Gunboats For The Paraguayan War

-The Yacare (Jacare) class gunboats were ordered under the 1900 fleet program as a security measure on the nation's inland waterways, such as the Amazon River. The admiralty also planned them for use against Paraguay, Brazil's biggest target for expansion. The Paraguay River was Paraguay's only supply line, and all water traffic came in and out of it, thus making it an objective of extreme strategic significance. The Imperial commanders knew that a fleet of gunboats would be the only way of controlling the river effectively, and thus 16 of the Yacare class vessels were laid down in local yards from Rio to Porto. Their construction and the construction of their associated equipment would all take place locally, serving as a significant boost to Brazilian technological prowess and national prestige. These boats were patrol craft for the most part, and were armed accordingly. Two 3-inch (75-mm) guns were placed fore and aft, based on a design from the British Vickers company. A license-made Hotchkiss 1-pounder gun was fitted on the aft of the superstructure for close-in firing missions. Driving the ship to the specified speed was a single vertical triple expansion engine developing roughly 2,500 horsepower driving a single shaft. Steam was provided by a pair of cylindrical high-pressure coal-fired boilers made by the machine works in Rio De Janeiro. The last of the 16 boats was launched in 1902, after 2 years of building the entirety of the class. 


-During pre-invasion analysis of Imperial strategy and taking inventory of the available weapons systems, it was found that Brazilian river forces would encounter heavy resistance from nearly-impregnable Paraguayan river forts. These forts had been constructed during the 1880's and 90's, but had been recently renovated with European artillery and communication systems, as well as structural reinforcement in anticipation of a war. The admiralty knew that they would be unable to destroy the river forts with the firepower they had available in the gunboat fleet, so they opted for a new solution entirely. They contracted for another 12 gunboats, but this time they would be different. These gunboats were specifically engineered to destroy the river forts, and to do this job they carried much heavier ordnance than anything yet seen on a gunboat in South America. To ease construction, the Empire took advantage of what they already had, recycling the hull from the Yacare-class in order to accommodate the new equipment and ordnance. Several changes to the hull were made, however, in order to make the change possible. While the same machinery was used, it was moved farther back, along with the funnel, and a new shaft arrangement was worked out, taking into consideration the slightly deepened draft. As with their predecessors, they were totally unarmored, except for in this case the light armor on the gun shield. The admiralty had originally planned for 6-inch guns, but after careful consideration, opted to mount an 8-inch ordnance piece, as they knew it would be capable of annihilating the forts at a far faster rate than any lighter piece. It would also offer longer range and more firepower than a 6-inch gun, allowing the relatively unarmored and slow gunboats to keep away from any artillery on the fort's ramparts. All 12 gunboats were completed in 1907, and ready for war the same year, joining the massive gunboat taskforce that was setting sail for the Paraguay River.