Editing USS Monitor (section)

==Design and description==
[[File:Monitor model2.jpg|thumb|left|upright=1.4|Model of ''Monitor'']]
[[File:USS Monitor plans.jpg|thumb|left|upright=1.4|alt=|Inboard plans of ''Monitor'']]

''Monitor'' was an unusual vessel in almost every respect and was sometimes sarcastically described by the press and other critics as "Ericsson's folly", "cheesebox on a raft"<ref>[[#Thulesius|Thulesius, 2007]], pp. 108, 113</ref><ref>[[#Bushnell|Bushnell, Ericsson, Welles, 1899]], pp. 17, 41</ref> and the "Yankee cheesebox".<ref>[[#McCordock|McCordock, 1938]], p. 103</ref> The most prominent feature on the vessel was a large cylindrical gun turret mounted [[amidships]] above the low-freeboard upper [[Hull (watercraft)|hull]], also called the "raft". This extended well past the sides of the lower, more traditionally shaped hull. A small armored [[pilot house]] was fitted on the upper deck towards the bow, however, its position prevented ''Monitor'' from firing her guns straight forward.<ref name=Tucker171/>{{efn|Ericsson later admitted that this was a serious flaw in the ship's design and that the pilot house should have been placed atop the turret.}} One of Ericsson's prime goals in designing the ship was to present the smallest possible target to enemy gunfire.<ref name=t8/> The ship was {{convert|179|ft|m|1}} [[long overall]], had a [[Beam (nautical)|beam]] of {{convert|41|ft|6|in|m|1}} and had a maximum draft of {{convert|10|ft|6|in|m|1}}. ''Monitor'' had a tonnage of 776 [[tons burthen]] and [[displacement (ship)|displaced]] {{convert|987|LT|t}}. Her crew consisted of 49 officers and enlisted men.<ref name=s9>[[#Silverstone|Silverstone]], p. 4</ref>

The ship was powered by a single-cylinder horizontal [[Marine steam engine#Vibrating lever|vibrating-lever steam engine]],<ref name=ck2/> also designed by Ericsson, which drove a {{convert|9|ft|m|1|adj=on}} propeller,<ref name=t8>[[#Thompson90|Thompson, 1990]], p. 228.</ref> whose shaft was nine inches in diameter.<ref>[[#Broadwater|Broadwater, 2012]], p. 128</ref> The engine used steam generated by two horizontal [[fire-tube boiler]]s<ref name=c4>[[#Canney|Canney, 1993]], p. 30</ref> at a maximum pressure of {{convert|40|psi|kPa kg/cm2|0|abbr=on|lk=on}}.<ref>[[#Thompson90|Thompson, 1990]], p. 227</ref> The {{convert|320|ihp|lk=on|adj=on}} engine was designed to give the ship a top speed of {{convert|8|kn|lk=in}}, but ''Monitor'' was {{convert|1|-|2|kn}} slower in service.<ref name=ck2>[[#Chesneau|Campbell, 1979]], p. 119</ref> The engine had a [[bore (engine)|bore]] of {{convert|36|in|mm|0}} and a [[stroke (engine)|stroke]] of {{convert|22|in|mm|0}}.<ref name=s9/> The ship carried {{convert|100|LT|t}} of coal.<ref name=ck2/> Ventilation for the vessel was supplied by two [[Centrifugal force|centrifugal]] blowers near the stern, each of which was powered by a {{convert|6|hp|adj=on}} steam engine. One fan circulated air throughout the ship, but the other one forced air through the boilers, which depended on this forced draught. Leather belts connected the blowers to their engines and they would stretch when wet, often disabling the fans and boilers. The ship's pumps were steam operated and water would accumulate in the ship if the pumps could not get enough steam to work.<ref name=t8/>

''Monitor''{{'}}s turret measured {{convert|20|ft|m|abbr=on}} in diameter and {{convert|9|ft|m|abbr=on}} high, constructed with {{convert|8|in|cm|0}} of armor (11 inches in front at the gun ports) rendering the overall vessel somewhat top heavy. Its rounded shape helped to deflect cannon shot.<ref>[[#Mindell|Mindell, 2000]], p. 41</ref><ref>[[#McCordock|McCordock, 1938]], p. 31</ref> A pair of steam-powered [[donkey engine]]s rotated the turret through a set of gears; a full rotation was made in 22.5 seconds during testing on 9 February 1862.<ref>[[#Thompson90|Thompson, 1990]], p. 226</ref> Fine control of the turret proved to be difficult; as there was no brake the steam engines would have to be placed in reverse if the turret overshot its mark, or another full rotation would have to be made. The only way to see out of the turret was through the [[Glossary of nautical terms (A-L)#gunport|gun ports]]; when the guns were not in use, or withdrawn for reloading during battle, heavy iron port stoppers would swing down into place to close the gunports.<ref>[[#Canney|Canney, 1993]], pp. 30, 80</ref> Including the guns, the turret weighed approximately {{convert|160|LT|t|0}}; the entire weight rested on an iron spindle that had to be jacked up using a wedge before the turret could rotate.<ref name="Thompson p. 225">[[#Thompson90|Thompson, 1990]], p. 225.</ref> The spindle was {{convert|9|in|cm|0}} in diameter which gave it ten times the strength needed in preventing the turret from sliding sideways.<ref>[[#Baxter|Baxter, 1933]], p. 256</ref> When not in use, the turret rested on a brass ring on the deck that was intended to form a watertight seal. In service, however, this proved to leak heavily, despite [[caulking]] by the crew.<ref name="Thompson p. 225"/> The gap between the turret and the deck proved to be a problem as debris and shell fragments entered the gap and jammed the turrets of several {{sclass|Passaic|monitor|3|warship}}s, which used the same turret design, during the [[First Battle of Charleston Harbor]] in April 1863.<ref>[[#Canney|Canney, 1993]], pp. 79–80</ref> Direct hits on the turret with heavy shot could bend the spindle, which could also jam the turret.<ref>[[#Reed|Reed, 1869]], pp. 253–54.</ref> To gain access to the turret from below, or to hoist up powder and shot during battle, the turret had to rotate to face [[starboard]], which would line up the entry hatch in the floor of the turret with an opening in the deck below.<ref>[[#Broadwater|Broadwater, 2012]], p. 8</ref><ref>[[#Wilson|Wilson, 1896]], p. 30.</ref> The roof of the turret was lightly built to facilitate any needed exchange of the ship's guns and to improve ventilation, with only gravity holding the roof plates in place.<ref>[[#Clancy|Clancy, 2013]], pp. 211–212</ref>

[[File:MonitorTurretInt.jpg|thumb|right|alt=|Side view of the cutaway replica of the turret in the [[Mariners' Museum]], with only one {{convert|11|in|adj=on}} [[Dahlgren gun]] mounted]]
The turret was intended to mount a pair of {{convert|15|in|adj=on}} [[smoothbore]] [[Dahlgren gun]]s, but they were not ready in time and {{convert|11|in|adj=on}} guns were substituted,<ref name="Thompson p. 225"/> weighing approximately {{convert|16000|lb}} each. ''Monitor''{{'}}s guns used the standard propellant charge of {{convert|15|lb|kg}} specified by the 1860 ordnance for targets "distant", "near", and "ordinary", established by the gun's designer Dahlgren himself.<ref>[[#Field|Field, 2011]], p. 33</ref> They could fire a {{convert|136|lb|1|adj=on}} round shot or shell up to a range of {{convert|3650|yd}} at an elevation of +15°.<ref>[[#Olmstead|Olmstead, Stark & Spencer, 1997]], p. 90</ref>

The top of the armored deck was only about {{convert|18|in|mm}} above the [[waterline]]. It was protected by two layers of {{convert|1/2|in|adj=on}} wrought iron armor. The sides of the "raft" consisted of three to five layers of {{convert|1|in|adj=on}} iron plates, backed by about {{convert|30|in|0}} of pine and oak. Three of the plates extended the full {{convert|60|in|0|adj=on}} height of the side, but the two innermost plates did not extend all the way down. Ericsson originally intended to use either six 1-inch plates or a single outer {{convert|4|in|adj=on}} plate backed by three {{convert|3/4|in|adj=on}} plates, but the thicker plate required too much time to roll.<ref name=c5>[[#Canney|Canney, 1993]], p. 29</ref> The two innermost plates were riveted together while the outer plates were bolted to the inner ones. A ninth plate, only {{convert|3/4|in|mm}} thick and {{convert|15|in|0}} wide, was bolted over the [[butt joint]]s of the innermost layer of armor. Glass [[porthole]]s in the deck provided natural light for the interior of the ship; in action these were covered by iron plates.<ref name=t8/>

After the duel between the two ironclads at Hampton Roads there was concern by some Navy officials who witnessed the battle that ''Monitor''{{'}}s design might allow for easy boarding by the Confederates. In a letter dated 27 April 1862 Lieutenant Commander O.C. Badger wrote to Lieutenant H. A. Wise, Assistant Inspector of Ordnance, advising the use of "liquid fire", scalding water from the boiler through hoses and pipes, sprayed out via the vents and pilothouse window, to repel enemy boarders.<ref>[[#Rawson|Rawson, 1898]], pp. 285–86.</ref> Wise who was aboard and inspected ''Monitor'' after the battle responded in a letter of 30 April 1862: "With reference to the Monitor, the moment I jumped on board of her after the fight I saw that a steam tug with twenty men could have taken the upper part of her in as many seconds&nbsp;... I hear that hot water pipes are arranged so as to scald the assailants when they may dare to set foot on her."<ref>[[#Rawson|Rawson, 1898]], pp. 293–94</ref> The chance to employ such a tactic never arose. There are conflicting accounts as to whether such an anti-personnel provision was installed.<ref name=Garrison140>[[#Garrison|Garrison, 1994]], p. 140</ref><ref>[[#Gentile|Gentile, 1993]], p. 70</ref>