 The 3-inch guns were all on pedestal mounts; the 90 mm AMTB batteries were authorized two fixed guns and two towed guns.Rockaway Point had AMTB 20 with two 3-inch M1902 guns and AMTB 21 with four 90 mm guns.All six 3-inch guns for these batteries came from Battery Catlin at Fort Wadsworth, and AMTB 18 was also called Battery New Catlin.