The design chronology runs from conception in 1881 to laying down in 1883, launch in 1885, and completion in 1887. The cited particulars are 4,050 tons displacement, 315 feet in length, a 46-foot beam, and a 19-foot-6-inch draught. The ships combined two 8-inch guns with ten 6-inch weapons, with the 6-inch battery providing most of their practical firepower. The fore-and-aft heavy guns, broadside weapons, and unused sailing rig show how many design traditions overlapped in this period. Direct-acting compound engines drove twin screws to 17 knots rather than using the newer triple-expansion machinery. Their cited 8,750-mile range at 10 knots far exceeded that of HMS Warrior and made the class much better suited to distant stations.
Chapter · 4:08-8:47
Mersey-class guns, machinery, and range
A design tour covers two 8-inch guns, the 6-inch battery, compound engines, 17-knot speed, and the long range needed for overseas service.