Evidence
7 evidence entries recorded; each entry has a stable permalink (#ev-1 … #ev-7).
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[1]DANFS vol. III (G-I), Grayback (SS-208) entry - construction, ten war patrols, loss narrative from captured Japanese records (printed-volume transcription via hazegray.org/Wayback; live NHHC page returned 404) [nhhc_danfs]
- Locator
- DANFS vol. III (G-I), Grayback entry and spec block
- Finding type
- vessel_history
- Finding
- Documented for this hull (DANFS): launched 31 January 1941 by Electric Boat Co., Groton, Conn. (sponsor Mrs. Wilson Brown); commissioned 30 June 1941 at New London, Lt. Willard A. Saunders. Caribbean patrol with Grampus September 1941; overhaul at Portsmouth, N.H. November 1941; Pearl Harbor from February 1942; Fremantle-based for most of the war. Ten war patrols: sank a 3,291-ton cargo ship off Port Lloyd 17 March 1942; Pharmacist's Mate Harry B. Roby performed an emergency appendectomy on patrol December 1942; battle-surfaced to sink four landing barges 20 December; sank Japanese submarine I-18 on 3 January 1943; rescued six downed B-26 aviators at Munda Bay (skipper Edward C. Stephan received the Navy Cross); took 19 depth charges 17 January 1943 - 'one blew a gasket on a manhole cover' and she returned to Brisbane leaking. First Submarine Force wolfpack with Shad and Cero under Capt. C. B. Momsen (eighth patrol); sank Awata Maru and others. Ninth patrol netted four ships incl. Gyokurei Maru and escort Numakaze. Tenth patrol: sailed 28 January 1944 for the East China Sea; final report 25 February; sank Ceylon Maru 27 February with her last two torpedoes; that same day a Japanese carrier-based plane attacked a surfaced submarine which 'exploded and sank immediately' per Japanese reports; the area was depth-charged until a heavy oil slick surfaced. Listed missing and presumed lost 30 March 1944. 63,835 tons sunk (20th), 14 ships (24th); two Navy Unit Commendations (7th-10th patrols); eight battle stars.
- Verification
- verified
- Role
- context
- Documentation level
- ship_specific
- Accessed
- 2026-09-18
- Study period
- 1940-1944
- Population
- EB Groton construction trades (1940-41); PNSY availability trades (Nov 1941); crew (1941-44)
- Limitations
- Ship-specific history only; no asbestos or material content. The 17 January 1943 'gasket on a manhole cover' mention identifies a component, not a material composition. Live NHHC DANFS page returned 404 - printed-volume transcription via hazegray.org/Wayback used. Loss date varies by source (26 vs 27 February) - variants in gaps.
- Atlas source
- true
- Evidence ID
- ev-uss-grayback-ss208-01
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[2]NavSource Submarine Photo Index, USS Grayback (SS-208) - milestones, spec block, disposition, wreck-discovery photo captions [other_primary]
- Locator
- NavSource SS-208 page - milestone block, spec block, wreck-discovery captions
- Finding type
- vessel_history
- Finding
- Milestones (NavSource): laid down 3 April 1940 at Electric Boat Co., Groton, CT; launched 31 January 1941; commissioned 30 June 1941; lost to enemy action, sunk by Japanese carrier-based aircraft and anti-submarine surface units 27 February 1944 in the East China Sea; struck from the Naval Register (date unknown). Two Navy Unit Commendations and eight battle stars. Photo captions document that the wreck was located by Tiburon Subsea CEO Tim Taylor and his 'Lost 52 Project' team and released for publication November 2019, at 1,427 feet depth, 50 nautical miles south of Okinawa. Spec block: surfaced 1,475 t., submerged 2,370 t.; length 307'2"; complement 5 officers, 54 enlisted.
- Verification
- verified
- Role
- context
- Documentation level
- ship_specific
- Accessed
- 2026-09-18
- Population
- Crew
- Limitations
- Secondary compilation - milestone/disposition detail consistent with DANFS. Carries the 27 February loss date and 'carrier-based aircraft' description; WDR-58 (official) gives 26 February off Okinawa - variants logged in gaps.
- Atlas source
- true
- Evidence ID
- ev-uss-grayback-ss208-02
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[3]War Damage Report No. 58 Appendix II (official Navy loss table) + NHHC chronological submarine-losses publication - official loss assessments for this hull [other_primary]
- Locator
- WDR-58 Appendix II loss entry (SS-208); NHHC 'U.S. Submarine Losses WWII' chronological PDF
- Finding type
- historical_record
- Finding
- Official loss assessment (WDR-58 App. II): Grayback, 10th patrol, loss dated 2/26/44 off Okinawa, cause bomb and depth charge - last heard from 25 February 1944; Japanese records indicate she was probably sunk 26 February by the combined attack of a carrier plane and surface escorts; the plane 'gave a direct hit at the sub, which exploded and sank immediately'. NHHC chronological losses list: '27 Feb 44, 80 killed - probably succumbed to damage inflicted by land-based Japanese naval aircraft suffered the day before in the East China Sea.' Wreck located 5 June 2019 ~1,427 ft deep ~50 nm south of Okinawa (Lost 52 Project; Navy verification reported).
- Verification
- verified
- Role
- context
- Documentation level
- ship_specific
- Accessed
- 2026-09-18
- Population
- Crew (final patrol)
- Limitations
- Official sources conflict on detail: WDR-58 gives 26 February off Okinawa by carrier plane + escorts; NHHC chronological list gives 27 February in the East China Sea by land-based aircraft. Both variants logged in gaps. No asbestos content.
- Atlas source
- true
- Evidence ID
- ev-uss-grayback-ss208-03
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[4]Era inference anchored to DANFS-documented construction and yard periods for this hull; Tambor/Gar-class diesel-electric plant per DANFS and NavSource specification blocks [other_primary]
- Locator
- construction-era inference from DANFS dates, NavSource spec block, documented yard periods
- Finding type
- asbestos_application
- Finding
- Era inference: a diesel-electric fleet submarine built 1940-41 at Electric Boat, Groton in the peak asbestos era would era-typically have carried asbestos-containing exhaust lagging, engine gaskets and packing, and thermal/acoustic insulation around machinery and galley/refrigeration equipment. NO boilers or steam plant. Documented yard windows for this hull: Electric Boat construction (1940-41); Portsmouth, N.H. overhaul (November 1941); San Francisco overhaul (mid-1943, yard unnamed in DANFS - see gaps); Pearl Harbor refits between patrols. Wreck located 2019 in deep water - condition surveys reported were archaeological, not hazmat; no material-condition record exists.
- Verification
- inferred
- Role
- supporting
- Documentation level
- class_or_era
- Accessed
- 2026-09-18
- Study period
- 1940-1944
- Population
- Construction and yard trades; crew
- Limitations
- CLASS/ERA INFERENCE ONLY - no ship-specific material schedule, insulation survey, or asbestos abatement record was located for this hull. Names era-standard applications, not confirmed installed materials. Establishes no quantity and no exposure for any individual.
- Atlas source
- true
- Evidence ID
- ev-uss-grayback-ss208-04
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[5]Kase v. Metalclad Insulation Corp., 6 Cal.App.5th 623 (Cal. Ct. App. 2016), No. A143590 - published opinion documenting the Navy specification regime for asbestos insulation [court_record]
- Locator
- Kase v. Metalclad Insulation Corp., 6 Cal.App.5th 623 (2016), discussion of Navy insulation specifications
- Finding type
- litigation_documented
- Finding
- Published appellate opinion (era context): the U.S. Navy's specifications called for asbestos in thermal insulation aboard Navy ships, and the Navy had studied asbestos insulation products (e.g., Unibestos) from the 1930s. Documents the specification regime under which this hull was built at a Navy-supervised commercial yard in 1940-41 - it does NOT name USS Grayback or any Tambor-class submarine.
- Verification
- verified
- Role
- context
- Documentation level
- class_or_era
- Accessed
- 2026-09-18
- Study period
- 1930s-1960s
- Population
- Navy shipboard workers (era level)
- Limitations
- Era/spec-regime documentation only; the case involves different vessels and defendants. Cannot be promoted into ship-specific evidence for this hull. Litigation-stage note: published appellate opinion describing the spec regime, not a finding about this vessel.
- Atlas source
- true
- Evidence ID
- ev-uss-grayback-ss208-05
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[6]GAO, Navy Efforts To Protect Workers From Asbestos Exposure, HRD-80-2 (Oct 18, 1979) [gao]
- Locator
- GAO HRD-80-2 product page
- 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 - covering the construction era and entire service life of this hull (lost 1944).
- Verification
- verified
- Role
- context
- Documentation level
- class_or_era
- Accessed
- 2026-09-18
- Study period
- 1930s-1970s
- Population
- Navy shipyard workers (program level)
- 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) - carried via product-page description.
- Atlas source
- true
- Evidence ID
- ev-uss-grayback-ss208-06
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[7]Negative finding: no qualifying non-litigation ship-specific asbestos record located across DANFS/NHHC (printed vol. III + hazegray/Wayback transcription), NavSource, War Damage Report No. 58, official USN Submarine Losses WWII volume, NHHC chronological submarine-losses publication, wreck-discovery reporting, and shipyard dataset searches [other_primary]
- Locator
- research sweep result - see search_ledger for repositories queried
- Finding type
- historical_record
- Finding
- No hull ACM survey, abatement contract, hazmat disclosure, or adjudicated exposure finding naming USS Grayback (SS-208) was located anywhere in the research sweep. The 2019 wreck documentation was archaeological in character; no material-condition or hazmat record was reported for the wreck site.
- Verification
- verified
- Role
- negative_finding
- Documentation level
- ship_specific
- Accessed
- 2026-09-18
- Limitations
- Absence of a located record is not proof no record exists. Yard-side work records, where they existed, were not retrievable in located sources. Litigation sweep is INCOMPLETE - CourtListener queries for this hull returned HTTP 429/403 (see search_ledger); no litigation negative is claimed.
- Atlas source
- true
- Evidence ID
- ev-uss-grayback-ss208-07