With recent acquisitions of modern warships by multiple nations, and the inflated state of the United States Navy after the Civil War, the Nicaraguans were worried about their own security and economic share in the Caribbean. To that end, they approached the British (the world's top builders of warships for foreign nations.) The design agreed upon was based on preliminary design studies for British colonial gunboat monitors, and displaced roughly 3,500 tons. At 225 feet, she was a stubby little craft, but a stable gun platform in the relatively calm waters off the Nicaraguan coast. In fact, her maiden voyage across the Atlantic for delivery was the most harrowing ordeal for her crew. She was, for a while, the most powerful warship in the service of any Central or South American nation, and even the Americans were eager to observe her on maneuvers. That being said, she was also extremely costly for the navy, and a strain on national resources, despite the nation being in a relative industrial boom time as a result of the Civil War and the economic improvements that resulted from it.
The Walker carried an armament of 4 main guns of 10-inch caliber, arranged symmetrically in twin turrets fore and aft. Manufactured by the Royal Arsenal in Great Britain, they fired
a 400-pound (181. 4 kg) shell to a maximum range of 6,000 yards (5,500 meters) at a muzzle velocity of 1,364 feet (416 meters) per second. The turrets were revolved by steam machinery powered by the engines, and the guns could be withdrawn into the turret and depressed to reload through the muzzle via hydraulic ramming. Secondary armament consisted of nothing but a pair of 12-pounder smoothbore muzzle-loaders that were mounted upon arrival in Nicaragua, replaced in the 1880's by a quartet of Gatling machine guns for defense against the emerging threat of torpedo-armed boats. Defense against this threat was strengthened again in the 1890's with the replacement of the Gatling guns by 6-pounder Hotchkiss guns and the addition of a pair of 3-inch swiveling guns.
Armor was based on the same scheme as contemporary British monitors, with the waterline belt armored with around 6-8 inches of steel, the breastwork being approximately 10 inches thick, and 10-inch armor on the turrets as well. She was also fitted with an armored deck of 1.25 inches thickness. Armored shutters 2.5-inches thick closed over the gun ports during reloading and non-combat situations, and gratings in the funnel prevented any debris or shrapnel from crippling the boiler plant below. One of the biggest design faults was that the deckhouses on the uppermost deck were completely unarmored and vulnerable to enemy fire, an issue made even more grave by the fact that the command staff used these structures during combat situations.
Propulsion was based around a steam plant manufactured by Maudslay Son and Field, and consisted of a pair of compound steam engines. These were driven by 4 coal-fired rectangular boilers, also manufactured in England. The machinery also served to drive the revolving mechanisms for the turrets. She could make 10 knots under good conditions, with 7 being the economical steaming speed. In total, the plant developed 1,750 horsepower driving two shafts.
The ship was delivered in 1871, and after a harrowing voyage across the Atlantic to reach Nicaragua, she engaged in a cruise around Central America, the United States, and the Caribbean. Her service career was quiet for the initial years, after which she was called into action to shell coastal towns in Honduras. For the rest of the war she served as a support vessel for landings on the Honduran coast, and even housed the Nicaraguan admiralty command staff during amphibious operations. After this, she was refitted at the Naval Yard in Puerto Cabezas, receiving the aforementioned Gatling guns on her uppermost deck around the funnel and deckhouses. She remained in this state until the 1890's, when she was fitted with new machinery and a larger funnel, as well as 4 x 6-pounder Hotchkiss QF guns and a pair of 3-inch guns on her lower deck to port and starboard. She was maintained in service until 1910, when she was deactivated and placed on reserve. By now the guns had been replaced with 8-inch guns of American make in new twin turrets. She was grounded on a sand bar outside Puerto Cabezas in 1917 when Nicaragua joined the USA in the First World War. In this position she acted as a stationary battery, and her masts and funnel had been cut down and replaced with a single larger mast amidships for carrying the gun directors. After a few years in this position, anything of value was taken off her and she was blown up by the Engineer Corps.
---The refitted version of the Walker will be posted as a separate entry.---