Evidence
12 evidence entries recorded; each entry has a stable permalink (#ev-1 … #ev-12).
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[1]research packet 970-packet.md (1 sources cited) [museum_official]
- Finding type
- vessel_history
- Finding
- Identity packet verdict: MISMATCH
- Verification
- verified
- Role
- correction
- Documentation level
- ship_specific
- Evidence ID
- uss-yms-480-pkt-970-packet-md
-
[2]NavSource Online, Mine Warfare Vessel Photo Archive, YDG-7 ex-YMS-480 ex-PCS-1462 (live page verified 2026-10-04, HTTP 200) [other_primary]
- Locator
- Header chronology, specifications block, and commanding-officer table
- Finding type
- vessel_history
- Finding
- NavSource's live timeline identifies the hull as laid down 25 May 1943 as Patrol Craft Sweeper PCS-1462 by the Bellingham Marine Railway and Boatbuilding Co., Bellingham, WA; reclassified Auxiliary Motor Minesweeper YMS-480 on 27 September 1943; launched 20 November 1943; reclassified District Degaussing Vessel YDG-7 on 23 December 1943; completed 15 March 1944; struck from the Navy Register 12 April 1946; transferred to the War Shipping Administration 27 August 1947 and sold; fate unknown. The page's commanding-officer table lists LCDR William A. Saleebey, USNR (15 March 1944 - May 1945), LT Herbert E. Bergquist, USNR (May 1945 - December 1945), and LTJG Peter Popovich, USNR (December 1945 - 26 March 1946). The same page lists specifications: displacement 270 t., length 136 ft, beam 24 ft 6 in, draft 8 ft, speed 15 kts, complement 32, two 20mm mounts, and two '1,800shp' General Motors 8-268A diesel engines with Snow and Knobstedt single reduction gear on two shafts.
- Verification
- partial
- Role
- supporting
- Documentation level
- ship_specific
- Accessed
- 2026-10-04
- Study period
- 1943-1947
- Population
- Bellingham Marine Railway and Boatbuilding construction trades (1943-44); U.S. Navy YDG-7 crew (1944-46); War Shipping Administration custody (1947)
- Limitations
- NavSource is a live secondary photo-archive compilation, not an official registry. It supports the stated timeline, commanding-officer list, and specifications only; it records 'Completed 15 March 1944' rather than an explicit commissioning event, prints an anomalous '1,800shp' engine figure (see gaps), and contains no asbestos, survey, abatement, product, or exposure evidence.
- Atlas source
- true
- Evidence ID
- ev-uss-yms-480-01
-
[3]NavSource timeline for YDG-7 and shipscribe USS YDG-6-class construction table, read with the supplied Trill fact-QA correction (crew signs 960-977, 2026-09-29) [other_primary]
- Locator
- NavSource header chronology (reclassified YDG-7 23 December 1943, completed 15 March 1944); shipscribe YDG-6-class construction row for YDG-7 (reclas. 23 Dec 43, commiss. 15 Mar 44)
- Finding type
- vessel_history
- Finding
- CORRECTION: Neither PCS-1462 nor YMS-480 was ever a commissioned service identity for this hull. She was laid down under the contract designation PCS-1462, reclassified YMS-480 on 27 September 1943 while still on the ways, then reclassified again to District Degaussing Vessel YDG-7 on 23 December 1943 - before her 15 March 1944 completion. Per the convergent shipscribe and NavSource chronologies she completed and commissioned as YDG-7; the batch fact-QA instruction (crew signs 960-977) confirms 'never served as PCS-1462', and the source chronology extends the same logic to YMS-480, a designation she held for under three months, entirely before completion.
- Verification
- verified
- Role
- correction
- Documentation level
- ship_specific
- Accessed
- 2026-10-04
- Study period
- 1943-1944
- Limitations
- Corrects designation framing only. Both carrying sources are secondary compilations; no live official register independently establishes the commissioning designation. The batch's fact-QA instruction says 'commissioned as YMS-480' - the sourced chronology refines that: the reclassification to YDG-7 predates completion, so YDG-7 was the commissioned identity. It establishes no asbestos fact.
- Atlas source
- true
- Evidence ID
- ev-uss-yms-480-02
-
[4]shipscribe.com, USS YDG-6 Class auxiliary-vessel data compilation (Stephen S. Roberts, compiled from U.S. Navy records; live page verified 2026-10-04, HTTP 200) [other_primary]
- Locator
- Construction table (YDG-7 row), disposition table (YDG-7 row), Class Notes, and Ship Notes (YDG-7)
- Finding type
- vessel_history
- Finding
- Stephen S. Roberts's shipscribe compilation of U.S. Navy auxiliary records documents: YDG-7 reclassified 23 December 1943; built by Bellingham Marine (keel 25 May 1943, launched 20 November 1943, commissioned 15 March 1944); decommissioned 25 March 1946; struck 12 April 1946; disposal 27 August 1947 (Maritime Commission disposal / sale). The class note records that on 20 December 1943 CNO authorized conversion of YMS-480 (which had been PCS-1462 until 27 September 1943) to a mobile degaussing vessel in place of PCS-1461. The ship note records: 'Ex YMS-480 23 Dec 43, ex PCS-1462 27 Sep 43. Decommissioned after teredo damage to the entire underwater hull was discovered.' Class specifications for the YDG-6 class: 196 light/277 full tons, 136.0 ft oa, diesel machinery (1,000 HP), 2 screws, 2-20mm armament (1944), complement 28 (1944).
- Verification
- verified
- Role
- supporting
- Documentation level
- ship_specific
- Accessed
- 2026-10-04
- Study period
- 1943-1947
- Population
- Bellingham Marine construction trades (1943-44); U.S. Navy YDG-7 crew (1944-46)
- Limitations
- shipscribe is a private data compilation built from Navy records, not the issuing agency's site - but it is the standard scholarly reference for U.S. auxiliary vessels and names the underlying authorization events. It establishes milestones, the CNO conversion authorization, and the teredo-damage decommissioning cause; it contains no asbestos, material-list, or exposure content.
- Atlas source
- true
- Evidence ID
- ev-uss-yms-480-03
-
[5]shipscribe.com USS YDG-6 Class class notes and photo captions (live 2026-10-04); Naval Marine Archive, Bellingham Shipyards hull table (live 2026-10-04, HTTP 200) [other_primary]
- Locator
- shipscribe Class Notes paragraph and photo captions; navalmarinearchive.com/sbh/shipyards/small/bellingham.html PCS 1462 row
- Finding type
- vessel_history
- Finding
- The shipscribe class notes describe the YDG conversion work: 'The conversion of YDG-6 and probably YDG-7 included an elongation of the forecastle deck house, a rearrangement of the spaces therein, and removal of the 3"/50 gun foundation.' Degaussing equipment described for the class included material for two complete independent coil ranges, portable magnetometers for calibration, cable and other equipment for deperming destroyers and smaller ships with the assistance of a minesweeper fitted with a diesel generator, and additional cable, floater hose, and accessories for the flash-D treatment of submarines. A photo caption notes YDG-7 'lacks a stack' consistent with her PCS-variant construction. Separately, the Naval Marine Archive's Bellingham Shipyards table independently lists hull PCS 1462 as 'Completed as YMS 480, later YDG 7, sold 1947' delivered 15-Mar-44 - corroborating the PCS-1462 -> YMS-480 -> YDG-7 chain.
- Verification
- partial
- Role
- supporting
- Documentation level
- class_or_era
- Accessed
- 2026-10-04
- Study period
- 1943-1946
- Population
- Bellingham conversion/outfitting trades (1943-44); YDG-7 crew during degaussing-range operations (1944-46)
- Limitations
- The conversion description is hedged by the source itself ('probably YDG-7') - the specific worklist is documented for the class, with YDG-7's inclusion probable but not separately attested. The Naval Marine Archive table is a secondary yard compilation. No asbestos, material, or exposure content. The 'first ordered as a PCE' wording in the shipscribe photo caption is loose terminology - the authoritative chain is PCS-1462 per every other source row.
- Atlas source
- true
- Evidence ID
- ev-uss-yms-480-04
-
[6]National Archives, Special List #44, by Ship Numbers (live PDF retrieved and text-extracted 2026-10-04, HTTP 200) [other_primary]
- Locator
- PDF table YDG section (entries YDG-3 through YDG-11; no YDG-7 row) and YMS section (YMS-481 row; no YMS-480 row)
- Finding type
- historical_record
- Finding
- NARA's Special List #44, by Ship Numbers, contains no entry for YDG-7, YMS-480, or PCS-1462: no deck-log coverage interval is indexed for this hull under any of her designations (the adjacent YDG entries run YDG-3, YDG-4, YDG-6, YDG-8, YDG-9, YDG-10, YDG-11; her sister YMS-481 shows indexed coverage 21 April 1944 - 31 March 1945). The absence distinguishes her from commissioned fleet minecraft and is consistent with her district-craft service profile.
- Verification
- verified
- Role
- archival_lead
- Documentation level
- ship_specific
- Accessed
- 2026-10-04
- Study period
- 1944-1946 records
- Limitations
- Absence from a finding aid is not proof that no logs exist - deck logs of district craft may be filed under a parent command or simply unindexed; a box-level NARA request naming YDG-7/YMS-480 is the next source path. Establishes no asbestos, event, or exposure fact.
- Atlas source
- true
- Evidence ID
- ev-uss-yms-480-05
-
[7]National Archives, An Introduction to Navy Deck Logs; Logbooks of the U.S. Navy at the National Archives (live page verified 2026-10-04, HTTP 200) [other_primary]
- Locator
- NARA deck-log guidance: commissioned-vs-in-service distinction, RG 24 and 1941-and-later College Park holdings; catalog search https://catalog.archives.gov/search?q=YDG-7
- Finding type
- historical_record
- Finding
- NARA's deck-log guidance explains the record path and a structural feature relevant to this hull: only deck logs of commissioned Navy ships are retained permanently, while most service vessels 'are classified as "in service" instead of "in commission" and do not possess their own administrative identity' - their logs, if kept, are not permanent records. Permanent logs are held in Record Group 24, with 1941-and-later logs generally at College Park. The public catalog search produced no digitized hull record for YDG-7/YMS-480 during this pass.
- Verification
- verified
- Role
- archival_lead
- Documentation level
- context_only
- Accessed
- 2026-10-04
- Study period
- 1944-1947 records
- Limitations
- Record-path guidance only, not proof that a particular YDG-7 log, construction file, or asbestos record survives - and NARA's own guidance suggests district craft logs may never have been permanent records. No box-level or paid reproduction request was made, and no asbestos finding is asserted.
- Atlas source
- true
- Evidence ID
- ev-uss-yms-480-06
-
[8]HyperWar (ibiblio), Ships of the U.S. Navy, 1940-1945, Yard and District Craft index (live 2026-10-04); NavSource YMS index class description (live 2026-10-04, HTTP 200) [other_primary]
- Locator
- ships-ya.html YDG category header and standing note; navsource.net/archives/11/19idx.htm class description paragraphs
- Finding type
- vessel_history
- Finding
- The HyperWar mirror of Ships of the U.S. Navy, 1940-1945 lists YDG-class vessels only as a category header under Yard and District Craft, with the standing note that 'published details on individual yard and district craft are virtually nonexistent' - consistent with the thin official record available for this hull. NavSource's YMS index supplies class context: the wood-hulled YMS type numbered 481 U.S. ships built at 35 yacht yards; YMS-135 through 445, 480, and 481 carried a single stack in the index's appearance note (though the shipscribe photo caption for YDG-7 notes she 'lacks a stack' consistent with her PCS-variant build).
- Verification
- verified
- Role
- context
- Documentation level
- class_or_era
- Accessed
- 2026-10-04
- Study period
- 1940-1945
- Limitations
- Class and category context only; establishes the YMS type's wooden hull and the general scarcity of published yard/district-craft detail. It does not locate YDG-7 geographically, establish operations, or contain any asbestos, equipment, or exposure information.
- Atlas source
- true
- Evidence ID
- ev-uss-yms-480-07
-
[9]NavSource YMS-481 page and YDG index; uboat.net YMS-481 entry; Naval Marine Archive Bellingham Shipyards table; NavSource YMS-460 page (all live-verified 2026-10-04) [other_primary]
- Locator
- NavSource 11/19481.htm header vs body text; uboat.net/allies/warships/ship/9897.html 'Former name' field; navalmarinearchive Bellingham table PCS-1462/PCS-1463 rows; NavSource 14/63idx.htm YDG-7 line and 11/19460.htm timeline
- Finding type
- historical_record
- Finding
- CORRECTION: Secondary compilations conflate this hull with her sister YMS-481 in two directions. (a) NavSource's YMS-481 page header correctly says 'ex-PCS-1463' but its body text repeats this hull's data - 'Laid down 25 May 1943 as Patrol Craft Sweeper, PCS-1462' - and uboat.net's YMS-481 page likewise lists former name PCS-1462 with identical dates; the Naval Marine Archive yard table resolves the split as PCS-1462 -> YMS-480 (later YDG-7) and PCS-1463 -> YMS-481 (sunk off Tarakan, Borneo, 2 May 1945), both delivered 15 March 1944. (b) NavSource's own YDG index mislabels 'YDG-7 ex YMS-460' while linking to the correct 19480 page; YMS-460 (ex-PCS-1415, Stadium Yacht Basin, Cleveland) was transferred to the Soviet Union as T-183 in 1945 and never held a YDG designation.
- Verification
- verified
- Role
- correction
- Documentation level
- ship_specific
- Accessed
- 2026-10-04
- Study period
- 1943-1947
- Limitations
- Corrects circulating attribution errors in secondary compilations; the carrying evidence is itself secondary-tier, but the three-way convergence (NavSource 19480 page + shipscribe + Naval Marine Archive yard table) supports the PCS-1462 -> YMS-480 -> YDG-7 chain for this hull. Establishes no asbestos fact.
- Atlas source
- true
- Evidence ID
- ev-uss-yms-480-08
-
[10]U.S. Government Accountability Office, Navy Efforts To Protect Workers From Asbestos Exposure, HRD-80-2 (1979) [gao]
- Locator
- GAO product record HRD-80-2; direct product and PDF requests returned HTTP 403 during this pass
- Finding type
- gov_survey
- Finding
- GAO's 1979 report Navy Efforts To Protect Workers From Asbestos Exposure is Navy-wide historical context for asbestos use and worker-protection efforts; it is retained only as class/era context for a Navy vessel constructed in 1943-44.
- Verification
- partial
- Role
- context
- Documentation level
- class_or_era
- Accessed
- 2026-10-04
- Study period
- 1979 report; vessel construction 1943-44
- Population
- Navy asbestos program and workers (program-level context)
- Limitations
- The report was not retrievable live because GAO returned HTTP 403 (confirmed 2026-10-04), so no detailed report proposition is attributed here. Navy-wide context cannot establish asbestos installation, product identity, quantity, condition, exposure, or causation aboard this hull.
- Atlas source
- true
- Evidence ID
- ev-uss-yms-480-09
-
[11]Research result for this batch; see search ledger and access gaps [other_primary]
- Locator
- Searches documented in search_ledger
- Finding type
- asbestos_application
- Finding
- No ship-specific asbestos survey, abatement record, hazmat disclosure, or product-identification record was located in the sources reviewed for this batch. Ship-specific asbestos documentation is unknown.
- Verification
- partial
- Role
- negative_finding
- Documentation level
- ship_specific
- Accessed
- 2026-10-04
- Study period
- 2026-10-04
- Limitations
- A bounded search result, not proof that records do not exist. NARA notes that many Navy records are not digitized and district-craft records are particularly thin; the NavSource, shipscribe, Naval Marine Archive, HyperWar, and secondary sources reviewed contain no asbestos information. No class-era inference is used to claim asbestos aboard this hull.
- Atlas source
- true
- Evidence ID
- ev-uss-yms-480-10
-
[12]CourtListener authenticated API v4 helper sweep, 2026-10-04; secondary web sweep same date [other_primary]
- Locator
- search_ledger rows sl-uss-yms-480-13 through sl-uss-yms-480-16; completed query response {count: 0, results: []}
- Finding type
- historical_record
- Finding
- No qualifying ship-specific asbestos litigation result was located in this pass. Of the four mandatory authenticated CourtListener base searches, the exact-name opinion query ("USS YMS-480", type=o, limit 20) completed with count 0. The exact-name docket search and both hull-number searches ("YMS-480", type=o and type=r) were repeatedly declined by the authenticated helper's fleet-wide pacing gate before results returned; those are access gaps, not zero-result findings. A separate secondary-web sweep for asbestos litigation naming this hull surfaced no qualifying case.
- Verification
- partial
- Role
- negative_finding
- Documentation level
- ship_specific
- Accessed
- 2026-10-04
- Study period
- 2026-10-04
- Limitations
- The zero-result exact-name opinion search does not prove no litigation exists: it covers only the opinion index under the exact string 'USS YMS-480'. Three of four base queries returned pacing stand-down rather than results, and no 'YDG-7' litigation query was run (the four-query protocol covers the ship's batch name only). No asbestos-qualified variants were run because no completed base query returned a 20-result overflow, and a zero base result implies a zero variant.
- Atlas source
- true
- Evidence ID
- ev-uss-yms-480-11