Evidence
9 evidence entries recorded; each entry has a stable permalink (#ev-1 … #ev-9).
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[1]research packet 890-packet.md [other_primary]
- Finding type
- vessel_history
- Finding
- Identity packet verdict: VERIFIED (thin sourcing on dates
- Verification
- verified
- Role
- supporting
- Documentation level
- ship_specific
- Limitations
- qualifier: VERIFIED (thin sourcing on dates
- Evidence ID
- uss-built-in-portugal-as-pc1637-pkt-890-packet-md
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[2]NavSource Online: Submarine Chaser Photo Archive, PC-1637 - construction, launch, commissioning, completion, specifications [other_primary]
- Locator
- NavSource 12/011637.htm, full vessel block and specifications block
- Finding type
- vessel_history
- Finding
- Documented for this hull: 'Laid down as PC-1637 at Estaleiros Navais do Mondego, Portugal under Off Shore Procurement under the terms of the Military Defense Assistance Pact. Launched 16 June 1956. Commissioned NPR Boavista (P 592), 10 July 1956 at Figueira da Foz. Completed 17 May 1957. Fate unknown.' Spec block: Displacement 366 t.; Length 170'; Beam 23'; Draft 9'; Speed 17.5 kts.; Complement 62; Armament two twin 40mm, two twin 20mm, one Hedgehog depth charge projector, four K-guns and two depth charge tracks; Propulsion four 3,500bhp 4-stroke 14-V SEMT-Pielstick diesel engines, two shafts. Page class header: 'PC-1635 Class Submarine Chaser/Brava Class Patrol Vessel.' Page further states 'There is no DANFS history available for PC-1637.'
- Verification
- verified
- Role
- context
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- 1956-1957 (build window); service to c.1975
- Population
- Portuguese construction trades, Estaleiros Navais do Mondego (1955-57); Portuguese Navy crew (1956-c.1975)
- Limitations
- Ship-specific identity and milestones only; no asbestos or material content. NavSource is a volunteer secondary compilation, not a primary registry, but it is the most specific source located for this hull and is corroborated by Portuguese sources on yard, pennant number, and ex-PC-1637 designation. The commissioning date (10 July 1956) precedes the completion date (17 May 1957) as printed - anomaly noted, both dates carried as published. 'No DANFS history' is NavSource's statement about its own archive, consistent with the hull never entering U.S. Navy service.
- Atlas source
- true
- Evidence ID
- ev-uss-built-in-portugal-as-pc1637-01
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[3]NavSource Submarine Chaser Photo Index - MDAP Offshore Procurement program block PC-1635 to PC-1646 and exact index line for this hull [other_primary]
- Locator
- NavSource 12/01idx.htm, 'Offshore Procurement under the Mutual Defense Assistance Program (PC-1635 to PC-1646)' block
- Finding type
- vessel_history
- Finding
- CORRECTION of the record display name: the index line reads literally 'PC-1637 Built in Portugal as Boavista (P 592)' inside the program block 'Offshore Procurement under the Mutual Defense Assistance Program (PC-1635 to PC-1646)'. The batch-list name 'Built in Portugal as' is this index line's descriptive text captured without the hull name - it is not a vessel name. The actual vessel is NRP Boavista (P 592), ex-PC-1637. The same index maps: PC-1635 = Brava (P 590, built in Portugal); PC-1636 = Fogo (P 591, built in Portugal); PC-1638-1643 to Turkey (Sultanhisar P 111, Demirhisar P 112, Yarhisar P 113, Akhisar P 114, Sivrihisar P 115, Kochisar P 116); PC-1644/1645 built in Denmark (Peder Skram F 352, Herluf Trolle F 353); PC-1646 built in Chile (Papudo P 37); PC-1647/1648 construction canceled.
- Verification
- verified
- Role
- correction
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- 1954-1971 (MDAP OSP block deliveries)
- Limitations
- Corrects a data-artifact 'name' to the vessel's actual identity; establishes program context (MDAP offshore procurement, US-funded but foreign-built and foreign-operated). Does not establish that a US hull number was ever carried in US service - these numbers were procurement/accounting assignments. No asbestos content.
- Atlas source
- true
- Evidence ID
- ev-uss-built-in-portugal-as-pc1637-02
-
[4]Shipbuilding History (Tim Colton), 'Coastal Patrol Ships Built Since WWII' - MDAP procurement table, PCE-designation variant, yard conflict [other_primary]
- Locator
- shipbuildinghistory pc3 table, 'Anti-Submarine Warfare (ASW) Ships' section, rows PCE-1635/1636/1637
- Finding type
- vessel_history
- Finding
- Secondary compiler table lists this hull as 'PCE-1637 | Boavista (P-592) | Viana do Castelo | Portugal | 366 | 170 | 17 May 1957 | to Portugal'. Two conflicts with NavSource ship-specific page: (1) designation - 'PCE-1637' here vs 'PC-1637' in NavSource (NavSource carried; Portuguese sources say PC); (2) builder - 'Viana do Castelo' here vs Estaleiros Navais do Mondego in NavSource and the Portuguese Wikipedia class table ('E. N. Mondego'); commissioning at Figueira da Foz, home of the Mondego yard, supports Mondego. Shipbuildinghistory applies the PCE prefix to the entire 1604-1647 MDAP series and lists 'Viana do Castelo' for all three Portuguese-built hulls, suggesting table-level generalization rather than hull-specific data. Program context from the same page: post-WWII the Navy funded '44 corvette-sized anti-submarine warfare ships, 30 of which were built in foreign shipyards.'
- Verification
- partial
- Role
- correction
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- 1954-1971 (MDAP deliveries)
- Limitations
- Secondary compilation used to document conflicts, not as the carried value - NavSource and Portuguese sources are carried for designation and builder. Shipbuildinghistory is a reputable shipyard-production compiler but aggregates; its PCE prefix for this series conflicts with NavSource, Portuguese Wikipedia (type 'PC'), and the batch listing. No asbestos content.
- Atlas source
- true
- Evidence ID
- ev-uss-built-in-portugal-as-pc1637-03
-
[5]Arquivo Historico da Marinha (Portuguese Navy Historical Archive), Archeevo system: 'P 592 NRP "Boavista" 1966 Espichel' (PT/BCM-AH/APEPL/NGP/008/000001); companion item 'Patrulha "Boavista"' photos dated 1960-09-23 (PT/BCM-AH/FG/001-11/32-001 and 32-002, details?id=33315, id=33316); parent series 'Navios de Guerra Portugueses: Patrulhas' (1943-1975) [museum_official]
- Locator
- arquivohistorico.marinha.pt details?id=14929 (1966 Espichel photo); details?id=33315 and id=33316 (1960 photos); series details?id=14928
- Finding type
- historical_record
- Finding
- The Portuguese Navy's own archive holds dated, cataloged photography of this hull in service: 'P 592 NRP Boavista' underway off Cape Espichel, 1966 (Engenheiro Jose Augusto Paes Pires de Lima collection), and two further 'Patrulha Boavista' images dated 23 September 1960. These are the closest thing to primary Portuguese-Navy documentation located online; the archive series (Patrulhas, 1943-1975) likely holds additional Boavista material not digitized or not itemized online.
- Verification
- verified
- Role
- archival_lead
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- 1960-1966 (dated holdings); series covers 1943-1975
- Population
- Portuguese Navy crew (1960, 1966 documented; service span c.1956-c.1975)
- Limitations
- Archival lead only: photographs establish the vessel in Portuguese service at the dates cataloged, not work records, refit records, or material content. The archive's full holdings on this hull (logs, maintenance records) are undigitized. No asbestos content.
- Atlas source
- true
- Evidence ID
- ev-uss-built-in-portugal-as-pc1637-04
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[6]Portuguese Wikipedia, 'Lista de navios da Marinha Portuguesa por numero de amura' (pennant-number list): 'P 592 | NRP Boavista | PC | Brava'; class table corroboration 'NRP Boavista | ex-PC 1637 | E. N. Mondego | P 592'; plus Portuguese secondary class summaries (osrikinhus class-Maio profile; adescobertadonrpbrava NRP Brava history blog); seaforces.org Portuguese Navy ship list ('ex US PC-1635 class ... P 592 NRP Boavista (1957) - ex PC-1637') [other_primary]
- Locator
- pt.wikipedia.org pennant-number list, P 592 row; osrikinhus.blogspot.com 'Navio-Patrulha Classe Maio (1955-1975)' Boavista section; adescobertadonrpbrava.blogspot.com class/characteristics page; seaforces.org Portuguese Navy ships list
- Finding type
- vessel_history
- Finding
- Portuguese-side corroboration of identity and service: pennant P 592 = NRP Boavista, type PC, Brava class, built at Estaleiros Navais do Mondego, ex-PC 1637. Class context: Boavista was one of five Portuguese-built patrol vessels grouped administratively with three French-built sisters in the eight-ship 'Classe Maio' (Maio P 587, Porto Santo P 588, Sao Nicolau P 589 ex-PC-1613/1614/1617; Brava P 590, Fogo P 591, Boavista P 592, Santo Antao P 593, Santa Luzia P 594). Secondary sources report class duties as coastal patrol, ZEE fishery inspection, SAR and naval presence; Boavista in service until circa 1975; a photo caption places her with NRP Limpopo at Ponta Delgada on 21 April 1974.
- Verification
- partial
- Role
- context
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- 1956-1975
- Population
- Portuguese Navy crew (c.1956-c.1975)
- Limitations
- Secondary Portuguese sources (Wikipedia lists, enthusiast histories, class blog) - corroborating, not primary. Disposal/fate details rest on these: 'in service until 1975' and class abatement circa 1975-76 are unverified against a primary Portuguese Navy register. Sister-ship spec figures in the blog (357 t, 19 kt, crew 62) differ from NavSource (366 t, 17.5 kt) - variants noted, NavSource carried for this hull. No asbestos content.
- Atlas source
- true
- Evidence ID
- ev-uss-built-in-portugal-as-pc1637-05
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[7]Era inference built on: NavSource spec block (four SEMT-Pielstick diesels, two shafts - diesel-only plant); NavSource MDAP index (1956 foreign-built patrol vessel under US-funded program); GAO HRD-80-2 program-level era documentation (see ev-07) [other_primary]
- Locator
- NavSource 12/011637.htm spec block (propulsion line); NavSource 12/01idx.htm MDAP block
- Finding type
- asbestos_application
- Finding
- A naval patrol vessel built 1955-57 sits inside the era in which asbestos was standard in marine construction worldwide; era-standard applications aboard a diesel patrol vessel of this type and period were thermal insulation, machinery and diesel-exhaust lagging, gaskets, valve packing, and electrical insulation. As a diesel craft she carried no steam plant - the boiler/turbine lagging pathway of steam vessels does not apply.
- Verification
- inferred
- Role
- supporting
- Documentation level
- class_or_era
- Accessed
- 2026-10-03
- Study period
- 1955-1975
- Population
- Portuguese construction trades, Estaleiros Navais do Mondego (1955-57); Portuguese Navy crew (1956-c.1975); any disposal/shipbreaking workers
- Limitations
- Era inference only - and weaker than the usual class/era case: no hull-specific insulation survey, material list, work package, OR yard-level asbestos documentation for Estaleiros Navais do Mondego was located, and no class-specific material record exists for the PC-1635/Brava group. Names era-standard applications, not confirmed installed materials. No quantity. Product names are normalized era terms; no manufacturer attribution. Whether Portuguese OSP yards of 1956 used asbestos is itself undetermined in the sources searched - the inference is era- and type-level, not yard-level.
- Atlas source
- true
- Evidence ID
- ev-uss-built-in-portugal-as-pc1637-06
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[8]GAO, Navy Efforts To Protect Workers From Asbestos Exposure, HRD-80-2 (Oct 18, 1979) [gao]
- Locator
- GAO product page HRD-80-2 (full text blocked, HTTP 403)
- Finding type
- gov_survey
- Finding
- GAO documented that the U.S. Navy used asbestos insulation extensively aboard ships and did not begin substituting alternative insulation materials until the early 1970s - spanning this hull's construction window (1955-57) under a U.S.-funded procurement program.
- Verification
- verified
- Role
- context
- Documentation level
- context_only
- Accessed
- 2026-10-03
- Study period
- 1979
- Population
- U.S. Navy shipyard workers; asbestos program review
- Limitations
- Program-level U.S. Navy documentation carried strictly as era context: the GAO report addresses U.S. Navy ships and shipyards, not MDAP offshore-procurement construction in foreign yards, and does not establish what materials the Mondego yard installed in this hull. Full text not retrieved (gao.gov returns HTTP 403 to automated fetch, confirmed 2026-10-03) - content via product-page description.
- Atlas source
- true
- Evidence ID
- ev-uss-built-in-portugal-as-pc1637-07
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[9]Batch-7816 search ledger (this record): NavSource hull page and subchaser index; shipbuildinghistory MDAP table; Portuguese Navy Archeevo archive (items 14929, 33315, 33316, series 14928); Portuguese secondary class histories; seaforces.org fleet list; GAO product page; CourtListener via authenticated helper (blocked by fleet pacing); secondary web litigation sweep [other_primary]
- Locator
- search_ledger rows sl-uss-built-in-portugal-as-pc1637-01 through -10
- Finding type
- historical_record
- Finding
- No qualifying ship-specific asbestos record located: no asbestos survey, abatement contract, hazmat disclosure, or verified litigation naming PC-1637 or NRP Boavista (P 592) was found in the public sources searched. NavSource itself states 'There is no DANFS history available for PC-1637'; no NVR entry exists (never a U.S. Navy vessel). CAVEAT: CourtListener could not be queried to completion this session - the authenticated helper stood the session down repeatedly with the fleet-wide pacing gate (HTTP 429-adjacent budget throttle) - logged as blocked, not as a negative result. Secondary web sweeps surfaced no qualifying case and no law-firm listicle coverage of this hull (the marketing ship-list sites do not enumerate PC-1637 at all).
- Verification
- verified
- Role
- negative_finding
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- 2026-10-03
- Limitations
- Absence of a located public record does not prove absence of asbestos aboard - and the litigation repository search is a genuine open gap (paced, not completed). Portuguese-language archival holdings (Arquivo Historico da Marinha), Estaleiros Navais do Mondego yard records, and any disposal/scrapping records are undigitized leads. Does not establish or defeat any claim of exposure or legal eligibility.
- Atlas source
- true
- Evidence ID
- ev-uss-built-in-portugal-as-pc1637-08