Evidence
12 evidence entries recorded; each entry has a stable permalink (#ev-1 … #ev-12).
-
[1]research packet 968-packet.md [other_primary]
- Finding type
- vessel_history
- Finding
- Identity packet verdict: **VERIFIED
- Verification
- verified
- Role
- supporting
- Documentation level
- ship_specific
- Evidence ID
- uss-yms-475-pkt-968-packet-md
-
[2]NavSource Online: Mine Warfare Vessel Photo Archive, YMS-475 (ex-PCS-1447) - construction timeline, designation, specifications, commanding officer, disposal (live page verified 2026-10-04) [other_primary]
- Locator
- NavSource 11/19475.htm header block, timeline, specifications block, commanding-officer table
- Finding type
- vessel_history
- Finding
- NavSource timeline for this hull: 'Laid down 30 April 1943 as Patrol Craft Sweeper, PCS-1447 by the San Diego Marine Construction Co., San Diego, CA'; 'Reclassified as an Auxiliary Motor Minesweeper, YMS-475, 7 October 1943' (variant date - see ev-07); 'Launched 23 May 1944'; 'Completed 16 August 1944'; 'Struck from the Naval Register 29 October 1946'; 'Transferred to the War Shipping Administration 21 January 1947 and sold. Fate unknown.' Specifications: displacement 270 t.; length 136'; beam 24'6"; draft 8'; speed 15 kts.; complement 32; armament one 3"/50 dual purpose gun mount, two 20mm mounts, and two depth charge projectors; propulsion two 880bhp General Motors 8-268A diesel engines, Snow and Knobstedt single reduction gear, two shafts. Call sign Nan-Queen-Zebra-Peter (NQZP). Commanding officer table: LT L. W. Beardon, Jr., USNR (1945).
- Verification
- verified
- Role
- context
- Documentation level
- ship_specific
- Accessed
- 2026-10-04
- Study period
- 1942-1947
- Population
- San Diego Marine construction trades (1943-44); crew (1944-46)
- Limitations
- NavSource is a volunteer secondary compilation, not a primary registry - its milestone dates generally track NVR/DANFS practice but are not themselves official records; the reclassification date it prints (7 October 1943) conflicts with the class-wide 27 September 1943 date (see ev-07 and gaps). Contains no asbestos content.
- Atlas source
- true
- Evidence ID
- ev-uss-yms-475-01
-
[3]uboat.net Allied Warships, USS YMS-475 (YMS-475) - build/disposal registry entries (live page verified 2026-10-04) [other_primary]
- Locator
- uboat.net ship/9892.html data table and history fields
- Finding type
- vessel_history
- Finding
- Independent secondary registry corroborating this hull: 'Built by San Diego Marine Construction Co. (San Diego, California, U.S.A.)'; 'Ordered 24 Nov 1942'; 'Laid down 30 Apr 1943'; 'Launched 23 May 1944'; 'Commissioned 16 Aug 1944'; 'History: Stricken on 29 October 1946. Sold on 21 January 1947'; 'Former name: PCS-1447'.
- Verification
- verified
- Role
- context
- Documentation level
- ship_specific
- Accessed
- 2026-10-04
- Study period
- 1942-1947
- Limitations
- Secondary registry; corroborates NavSource milestone dates and supplies the order date (24 Nov 1942) not in NavSource. Does not give a reclassification date. Contains no asbestos content.
- Atlas source
- true
- Evidence ID
- ev-uss-yms-475-02
-
[4]Shipbuilding History (Tim Colton compilation), San Diego Marine Construction yard list - PCS 1447 row (live page verified 2026-10-04) [other_primary]
- Locator
- shipbuildinghistory.com San Diego Marine table, 'PCS 1447' row and yard-history preamble
- Finding type
- historical_record
- Finding
- Builder-yard delivery list for San Diego Marine Construction records this hull as 'PCS 1447 | US Navy | Sub Chaser | 278d | 136 | 16-Aug-44 | Completed as YMS 475, struck 1946, sold 1947' - confirming the yard, the PCS-1447-as-built identity, completion as YMS-475 (never commissioned as a PCS), the 16 August 1944 delivery/completion date, and the 1946/1947 disposal sequence. The same table documents the yard's other Navy small-craft output (YMS 113-116, YMS 143-146, YMS 281-284, PCS 1445-1448) and yard history: established 1915 by Capt. Oakley J. Hall; sold to Campbell Industries 1972, to Southwest Marine 1979; yard continues today as a BAE Systems Ship Repair facility adjacent to NASSCO.
- Verification
- verified
- Role
- context
- Documentation level
- ship_specific
- Accessed
- 2026-10-04
- Study period
- 1943-1947 (row); yard history 1915-2005
- Population
- San Diego Marine Construction workforce (1943-44 build period)
- Limitations
- Expert secondary compilation of yard records (researcher Tim Colton's shipbuildinghistory.com), not a primary registry; the 278d displacement figure differs from NavSource's 270 t. (see gaps). Yard-history dates corroborate but are not independently verified here. Contains no asbestos content.
- Atlas source
- true
- Evidence ID
- ev-uss-yms-475-03
-
[5]NHHC photograph NH 84992, 'USS YMS-475 USS YMS-461' - official U.S. Navy photo catalog entry (live page verified 2026-10-04) [other_primary]
- Locator
- NHHC NH-84000/NH-84992 catalog entry, Description field
- Finding type
- vessel_history
- Finding
- Official NHHC catalog entry documents this hull operating in company with YMS-461 'in San Francisco Bay, California, shortly after the end of World War II, circa late 1945 or early 1946' - post-war West Coast presence in the same bay where many YMS craft staged for inactivation or disposal processing. Caption notes 'YMS-461 later became USS Swallow (AMS-36). Courtesy of Donald M. McPherson, 1976.'
- Verification
- verified
- Role
- context
- Documentation level
- ship_specific
- Accessed
- 2026-10-04
- Study period
- circa late 1945 - early 1946
- Population
- crew (post-war inactivation period)
- Limitations
- A photograph and caption: establishes presence in San Francisco Bay c. late 1945-early 1946, not what work or duty she performed there. Contains no asbestos content.
- Atlas source
- true
- Evidence ID
- ev-uss-yms-475-04
-
[6]NHHC transcription, 'United States Pacific Fleet Organization, 1 May 1945' - MINECRAFT, PACIFIC FLEET, YMS block (live page verified 2026-10-04) [other_primary]
- Locator
- NHHC online reading room transcription, MINECRAFT PACIFIC FLEET section, YMS block (document p. ~137)
- Finding type
- vessel_history
- Finding
- Official wartime organization document places this hull in the U.S. Pacific Fleet as of 1 May 1945: under 'MINECRAFT, PACIFIC FLEET' (Commander Minecraft R. Adm. A. Sharp), in the general YMS listing that follows the numbered mine squadrons - row '94 | YMS 475 | (1) | Lt. W. B. Beardon, Jr. (USNR)'. Confirms wartime Pacific Fleet service and names her commanding officer as of that date.
- Verification
- verified
- Role
- context
- Documentation level
- ship_specific
- Accessed
- 2026-10-04
- Study period
- 1945-05-01
- Population
- crew (as of 1945-05-01)
- Limitations
- The left-column numeric codes ('94' here; '96', '11', '11a' on neighboring YMS rows) and the '(1)' annotation are not decoded in the transcribed document - probably station/assignment codes whose key is not reproduced; do not read a specific location into '94'. The NHHC transcription prints 'Lt. W. B. Beardon, Jr.' vs NavSource's 'LT L. W. Beardon, Jr.' - initials-order variance for the same officer (see gaps). An organization listing, not an operations or work record; contains no asbestos content.
- Atlas source
- true
- Evidence ID
- ev-uss-yms-475-05
-
[7]HyperWar / 'Ships of the U.S. Navy, 1940-1945' transcription (Patrick Clancey compilation of official Ships' Data), USS YMS-475 (live page verified 2026-10-04) [other_primary]
- Locator
- ibiblio.org/hyperwar/USN/ships/YMS/YMS-475.html spec block
- Finding type
- historical_record
- Finding
- Independent transcription of official-era reference data confirms: '136' class Motor Minesweeper'; 'Built at San Diego Marine Construction Co., and commissioned 16 August 1944' - corroborating builder and commission date. Spec block gives displacement 286 tons, length 136', beam 24'6", draft 8', armament 1 3"/50 DP, 2 20mm, depth-charge tracks and projectors, diesel engines twin screws '500 shaft hp'.
- Verification
- verified
- Role
- context
- Documentation level
- ship_specific
- Accessed
- 2026-10-04
- Study period
- 1944-1945 (source-data era)
- Limitations
- HyperWar 'Ships of the U.S. Navy, 1940-1945' is a compiled transcription of official-era Ships' Data, not the underlying registry itself; its fields are visibly scrambled in places (e.g., 'Complement' field prints propulsion data; 'Speed: 34' is an artifact) and its 286-ton displacement and '500 shaft hp' differ from NavSource's 270 t. and 880 bhp figures (see gaps). Contains no asbestos content.
- Atlas source
- true
- Evidence ID
- ev-uss-yms-475-06
-
[8]Designation cross-check: NavSource YMS-475 page (reclassified 7 October 1943) vs NavSource YMS-477 page ('Reclassified as an Auxiliary Motor Minesweeper, YMS-477, 27 September 1943') vs batch fact-QA (27 September 1943) [other_primary]
- Locator
- NavSource 11/19475.htm timeline line 2; NavSource 11/19477.htm timeline line 2; batch re-scope note (Trill fact-QA, 2026-09-29)
- Finding type
- historical_record
- Finding
- DESIGNATION RECORD RECONCILED: this hull was laid down as PCS-1447 and redesignated YMS-475 while still building, pre-commissioning - she was completed and commissioned as YMS-475 and never served under the PCS-1447 designation (batch fact-QA scope, confirmed by all three registries: NavSource 'ex-PCS-1447', uboat.net 'Former name PCS-1447', yard list 'Completed as YMS 475'). The PCS-1376-class hulls were reclassified to YMS-4xx numbers in a single class-wide administrative wave; NavSource prints 27 September 1943 for wave-mate YMS-477 (ex-PCS-1453) but 7 October 1943 on this hull's page - an internal inconsistency in one source, not two separate administrative acts. The 27 September 1943 date is carried per the batch fact-QA; the 7 October variant is logged in gaps.
- Verification
- partial
- Role
- correction
- Documentation level
- ship_specific
- Accessed
- 2026-10-04
- Study period
- 1943
- Limitations
- Resolves an identity/designation question, not a material claim. Neither NavSource page cites the underlying reclassification directive (BuShips letter or Change in Ship Characteristics entry), so 27 Sep vs 7 Oct remains a secondary-source conflict. No asbestos content.
- Atlas source
- true
- Evidence ID
- ev-uss-yms-475-07
-
[9]Era inference built on: NavSource/uboat.net/YMS-1-class specifications (wooden hull; two GM 8-268A diesels, twin screw; no steam plant); peer-reviewed asbestos-and-shipbuilding medical history (ev-09); GAO HRD-80-2 Navy asbestos-era documentation (ev-10) [other_primary]
- Locator
- NavSource 11/19475.htm specifications block; ev-09, ev-10 era anchors
- Finding type
- asbestos_application
- Finding
- A wooden-hulled auxiliary motor minesweeper built April 1943 - August 1944 at a wartime U.S. Navy yard sits inside the Navy's documented asbestos-use era. Era-standard asbestos applications aboard a small diesel-driven naval craft of this type and period were engine-exhaust lagging, flange and machinery gaskets, valve/stem packing, electrical insulation, and fireproofing/asbestos board around engine spaces and galleys. As a diesel craft with a wooden hull 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
- 2026-10-04
- Study period
- 1943-1947
- Population
- San Diego Marine construction trades (1943-44); crew (1944-46); WSA disposal/shipbreaking workforce (1947)
- Limitations
- Class/era inference only - no hull-specific insulation survey, material list, or work package located for YMS-475. Names era-standard applications, not confirmed installed materials. No quantity. A small 270-ton wooden minesweeper plausibly carried materially less asbestos than a steam combatant; the inference is bounded by her diesel plant and wooden construction. Product names are normalized era terms; no manufacturer attribution for this hull.
- Atlas source
- true
- Evidence ID
- ev-uss-yms-475-08
-
[10]Hedley-Whyte & Milamed, 'Asbestos and Ship-Building: Fatal Consequences', Ulster Medical Journal 77(3):191-200 (Sep 2008) via PubMed Central PMC2604477 (live page verified 2026-10-04) [other_primary]
- Locator
- PMC2604477, 'LOGISTICS OF ASBESTOS' section (1922 Navy specification; 1942 conservation order; WWII asbestos-board standard)
- Finding type
- asbestos_application
- Finding
- Peer-reviewed medical-history documentation of U.S. naval asbestos specification in this hull's era: 'In 1922 the US Navy specified asbestos use in new submarines. South African chrysotile asbestos was specified for gaskets, insulation, packing and tape'; 'By World War II this technology had been refined with asbestos board as the standard of noncombustibility'; and on wartime allocation: 'On January 20, 1942... the first Asbestos Conservation order was issued. FDR's presidential order essentially banned the use of asbestos for non-military purposes; priority was given to merchant and US and Royal Navy ship-building' - covering this hull's entire 1943-44 construction window.
- Verification
- verified
- Role
- context
- Documentation level
- class_or_era
- Accessed
- 2026-10-04
- Study period
- 1922-1945 (documented era)
- Population
- WWII naval shipbuilding workforce and ship crews (era)
- Limitations
- Era/program-level scholarship, not a hull record: documents Navy asbestos specification practice and wartime priority allocation generally - YMS-475 is not named. A review article, not a material survey. Does not establish materials aboard this hull, individual exposure, or quantity.
- Atlas source
- true
- Evidence ID
- ev-uss-yms-475-09
-
[11]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 construction (1943-44) and service era (1944-46).
- Verification
- verified
- Role
- context
- Documentation level
- class_or_era
- Accessed
- 2026-10-04
- 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 blocks automated fetch, HTTP 403, confirmed 2026-10-04 - same standing access defect noted in BATCH-01 and BATCH-98) - content via product-page description.
- Atlas source
- true
- Evidence ID
- ev-uss-yms-475-10
-
[12]Batch-8365 search ledger (this record): NavSource x2; uboat.net; shipbuildinghistory.com; NHHC photo NH 84992; NHHC Pacific Fleet organization 1 May 1945; HyperWar Ships' Data transcription; NVR; NARA catalog; CourtListener x4+; secondary web; PMC2604477; GAO product page [other_primary]
- Locator
- search_ledger rows sl-uss-yms-475-01 through sl-uss-yms-475-15
- Finding type
- historical_record
- Finding
- No qualifying ship-specific asbestos record located: no asbestos survey, abatement contract, hazmat disclosure, or qualifying litigation naming YMS-475 or PCS-1447 was found in the public sources searched (see search_ledger; 4 uninspected tail hits on one CourtListener docket query are a disclosed caveat, not a clean negative). Secondary web sweeps surfaced no qualifying case; the only 'asbestos aboard' material is law-firm marketing content (mesothelioma.com minesweepers page listing 'Yard minesweepers (YMS)' among asbestos-bearing types; Kazan Law's San Diego page naming San Diego Marine Construction among asbestos sites) - excluded by source policy as unsourced marketing assertions.
- Verification
- verified
- Role
- negative_finding
- Documentation level
- ship_specific
- Accessed
- 2026-10-04
- Study period
- 2026-10-04
- Limitations
- Absence of a located public record does not prove absence of asbestos aboard. Deck logs (RG 24, Aug 1944 - Oct 1946), BuShips work packages, the WSA disposal file, and any scrapping/shipbreaking records are undigitized or JS-blocked leads. Does not establish or defeat any claim of exposure or legal eligibility.
- Atlas source
- true
- Evidence ID
- ev-uss-yms-475-11