Editing Keeper-class cutter (section)

== Construction and characteristics ==
All fourteen ships of the Keeper class were built at Marinette Marine's shipyard in [[Marinette, Wisconsin]].  Their hulls were built of welded steel plates.  The ships are {{Convert|175|ft|m}} long, with a [[Beam (nautical)|beam]] of {{Convert|36|ft|m}}, and a full-load [[Draft (hull)|draft]] of {{Convert|8|ft|m}}.<ref name=":15" />  They [[Displacement (ship)|displace]] 850 long tons fully loaded.<ref name=":3">{{Cite journal |last=DiNicola |first=Commander Peter J. |year=1997 |title=The New Keeper Class WLM |url=https://books.google.com/books?id=a-o6AQAAMAAJ&dq=%22coast+guard%22+%22keeper+class%22&pg=RA2-PA19 |journal=Proceedings of the Marine Safety Council |volume=54 |issue=3 |pages=12–19}}</ref>  Their [[gross tonnage]] is 904, and their [[net tonnage]] is 271.<ref>{{Cite web |title=USCG Maritime Information Exchange |url=https://cgmix.uscg.mil/PSIX/PSIXSearch.aspx |access-date=2023-08-11 |website=cgmix.uscg.mil}}</ref>  The top of the mast is {{Convert|58.75|ft|m}} above the waterline.<ref name=":4">{{Cite book |url=https://imlive.s3.amazonaws.com/Federal%20Government/ID123864553738997015602050111672157759592/Attachment%202%20-%20Work%20Specification.pdf |title=USCGC HARRY CLAIBORNE (WLM 561) SPECIFICATION FOR DRYDOCK REPAIRS |publisher=Surface Forces Logistics Center, United States Coast Guard |year=2021}}</ref>

Rather than building the ships from the keel up as a single unit, Marinette Marine used a modular fabrication approach.  Eight large modules, or "hull blocks" were built separately and then welded together.<ref name=":15">{{Cite journal |last1=O'Brien |first1=Christina T. |last2=Thornton |first2=Lt. Chris |date=January 1996 |title=New Life |url=https://books.google.com/books?id=2IHhu-STif0C&dq=%22coast+guard%22+%22keeper+class%22&pg=PA4 |journal=Commandant's Journal |pages=2–5}}</ref>

[[File:Z-drives on Keeper-class buoy tender.png|thumb|Z-drives on a Keeper-class ship]]

The ships have two [[Caterpillar Inc.|Caterpillar]] 3508 DITA ([[Fuel injection|direct-injection]], [[Turbocharger|turbocharged]], [[Intercooler|aftercooled]]) 8-cylinder [[Diesel engine|diesel engines]] which produce {{convert|1000|hp|lk=on}} each.  These drive two [[Ulstein Group|Ulstein]] Z-drives. Keeper-class ships were the first Coast Guard cutters equipped with Z-drives, which markedly improved their maneuverability.<ref name=":22" />  The Z-drives have four-bladed propellers which are {{Convert|57.1|in|cm}} in diameter<ref name=":4" /> and are equipped with [[Ducted propeller|Kort nozzles]].  They can be operated in "tiller mode" where the Z-drives turn in the same direction to steer the ship, or in "Z-conn mode" where the two Z-drives can turn in different directions to achieve specific maneuvering objectives.  An implication of the Z-drives is that there is no reverse gear or rudder aboard Keeper-class ships.  In order to back a ship, the Z-drives are turned 180 degrees which drives a ship stern-first even though the propellers are spinning in the same direction as they do when the ship is moving forward.<ref name=":1">{{Cite book |url=https://www.forcecom.uscg.mil/Portals/3/Documents/ttp/downloads/Keeper_Class_WLM-175_Operational_Guide_for_Ice_Operations_SFLC-NASEC-011-001.pdf |title=175-ft WLM Keeper Class Guide for Ice Operations |date=July 2011 |publisher=US Coast Guard |location=Baltimore, Maryland}}</ref>  Their maximum speed is {{convert|12|kn|lk=in}}.<ref name=":22" />  Their tanks can hold {{convert|16,385|USgal}} of diesel fuel<ref name=":4" /> which gives them an unrefueled range of {{convert|2000|nmi|lk=in}} at {{convert|10|kn}}.<ref>{{Cite book |last=Polmar |first=Norman |title=Ships and Aircraft of the United States Fleet |publisher=Naval Institute Press |year=1997 |isbn=1-55750-686-8 |edition=16th |location=Annapolis, Maryland |pages=521}}</ref>

The ships have a {{convert|500|hp|adj=on}} [[bow thruster]]. The Z-drives and bow thruster can be linked in a [[Dynamic positioning|Dynamic Positioning System]]. This gives Keeper-class vessels the ability to hold position in the water even in heavy currents, winds, and swells. This advanced capability is useful in bringing buoys aboard that can weigh more than {{convert|16000|lb}}.<ref name=":3" />  

Electrical power aboard is provided by three Caterpillar 3406 DITA generators which produce 285 kW each.<ref name=":3" />  Each ship also has a 210 kW emergency generator, which is a Caterpillar 3406 DIT.<ref name=":4" />

The buoy deck has {{Convert|1335|sqft|m2}} of working area.  A crane with a boom {{Convert|42|ft|m}} long lifts buoys and their mooring anchors onto the deck.  The crane can lift up to {{Convert|20000|lb|kg}}.<ref name=":3" />

The ships' fresh water tanks can hold {{convert|7339|USgal}}.<ref name=":4" />  They also have three [[ballast tank]]s that can be filled to maintain their trim, and tanks for oily waste water, sewage, gray water, new lubrication oil, and waste oil.<ref name=":4" />

Accommodations were designed for mixed gender crews from the start.  Crew size and composition has varied over the years.  When ''Ida Lewis'', the lead ship of the class was commissioned in 1997, she had a crew of 18, commanded by a [[Warrant officer (United States)|Chief Warrant Officer]].<ref name=":0" />  By 2000 the crew had been increased to 20 personnel.<ref>{{Cite web |title=USCGC Henry Blake (WLM 563) |url=https://www.pacificarea.uscg.mil/Our-Organization/District-13/Units/USCGC-Henry-Blake/ |access-date=2023-08-11 |website=www.pacificarea.uscg.mil}}</ref>  Currently, the crew is 2 officers and 22 enlisted personnel.<ref>{{Cite web |title=USCGC GEORGE COBB (WLM 564) |url=https://www.pacificarea.uscg.mil/Our-Organization/District-11/District-Units/cgcGeorgeCobb/ |access-date=2023-08-11 |website=www.pacificarea.uscg.mil}}</ref>

[[File:USCGC Marcus Hanna ice breaking near Boston.jpg|thumb|USCGC ''Marcus Hanna'' breaking ice near Boston]]

Keeper-class hulls have a strengthened "ice belt" along the waterline so that they can work on aids to navigation in ice-infested waters.  Not only is the hull plating in the ice belt thicker than the rest of the hull, but framing members are closer together in areas that experience greater loads when working in ice.  Higher grades of steel were used for hull plating in the ice belt to prevent cracking in cold temperatures.  Keeper-class bows are sloped so that rather than smashing into ice, they ride up over it and break it with the weight of the ship.  The ships are capable of breaking flat, {{convert|9|in|adj=on}} thick ice at {{convert|3|kn}}.<ref name=":1" />

Each ship carries a cutter boat on [[davit]]s.  They were originally equipped with CB-M boats which were replaced in the mid-2010s with CB-ATON-M boats.  These were built by Metal Shark Aluminum Boats and were estimated to cost $210,000 each.<ref>{{Cite book |url=https://www.dhs.gov/sites/default/files/publications/OCFO/United%20States%20Coast%20Guard%20%28USCG%29%20-%20Small%20Boat%20Purchases%20FY%202015.pdf |title=Boat Expenditure Plan |date=12 June 2015 |publisher=US Coast Guard}}</ref>  The boats are {{Convert|18|ft|m}} long and are equipped with a [[Mercury Marine]] inboard/outboard diesel engine.<ref>{{Cite web |date=2015-05-27 |title=Mercury Diesel Engines for 16 New USCG Boats |url=https://www.marinelink.com/news/mercury-engines-diesel391941 |access-date=2023-08-11 |website=MarineLink |language=en}}</ref>

All 14 Keeper-class cutters are named after distinguished American lighthouse keepers.