Evidence
9 evidence entries recorded; each entry has a stable permalink (#ev-1 … #ev-9).
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[1]research packet 909-packet.md [other_primary]
- Finding type
- vessel_history
- Finding
- Identity packet verdict: VERIFIED
- Verification
- verified
- Role
- supporting
- Documentation level
- ship_specific
- Evidence ID
- uss-pc-575-pc575-pkt-909-packet-md
-
[2]NavSource Naval History, Submarine Chaser Photo Archive, PC-575 page (live .net domain, verified 2026-10-03); corroborated by uboat.net Allied Warships register, ship/8552 (ordered 1 Apr 1941; Dravo Corp., Pittsburgh) [other_primary]
- Locator
- PC-575 page, chronology block + specifications block; photo caption 'c. 1969, Royal Thai Navy photo'
- Finding type
- vessel_history
- Finding
- Identity and disposition record for this hull: PC-461-class submarine chaser laid down 24 February 1942 by Dravo Corp., Pittsburgh, PA; launched 5 May 1942; commissioned USS PC-575, 8 August 1942; rescued survivors of U.S. freighter James Robertson, torpedoed by U-185 on 7 July 1943, landing them at Trinidad 15 July 1943; struck from the Naval Register 13 December 1946; transferred to the Foreign Liquidation Commission March 1947, sold to Thailand as HTMS Thayanchon (PC 2); Royal Thai Navy decommissioned 26 May 1982; fate unknown. Page carries a c.1969 Royal Thai Navy photograph and notes 'There is no DANFS history available for PC-575.'
- Verification
- verified
- Role
- supporting
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- 1942-1982
- Population
- Dravo Neville Island construction trades (1942); USN crew 1942-46 (design complement 65); Royal Thai Navy crew 1947-82
- Limitations
- NavSource is the standard private vessel-history archive (compiles DANFS, Navy registers, shipmate submissions), not a government source - used here because no DANFS entry exists for this hull. Specifications are class-level data attached to the hull page. Contains no asbestos or materials information; Thai-service decommissioning date rests on this source alone.
- Atlas source
- true
- Evidence ID
- ev-uss-pc-575-pc575-01
-
[3]NARA RG 38, WWII War Diaries: USS PC-575 War Diary, 9/1-30/43 (NAID 78191808, Roll A580); plus War Diary 8/1-31/43 (NAID 135942813, Roll A541) and 10/1-31/43 (NAID 134331186, Roll A633) [other_primary]
- Locator
- catalog.archives.gov NAIDs 78191808 (Sep 1943, image 0850 sequence - Sept 1-2 entries), 134331186 (Oct 1943, image 0355 - 1 October entry), 135942813 (Aug 1943)
- Finding type
- vessel_history
- Finding
- The ship's own contemporaneous operational record is digitized and readable: the September 1943 diary (first pages inspected) shows PC-575 moored at Section Base, Trinidad, B.W.I., alongside PC-574 and PC-1194 among minesweepers and minor war craft, with Lt.Cdr. Henry C. M. Lamkin, USNR signing as commanding officer; the 1 October 1943 diary page shows her en route Recife, Brazil, to Trinidad as one of six escorts (PG-19 as escort commander; PG-70; PCs 488, 574, 498, 575) screening a 26-ship merchant convoy, steaming 450 RPM on both engines, radar in operation, sound search 195-015(T), depth charges set 50/100 ft - with Lt. H. M. Bashinski, USNR signing as commanding officer (consistent with the 21 September 1943 turnover in the compiled roster). Confirms Fourth Fleet South Atlantic convoy-escort and anti-submarine operations for this hull.
- Verification
- verified
- Role
- supporting
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- 1943
- Population
- USN crew aboard PC-575, Aug-Oct 1943
- Limitations
- War diaries document operations, positions, and material-condition remarks - they contain no asbestos or insulation information and were not exhaustively reviewed page-by-page for material-condition entries. Only three monthly file units (Aug-Oct 1943) are digitized for this hull; other months are not located in the digitized series. Digitization via Fold3 microfilm partnership.
- Atlas source
- true
- Evidence ID
- ev-uss-pc-575-pc575-02
-
[4]NARA RG 24, Muster Rolls of U.S. Navy Ships, Stations, and Other Naval Activities: file unit 'PC-575, 8/8/42-3/4/46' (NAID 192660951, Roll 5796, 323 images, digitized via Ancestry partnership) [other_primary]
- Locator
- catalog.archives.gov NAID 192660951, file-unit description page (323 images)
- Finding type
- historical_record
- Finding
- The complete muster-roll run for this hull is digitized at NARA, spanning her entire U.S. Navy commission from 8 August 1942 through 4 March 1946 - every crewman's reporting and detachment is named. This is the highest-value lead for personnel-level exposure research (rosters of who served aboard and when) and fixes the end of USN administrative control at about 4 March 1946.
- Verification
- verified
- Role
- archival_lead
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- 1942-1946
- Population
- All personnel who served aboard PC-575, 1942-1946
- Limitations
- Muster rolls are personnel rosters, not material records - they contain no asbestos or insulation data. Pages were not individually reviewed; the end date 1946-03-04 marks coverage but the decommissioning event and place are not stated in the catalog metadata. Digitization quality and completeness per Ancestry/NARA partnership scan.
- Atlas source
- true
- Evidence ID
- ev-uss-pc-575-pc575-03
-
[5]Cressman, The Official Chronology of the U.S. Navy in World War II (NHHC publication, verbatim HyperWar/ibiblio transcription), entry for 7 July 1943 [nhhc_danfs]
- Locator
- USN-Chron-1943.html, Chapter V July, entry for 7 July 1943 (search 'PC-575'); uboat.net/allies/merchants/ship/2990.html
- Finding type
- vessel_history
- Finding
- Official Navy chronology records this hull by name: on 7 July 1943 German submarine U-185 attacked convoy BT 18 off Brazil, torpedoing U.S. freighter James Robertson at 04°00'S, 36°00'W; 'Submarine chaser PC-575 rescues 21 men.' The merchant complement had abandoned in boats and rafts after colliding with two other convoy ships; PC-575 landed the survivors at Trinidad on 15 July 1943 (NavSource; corroborated by uboat.net's James Robertson record - 21 men picked up from rafts, one boat, and the water).
- Verification
- verified
- Role
- supporting
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- 1943
- Population
- PC-575 crew; 21 rescued merchant mariners/Armed Guard of James Robertson
- Limitations
- Operational-history source only - no asbestos or materials content. Survivor count (21) is consistent across the official chronology and uboat.net; NavSource does not give a count. The uboat.net warship page misprints the event date as '3 Jul 1943' - 7 July per the official chronology and uboat.net's own merchant-ship record.
- Atlas source
- true
- Evidence ID
- ev-uss-pc-575-pc575-04
-
[6]DANFS, LCI(L)-777 (NHHC, live page verified 2026-10-03) - PC-575 appears in this sister vessel's history [nhhc_danfs]
- Locator
- DANFS LCI(L)-777 entry, 1944-1949 section (Shanghai departure 25 Nov 1945 through Tsingtao arrival 30 Nov 1945)
- Finding type
- vessel_history
- Finding
- DANFS records PC-575's post-hostilities western Pacific movement: she departed Shanghai in company with LCI(L)-777 on 25 November 1945 bound for Jinsen (Inchon), Korea; on 26 November PC-575 suffered a mechanical failure resolved within about half an hour while LCI(L)-777 reversed course to assist; both ships stood up the swept channel to Jinsen on 27 November and sailed again in company on 29 November for Tsingtao, China, arriving the afternoon of 30 November and remaining through the first week of December 1945. Documents the hull operating in China/Korea waters in the months before decommissioning.
- Verification
- verified
- Role
- supporting
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- 1945
- Population
- PC-575 crew, November-December 1945
- Limitations
- PC-575 appears as a supporting actor in another ship's DANFS entry - the passage documents movements and one mechanical casualty, nothing about materials or asbestos. No DANFS entry exists for PC-575 herself; this is the principal official narrative record of her late-service operations.
- Atlas source
- true
- Evidence ID
- ev-uss-pc-575-pc575-05
-
[7]NavSource PC/SC index (class composition and characteristics) + NavSource PC-575 specifications block (H-O-R R-99DA diesels) + shipbuildinghistory.com Dravo Pittsburgh hull list [other_primary]
- Locator
- NavSource 01idx class index; PC-575 specifications block; shipbuildinghistory.com/shipyards/large/dravoboats.htm (PC 575 row)
- Finding type
- asbestos_application
- Finding
- Era/class inference: PC-575 is a 1942 steel-hulled PC-461-class submarine chaser (second series, PC-542 to PC-627) built during the period when the U.S. Navy used asbestos insulation materials extensively aboard ships (GAO HRD-80-2: substitution of alternative insulation did not begin until the early 1970s). Her propulsion was twin diesel (two 1,440-bhp Hooven-Owen-Rentschler R-99DA engines, Westinghouse single-reduction gear, two shafts) - no boilers or steam plant - so the asbestos-relevant applications for a craft of this type and era were diesel exhaust lagging, machinery thermal insulation, valve/flange gaskets, machinery packing, electrical cable insulation, and deck coverings rather than boiler/turbine lagging. Builder Dravo Corp. (Neville Island, Pittsburgh) is confirmed by the yard's own hull list at shipbuildinghistory.com; Dravo is not in the Atlas shipyards.json dataset.
- Verification
- inferred
- Role
- supporting
- Documentation level
- class_or_era
- Accessed
- 2026-10-03
- Study period
- 1942-1982
- Population
- Dravo Neville Island construction trades (1942); USN crew 1942-46; RTN crew and yard workers 1947-82
- Limitations
- Class/era inference only - no hull-specific insulation survey, material list, or work package located for PC-575. Names era-standard applications, not confirmed installed materials; no quantity; no manufacturer attribution. The smaller, simpler plant of a 173-ft diesel patrol craft implies lower asbestos-relevant material than a steam combatant, but this is inference, not measurement.
- Atlas source
- true
- Evidence ID
- ev-uss-pc-575-pc575-06
-
[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 Navy used asbestos insulation extensively aboard ships and did not begin substituting alternative insulation materials until the early 1970s - spanning this hull's entire U.S. construction (1942) and service era, and overlapping her Royal Thai Navy service (1947-82).
- Verification
- verified
- Role
- context
- Documentation level
- class_or_era
- Accessed
- 2026-10-03
- Study period
- 1979
- Population
- Navy shipyard workers; asbestos program review
- Limitations
- Program-level documentation; supports era context only, not any fact specific to this hull. Full text not retrieved (gao.gov returns HTTP 403 to automated fetch, confirmed 2026-10-03) - content via product-page description, same limitation as Batch-01/Batch-98.
- Atlas source
- true
- Evidence ID
- ev-uss-pc-575-pc575-07
-
[9]Batch-7950 search ledger (this record): NavSource hull page and class index; NARA catalog (war diaries NAIDs 135942813/78191808/134331186; muster rolls NAID 192660951); NHHC DANFS LCI(L)-777 page and PC-575 URL probes (404); USN Official Chronology (HyperWar); NVR hull-detail probe; CourtListener (blocked - fleet pacing, see search_ledger); secondary web litigation sweep; shipbuildinghistory.com Dravo Pittsburgh hull list; Historic Pittsburgh Dravo collections lead [other_primary]
- Locator
- search_ledger rows sl-uss-pc-575-pc575-01 through -10
- Finding type
- historical_record
- Finding
- No qualifying ship-specific asbestos record located: no asbestos survey, abatement contract, hazmat disclosure, material inventory, or verified litigation naming PC-575/Thayanchon was found in the public sources searched (see search_ledger). CAVEAT: CourtListener could not be queried this session - the fleet pacing budget was momentarily spent on every attempt across the session (~5 tries over ~90 minutes); logged as blocked, not a negative result. A general web sweep surfaced no qualifying case or exposure claim naming this hull - only name collisions (a polycarbonate product code, a county casework code, law-firm 'P.C.' strings).
- 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 - a 1942 steel combatant of this class sat squarely in the Navy's documented asbestos era. The litigation repository search is a genuine open gap (pacing-blocked, not run). Does not establish or defeat any claim of exposure or legal eligibility.
- Atlas source
- true
- Evidence ID
- ev-uss-pc-575-pc575-08