These were Elswick guns of Pattern CC.

Actual bore diameter of all British 4.7" guns was 4.724" (12 cm).

Gun Characteristics

Designation 4.7"/50 (12 cm) BL EOC
Ship Class Used On Minas Gerais, Bahia and Rio Grande do Sul classes
Possibly also used on river monitor Paraguacu
Date Of Design About 1908
Date In Service 1909
Gun Weight 3.316 tons (3.369 mt) including BM
Gun Length oa N/A
Bore Length about 236.2 in (6.000 m)
Rifling Length N/A
Grooves N/A
Lands N/A
Twist N/A
Chamber Volume N/A
Rate Of Fire 6 - 7 rounds per minute (?)


Type Bag
Projectile Types and Weights HE: 45 lbs. (20.4 kg)
Bursting Charge N/A
Projectile Length N/A
Propellant Charge 15.1 lbs. (6.85 kg) CSP2
Muzzle Velocity 3,000 fps (914 mps)
Working Pressure N/A
Approximate Barrel Life N/A

Mount/Turret Data

Designation Single Pedestal Mountings: Minas Gerais (22)
Weight N/A
Elevation -10 / +20 degrees (?)
Elevation Rate Manually operated, only
Train about -80 / +80 degrees
Train Rate Manually operated, only
Gun recoil N/A


Data from:

  • "Naval Weapons of World War Two" by John Campbell