Editing Indiana-class battleship (section)

== Design ==

[[File:USS Oregon 1893 USNHC NH 76619 010332.jpg|thumb|Outboard profile of ''Oregon'', with position and arc of fire of the armament|alt=drawing schematic, showing two large turrets before and aft and four smaller turrets on wing positions midships]]

=== General characteristics ===

The ''Indiana''-class ships were designed specifically for coastal defense and were not intended for offensive actions.{{sfn|Scientific American|1896|p=297}} This design view was reflected in their moderate coal endurance, relatively small displacement and low freeboard, which limited seagoing capability.{{sfn|Gardiner|Lambert|1992|p=121}} However, they were heavily armed and armored, so much in fact that ''Conway's All the World's Fighting Ships'' describes them as "attempting too much on a very limited displacement."{{sfn|Chesneau|Koleśnik|Campbell|1979|p=140}} They resembled the British battleship {{HMS|Hood|1891|6}}, but were {{cvt|60|ft}} shorter and featured an intermediate battery consisting of eight 8-inch guns not found in European ships,{{sfn|Gardiner|Lambert|1992|p=121}} giving them a very respectable amount of firepower for their time.{{sfn|Reilly|Scheina|1980|p=52}}

The original design of the ''Indiana'' class included [[bilge keel]]s, but with keels they would not fit in any of the American drydocks at the time, so they were omitted during construction. This meant a reduction in stability and caused a serious problem for ''Indiana'', when both main turrets broke loose from their clamps in heavy seas a year after being commissioned. Because the turrets were not centrally balanced, they swung from side to side with the motion of the ship, until they were secured with heavy ropes. When the ship encountered more bad weather four months later, she promptly steamed back to port for fear the clamps would break again.{{sfn|Reilly|Scheina|1980|p=59}} This convinced the navy that bilge keels were necessary and they were subsequently installed on all three ships.{{sfn|Reilly|Scheina|1980|p=60}}

=== Armament ===
Given their limited displacement, the ''Indiana'' class had formidable armament for the time: four 13-inch guns, an intermediate battery of eight 8-inch guns and a secondary battery of four 6-inch guns, twenty [[QF 6 pounder Hotchkiss|Hotchkiss 6-pounders]], and six [[QF 1 pounder pom-pom|Maxim-Nordenfelt 1-pounders]], as well as six{{efn|name=torpedo}} [[American 18 inch torpedo|18 inch (450 mm)]] tubes.{{sfn|Reilly|Scheina|1980|pp=54–55}}

[[File:USS Indiana (BB-1) - NH 52653.jpg|thumb|left|alt=several men stand on deck next to a large turret, with a smaller one visible in the background|The forecastle of ''Indiana'', showing its fore 13-inch turret and one of the 8-inch turrets]]

The 13-inch gun was 35 [[Caliber (artillery)|calibers]] long and used [[black powder]], giving a range of about {{convert|12000|yd}} at 15 degrees of elevation. At {{convert|6000|yd}}, a shell was expected to penetrate {{convert|10|-|12|in}} of side armor.{{sfn|NavWeaps 13"/35 (33 cm) Marks 1 and 2}} The four guns were mounted in two centerline turrets, located fore and aft. The turrets were originally designed to feature sloping side armor, but space requirements made this impossible without using significantly larger gun turrets or redesigning the gun mounts (which was later done for the {{sclass|Illinois|battleship}}s).{{sfn|Reilly|Scheina|1980|p=55}} The ships' low freeboard greatly hindered the use of the main battery in rough weather conditions, because the deck would become awash. Also, because the ship lacked a counterweight to offset the weight of the gun barrels, the ship would [[List (watercraft)|list]] in the direction the guns were aimed. This reduced the maximum arc of elevation (and thus range) to about five degrees, brought the main armor belt under water on that side, and exposed the unarmored bottom on the other. It was considered in 1901 to replace the turrets with new balanced models used in later ships, but that was decided to be too costly as the ships were already obsolete. Instead, counterweights were added, which partially solved the problem. The hydraulic rammers and turning mechanisms of the 8-inch turrets were also replaced by faster and more efficient electric equivalents, new sights were fitted on ''Indiana'' and ''Massachusetts'', and new turret hoists were installed to improve the reloading speed,{{sfn|Reilly|Scheina|1980|p=62}} but the gun mountings never performed in an entirely satisfactory manner.{{sfn|Gardiner|Lambert|1992|p=121}}

The eight 8-inch guns were mounted in pairs in four wing turrets placed on the superstructure. Their [[arc of fire]], although big on paper, was in reality limited. Adjacent gun positions and superstructure would be damaged by their muzzle blast if the gun was trained alongside it, a defect also suffered by the 13-inch guns.{{sfn|Reilly|Scheina|1980|p=60}} The smaller 6-inch guns were mounted in twin wing [[casemate]]s midships on the main deck level, with a 6-pounder in between. The other Hotchkiss 6-pounders lined the superstructure and bridge decks. Four of the 1-pounders were placed in hull casemates at the bow and stern of the ship and two more in the [[fighting top]]s of the masts.{{sfn|Reilly|Scheina|1980|p=52}} In 1908, all the 6-inch and most of the lighter guns were removed to compensate for the counterweights added to the main battery and because ammunition supply for the guns was considered problematic. A year later, twelve [[3"/50 caliber gun|{{convert|3|in|adj=on|0}}/50-caliber]] single-purpose guns were added midships and in the fighting tops.{{sfn|Reilly|Scheina|1980|p=62}}

Sources conflict on the number of torpedo tubes originally included in the ships,{{efn|name=torpedo}} but it is clear they were located on the [[berth deck]] and had above-water ports located on the extreme front and aft and midships. Located too close to the waterline to allow use while moving and vulnerable to gunfire when opened, they were considered useless and were quickly reduced in number, and removed entirely before 1908.{{sfn|Reilly|Scheina|1980|p=62}}
 
In 1918 there was a proposal to modify the three ''Indiana''-class ships to carry a single 98-caliber {{convert|9|in|mm|adj=on|0}} gun built by lining down a 50-caliber [[14"/50 caliber gun|{{convert|14|in|mm|adj=on|0}} gun]] to that size. Preliminary design of the turret for the gun was completed in October for service in mid-1919, but the end of the war the following month caused the program to be converted into a test program for long-range guns. The [[Bureau of Ordnance]] decided to first test a [[7"/44 caliber gun|{{convert|7|in|mm|adj=on|0}} gun]] lined down to 3 inches as a proof of concept, but those tests did not commence until 1922.{{sfn|Wright|2007|pp=143–145}}

=== Protection ===
With the exception of the deck armor, 8-inch turrets and [[conning tower]]—which consisted of conventional nickel steel—the ''Indiana'' class was protected with the new [[Harvey armor]]. Its main protection was a belt {{cvt|18|in|0}} thick, placed along two-thirds of the length of the hull from {{cvt|3|ft}} above to {{cvt|1|ft}} under the waterline. Beyond this point, the belt gradually grew thinner until it ended {{cvt|4|ft|3|in}} under the waterline, where the belt was only {{cvt|8.5|in}} thick. Below the belt the ship had no armor, only a double bottom. On both ends the belt was connected to the [[barbette]]s of the main guns with {{convert|14|in|adj=on}} armored [[Bulkhead (partition)|bulkheads]]. In the waterline sections outside this central citadel, compartments were filled with compressed cellulose, intended to self-seal when damaged. Between the deck and the main belt, 5-inch hull armor was used. The deck armor was {{cvt|2.75|in}} thick inside the citadel and {{cvt|3|in}} outside it. The hollow conning tower was a single forging 10 inches thick. The 13-inch gun battery had {{cvt|15|in}} of vertical turret plating and {{convert|17|in|mm|adj=mid|-thick}} barbettes, while the 8-inch cannons had only 6{{nbsp}}inches of vertical turret plating and {{convert|8|in|mm|adj=mid|-thick}} barbettes. The casemates protecting the 6-inch guns were 5{{nbsp}}inches thick and the other casemates, lighter guns, shell hoists and turret crowns were all lightly armored.{{efn|name=armor}}{{sfn|Reilly|Scheina|1980|pp=56, 58 & 68}}

[[File:Fire room Massachusetts.jpg|thumb|alt=Two dirty men feeding coal into an oven in a rather gloomy looking room| The fire room (boiler room) of ''Massachusetts'']]

The placement of the belt armor was based on the [[draft (hull)|draft]] from the design, which was {{convert|24|ft}} with a normal load of {{convert|400|LT|t ST|0}} of coal on board. Her total coal storage capacity was {{convert|1600|LT|t ST|0}}, and fully loaded her draft would increase to {{convert|27|ft}}, entirely submerging the armor belt. During actual service, especially at war, the ships were kept fully loaded whenever possible, rendering her belt armor almost useless. That this was not considered in the design outraged the Walker policy board–convened in 1896 to evaluate the existing American battleships and propose a design for the new {{sclass|Illinois|battleship}}s–and they set a standard that the load of coal and ammunition that future ships were designed for had to be at least two-thirds of the maximum, so similar problems would be prevented in new ships.{{sfn|Friedman|1985|p=29}}

=== Propulsion ===
Two vertical inverted [[triple expansion]] [[reciprocating steam engine]]s powered by four [[Scotch marine boiler#Double-ended|double-ended Scotch boilers]] drove twin propellers, while two single-ended Scotch boilers supplied steam for auxiliary machinery.{{sfn|Reilly|Scheina|1980|p=58}} The engines were designed to provide {{convert|9000|ihp|lk=on}}, giving the ships a top speed of {{convert|15|kn|lk=on}}.{{sfn|Friedman|1985|p=425}} During [[sea trial]]s, which were conducted with limited amounts of coal, ammunition and supplies on board, it was found that the indicated horsepower and top speed exceeded design values and a significant variation between the three ships existed. The engines of ''Indiana'' delivered {{cvt|9700|ihp}}, giving a top speed of {{cvt|15.6|kn}}. ''Massachusetts'' had a top speed of {{cvt|16.2|kn}} with {{cvt|10400|ihp}} and ''Oregon'' reached a speed of {{cvt|16.8|kn}} with {{cvt|11000|ihp}}.{{sfn|Reilly|Scheina|1980|p=68}} Eight [[Babcock & Wilcox boiler]]s, including four with [[superheater]]s, were installed on ''Indiana'' in 1904 and the same number on ''Massachusetts'' in 1907 to replace the outdated Scotch boilers.{{sfn|Reilly|Scheina|1980|p=62}}