find the item to see completed examples.

These mounts are particularly well done and a welcome addition to any 1/700 USN kit in an early war fit. Mk.49 directors for these mounts, with tubs, can also be purchased separately from Shelf Oddity. 
Highly recommended.

At the current exchange rate, the set costs approximately US$9.80. The item # is SO700126. This item can be purchased directly from the Shelf Oddity website: 
Many thanks to Shelf Oddity for providing a review set.

More of Dan Kaplan's work.
Updated 1/4/2021