Project Flat Top

{{Short description|US mobile helicopter repair ship in use during the Vietnam War}} {{Use dmy dates|date=April 2022}} {{About|This page is about the US military project during the Vietnam War|the 2023 Texas takeover of Fronton Island, and Operation Flatop|Fronton Island#Texas Takeover|}}

[[File:Aft view of USNS Corpus Christi Bay (T-ARVH-1) at anchor off Vung Tau, Vietnam, circa 1967-1969.jpg|thumb|250px|{{USNS|Corpus Christi Bay|T-ARVH-1}} at anchor off Vung Tau, South Vietnam, circa 1967–1969. Two UH-1 "Huey" helicopters sit atop her aft flight deck.]]

'''Project Flat Top''' was a United States Army project during the Vietnam War to convert {{USS|Albemarle|AV-5|6}}, a World War II-era seaplane tender, into a forward theater, offshore helicopter repair facility. Helicopters had been used during the Korean War to ferry wounded and supplies. Some US combat officers recognized the possibility of using armed helicopters to provide close air support. But other organizations and branches strenuously objected to allowing the Army to deliver ordnance via aircraft. The Army Staff in The Pentagon responded slowly to a study from the Army Aircraft Requirements Review Board chaired by Lieutenant general (LTG) Gordon B. Rogers that suggested adopting helicopters for use in a combat role. Defense Secretary Robert McNamara bypassed Secretary of the Army Elvis Jacob Stahr Jr. and directed LTG Hamilton H. Howze, the Army's first director of aviation, to conduct a review of the tactical possibilities suggested by the study. The Howze Board report received by McNamara in September 1962 proposed huge changes in Army doctrine, prescribing an airmobility doctrine integrating helicopters into combat.

With helicopters increasingly at the center of Army doctrine as a result of the Howze Board's recommendations, it became apparent that a logistical gap would arise between the operational area and repair bases in the US. Lieutenant Colonel (LTC) John Sullivan, a respected Army aviator, conceived of the idea to convert a ship into a floating helicopter repair facility.<ref name="pearson24"/> Sullivan was named by General Frank Besson, commanding general of the newly formed United States Army Materiel Command (AMC), to lead the project.

After considerable research, Sullivan and his team selected the World War II {{sclass|Curtiss|seaplane tender}} USS ''Albemarle'' (AV-5). When progress slowed for almost a year, Sullivan bypassed Army leadership and persuaded influential Congressman Mendel Rivers of South Carolina, chairman of the House Armed Services Committee, to support the project. New shops, instruments, technology, communications, and storage were added to the ship over 15 months at a cost of $25 million. Rechristened as {{USNS|Corpus Christi Bay|T-ARVH-1}}, a civilian United States Merchant Marine (USMM) crew was chosen to operate the bridge, engine room, and man the ship's watches. This was a controversial move that generated concern about their placement near a combat zone and their potential treatment under the Geneva Conventions. US Army soldiers staffed the multiple repair shops that were equipped with custom facilities that could repair or fabricate parts to factory standards.

The ship offered the same echelon of depot-level service available in the U.S. at the Army Aeronautical Depot Maintenance Center in Corpus Christi, Texas while it served off the coast of South Vietnam for 6½&nbsp;years. The soldiers repaired as many as 20,000 aircraft components a month and saved the military millions of dollars. When the war was drawing down, the ship left for the U.S. in late 1972. On 17 July 1975, after more than 36 years of service, the ship was scrapped.

== Background == thumb|right|LTC John F. Sullivan conceived of building a floating aircraft repair ship for service off South Vietnam

At the beginning of the 1960s, the US Army evaluated a concept called FAMF (Floating Aircraft Maintenance Facility), a way to support aircraft far abroad on a mobile ship. The Army Materiel Command established a top-level Project Management Office called “Project Flat-Top”. It was originally envisioned the project would acquire and convert a mothballed WWII US Navy small aircraft carrier.

In October 1961, LTC John F. Sullivan was selected by the Army Chief of Transportation in the US Army Transportation Materiel Command (TMC) to study production management at the Army Aeronautical Depot Maintenance Center (ARADMAC). In January, 1962, Sullivan passed a highly selective screening process and was temporarily assigned to attend the Armed Forces Staff College in Norfolk, Virginia.<ref>{{cite web|publisher=Corpus Christi Caller-Times |url=https://www.newspapers.com/clip/100786220/ |title=Sullivan to Attend Staff College |location=Corpus Christi, Texas |date=20 January 1962 |page=11}}</ref> When he returned to ARADMAC in May he was appointed Director of Production Control.

On 20 August 1962, the Howze Board proposed significant changes to Army doctrine, including the use of helicopters for reconnaissance, command and control, troop transport, attack gunships, aerial rocket artillery, medical evacuation, and supply.<ref name=stanton>{{cite book| last = Stanton|first = Shelby L.|title = Anatomy of a Division: 1st Cav in Vietnam|publisher = Presidio|year = 1987|location = Novato, CA|url = https://archive.org/details/anatomyofdivisio00stan|url-access = registration}}</ref>{{rp|21}} In response, Sullivan suggested to his superiors at ARADMAC that the Army should build a ship-based helicopter repair facility, similar to the Aircraft Repair Unit-Floating (ARU(F)) of World War II.<ref name="pearson24"/><ref name="amc"/><ref name=shyboygan>{{cite web | publisher=The Sheboygan Press |location=Sheboygan, Wisconsin |date=10 Oct 1964 |page=31 |title=U.S. Army is Set for 'Sea Duty' |url=https://www.newspapers.com/image/?clipping_id=75030503 |quote="It was all his idea."}}</ref><ref name="nothing"/>

Sullivan had fought in World War II during 1942<ref>{{cite web |title='Flat Top' Project Manager Named Colonel |url=https://www.newspapers.com/paper/janesville-daily-gazette/574/ | publisher=Janesville Daily Gazette |accessdate=19 May 2022|location=Janesville, Wisconsin |date=6 May 1966| page=3}}</ref> in New Guinea as a 1LT and air controller in the 107th Quartermaster Company, 126th IR, 32nd Infantry Division, the first to be transported into combat as a division.<ref name=michigan>{{cite web|title=Michigan National Guard in World War II|url=http://www.michigan.gov/dmva/0,4569,7-126-2360_3003_3009-26798--,00.html|publisher=State of Michigan|access-date=14 November 2012|url-status=live|archive-url=https://web.archive.org/web/20121226075124/http://www.michigan.gov/dmva/0,4569,7-126-2360_3003_3009-26798--,00.html|archive-date=26 December 2012}}</ref><ref>{{cite book |last1=Blakeley |first1=Harold Whittle |title=The 32nd Infantry Division in World War II |date=2000 |publisher=Battery Press |location=Nashville |isbn=978-0898393019}}</ref> Wounded in an air crash, he returned to duty and was assigned to an Aviation Ordnance Maintenance Company in Townsend, Australia. <ref>{{cite book|last1=Williams |first1=James W.|title=A History of Army Aviation: From Its Beginnings to the War on Terror|date=September 2005|isbn=978-0-595-36608-8|page=141|publisher=iUniverse |url=https://books.google.com/books?id=Be6XiVviR-QC|access-date=10 February 2022|language=en}}</ref><ref>{{cite book|title=Army |date=1964|publisher=Association of the United States Army|location=University of Illinois at Urbana-Champaign|page=10|url=https://books.google.com/books?id=3HEue_KetcoC |language=en}}</ref><ref name=nothing/><ref name=2ndaruhistory>{{cite web|url= http://www.cbi-history.com/documents/2nd_aru_history.pdf|title= The Second Was Always First|access-date= 6 December 2017 |archive-date= 4 March 2016|archive-url= https://web.archive.org/web/20160304185852/http://www.cbi-history.com/documents/2nd_aru_history.pdf|url-status= live}}</ref>

Once Sullivan persuaded his immediate superiors at ARADMAC to support the idea of a floating aviation repair depot, it took him more than two years to win over the heads of the Supply and Maintenance Command and then the Transportation Materiel Command. Sullivan assumed broad responsibility for initial development of a "floating aircraft maintenance facility" (FAMF) and put considerable effort into selling it to senior Army leadership.<ref name="pearson24">{{cite web |last1=Pearson |first1=Spencer |title=USNS Corpus Christi Bay |url=https://www.newspapers.com/image/756077701/ |website=Newspapers.com |publisher=Corpus Christi Caller-Times |access-date=24 April 2022}}</ref><ref name="pearson">{{cite web |last1=Pearson |first1=Spencer |title=USNS Corpus Christi Bay |url=https://www.newspapers.com/image/756077701/ |access-date=11 February 2022 |publisher=Corpus Christi Caller-Times |date=16 Jan 1966 |location=Corpus Christi, Texas}}</ref> Sullivan wrote a number of reports and held conferences to advance his idea. He spent so much time in Washington D.C. that he was given a second office there. Sullivan made trips to Germany, Vietnam, Korea, Japan, Hawaii, both coasts of the United States and many bases between, gathering information.<ref name=shyboygan/>

Sullivan then successfully sought the attention and approval of General Frank S. Besson, who had recently been appointed as commanding officer of the newly formed United States Army Materiel Command (AMC).<ref name=shyboygan/><ref name=pearson09Aug/> The formation of AMC represented a major reorganization within the Army, consolidating all seven Army technical services: the Offices of the Quartermaster General, the Chief of Ordnance, the Chief of Engineers, the Surgeon General, the Chief Signal Officer, the Chief Chemical Officer, and the Chief of Transportation. Besson's success later resulted in his receiving the Merit Award of the Armed Forces Management Association in 1963.<ref>{{cite web |title=General Frank S. Besson Jr - Army Transportation Museum, Joint Base Langley-Eustis, Virginia |url=https://transportation.army.mil/museum/about/GenBesson.html |archive-url=https://web.archive.org/web/20180531181513/http://www.transportation.army.mil/museum/about/GenBesson.html |url-status=dead |archive-date=31 May 2018 |website=transportation.army.mil |access-date=2 May 2022}}{{pd-notice}}</ref><ref>{{cite web |title=Records of the United States Army Materiel Command |url=https://www.archives.gov/research/guide-fed-records/groups/544.html |website=National Archives |access-date=3 May 2022 |language=en |date=15 August 2016}}</ref>

On 17 June 1964, Besson relieved LTC Sullivan of his role as Director of Production Control and assigned him full time as project officer of Project Flat Top.<ref name=pearson09Aug/><ref name=williamsj>{{cite book |last1=Williams |first1=James W. |title=A History of Army Aviation: From Its Beginnings to the War on Terror |date=September 2005 |isbn=978-0-595-36608-8 |page=141 |publisher=iUniverse |url=https://books.google.com/books?id=Be6XiVviR-QC |access-date=10 February 2022 |language=en |archive-date=10 February 2022 |archive-url=https://web.archive.org/web/20220210201730/https://www.google.com/books/edition/A_History_of_Army_Aviation/Be6XiVviR-QC |url-status=live }}</ref><ref name="amc"/> In August 1964 Besson directed the Transportation Materiel Command to explore the feasibility of using a ship as a floating maintenance facility to provide helicopter support in the Far East.<ref name=avian>{{cite journal|title=Information for FAMF 1 TC BN ARADMAC |url=https://www.vhpa.org/KIA/panel/battle/70101508.HTM |website=www.vhpa.org |access-date=25 April 2022 |date=October 1970 |volume= II |number=3}}</ref>

=== Ship selection=== thumb|{{USS|Bogue|CVE-9}} near Norfolk, Virginia on 20 June 1943 was one ship considered for conversion. [[File:USS Albemarle (AV-5) underway 1943.jpg|thumb|World War II seaplane tender ''Albemarle'', 30 July 1943 was the final choice.]] Sullivan's mission was to create a floating aircraft maintenance facility. Choosing a specific ship, planning and designing the changes for its new use, and then converting the ship was a complex, lengthy, frustrating, and expensive effort. Sullivan originally assumed that the selected ship would be one of the US Navy's World War II escort carriers.<ref name="afterwwii"/><ref name=shyboygan/> A special team, including several enlisted men who had started as aircraft mechanics trained by the Air Force in the mid-1950s, crawled through 17 mothballed World War II vessels of all sorts: escort carriers, tank landing ships, cargo ships, and seaplane tenders. They found that the cost of reactivating one of the mothballed escort carriers would be prohibitive.<ref name="afterwwii"/><ref>{{cite news |title=Soldiers to Go to Sea |publisher=Army Times |date=9 Aug 1964 }}</ref>

They also reasoned that the aircraft destined for repair would not be in flying condition anyway and that a seaplane tender already came equipped with some shops.<ref name=shyboygan/> They finally chose the recently decommissioned World War II ''Curtiss''-class seaplane tender USS ''Albemarle''.<ref name="amc"/> Compared to a {{sclass|Bogue|escort carrier}}, ''Albemarle'' was longer: 527&nbsp;ft 4 in (160.73 m) vs. 495&nbsp;ft (151 m), drew less water: 21&nbsp;ft 1 in (6.43 m) vs 23&nbsp;ft 3 in (7.09 m) vs, and was slightly faster: 20 kn (23&nbsp;mph; 37&nbsp;km/h) vs. 18 kn (33&nbsp;km/h; 21&nbsp;mph).<ref name=DANFS/><ref>{{cite web |title=USS BOGUE (CVE-9) Deployments & History |url=https://www.hullnumber.com/CVE-9 |website=www.hullnumber.com |access-date=5 May 2022}}</ref>

Sullivan had to convince the Navy to give up a vessel to another service branch, which was highly unusual, particularly after the interservice difficulties following the establishment of the United States Air Force when the Army wanted organic fixed-wing aviation assets. The Army, which had been accused by the Air Force of beginning another "Air Corps", found the Navy wary of the Army's attempts to get its own "aircraft carrier", but the Navy agreed as long as the Army paid the costs of converting the ship.<ref name=Tolson>{{cite book|last=Tolson|first=John|title=Vietnam Studies Airmobility 1961-1971|publisher=Department of the Army|year=1973|url=https://history.army.mil/html/books/090/90-4/index.html|archive-url=https://web.archive.org/web/20111117204605/http://www.history.army.mil/html/books/090/90-4/index.html|url-status=dead|archive-date=17 November 2011|isbn=978-1105081699}}{{PD-notice}}</ref>{{rp|91-2}}

== Conversion == === Reactivation=== thumb|The stern of ''Albemarle'' was modified to berth Martin P6M Seamaster flying boats.

''Albemarle'' was laid down in Camden, New Jersey by the New York Shipbuilding Company on 12 June 1939. She was launched on 13 July 1940 and was commissioned into the fleet on 20 December 1940 as USS ''Albemarle'' (AV-5).<ref name=DANFS/>

On 6 February 1956, ''Albemarle'' was selected for conversion to tend Martin P6M Seamaster jet flying boats. During the transformation, the aft portion of the ship was lowered to berth a seaplane. The ship was equipped to serve as a highly mobile seadrome capable of supporting jet seaplanes anywhere. ''Albemarle'' was recommissioned at Philadelphia on 21 October 1957. The Seamaster program was cancelled in 21 August 1959 before the ship had a chance to carry out its new mission.<ref name=DANFS/><ref>{{Cite web|url=https://www.defensemedianetwork.com/stories/what-might-have-been-the-martin-p6m-seamaster/|title=The Martin P6M SeaMaster - What Might Have Been|first1=Robert F.|last1=Dorr|date=26 April 2017}}</ref><ref>{{Cite web|url=https://jenikirbyhistory.getarchive.net/amp/media/aft-view-of-uss-albemarle-av-5-underway-circa-in-1957-nh-57782-cd387b|title=Aft view of USS ''Albemarle'' (AV-5) underway, circa in 1957 (NH 57782) - PICRYL Public Domain Image|website=jenikirbyhistory.getarchive.net}}</ref>

After nearly two decades of service as a ''Curtiss''-class seaplane tender, ''Albemarle'' was decommissioned on 21 October 1960. She was consigned to the Norfolk group of the Atlantic Reserve Fleet and later transferred to the James River, Reserve Fleet. She was struck from the Naval Vessel Register on 1 September 1962.<ref name=DANFS>{{cite web|title=''Albemarle''|work=Dictionary of American Naval Fighting Ships|url=http://www.history.navy.mil/danfs/a5/albemarle-iii.htm|access-date=19 June 2007|archive-url=https://web.archive.org/web/20070629082911/http://www.history.navy.mil/danfs/a5/albemarle-iii.htm|archive-date=29 June 2007|url-status=bot: unknown}}</ref>

On 7 April 1964, ''Albemarle'' was moved from the James River Fleet near Fort Eustis in Newport News, Virginia. On 7 August 1964, the United States Maritime Administration transferred the ship, earmarked for conversion to a floating aeronautical maintenance facility for helicopters, back to the Navy. On 27 March 1965 the ship was reinstated on the Navy Vessel Register and on 16 April 1965 she received a new name and classification as USNS ''Corpus Christi Bay'' (T-ARVH-1), named for Corpus Christi Bay, the ship's future home port. The ship's designation, "T-ARVH-1", classifies the ship as (T) civilian-crewed (USMM), (AR) repair ship, (V) aircraft, (H) helicopter and, (1) the first in a series.<ref name=renamed>{{cite web |title=Repair Ship Rename 'Corpus Christi Bay' |url=https://www.newspapers.com/image/758618149 |website=Newspapers.com |publisher=Corpus Christi Times |access-date=24 April 2022 |language=en |date=16 Apr 1965}}{{subscription required}}{{verification needed|date=June 2022}}</ref> The ship was transferred to Military Sealift Command (MSC) on 11 January 1966. By law, MSC ships are not commissioned warships, are unarmed, and are prefixed with "USNS", for United States Naval Ship, instead of "USS", for United States Ship.<ref name=DANFS/><ref name="afterwwii"/>

=== Design and construction issues=== The project team had to design multiple shops. This was a cumbersome process because of the technology at the time. For each design, craftsmen built a three-dimensional model that was used to estimate funding required. Sullivan continued to advance his idea up the chain of command to the Department of the Army and then the Department of Defense.<ref name=pearson09Aug>{{cite web|first1=Spencer|last1=Pearson|publisher=Corpus Christi Times|location=Corpus Christi, Texas| date=9 Aug 1964|page=15|url=https://www.newspapers.com/image/758540065/| title=Floating Aircraft Repair Depot Idea Nears Reality}}</ref> The project slowed down for almost a year and threatened to stall altogether over a host of issues, including legal gray area issues about a civilian crew under the Geneva Convention in a combat zone, the costs of conversion, and interservice concerns.<ref name="amc"/>

Eventually Sullivan contacted Congressman Mendel Rivers of South Carolina, chairman of the House Armed Services Committee. Rivers was an ardent supporter of the military and the war in Vietnam.<ref name="Rivers">{{cite book | last = Rivers | first = Margaret Middleton |author2=Margaret M.R. Eastman |author3=L. Mendel Rivers Jr | title = Mendel & Me: Life With Congressman L. Mendel Rivers | publisher= The History Press | year=2007 | isbn=978-1-59629-288-8 }}</ref>{{rp|193}} Sullivan talked to Rivers about using the Charleston Naval Shipyard in his district for the ship conversion project. Rivers believed that Congress should set the priorities for the Secretary of Defense<ref name="Rivers" />{{rp|132}} and he successfully persuaded Robert McNamara to support the project.<ref name=amc/>

Sullivan repeatedly traveled between ARADMAC in Corpus Christi, the shipyard in Charleston, and the Pentagon in Washington D.C. to resolve the many challenges inherent in converting ''Albemarle'' to a floating helicopter repair depot.<ref name=amc/> The project's initial cost, estimated at less than $5 million, ballooned with design changes to $25 million (equivalent to ${{Inflation|US|25|1965|r=2}}&nbsp;million in {{Inflation/year|US}}). The ship also required standing up two Aircraft Maintenance Battalions. The battalions would alternate manning the ship and augmenting the ARADMAC at Corpus Christi when not deployed.<ref name="amc"/>

When complete, the ship would provide services equal to those found at ARADMAC. At its peak, ARADMAC was the largest helicopter repair facility on Earth.<ref name="afterwwii"/> ARADMAC was renamed in 1974 as the Corpus Christi Army Depot.<ref name=korte>{{cite web |title=Hangar 8 renovation – Corpus Christi Army Depot, TX {{!}} The Korte Company |url=https://www.korteco.com/construction-projects/ccad-hangar-8-renovation-corpus-christi-army-depot-tx/ |website=www.korteco.com |date=21 May 2019 |access-date=27 April 2022}}</ref>

=== New shops and facilities=== thumb|''Corpus Christi Bay'' in the Charleston Naval Shipyard Along with his offices at ARADMAC in Corpus Christi and in Washington D.C., Sullivan set up an office in the Charleston shipyard and another in the Charleston Army Depot where production equipment was received.<ref name=pearson23aug>{{cite web | url=https://www.newspapers.com/image/756075361/ |title=Floating Seaplane May Go to Sea for 14 Months |first1=Spencer |last1=Pearson|publisher=Corpus Christi Times |location=Corpus Christi, Texas |date=23 Aug 1964}}</ref><ref name=digest>{{cite journal|title=Project Flattop | first=A.E. |last=D'Angelo | journal= United States Army Aviation Digest | volume=2| number=4 |date= April 1965| pages=1–6 |url= https://www.scribd.com/document/234497827/Army-Aviation-Digest-Apr-1965}}</ref><ref name=revived>{{cite web | title= ARADMAC Revitalized City After O&R Closed Doors | publisher= Corpus Christi Caller Times | date=17 June 1965 | page=46 | location=Corpus Christi, Texas | url= https://www.newspapers.com/image/756478536/}}</ref>

The entire project, from design to launch, took 3½&nbsp;years. The conversion work aboard the ship in the Charleston Naval Shipyard in North Charleston, South Carolina took 15 months<ref name="pearson24"/><ref name="pearson"/> and employed up to 1,000 workers.<ref name=nothing/>

''Corpus Christi Bay'' emerged from the yard only faintly resembling her former self. The entire stern transom area and the prominent seaplane ramp aft was replaced by a built-up superstructure topped by a {{convert|50|x|150|ft}} helicopter landing pad. A smaller forward deck pad was used by helicopters that were not being repaired.<ref name="pearson"/> The hangar bay was {{convert|180|x|82|ft}} and {{convert|26|ft}} high.<ref name="pearson"/> All remaining seaplane-related structures and equipment along with all World War II weapons, electronics, rangefinders, magazines, and support gear were removed.<ref name=afterwwii/>

Two {{convert|22|shtn}} cranes were added to lift equipment and aircraft onto and off the ship. The redesigned ship contained {{convert|42,000|sqft}} of workshops and {{convert|112400|cuft}} of storage.<ref name=afterwwii/><ref name=dvidshub>{{cite web |first1=Kaylene |last1=Hughes |title=Evolution to AMCOM: The Formation of the U.S. Army Aviation and Troop Command (ATCOM) Part III: Field Operating Activities, 1961-1975 |url=https://www.dvidshub.net/news/253663/evolution-amcom-formation-us-army-aviation-and-troop-command-atcom-part-iii-field-operating-activities-1961 |website=DVIDS |access-date=2 May 2022 |language=en}}{{pd-notice}}</ref> The interior provided space for 26 production and 16 support shops, including limited airframe repair, engine overhaul repair, rebuilding, and test, transmission repair and test, a hydraulics shop, a sheet metal shop, a gunsmith, a foundry, an electronics shop, and others. The ship was fitted with equipment ranging from hand tools to a USD$3 million, 36-ton test instrument. The shops included engine test stands where helicopter turboshaft engines could be run up to speed.<ref name=dvidshub/><ref name=afterwwii/> About $2.5 million was spent on more than 8,000 specialized tools and equipment.<ref name=pearson23aug/>

Two unusual innovations were implemented on the ship. The first was an IBM 360/20 16 bit computer with 32 KB core memory. Computers aboard warships were extremely new and it was at the time one of the most powerful computers ever sent to sea.<ref name="afterwwii"/> The computer was used to manage an extensive technical library and inventory. The second innovation was the technical data library that contained a complete set of 180,000 engineer drawings on film of aircraft systems, components, and special tools. The {{convert|20|x|30|ft}} library duplicated the library in Corpus Christi and included 35mm aperture cards that allowed staff to print blueprints that they could take to the shop and use to fabricate the part. It was the only such printer in Vietnam. The library contained 785,000 images that could be broadcast to shops on the ship via closed circuit TV.<ref name=afterwwii/><ref name="lilly"/>

There was an internal communications system that allowed multiple shops to talk with each other and production control about their work. This allowed the shops to respond in real-time to requests for repairs and quickly make decisions about whether they could immediately accommodate a request or if they needed additional parts.<ref name="lilly" /><ref name="nothing" /> Previously, damaged helicopters had to be transported {{convert|8000|mi}} back to the US for refit; with the advent of this new ship type, repairs could be accomplished near the forward areas. Damaged helicopter components could be barged out to the ship and lifted on board by one of the cranes or flown out via helicopter.<ref name=armyaviationmagazine>{{Cite web|url=http://www.armyaviationmagazine.com/index.php/archive/looking-back-again/665-42-years-ago-usns-corpus-christi-bay|title=42 Years Ago: USNS Corpus Christi Bay|website=www.armyaviationmagazine.com|access-date=10 February 2022|archive-date=10 February 2022|archive-url=https://web.archive.org/web/20220210061822/http://www.armyaviationmagazine.com/index.php/archive/looking-back-again/665-42-years-ago-usns-corpus-christi-bay|url-status=dead}}</ref> The Army estimated it would save 30 percent on the cost of repairing components by completing the work aboard the ship.<ref name="pearson24"/>

While the ship was rebuilt, soldiers received extensive training to manage the various shops. One of the crew, a sheet metal fabricator and airframe repairman, received a year of training in airframe repair and sheet metal work at Fort Eustis, Virginia. He then received an additional year of training at the Army aircraft maintenance facility in Corpus Christi, as did most soldiers who served on the ship.<ref name=afterwwii/>

The ship conversion was completed in December 1965 and the ship arrived in Corpus Christi Bay on 23 January 1966.<ref>{{cite web |last1=Pearson |first1=Spencer |title=ARADMAC - Biggest Repair Garage in Town |url=https://www.newspapers.com/image/756478875/ |website=Newspapers.com |publisher=Corpus Christi Caller-Times |access-date=24 April 2022 |date=21 Nov 1965}}</ref> During sea trials, the inspection team found that the ship was excessively top-heavy due to the new superstructure aft. To resolve this, they poured in several tons of concrete ballast.<ref name="afterwwii" />

==Deployed to South Vietnam== thumb|Military Sealift Command helicopter repair ship ''Corpus Christi Bay'' at anchor off Vũng Tàu, South Vietnam.

=== In-theatre aviation support=== On 18 February 1966 the ship sailed for South Vietnam. After a six week transit, the ship arrived in Cam Ranh Bay on 2 April 1966 and began 6½&nbsp;years of service.<ref>{{cite journal| title= Army 'Flattop' Operating As Aircraft Repair Facility In Cam Ranh Bay Vicinity | page=16 |date= June 1966 | publisher = Army Research and Development Newsmagazine | volume=7 | number=6 | location= Washington DC}}</ref>

Cam Ranh Bay was chosen because it was the largest harbor facility in South Vietnam. In March 1967 she moved to Vũng Tàu from which she would periodically move up the coast of South Vietnam to Quy Nhon and Da Nang. On these trips, cargo was unloaded and unserviceable components taken aboard.<ref name=avian/><ref name="amc"/> Later on the ship moved back to Quy Nhon to be closer to the 1st Cavalry.<ref>{{cite web |title=Under New Management |url=https://www.newspapers.com/image/758625625/ |website=Newspapers.com |publisher=Corpus Christi Times |access-date=24 April 2022 |language=en |date=27 Mar 1967}}</ref> The ship moved back to Vũng Tàu in 1970 which was in the vicinity of the parent 34th General Support Group<ref name="amc"/> and operated about {{convert|1|mi}} off the coast.<ref name="lilly"/>

To avoid a repeat of the successful sapper attack on the escort carrier turned helicopter transport {{USS|Card}}, security procedures were stepped up while in port. Helmets and flak jackets were kept at the ready topside, sandbags were placed around the bridge, screens were secured over portholes, bilge and ballast pumps were kept warmed up, and extra medical kits and firefighting equipment was kept ready. While the civilian merchant marine crew could not bear arms, the soldiers had been trained to handle weapons and maintained a large arms locker that included replacement M60 machine guns for the Huey gunships.<ref name="warship"/>

=== Crew and operations === thumb|right|A Huey helicopter assigned to ''Corpus Christi Bay''. The nose art is the unit crest of the 1st Transportation Battalion (Aircraft Maintenance Depot, Seaborne). The first commander of ''Corpus Christi Bay'' was Captain Harry Anderson. He had a crew of 129 civilian merchant marine crew under the Military Sea Transport Service (MSTS),<ref name="pearson"/> a fraction of the ship's original complement of 1,135 crew members assigned to her during World War II. They manned the bridge, the engine room, and the ship's watches.<ref name="lilly"/>

The aircraft maintenance facilities aboard the ship were operated by the First Transportation Battalion (Seaborne), commanded by LTC Harry O. Davis, US Army, with 308 aircraft technicians, specialists and mechanics. There were 19 officers, 11 warrant officers, and 350 enlisted men.<ref name=photoindex/><ref>{{cite news |title=Angeloan To Serve On New Army Ship |url=https://www.newspapers.com/image/780419923 |access-date=10 February 2022 |issue=242 |publisher=San Angelo Standard-Times |date=29 September 1968 |volume= 41}}</ref><ref name="amc"/>

The Army formed the 1st Material Group on 26 May 1966, the first of its kind in the Army Material Command, and named COL Sullivan as its commander.<ref>{{cite web|title=Viet Nam Shipments to ARADMAC Up|url=https://www.newspapers.com/image/758619264|website=Newspapers.com|publisher=Corpus Christi Times |access-date=24 April 2022|language=en |date=26 May 1966}}</ref> On 7 October 1966, the Second Transportation Battalion (Seaborne) was formed at ARADMAC. Sullivan presented the unit's new colors to its commanding officer, LTC John Bergner on 8 October 1966.<ref>{{cite web |last1=Pearson |first1=Spencer |title=Commissioning Set Friday |url=https://www.newspapers.com/image/758629839/ |website=Newspapers.com |publisher=Corpus Christi Times |access-date=24 April 2022 |language=en |date=3 Oct 1966}}</ref> The unit was trained in Corpus Christi to prepare all personnel who would deploy to serve aboard the ship. The two battalions initially rotated about every 12 months from Corpus Christi to South Vietnam, until deployments were phased in year-round.<ref name="amc"/>

In May 1967, Colonel (COL) Morgan C. Light assumed management of the 1st Material Group and Project FLATTOP, replacing COL Sullivan. Sullivan was transferred to head the Aviation Maintenance Depot for HQ US Army Europe in Mannheim, Germany.<ref>Pearson, Spencer ''Col. Light is new Group Commander'' Corpus Christi Times, Corpus Christi, Texas. 8 May 1967. Page 15</ref>

=== Ship fails audit === In late 1969, the Army Audit Agency notified the ship's commander that ''Corpus Christi Bay'' was being recalled to the United States. The commander was informed that during the 1967 fiscal year the ship had failed to attain a Pentagon goal for parts repaired. ARADMAC strongly resisted the criticism of the ship's cost-effectiveness and the accuracy of the audit. Costs were in part controlled by the archaic procurement processes used by the federal government. The value of the ship's work varied depending on which organization was evaluating the cost. Production fell under two accounts, one type the Army in Vietnam paid for directly, while the other it didn't.<ref>{{cite web |title=Seashore Boardwalk In Budget |url=https://www.newspapers.com/image/756613215 |publisher=Corpus Christi Caller-Times |access-date=10 February 2022 |page=14 |date=25 Jan 1967}}</ref><ref name="pearson"/> The ship remained in South Vietnam while the recall was appealed and it was eventually overturned.<ref name=afterwwii/>

=== Services available === ''Corpus Christi Bay'' had the largest and best equipped fabrication facilities in Vietnam, including milling machines, lathes, molten-salt heat-treating ovens, metal-plating, chemical and metallurgical testing, and presses.<ref name="amc"/> Her shops provided the highest echelon of repair services to Army aircraft. Every piece that came through the ship's shops was restored to factory specifications. These included components such as engines, avionics, and armament.<ref name="nothing"/> The ship also provided a chemical laboratory in which soldiers could test the purity and viscosity of lubricants and hydraulic fluids.<ref name=avian/>

The ship's crew supported numerous other systems aside from aircraft. They conducted a limited fabrication program, including some non-aviation items<ref name="amc"/> and special projects. They manufactured flash suppressors for machine guns, skid shoes for the OH-6A Light Observation Helicopter, and helicopter flare racks that could be jettisoned.<ref name=avian/> They manufactured parts for the Patrol Air Cushion Vehicles which were relatively few in number and thus had a hard time obtaining parts. There was such a demand for hydraulic tubing and fuel lines that they fabricated them and kept them in inventory.<ref name="amc"/>

The ship could perform all the maintenance functions of the depot level aircraft maintenance facility at Corpus Christi, including overhauling and rebuilding aircraft components, directly in service to Military Assistance Command, Vietnam.<ref name=Tolson/>{{rp|91}}<ref name="lilly"/> Production increased slowly and stayed below planned through mid-1967 but was still highly valuable. The work avoided costs and, more importantly, returned aircraft to use more quickly.<ref name=afterwwii/> One veteran said, "The guys aboard this FAMF could fix anything."<ref name="warship"/>

=== Expedited repair === thumb|One of two Hueys assigned to ''Corpus Christi Bay'' thumb|Huey helicopters under repair at the Corpus Christi Army Depot

She had two UH-1s assigned to the ship for administrative use and transporting light supplies and picking up and delivering light aircraft components. Flattop 086 (68-16086) and Flattop 045 (69-15045) each had its own operating and maintenance crews.<ref name=digest/><ref name="warship">{{cite web |title=Warship Wednesday, Sept. 1st, 2021: Fortunate Son, the Army Flat Top Edition |url=https://laststandonzombieisland.com/2021/09/01/warship-wednesday-sept-1st-2021-fortunate-son-the-army-flat-top-edition/ |website=laststandonzombieisland |access-date=2 May 2022 |language=en |date=1 September 2021}}</ref>

During the height of the ship's service off Vietnam, crewmen worked three shifts to repair helicopter parts.<ref>{{cite news |last1=North |first1=Kerry |title=Atmosphere gray on Army repair ship to be retired |url=https://www.newspapers.com/image/757107947 |access-date=11 February 2022 |publisher=Corpus Christi Caller-Times| volume=91 | issue=256 |page=12}}</ref> Each shop was responsible for maintaining its repair parts listing, program, and production, and was expected to operate on a 24-hour schedule.<ref name="lilly"/>

Due to space constraints, the men's goal was to turn around as many unserviceable components as quickly as possible. They prioritized repairing the components that required the least amount of work and sent the components that required the greatest amount of work back to Corpus Christi. To maintain maximum aircraft readiness, they also responded to urgent requirements if a component was grounding an aircraft.<ref name="lilly">{{cite web |title=Service Career of Aaron Lucurgus Lilly Jr. Major General |url=https://transportation.army.mil/history/GO_bios/lilley.pdf |publisher=United States Army Transportation Corp |access-date=13 February 2022 | archive-url=https://web.archive.org/web/20161027235222/https://transportation.army.mil/history/GO_bios/lilley.pdf |archive-date=27 October 2016 |location=Ft. Lee, Virginia |pages=17 |date=19 Feb 1986 |url-status=dead}}</ref>

Instead of flying entire helicopters onto the ship, it was preferable to extract aircraft and helicopter components or sub-components ashore and then bring them aboard. They were sometimes brought to the ship via helicopter, but they were typically delivered by an amtruc (wheeled 15-ton amphibious truck) or a “mike boat” (converted WWII landing craft). A barge was often tied alongside to allow the amtruc or boat to moor in a position that allowed the crane operator better visibility.<ref>[https://wwiiafterwwii.wordpress.com/2020/11/16/uss-albemarle-usns-corpus-christi-bay/ USS Albemarle / USNS Corpus Christi Bay]</ref>

The ship could repair minor damage to airframes, but if airframe was badly damaged, it was sent to Texas. When sent aboard a ship, the aircraft had to be wrapped in "Spraylot" (shrink-wrapped) coverings to protect it against the elements. The Army experimented with doped fabric, then blown plastic, and finally peel-off plastic to protect the aircraft while in transit.<ref name="afterwwii"/><ref name=salvatore>Mercogliano, Salvatore R. [https://www.history.navy.mil/content/dam/nhhc/research/publications/publication-508-pdf/NHHC4thArmDefense_final_508.pdf Fourth Arm of Defense: Sealift and Maritime Logistics in the Vietnam War] 2017. Naval Historical Foundation</ref> Space had to be found aboard one of the Seatrain chartered freighters or one of the converted World War II escort carriers such as {{USNS|Croatan}}. Then it took 18 days to ship the helicopter across the Pacific and through the Panama Canal to the ARADMAC in Corpus Christi. Once repairs were complete, the process had to be reversed. A repair that required a week of real-time labor could end up taking two months.<ref name=afterwwii>{{Cite web|url=https://wwiiafterwwii.wordpress.com/2020/11/16/uss-albemarle-usns-corpus-christi-bay/|title=USS Albemarle / USNS Corpus Christi Bay|date=November 16, 2020}}</ref>

On 1 April 1968, to lessen the time it took to return aircraft to service, the Army began to use Air Force C-133 and C-141 cargo aircraft of the Military Airlift Command to transport damaged helicopters, engines, and component parts to and from Vietnam.<ref>{{cite web |author=United States Department of the Army |title=Re-Designation of the Depot Maintenance Center Ceremony |url=https://tamucc-ir.tdl.org/handle/1969.6/26481 |access-date=2 May 2022 |language=English |date=28 June 1974}}{{pd-notice}}</ref> If ''Corpus Christi Bay'' did not have the necessary parts, they requested them from Texas. If the parts were deemed high priority, they were put aboard the C-133 or C-141 aircraft that were transporting repaired aircraft back to Vietnam.<ref name="lilly"/> In 1968, ARADMAC inaugurated a Department of the Army approved Special Assignment Airlift Mission (SAAM) which involved the direct airlift of helicopter engines to South Vietnam. They were delivered to the Aviation Materiel Management Center (AMMC) depots. By the end of the year, 3,169 engines had been airlifted in 88 flights.<ref>{{Cite web|url=https://www.army.mil/article-amp/197122/evolution_to_amcom_the_formation_of_the_atcom_part_iv_aviation_logistics_and_the_red_ball_express|archive-url=https://web.archive.org/web/20220506152253/https://www.army.mil/article-amp/197122/evolution_to_amcom_the_formation_of_the_atcom_part_iv_aviation_logistics_and_the_red_ball_express|url-status=dead|archive-date=6 May 2022|title=Evolution to AMCOM: The Formation of the ATCOM Part IV: Aviation Logistics and the Red Ball Express|website=www.army.mil}}</ref> In some circumstances they could pick up parts at Tan Son Nhut Air Base or Bien Hoa Air Base airport less than 48 hours after requesting them.<ref name="lilly"/>

=== Shore teams === The crew provided contact teams nicknamed "Sand Crabs" that worked ashore. They gathered parts needing repair as they were sent in by combat units, boxed them up, and transported them aboard an amphibious boat to the ship.<ref name="nothing"/> Service members also went ashore regularly to provide medical care, food, gifts, clothing, and toys at a Vietnamese orphanage near Cam Ranh Bay. They built a building to house the orphans and provided 60 beds, among other projects.<ref>{{cite news|last1=Olson|first1=Jennifer|title=Blue water veterans, Part 1|url=https://www.newspapers.com/image/591169480|access-date=11 February 2022|number=32|volume=153|publisher=The Des Moines Register|date=7 Aug 2019|location=Des Moines, Iowa |page=4C}}</ref><ref>{{cite web|title=Notes from A Vietnam Diary|url=https://www.newspapers.com/image/756597228|website=Newspapers.com |publisher=Corpus Christi Caller-Times|access-date=24 April 2022|language=en|date=6 Aug 1967}}</ref><ref>{{cite web|first1=Spencer |last1=Pearson|title=Local Battalion Aids Viet Nam Children With Gifts from Here|url=https://www.newspapers.com/image/758633906/|publisher =Corpus Christi Times|location=Corpus Christi, Texas|date=23 Oct 1966|page=12}}</ref>

== Final disposition == The ship left South Vietnam in late 1972 and was given one more mission; during Operation Hula Hoop 73,<ref name="HulaHoop">{{cite web|title=CINCPAC Command History 1973|date=17 September 2012 |pages=246-249 (272/818 to 275/818)|url=https://nautilus.org/foia-document/cincpac-command-history-1973-volume-i/}}</ref> the ship, along with {{USNS|Wheeling|T-AGM-8}}, monitored French nuclear tests in the Tuamotu Archipelago. The Army troops were flown directly back to Texas. Only the civilian maritime crew remained aboard.<ref name=salvatore/><ref name=jaye>{{Cite web|url=https://archive.sri.com/sites/default/files/brochures/apr-10.pdf|title=Adventures At Sea in the South Pacific|publisher=sri.com|date=1 April 2010|archive-url=https://web.archive.org/web/20200718193717/https://archive.sri.com/sites/default/files/brochures/apr-10.pdf|archive-date=18 July 2020|access-date=14 June 2022}}</ref> During the voyage, the ship was hit by a typhoon that caused a crack in the hull. En route to Mururoa, the ship began to leak so badly that she needed immediate repair. Relying on the Law of the sea that allows a ship in distress to enter the nearest port, she anchored at Papeete on Tahiti, French Polynesia. A US Navy repair crew was sent from Pearl Harbor to patch the ship. While returning to the US, she stopped in Guam and Hawaii.<ref name=jaye/>

''Corpus Christi Bay'' traversed the Panama Canal and sailed to her home base of Corpus Christi, arriving on 19 December 1972.<ref name=armyaviationmagazine/> Upon inspection in Charleston, the condition and age of the ship did not warrant the expense of further repair.<ref name="lilly"/> The ship was ultimately determined by Military Sealift Command to be "in excess of current and future requirements". ''Corpus Christi Bay'' was taken out of service in 1973 and berthed in ready reserve status at Corpus Christi.

By mid-1974 a host of factors converged and led HQDA to reject continuing use of the ship. Among considerations were direct costs of maintaining the ship due to fiscal constraints in the drawdown after the end of the Vietnam war, the increasing promise of being able to air transport aircraft to temporary repair facilities, and eliminating the cost of the two battalions. The ship was finally struck from the Naval Vessel Register on 31 December 1974, and on 8 January 1975 the ship left Corpus Christi for further disposal. On 17 July 1975, Brownsville Steel and Salvage, Inc. paid $387,766 (equivalent to ${{Inflation|US-GDP|387766|1975|fmt=c}} in {{Inflation/year|US}}) to scrap the ship.<ref name="amc"/><ref name="afterwwii"/>

== Legacy == The Floating Aircraft Maintenance Facility allowed the Army to repair helicopters in-theater instead of shipping them back to Corpus Christi in the United States.<ref name=amc>[https://www.amc.army.mil/Organization/History/Overview/1962-1975/ The Early Years of AMC — 1962-1975] Army Material Command</ref> Transporting damaged aircraft back to the United States for repairs was an expensive, logistical nightmare.<ref name="mighty">{{cite web |title=This WWII-era ship got new life fixing helicopters in Vietnam |url=https://www.wearethemighty.com/mighty-tactical/usns-corpus-christi-bay-albemarle/ |website=We Are The Mighty |access-date=21 April 2022 |date=12 September 2019}}</ref> The ship returned deadlined aircraft in an average of six days compared to 18 days for aircraft returned to the continental United States. The ship repaired as many as 20,000 aircraft components a month and saved the military millions of dollars.<ref name="nothing">{{cite web |title=Transportation Updates - 'Nothing We Couldn't Build' |url=https://giftshop.atmfoundation.org/blogs/httpswwwmilitaryfactorycommodern-armorunited-state/nothing-we-couldnt-build/ |website=ATMF Gift Shop |date=3 May 2019 |access-date=20 April 2022 |language=en-us}}</ref>

Productivity peaked in late 1969 and early 1970 when the soldiers repaired helicopter parts valued at roughly $3.76 million (equivalent to ${{Inflation|US-GDP|3.76|1969|r=2}}&nbsp;million in {{Inflation/year|US}}) each month. Over the term of her service off the shore of Vietnam, the ship repaired about 270,000 items valued at $220 million (equivalent to $1.1 billion in 2021). This more than offset the cost of building and equipping the ship.<ref>{{ cite news | publisher=Corpus Christi Times |location=Corpus Christi, Texas |date=17 Dec 1972 |title=USNS Corpus Christi Bay Due to come home Tuesday|page=2 | url=https://www.newspapers.com/image/759434400/}}</ref><ref name="afterwwii"/>

==Awards== The First Transportation Corps Battalion (Aircraft Maintenance Depot) (Seaborne) earned four Meritorious Unit Commendations.<ref name="armyaviationmagazine"/> The ship and its military crew was also awarded the National Defense Service Medal, the Vietnam Service Medal, and the Republic of Vietnam Campaign Medal.<ref name=photoindex>{{cite web |title=Aircraft Tender Photo Index (AV) |url=https://www.navsource.net/archives/09/41/4105.htm |website=NavSource |access-date=21 April 2022}}</ref> A plaque dedicated to her stated:<ref name="afterwwii"/>

{{quotebox|align=center|qalign=center|width=30%|<poem> CORPUS CHRISTI BAY (T-ARVH-1) ACTIVATED AND CONVERTED AT THE CHARLESTON NAVAL SHIPYARD AUGUST 1964-DECEMBER 1965 FROM THE MEN WHO DID THEIR BEST TO MAKE HER THE BEST TO SERVE THE BEST </poem>}}

The ship’s bell, a scale model of the ship and other artifacts are displayed at the Corpus Christi Army Depot in Texas. The US Army Transportation Museum revealed a large scale model of ''Corpus Christi Bay'' in September 2021.<ref name="warship"/><ref>{{cite web |title=Corpus Christi Army Depot Held a Dedication Ceremony For a Ship Model | website=YouTube |url=https://www.youtube.com/watch?v=He46uhKYxL0 |access-date=2 May 2022 |language=en}}</ref>

On 8 July 1967, COL Sullivan was awarded the Legion of Merit, the US Army's second highest non-combat award, by GEN Frank Besson. He was cited for "developing a new versatile, mobile depot maintenance capability." He was credited with the planning, creativity, management ability, and leadership that made the ship available during the peak period when aircraft maintenance was initially needed in 1966.<ref name=gazette1967>{{cite news |title=Legion of Merit |url=https://www.newspapers.com/clip/75030763/john-f-sullivan-legion-of-merit/ |access-date=12 February 2022 |publisher=Janesville Daily Gazette |date=27 December 1967 |location=Janesville, Wisconsin |page=55}}</ref>

Initial plans called for a second floating aircraft maintenance depot to be named the USNS ''Oso Bay''.<ref>{{cite web |last1=Pearson |first1=Spencer |title=Military Giant Worker |url=https://www.newspapers.com/image/758614247/ |website=Newspapers.com |publisher=Corpus Christi Times |access-date=24 April 2022 |language=en |date=5 Feb 1967}}</ref> The ship was to be an escort carrier with a flight hangar built on the deck. After the cost of converting ''Albemarle'' ballooned, the second ship was considered cost prohibitive and never implemented.<ref name="lilly"/> Interservice rivalries led to some criticism of the success of ''Corpus Christi Bay''. But according to a special operational report on the 34th Support Group published in November 1969, the efforts of the 1st Transportation Battalion made it possible for the US Army to "maintain helicopters in numbers sufficient to meet the full range of combat operations."<ref name=williamsj/>

== References == {{reflist|30}}

== External links ==

* [https://www.youtube.com/watch?v=czhSpB6eflM Vietnam War Aircraft Repair Ship, Helicopter, T ARVH 1 at Cam Ranh Bay 1966 US Army] (video) * [https://www.youtube.com/watch?v=FXPf9ucebT8 USNS Corpus Christi Bay (T-ARVH-1) - The Army Aviation Floating Workshop] (video)

{{ACMH| url = https://www.army.mil/article/185435/u_s_army_helicopter_evolution_during_the_vietnam_war_part_ii| article = U.S. Army Helicopter Evolution during the Vietnam War, Part II}} {{DANFS}}

Category:Vietnam War Category:Curtiss-class seaplane tenders Category:1940 ships Category:1979 disestablishments in the United States Category:Vietnam War ships of the United States Category:Corpus Christi, Texas