USS Constant (AM-86)

Evidence

12 evidence entries recorded; each entry has a stable permalink (#ev-1 … #ev-12).

1. [1]DANFS, 'Constant' I (AM-86) - verbatim transcription at the losthistory.net/hazegray mirror (live history.navy.mil DANFS URL patterns constant.html / constant-i.html / constant-am-86.html return 404 - standing link rot, same as BATCH-01/1433); second verbatim transcription at ibiblio HyperWar dafs/PC/pc1590.html [nhhc_danfs]

   Locator

   losthistory.net/hazegray/danfs/mine/am86.htm - full 'Constant I' entry, specifications block + service narrative; ibiblio.org/hyperwar/USN/ships/dafs/PC/pc1590.html (parallel transcription)

   Finding type

   vessel_history

   Finding

   Official DANFS record for this hull: spec block 'AM-86: dp. 275; l. 173'8"; b. 23'; dr. 7'7"; s. 18 k.; a. 1 x 3"; cl. Adroit' (no complement printed in the AM-86 block). 'The first Constant (AM-86) was launched 9 May 1942 by Commercial Iron Works, Portland, Oreg.; and commissioned 21 September 1942, Lieutenant R. C. Gloss, USNR, in command.' Service per DANFS: convoy escort San Francisco-Pearl Harbor 20 December 1942 - 4 March 1943; sailed Pearl Harbor 8 March for Espiritu Santo (arrived 25 March) for local escort duty operating from Espiritu Santo and Noumea in support of the Guadalcanal operation; arrived Tulagi 3 September 1943 and 'remained in the Solomons on interisland escort and minesweeping duty with occasional convoy voyages to Noumea and Espiritu Santo' until 3 April 1944; brief overhaul at Auckland, New Zealand; returned Port Purvis 13 May. 'On 1 June 1944 her name was canceled and she was reclassified PC-1590.' Continued service at Espiritu Santo, Noumea, Samoa and Tongatabu until 6 May 1946; returned to Pearl Harbor and decommissioned 19 June 1946. Assigned to the 14th Naval District for Naval Reserve training 28 October 1946; placed in commission in reserve 5 May 1950; in full commission from 20 March 1951 'until decommissioned 22 October 1954. She was sunk as a target.' No battle-star line appears in the AM-86 entry (contrast sister Adroit AM-82's 'one battle star').

   Verification

   verified

   Role

   supporting

   Documentation level

   ship_specific

   Accessed

   2026-09-22

   Study period

   1942-1955

   Population

   Commercial Iron Works construction trades (Portland, 1942); wartime crew (complement not DANFS-printed for this hull); Naval Reserve training crews, 14th Naval District (1946-1954)

   Limitations

   DANFS documents identity, builder, dates, and service narrative - not materials or asbestos content, and no keel-laying or stricken date for this hull. The ibiblio transcription prints '3 April 21944' - a transcription typo for 3 April 1944 (hazegray prints it correctly); flagged in ev-09, not carried. Mirror transcriptions cited because the live NHHC page returns 404 on every URL pattern tried.

   Atlas source

   true

   Evidence ID

   ev-uss-constant-am86-01

2. [2]NavSource Online: Mine Warfare Vessel Photo Archive - PC-1590 ex-Constant (AM 86), file 11/02086 (navsource.org unreachable; navsource.net mirror fetched live) [other_primary]

   Locator

   NavSource 11/02086 - chronology block, specifications block, propulsion line, photo captions (NARA 80-G-630830, 80-G-659441), CO roster (6 COs)

   Finding type

   vessel_history

   Finding

   NavSource per-hull record: 'The first Constant was laid down 21 February 1942 by the Commercial Iron Works, Portland, OR; Launched 9 May 1942; Commissioned USS Constant (AM 86), 21 September 1942; Reclassified as a Submarine Chaser, PC-1590, 1 June 1944; Decommissioned 19 June 1946 at Pearl Harbor, HI; Assigned to the 14th Naval District (Hawaiian Islands) and placed in service for Naval Reserve duty, 28 October 1946; Placed in commission, in reserve 5 May 1950; Placed in full commission 20 March 1951; Placed out of commission, in reserve 21 September 1954 and laid up in the Columbia River Reserve Fleet; Decommissioned 22 October 1954; Sunk as a target 27 January 1955.' Call sign Nan-Baker-Victor-Jig. Spec block: 295 t.; 173'8"; 23' beam; 6'6" draft; 16 kts; complement 65; one 3"/50 dual-purpose gun mount, one 40mm mount, five 20mm mounts, two depth-charge tracks and two depth-charge projectors; propulsion 'Two 900hp Cooper Bessemer GNB8 diesel engines (Serial No. 1978 and 1979), Farrel-Birmingham single reduction gear, two shafts.' Photo captions: 'Off Able Docks, Pearl Harbor, Territory of Hawaii, en route to West Loch, 15 January 1953' (National Archives photo 80-G-630830, National Museum of the U.S. Navy); '27 January 1955 - Sinking after being torpedoed by USS Tiru (SS 416) and USS Stickleback (SS 415) off Oahu, Territory of Hawaii' (National Archives photo 80-G-659441). Commanding-officer roster of six: LT Robert Charles Gloss, USNR (21 Sep 1942) through LTJG Robert C. Winkler, USNR (Nov 1945 - 19 Jun 1946).

   Verification

   partial

   Role

   supporting

   Documentation level

   ship_specific

   Accessed

   2026-09-22

   Study period

   1942-1955

   Population

   Commercial Iron Works trades (1942); commissioned crew; 14th Naval District reserve-training crews (1946-1954); Pearl Harbor-area maintenance personnel

   Limitations

   Specialist secondary compilation - detailed but non-official; consistent with DANFS on all construction, reclassification, and decommissioning dates. Its spec block is the class template (295 t, 6'6", 16 kts) not AM-86's DANFS-printed values (275 t, 7'7", 18 k) - flagged in ev-09. Its 'laid up in the Columbia River Reserve Fleet' conflicts with the same page's NARA-captioned photo of the hull sinking off Oahu on 27 January 1955 - flagged in ev-09, unresolved. Its 'Two 900hp' per-engine rating conflicts with the class index's '1,770 bhp' - flagged in ev-09. Contains no asbestos information; supports no asbestos claim.

   Atlas source

   true

   Evidence ID

   ev-uss-constant-am86-02

3. [3]Shipbuilding History (Tim Colton compilation), 'Commercial Iron Works, Portland OR' yard table - Constant (AM 86) row + yard history header [other_primary]

   Locator

   shipbuildinghistory.com/shipyards/small/commercial.htm - 'COMMERCIAL IRON WORKS, Portland OR' table, row 38 (AM 86) + rows 34-40 (AM 82-88 Portland block) + yard-history header

   Finding type

   vessel_history

   Finding

   Yard-table row for this hull: '38 | AM 86 | Constant | US Navy | Minesweeper | 1,250 | 174 | 21-Sep-42 | Later PC 1590, struck 1954, sunk as target' - the delivery date matching the 21 September 1942 commissioning exactly, and the only located source giving a stricken year (1954). The Portland-built block of the class runs as consecutive yard rows: AM 82 Adroit (28-Jul-42), AM 83 Advent (19-Aug-42), AM 84 Annoy (2-Sep-42), AM 85 Conflict (7-Sep-42), AM 86 Constant (21-Sep-42), AM 87 Daring (10-Oct-42), AM 88 Dash (27-Oct-42). Yard history header: 'Commercial Iron Works was started in November 1916, by William T. Casey, Otto J. Hoak and Robert Boogs, on a 30-acre site just south of the Ross Island Bridge. It closed in 1946, after building an astonishing 188 boats during the course of WWII. The site was sold to Zidell Marine as a ship dismantling facility.'

   Verification

   verified

   Role

   supporting

   Documentation level

   ship_specific

   Accessed

   2026-09-22

   Study period

   1916-1946 (yard history); 1942-1955 (this hull's row)

   Population

   Commercial Iron Works workforce (Portland, OR, 1942; yard closed 1946)

   Limitations

   Compiler's yard table, secondary - corroborates builder, type, delivery (21-Sep-42 = commissioning), and disposal milestones ('struck 1954, sunk as target'; no exact stricken date given). The '1,250' figure in the tonnage column conflicts with every documented displacement for this hull (275 standard / 295 class template / 450 full load) and reads as a different metric - flagged in ev-09. A yard table does not carry keel/launch dates. Contains no asbestos information; supports no asbestos claim.

   Atlas source

   true

   Evidence ID

   ev-uss-constant-am86-03

4. [4]NavSource Online: Submarine Chaser (SC/PC) photo index - 'Submarine Chaser 173-foot Steel Hull' class narrative covering the PC-461 type and the Adroit-class minecraft variant [other_primary]

   Locator

   navsource.net/archives/12/01idx.htm - 'Submarine Chaser 173' Steel Hull' header narrative + Adroit-class paragraph

   Finding type

   vessel_history

   Finding

   Class-level construction narrative: the WWII 173-foot patrol craft was 'steel hulled, twin diesel propelled'; 'in addition to 403 173-foot PC-class patrol craft ordered for the U.S. Navy in 1941, eighteen 173-foot hulls were ordered for use as minesweepers, as the Adroit class' - given names AM-82 through AM-99 (Adroit, Advent, Annoy, Conflict, Constant, Daring, Dash, Despite, Direct, Dynamic, Effective, Engage, Excel, Exploit, Fidelity, Fierce, Firm, Force). 'AM 82 through 88, built at Portland, Oregon' - this hull sits inside the Portland block. As completed they differed from the PCs in the sweep-cable reel at the stem, a longer superstructure with a squat dummy funnel, a kingpost and boom, and two stem davits. 'Only the Annoy (AM-84) is recorded as having been used to sweep for mines ... the others principally were employed as convoy escorts' - consistent with this hull's documented escort career. 'On 1 June 1944, all 18 lost their names and were reclassified PC-1586 through 1603' - this hull became PC-1590. 'At 450 tons full load, the Adroit class displaced 18 tons more than did the PCs. All but the last four built were propelled by two 1,770 brake horsepower Cooper-Bessemer GNB-8 diesels; AM-96-99 were given 1,440 brake horsepower Busch-Sulzer BS 539 diesels ... able to achieve 16.8 knots at 330 tons displacement ... about 4,000 nautical miles at 12 knots, and the normal crew comprised four officers and 61 enlisted personnel.' The index also records Atlantic units cycling through Norfolk Navy Yard May-June 1944 and 'the Pacific units were modified at Pearl Harbor' - a class-level conversion statement that does NOT cleanly map to this hull, which remained in the Solomons/South Pacific continuously through May 1946 (flagged in ev-09).

   Verification

   verified

   Role

   supporting

   Documentation level

   class_or_era

   Accessed

   2026-09-22

   Study period

   1941-1946

   Population

   Construction trades at the class yards (1941-42); crew complement 4 officers + 61 enlisted (class figure)

   Limitations

   Class-level description that names this hull's design family and builder block but carries no hull-specific materials information. Its 'Pacific units modified at Pearl Harbor' cannot be reconciled with this hull's documented uninterrupted South Pacific service to May 1946 - whether PC-1590 received the ASW/AA modification at all is undocumented. Contains no asbestos information; supports no asbestos claim.

   Atlas source

   true

   Evidence ID

   ev-uss-constant-am86-04

5. [5]HyperWar 'Ships of the U.S. Navy, 1940-1945' - PC-1590 (USS Constant) specification page (Patrick Clancey compilation) [other_primary]

   Locator

   ibiblio.org/hyperwar/USN/ships/PC/PC-1590.html - specification block

   Finding type

   historical_record

   Finding

   PC-configuration spec block for this hull: 'PC-1568 class Submarine Chaser (ex Adroit class Minesweeper): Displacement: 450 tons; Length: 173'8"; Beam: 23'; Draft: 11'7"; Speed: 17 knots; Armament: 1 3"/50, 1 40mm; Complement: 105; Cooper Bessemer diesel engine, twin screws, 1,770 shaft hp. Built at Commercial Iron Works, and commissioned as AM-86 21 September 1942; Converted to Sub Chaser (PC-1590) 1 June 1944.' The 450-ton figure matches the NavSource class index's full-load displacement ('At 450 tons full load, the Adroit class displaced 18 tons more than did the PCs'); DANFS's 275 is this hull's printed standard/design displacement.

   Verification

   partial

   Role

   context

   Documentation level

   ship_specific

   Accessed

   2026-09-22

   Study period

   1944-1955 (PC configuration)

   Population

   n/a (specification record)

   Limitations

   Secondary compilation consistent with the sister-hull pattern: its complement (105), draft (11'7"), and displacement (450) conflict with DANFS/NavSource values - likely PC-fit vs AM-fit or full-load conventions, unresolved (flagged in ev-09). Its '1,770 shaft hp' is a total-plant reading between NavSource's 900-hp-per-engine (1,800) and the class index's 1,770-bhp-per-engine (3,540) - flagged in ev-09. Header prints 'PC-1568 class' for the ex-Adroit PCs - a classing label that conflicts with the PC-1586-1603 designation series; flagged in ev-09. Contains no asbestos information.

   Atlas source

   true

   Evidence ID

   ev-uss-constant-am86-05

6. [6]Consolidated era/design inference - documented construction and machinery (NavSource class index: steel-hulled, twin-diesel PC-461-type hull; 'two 1,770 bhp Cooper-Bessemer GNB-8 diesels'; NavSource per-hull spec block: 'Two 900hp Cooper Bessemer GNB8 ... two shafts') + documented builder and construction era (DANFS; Colton Commercial Iron Works table, 1942) [other_primary]

   Locator

   NavSource 12/01idx class narrative (steel hull, machinery, class conversion) + 11/02086 propulsion line; DANFS AM-86 entry; Colton commercial.htm yard row

   Finding type

   asbestos_application

   Finding

   Era/design inference: this hull is a 1942-built, steel-hulled, twin-diesel vessel - a PC-461-type hull completed as a minesweeper - with no boilers and no steam distribution, so its insulation load was materially lighter than a steam combatant's but not negligible: a steel hull still carried accommodation joiner work, electrical systems, and machinery requiring lagging and gasketing, and construction fell squarely inside the Navy's asbestos-use era (substitution did not begin until the early 1970s). Era-typical asbestos applications for a vessel of this type and period: engine and exhaust-system lagging on the two diesels and generator sets; machinery gaskets and packing; electrical-cable insulation; joiner/accommodation insulation; deck coverings/floor tile of the period; winch and windlass brake linings. Exposure-relevant populations if any such material was present: Commercial Iron Works construction trades (Portland, 1942 - the yard closed 1946); the commissioned crew (class complement figure 65) across the 1942-46 Espiritu Santo/Noumea/Guadalcanal/Solomons and Samoa/Tongatabu service; Auckland overhaul workers (April-May 1944); Pearl Harbor inactivation/decommissioning workers (1946) and 14th Naval District reserve-training crews and maintainers (1946-1954); and the Navy crews who stripped, towed, and sank the hull as a torpedo target off Oahu (January 1955).

   Verification

   inferred

   Role

   supporting

   Documentation level

   class_or_era

   Accessed

   2026-09-22

   Study period

   1942-1955

   Population

   CIW trades 1942; crew 1942-46; Auckland overhaul workers 1944; PH inactivation workers 1946; reserve-training crews/maintainers 1946-54; target-disposal crews 1955

   Limitations

   Inference from documented design, machinery type, and construction era - NOT a hull materials record. No survey, specification, or material schedule naming AM-86/PC-1590 was located; establishes no asbestos content, quantity, location, condition, individual exposure, or causation. The diesel (non-steam) plant weakens the inference relative to steam vessels of the same era, though the steel hull and 1942 construction keep it within the asbestos-era window.

   Atlas source

   true

   Evidence ID

   ev-uss-constant-am86-06

7. [7]GAO, Navy Efforts To Protect Workers From Asbestos Exposure, HRD-80-2 (Oct 18, 1979) - product-page description (gao.gov returns HTTP 403 to automated fetch - standing condition since BATCH-01); and T.J. Bigley (Navy) letter to GAO, 5 Jan 1979, as quoted in 'The Asbestos Health Hazards Compensation Act,' Journal of Legislation (Notre Dame) 10(1) [gao]

   Locator

   gao.gov/products/hrd-80-2 product page; Notre Dame J. Legislation 10(1), 'The Asbestos Health Hazards Compensation Act' (scholarship.law.nd.edu/jleg/vol10/iss1/3) quoting Bigley letter of 5 Jan 1979

   Finding type

   gov_survey

   Finding

   Program-level documentation of the asbestos window containing this hull's entire construction and commission: GAO HRD-80-2 records that the Navy's product specifications for thermal insulation were changed in 1973 to specify asbestos-free materials, but asbestos materials already purchased were still installed - 'some ships were delivered with asbestos insulation as late as May 1978'; the Navy's elimination policy issued October 1975. A Navy letter to GAO dated 5 January 1979 (T.J. Bigley to Robert F. Hughes, quoted in the Notre Dame Journal of Legislation) states: 'all ships presently in service contain some quantity of asbestos.' AM-86/PC-1590 was built in 1942 and in commission (active and reserve) 1942-54 - entirely inside the pre-1973 as-built asbestos era.

   Verification

   verified

   Role

   context

   Documentation level

   class_or_era

   Accessed

   2026-09-22

   Study period

   1973-1979 policy window documented; hull era 1942-1955

   Population

   Navy personnel and shipyard workers, service-wide (era context)

   Limitations

   Program/era-level documentation; neither source names this vessel, class, or builder. GAO's fieldwork concerned shipyard workers (Long Beach, Norfolk). The 'all ships' statement is quoted from a primary letter via a law-review source - the letter itself was not retrieved. gao.gov returned HTTP 403 to automated fetch (standing since Batch 01); the product-page description was relied on. Establishes nothing about this hull's materials, condition, or any individual exposure - and for a diesel-plant vessel the proposition applies with materially reduced scope.

   Atlas source

   true

   Evidence ID

   ev-uss-constant-am86-07

8. [8]Oregon Department of Environmental Quality, 'Zidell Waterfront Property Cleanup' (2012 community presentation, Scott Manzano, oregon.gov/DEQ) + U.S. Coast Guard, 'Regulated Navigation Area; Zidell Waterfront Property, Willamette River, OR,' Federal Register doc. 2012-7784 (33 CFR Part 165), April 2012 [federal_register]

   Locator

   oregon.gov/deq/FilterDocs/ph-ZidellCAG.pdf (DEQ cleanup presentation, 2012); Federal Register doc. 2012-7784 (USCG RNA rule) via federal.elaws.us mirror; djcoregon.com (22 Dec 2009); oregonlive.com (2010)

   Finding type

   environmental_record

   Finding

   Builder-site environmental record: the Commercial Iron Works yard that built this hull became the Zidell ship-dismantling facility (purchased 1946; 336 ships dismantled over ~30 years; scrap sold, waste used as site fill - 32 acres upland + 12 acres in-water sediment). Per the Oregon DEQ record: 'Ironworks shipyard before WWII; Building, repair and salvage of Victory Ships during WWII'; contaminants documented at the site include metals, petroleum hydrocarbons/PAHs, PCBs, butyltins, and asbestos; cleanup milestones: 1987 DEQ/EPA joint site assessment, 1995 voluntary RI/FS agreement, 2003 RI complete, 2005 Record of Decision (upland hot-spot removal/relocation/capping; in-water limited dredging and capping), 2006 consent decree; 'Asbestos abatement project - all workers certified, air monitoring, bulk ACM disposal.' The 2012 USCG Federal Register rule established a Regulated Navigation Area at the site (Willamette River RM ~13.5-14.2) to protect the engineered sediment cap over contaminated sediments from the site's shipbuilding, dismantling, scrap-metal, wire-burning, and smelting history. Reputable-press corroboration: Daily Journal of Commerce (2009) - PCBs, lead, and asbestos in the river bottoms, Commercial Iron Works founded 1916 and delivered 185 ships to the Navy in WWII; OregonLive (2010) - 17,000 cubic yards of asbestos- and metal-laden soil removed/capped under the $20M state-mandated cleanup.

   Verification

   verified

   Role

   context

   Documentation level

   context_only

   Accessed

   2026-09-22

   Study period

   1987-2012 (cleanup record); site industrial era 1916-1980s

   Population

   Zidell ship-dismantling workforce (1946-1970s); cleanup/abatement workers (2010-2012); site workers generally

   Limitations

   Site-level environmental record for the builder's yard, NOT a hull record: the contamination documented spans the site's full industrial history - wartime construction AND the 1946-1970s ship-dismantling era (336 ships scrapped on site) plus wire burning and smelting - so the asbestos finding cannot be attributed to AM-86's construction specifically. Establishes nothing about this hull's materials, condition, or any exposure. FR text verified via the elaws mirror; federalregister.gov serves an anti-bot redirect to automated fetch.

   Atlas source

   true

   Evidence ID

   ev-uss-constant-am86-08

9. [9]Source-discrepancy resolution - DANFS (hazegray mirror) vs NavSource 11/02086 + 12/01idx class index vs HyperWar PC-1590 spec block vs Colton yard table vs Wikipedia/uboat.net [other_primary]

   Locator

   losthistory.net/hazegray/danfs/mine/am86.htm; ibiblio.org/hyperwar/USN/ships/dafs/PC/pc1590.html + ships/PC/PC-1590.html; navsource.net/archives/11/02086.htm + 12/01idx.htm; shipbuildinghistory.com/shipyards/small/commercial.htm; uboat.net/allies/warships/9249.html; en.wikipedia.org/wiki/USS_Constant_(AM-86)

   Finding type

   historical_record

   Finding

   Source discrepancies logged, not silently merged: (a) Displacement - DANFS AM-86 spec block 'dp. 275' vs NavSource per-hull '295 t.' (class template) vs HyperWar '450 tons' vs NavSource class index 'At 450 tons full load' - resolved as standard/design (275-295) vs full-load (450) conventions; Colton's tonnage-column figure '1,250' fits neither and reads as a different metric (possibly contract price) - flagged. (b) Draft - DANFS '7'7"' vs NavSource '6'6"' vs HyperWar '11'7"' - AM-fit vs PC-fit or class-template variance; unresolved. (c) Speed - DANFS '18 k.' vs NavSource '16 kts' vs class index '16.8 knots at 330 tons' vs HyperWar '17 knots' - consistent range, variants flagged. (d) Complement - absent from the AM-86 DANFS spec block (unlike AM-82/AM-84 entries which print 'cpl. 65'); NavSource '65' and class index 'four officers and 61 enlisted' (=65) are class-figure blocks; HyperWar '105' is PC-fit; none carried as hull-verified - in gaps. (e) Propulsion - NavSource per-hull 'Two 900hp Cooper Bessemer GNB8' (=1,800 total, serial nos. 1978/1979) vs class index 'two 1,770 brake horsepower Cooper-Bessemer GNB-8' (=3,540) vs HyperWar '1,770 shaft hp' (total) vs Wikipedia '2 x 1,770 bhp' - engine type (Cooper-Bessemer GNB-8, two, twin screw) consistent; rating unresolved. (f) 1954 disposition - NavSource 'laid up in the Columbia River Reserve Fleet' (out of commission in reserve 21 September 1954) vs the same page's NARA-captioned photo of the hull sinking off Oahu 27 January 1955 - unreconciled; a Columbia River lay-up followed by an Oahu sinking within ~4 months is possible only if towed back, and no tow or transit record was located. (g) Stricken date - only Colton's 'struck 1954' exists; DANFS and NavSource print none; carried as '1954' flagged. (h) Class-level 'Pacific units modified at Pearl Harbor' (NavSource index) cannot map onto this hull, which remained in the South Pacific through May 1946 - whether PC-1590 was ever taken in hand for the ASW/AA conversion is undocumented. (i) The ibiblio DANFS transcription prints '3 April 21944' - transcription typo (hazegray prints '3 April 1944' correctly). (j) HyperWar's PC-1590 header prints 'PC-1568 class' - a classing label inconsistent with the PC-1586-1603 designation series. (k) Ordered date - uboat.net alone gives '1 Apr 1941'; not corroborated by any primary or secondary naval reference checked - in gaps.

   Verification

   partial

   Role

   correction

   Documentation level

   ship_specific

   Accessed

   2026-09-22

   Study period

   1942-1955

   Limitations

   Resolves publication-level discrepancies among the official DANFS text and secondary compilations, adopting the better-supported values and flagging the rest. None of the sources bears on asbestos; the spec conflicts are documented so no downstream user silently merges incompatible figures.

   Atlas source

   true

   Evidence ID

   ev-uss-constant-am86-09

10. [10]Air & Liquid Systems Corp. v. DeVries, 586 U.S. 446 (2019), CourtListener 4601080 [court_record]

    Locator

    CourtListener opinion 4601080; Google-indexed sweeps for 'USS Constant,' 'PC-1590,' 'AM-86' (search_ledger sl-06, sl-07, sl-08)

    Finding type

    litigation_documented

    Finding

    No case located names this hull (see negative_finding row ev-11 and search_ledger). Doctrinal context only for the vessel's type: claims arising from Navy-vessel asbestos exposure ran under maritime law against equipment manufacturers, and the Supreme Court's DeVries decision settled the 'bare-metal defense' framework - manufacturers that supplied bare equipment had a duty to warn where their products required asbestos-containing parts. It illustrates the litigation posture a claim arising from service aboard a WWII diesel minesweeper/subchaser would have faced; no such claim naming Constant, AM-86, or PC-1590 was located. Name-collision screen: 'USS Constellation' (CV-64) appears in VA BVA asbestos decisions - a different vessel; a second USS Constant (AM-427/MSO-427, Agile class) commissioned September 1954 exists - any post-1954 'USS Constant' reference requires hull disambiguation; marketing rosters (mesotheliomahelp.org minesweeper list) carry 'USS Constant' in generic ship tables - excluded per source rules.

    Verification

    verified

    Role

    context

    Documentation level

    class_or_era

    Accessed

    2026-09-22

    Study period

    2019 decision; sweeps 2026-09-22

    Limitations

    Doctrinal context only - the cited case does not name or involve this hull, and DeVries addressed manufacturers' duty to warn for asbestos-containing components on Navy vessels generally (its facts post-date this hull's era). A complaint's vessel list would be a pleading allegation, not a finding; no pleading naming this hull was located. Does not establish or defeat any exposure claim or legal eligibility.

    Atlas source

    true

    Evidence ID

    ev-uss-constant-am86-10

11. [11]Batch-1437 search ledger (this record): DANFS via hazegray/losthistory mirror + ibiblio HyperWar transcription; NavSource 11/02086 + 12/01idx class index; HyperWar Ships of the U.S. Navy PC-1590 page; Shipbuilding History Commercial Iron Works table; uboat.net; Wikipedia; globalsecurity; NavalCoverMuseum; Oregon DEQ + Federal Register Zidell records; CourtListener API v4 (authenticated - throttled) + Google-indexed sweeps; VA BVA index via Google; live NHHC URL probes (404); NARA catalog (JS shell) [other_primary]

    Locator

    search_ledger rows sl-uss-constant-am86-01 through sl-uss-constant-am86-11

    Finding type

    historical_record

    Finding

    No qualifying ship-specific asbestos record located for USS Constant / AM-86 / PC-1590: no asbestos survey, abatement contract, hazmat disclosure, material schedule, court finding, docketed asbestos case, or VA Board of Veterans' Appeals decision naming this hull was found in the public sources searched (see search_ledger). CourtListener coverage caveat: the authenticated API returned HTTP 429 ('Request was throttled. Rate limit exceeded: 2800/day. Expected available in ~15,500 seconds' - the shared quota was exhausted by earlier same-day batch work; no unauthenticated queries were run). The litigation sweep therefore ran through Google-indexed CourtListener content and general web: no 'PC-1590' or 'AM-86' vessel reference surfaced in any opinion or docket index reachable, and 'USS Constant' hits are marketing-roster entries (excluded) or name collisions (USS Constellation CV-64 in BVA decisions; USS Constant AM-427/MSO-427, a different hull commissioned September 1954). The hull was sunk as a target in 1955, so no present-day survey pathway exists.

    Verification

    verified

    Role

    negative_finding

    Documentation level

    ship_specific

    Accessed

    2026-09-22

    Study period

    2026-09-22

    Limitations

    Absence of a located public record does not prove absence of asbestos aboard - a 1942 steel-hulled naval vessel is era-consistent with asbestos-containing materials even accounting for its lighter diesel insulation load. The CourtListener sweep is incomplete (shared-cap exhaustion) - a fully authenticated re-sweep of opinions and RECAP dockets remains an open verification step. Does not establish presence or absence; does not establish or defeat any exposure claim or legal eligibility.

    Atlas source

    true

    Evidence ID

    ev-uss-constant-am86-11

12. [12]Archival leads - NARA RG 24 deck logs for this hull's September 1942 - June 1946 first commission and the 1950-54 Naval Reserve period (the documentary base for the Solomons escort/minesweeping operations, the Auckland overhaul, and any machinery-space events); WWII muster rolls; NARA RG 19 Bureau of Ships records per the asbestos guided-topic page - hull-designation correspondence ('AM86'/'PC1590'), class correspondence under the PC-461/Adroit-class series, 'QM/Commercial Iron Works' contract files, Entry P-11 'Minesweeper and Minelayer General Information Books' (Item S-68), and hull-number-arranged Ship Engineering Drawings (S39 Insulation and Lagging, S48 Piping, S103 Booklets of General Plans); RG 181 Pearl Harbor Naval Shipyard job files (1946 inactivation/decommissioning; 1946-54 reserve-upkeep work); the NARA photographs already located (80-G-630830, 15 January 1953; 80-G-659441, sinking 27 January 1955); and any 1954-55 target-tow/stripping orders for the Oahu sinking [other_primary]

    Locator

    archives.gov RG 19/24/181 group guides + asbestos guided-topic page (archives.gov/research/military/navy/guided-topics/asbestos); NavSource 11/02086 photo credits (NARA 80-G-630830, 80-G-659441)

    Finding type

    historical_record

    Finding

    Archival leads (not retrieved - require research-room or reproduction order; no spend authorized; NARA catalog returns only its JS application shell to automated fetch): (a) NARA RG 24 deck logs, Sep 1942 - Jun 1946 and the 1950-54 reserve commission - the documentary base for the documented operations; (b) muster rolls for the commission periods; (c) NARA RG 19 BuShips records per the asbestos guided-topic page - hull files 'AM86'/'PC1590,' class files for the PC-461/Adroit series, 'QM/Commercial Iron Works' contract correspondence, P-11 minesweeper GIBs, and S39/S48/S103 hull-series drawings - the plausible home of hull-level material schedules; (d) RG 181 Pearl Harbor Naval Shipyard job files for the 1946 inactivation and 1946-54 reserve upkeep - this hull spent its entire postwar career in Hawaiian waters (documented at Able Docks/West Loch, January 1953); (e) the 1954-55 disposal file - stricken-1954 paperwork and target-sinking orders for the 27 January 1955 torpedo exercise off Oahu, the only plausible documentary path to the Columbia-River-vs-Oahu discrepancy.

    Verification

    unverified

    Role

    archival_lead

    Documentation level

    context_only

    Accessed

    2026-09-22

    Study period

    1942-1955 records

    Limitations

    Record-group mapping only - no box-level retrieval performed; existence of asbestos-specific documents for AM-86/PC-1590 is unknown until surveyed in person. Deck logs, muster rolls, and contract files are personnel/operations records, not materials documentation; the BuShips design file is the best candidate for a material schedule. Nothing in this row is an asbestos finding.

    Atlas source

    true

    Evidence ID

    ev-uss-constant-am86-12