Evidence
13 evidence entries recorded; each entry has a stable permalink (#ev-1 … #ev-13).
-
[1]research packet 855-packet.md [other_primary]
- Finding type
- vessel_history
- Finding
- Identity packet verdict: VERIFIED
- Verification
- verified
- Role
- supporting
- Documentation level
- ship_specific
- Evidence ID
- uss-assurance-mso521-pkt-855-packet-md
-
[2]DANFS, Assurance (MSO-521) - construction, sponsor, commissioning, MinDiv assignments, Mediterranean deployments, yard availabilities, AG-521 redesignation, decommissioning and sale (verbatim transcription; live NHHC DANFS page returned 'Page Not Found' on 2026-10-03) [nhhc_danfs]
- Locator
- DANFS service narrative and spec block, full entry
- Finding type
- vessel_history
- Finding
- Documented for this hull: 'The first Assurance (MSO-521) was laid down on 28 January 1957 at Sturgeon Bay, Wis., by Peterson Builders, Inc.; launched on 31 August 1957, sponsored by Mrs. Vernon W. Thomson; and commissioned at Boston, Mass., on 21 November 1958, Lt Comdr. Frank L. Crump, Jr., in command.' Assigned to Mine Force, Atlantic Fleet, MinDiv 45, home port Charleston, SC; transferred 1 July 1959 to MinDiv 81, home port Panama City, FL, as a test platform for the Mine Defense Laboratory. Mediterranean deployments Feb-Aug 1962, Oct 1964-Mar 1965 (Operation Steel Pike II; TF 61, Aranci Bay, Sardinia), Jun-Sep 1966 (Phiblex 1-66; special surveillance off Tunisia), Jan-May 1969. Yard periods documented: Charleston drydock repairs May 1964; Charleston Naval Shipyard overhaul July-Sep 1965; Charleston interim overhaul Jan-Mar 1967 and overhaul ending 15 December 1967; Charleston overhaul 13 November 1969 - early April 1970; Atlantic Drydock Corp. (Fort George Island, FL) overhaul/conversion March-June 1973 (minesweeping gear removed); Charleston restricted availability Feb-May 1974; Detyen's Shipyard (Wando, SC) overhaul 16 June - 11 November 1975; Mayport drydock 10 January - 7 March 1977. Redesignated AG-521 on 1 March 1973. Decommissioned at Charleston 30 September 1977 and name struck from the Navy list simultaneously. 'In December of 1979, the former minesweeper was sold to the Ampol Corp. for scrapping.' Spec block: MSO-521: dp. 960; l. 190'; b. 36'; dr. 12'; s. 15 k.; cpl. 83; a. 1 40mm.; cl. Ability.
- Verification
- verified
- Role
- context
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- 1957-1979 (entry coverage)
- Population
- Peterson Builders construction trades (1957-58); crew (1958-77); Charleston NSY, Atlantic Drydock, Detyen's, Mayport yard trades at availabilities
- Limitations
- Ship-specific history only; no asbestos or material content. Disposal sentence conflicts with NavSource/Shipscribe (December 1979 'Ampol Corp.' vs 1 July 1978 DRMS sale to 'Ampel Wrecking and Dismantling Corp.') - see ev-10 and gaps. Live NHHC DANFS page returned 'Page Not Found' on 2026-10-03; verbatim transcription via losthistory.net mirror used (curl-verified HTTP 200).
- Atlas source
- true
- Evidence ID
- ev-uss-assurance-mso521-01
-
[3]NavSource Online: Mine Warfare Vessel Photo Archive, Assurance (AG 521) ex-MSO-521 - designation timeline, specifications, commanding officers, disposal (verified live, HTTP 200) [other_primary]
- Locator
- NavSource 11/02521.htm header block, specifications block, photo captions, CO roster
- Finding type
- vessel_history
- Finding
- NavSource timeline for this hull: 'Laid down 28 January 1957 by Peterson Builders, Inc., Sturgeon Bay, WI; Launched, 31 August 1957; Commissioned USS Assurance (MSO-521), 21 November 1958 at Boston Naval Shipyard, Charlestown, MA; Reclassified as a Miscellaneous Auxiliary, AG-521, 1 March 1973; Decommissioned, 30 September 1977 and struck from the Navy Register; Sold for scrap 1 July 1978 by the Defense Reutilization and Marketing Service to Ampel Wrecking and Dismantling Corp.' Specifications: displacement 934 t.; length 190'; beam 36'; draft 12'; speed 15 kts.; complement 83; armament two .50 cal. machine guns; propulsion two 1,400 hp General Motors 8V498 diesel engines, two shafts, two controllable pitch propellers. Page photographs document Valletta, Malta visits c.1965 and c.1969, AG-521 configured as 'a Sonar Research Ship' c.1973, and Nassau, Bahamas c.1973 (astern of RMS Queen Elizabeth 2); one photo credited as National Archives UA 50.01.01. Commanding-officer roster lists 12 COs, LCDR Frank Lyons Crump, Jr. (21 Nov 1958) through LT Richard Scott Hillyer (to 30 Sep 1977).
- Verification
- verified
- Role
- context
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- 1957-1978
- Population
- Peterson Builders construction trades (1957-58); crew (1958-77); shipbreakers at the Ampel/Ampol dismantling (1978-79)
- Limitations
- NavSource is a volunteer secondary compilation, not a primary registry; milestone dates generally track NVR/DANFS. Disposal conflicts with DANFS (1 July 1978 'Ampel Wrecking and Dismantling Corp.' vs December 1979 'Ampol Corp.') - see ev-10 and gaps. Contains no asbestos content. The 1978 sale predates modern ACM-handling regulation; no hazmat or material record for the breakup was located.
- Atlas source
- true
- Evidence ID
- ev-uss-assurance-mso521-02
-
[4]Shipscribe (Stephen S. Roberts, compiled 2021), USS Alacrity (AG 520, ex MSO) class page - SCB 45B design data, AG conversion details, disposal table [other_primary]
- Locator
- Shipscribe AG-520 class page - Specs, Construction table, Disposition table, Class Notes, Ship Notes
- Finding type
- vessel_history
- Finding
- Compiled official-data summary for this hull's class: approved characteristics for an Ocean Minesweeper (MSO) of a new 182-ft type with a WOODEN HULL, SCB Project 45B, promulgated 16 March 1955; three MSOs ordered 26 October 1955 from Peterson (MSO-519/520/521); a fourth, MSO-522, ordered 25 June 1958 under the foreign assistance program became the Belgian Van Haverbeke. Design: 801 light / 934 full tons; 190' oa x 36' x 12'; geared diesel, 2 screws, 2,700 hp; 15 kts; accommodations 8 officers + 75 enlisted. On 18 January 1973 CNO reclassified MSO-521 (Assurance) to AG-521 effective 1 March 1973. At the 23 March 1973 Atlantic Drydock Corp. overhaul her minesweeping gear was removed 'and she was converted for use as a trials ship for the AN/SQR-15 tactical towed array sonar system (TASS). Her fuel tanks were also modified and habitability was improved' - the cable reels aft of the stack were replaced by a deck structure/van for TASS electronics. Disposition table: decommissioned and struck 30 September 1977; disposal 1 July 1978, Navy sale. Class note: sister Ability (MSO-519) began a cancelled SCB 502.69 minehunter modernization at Todd Brooklyn 1970; the plan to inactivate the two unmodified sisters was cancelled mid-December 1970, matching DANFS's account of Assurance's reversed decommissioning order.
- Verification
- verified
- Role
- context
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- 1955-1978
- Population
- Peterson Builders construction trades (ordered 1955, built 1957-58); AG-521 conversion yard trades at Atlantic Drydock (1973)
- Limitations
- Shipscribe is a compiled secondary reference (Roberts, working from SCB/NVR/official records) - it is not the underlying official document; carried as ship_specific context because it tables this hull by number, but claims needing primary anchoring (e.g., the TASS electronics-van detail is 'presumably' per the compiler) are hedged. Its 'ex-AM 520' note printed against AG-521 is a probable transcription slip - see ev-11. Contains no asbestos content.
- Atlas source
- true
- Evidence ID
- ev-uss-assurance-mso521-03
-
[5]NHHC photo catalog: USN 1127291 'USS Assurance (MSO-521)' (caption: 'Sailors man the rails of ocean minesweeper USS Assurance (MSO-521)', copyright owner National Archives); plus NHHC UA 50.01.02 'USS Assurance (MSO-521)' (copyright NHHC; sibling UA 50.01.03 also exists) [other_primary]
- Locator
- NHHC photo pages USN-1127291 and UA 50.01.02 (Title/Caption/Catalog # fields); NavSource caption crediting NARA UA 50.01.01
- Finding type
- historical_record
- Finding
- Official NHHC photographic holdings for this hull are live in the NHHC online catalog: USN 1127291 (NARA-sourced USN photo, the c.1960s underway image in wide secondary circulation) and UA 50.01.02 (NHHC-series photo; a UA 50.01.03 page also exists). NavSource credits National Archives photo 'UA 50.01.01' for the AG-521-configuration image - three UA-series catalog numbers for this hull.
- Verification
- verified
- Role
- context
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- circa 1960s-1973 (photo subjects)
- Limitations
- Photographic holdings only - they document the hull's existence and configuration, not materials or working conditions aboard. NHHC serves these pages with valid content but an HTTP 404 status to curl; content verified via full render 2026-10-03. No asbestos content.
- Atlas source
- true
- Evidence ID
- ev-uss-assurance-mso521-04
-
[6]Era inference built on: Shipscribe class data (SCB 45B wooden-hull design, geared diesel); NavSource specifications (2 x GM 8V498 diesels); DANFS spec block; shipyard-exposure-map documented asbestos product lists for charleston-naval-shipyard and boston-naval-shipyard; GAO HRD-80-2 (see ev-06) [other_primary]
- Locator
- Shipscribe SCB 45B design line; NavSource specifications; DANFS spec block; shipyards.json product lists
- Finding type
- asbestos_application
- Finding
- A wooden-hulled, nonmagnetic ocean minesweeper built 1957-58 sits inside the Navy's documented asbestos-use era; era-standard applications aboard a small geared-diesel combatant of this period were thermal insulation on machinery and diesel exhaust runs, gaskets, valve and pump packing, electrical insulation, and fireproofing materials. As a diesel-driven vessel with no steam plant, the boiler/turbine lagging pathway of steam ships does not apply; her material footprint was smaller than a steam vessel's but not nil.
- Verification
- inferred
- Role
- supporting
- Documentation level
- class_or_era
- Accessed
- 2026-10-03
- Study period
- 1957-1979
- Population
- Peterson Builders construction trades (1957-58); crew (1958-77); yard trades at Charleston, Boston, Atlantic Drydock, Detyen's, Mayport availabilities; shipbreakers (1978-79)
- Limitations
- Class/era inference only - no hull-specific insulation survey, material list, or work package located for MSO-521. Names era-standard applications, not confirmed installed materials. No quantity. Product names are normalized era terms; no manufacturer attribution for this hull.
- Atlas source
- true
- Evidence ID
- ev-uss-assurance-mso521-05
-
[7]GAO, Navy Efforts To Protect Workers From Asbestos Exposure, HRD-80-2 (published Oct 18, 1979; released Oct 22, 1979) [gao]
- Locator
- GAO product page HRD-80-2, Highlights/abstract
- Finding type
- gov_survey
- Finding
- GAO documented that the Navy used asbestos insulation aboard ships and regulated its removal late: the 1975 policy was 'to remove and replace with nonasbestos materials only insulation that was damaged or had to be removed to accomplish necessary repairs,' modified in 1979 'to include selectively replacing asbestos insulation in high-maintenance areas where repairs would be expected during a ship's next operating cycle.' Fieldwork was at Long Beach and Norfolk Naval Shipyards. The policy window spans this hull's entire service life (1958-77) including her 1973 Atlantic Drydock conversion, 1974 Charleston restricted availability, 1975 Detyen's overhaul, and 1977 Mayport drydocking.
- Verification
- verified
- Role
- context
- Documentation level
- class_or_era
- Accessed
- 2026-10-03
- Study period
- 1979 (report); policy window 1975-79 over her service era
- Population
- Navy shipyard workers; asbestos program review
- Limitations
- Program-level documentation; supports era context only, not any fact specific to this hull - the yards reviewed were Long Beach and Norfolk, not the yards that worked this hull. Full report PDF linked from the product page (26 pages); product page and abstract verified live via Firecrawl 2026-10-03 (direct curl returned 403 - same standing gao.gov automated-fetch block noted in BATCH-01/98).
- Atlas source
- true
- Evidence ID
- ev-uss-assurance-mso521-06
-
[8]DANFS-documented Charleston yard periods for this hull + shipyard-exposure-map shipyards.json entry 'charleston-naval-shipyard' (evidence_tier 2: magnesia pipe insulation, 5-50% asbestos pipe insulation, 15%-asbestos boiler coatings, spray-on insulation for ship interiors, asbestos gaskets/packing, electrical insulation throughout vessels; OSHA Inspection 100361849 citing Commander, Charleston Naval Shipyard under 29 CFR 1910.1001; Whalen v. John Crane $70.8M verdict 2014 and Twidwell v. Aerco $40M verdict 2018 documented at yard level) [other_primary]
- Locator
- DANFS service narrative (yard-period entries); shipyards.json charleston-naval-shipyard evidence rows ev-charleston-naval-shipyard-osha-1988-100361849, -06, -07
- Finding type
- gov_survey
- Finding
- This hull spent repeated periods at Charleston: drydock repairs May 1964; Charleston Naval Shipyard overhaul July-September 1965; interim overhaul January-March 1967 and a second overhaul July-15 December 1967; overhaul 13 November 1969 - early April 1970; pre-inactivation work September-December 1970; and restricted availability February-May 1974. The yard itself is documented in the Atlas yard dataset (tier 2) with an extensive asbestos product list spanning shipboard insulation, gaskets, packing, and electrical insulation, and OSHA inspection 100361849 records a citation against Commander, Charleston Naval Shipyard under the asbestos standard (1988-era record, case closed 2 May 1990).
- Verification
- partial
- Role
- context
- Documentation level
- class_or_era
- Accessed
- 2026-10-03
- Study period
- 1964-1974 (her yard periods); yard documentation through 1990
- Population
- Charleston Naval Shipyard trades during this hull's availabilities (1964-1974 window)
- Limitations
- Yard-level context, not a hull finding: documents asbestos products and enforcement at the yard generally - this hull is not named in any asbestos document located. The OSHA IMIS page is blocked to automated access this session (curl HTTP 403; all Firecrawl engines failed) and no Wayback capture exists - the OSHA datum is carried from the yard dataset, live verification open. Yard availabilities establish presence, not what work was performed; no work package located.
- Atlas source
- true
- Evidence ID
- ev-uss-assurance-mso521-07
-
[9]Ozzello v. Peterson Builders, Inc., 743 F. Supp. 1302 (E.D. Wis. 1990) - non-asbestos litigation naming the builder yard; plus shipyards.json 'boston-naval-shipyard' (tier 3: John Crane gasket/sealing-material allegation, In re John Crane, Inc., Tex. App. 2003) for the commissioning yard [other_primary]
- Locator
- 743 F. Supp. 1302 (E.D. Wis. 1990) via Justia; shipyards.json boston-naval-shipyard products_documented pd-boston-naval-shipyard-01
- Finding type
- litigation_documented
- Finding
- Builder-yard litigation context: a published federal opinion exists naming this hull's builder - Ozzello v. Peterson Builders, Inc. (E.D. Wis. 1990), a workplace-injury (hose trip-and-fall) case aboard MCM-1 under construction at Sturgeon Bay in 1987. It is NOT asbestos litigation and involves a different hull and era, but confirms the yard's continued naval shipbuilding into the MCM era. No asbestos-specific documentation for Peterson Builders was located. For the commissioning yard, the Atlas yard dataset documents Boston Naval Shipyard at tier 3 via an allegation of John Crane gasket/sealing-material exposure (In re John Crane, Inc., Tex. App. 1st Dist. 2003) - yard-level, not hull-level.
- Verification
- partial
- Role
- context
- Documentation level
- class_or_era
- Accessed
- 2026-10-03
- Study period
- 1957-1990
- Population
- Peterson Builders trades (1957-58 construction; 1987 case era); Boston Naval Shipyard trades (1958 commissioning)
- Limitations
- Yard-level context only: Ozzello is a personal-injury opinion with no asbestos or MSO-521 content; the John Crane allegation is a pleading-stage claim tied to Boston Naval Shipyard generally, not to this hull's 1958 commissioning presence. Neither establishes material aboard this hull. Peterson Builders is absent from the Atlas yard dataset - flagged in gaps.
- Atlas source
- true
- Evidence ID
- ev-uss-assurance-mso521-08
-
[10]Batch-7616 search ledger (this record): DANFS transcription (losthistory.net); NavSource; Shipscribe class page; NHHC photo catalog (USN 1127291, UA 50.01.02); GAO product page; NARA digitized deck-log index; CourtListener (blocked); secondary web litigation sweep [other_primary]
- Locator
- search_ledger rows sl-uss-assurance-mso521-01 through -11
- Finding type
- historical_record
- Finding
- No qualifying ship-specific asbestos record located: no asbestos survey, abatement contract, hazmat disclosure, or verified litigation naming USS Assurance (MSO-521/AG-521) was found in the public sources searched. CAVEAT: CourtListener could not be queried this session - authenticated API helper reported the daily quota exhausted (~4.2 h to reset); logged as blocked in search_ledger, not as a negative result. Secondary web sweeps surfaced no qualifying case; the only 'asbestos aboard' material is law-firm marketing content (mesotheliomaveterans.org, simmonsfirm.com, mesotheliomahope.com, lungcancergroup.com, elslaw.com list the hull as 'USS Assurance (AG-521)' on their asbestos-ship lists) asserting asbestos without primary sourcing - excluded by source policy.
- 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 - and the litigation repository search is a genuine open gap (quota-blocked, not run). Deck logs, Peterson Builders/yard work packages, and any scrapping-contract records are undigitized leads. Does not establish or defeat any claim of exposure or legal eligibility.
- Atlas source
- true
- Evidence ID
- ev-uss-assurance-mso521-09
-
[11]Disposal cross-check: NavSource 11/02521.htm disposal line; Shipscribe AG-520 class Disposition table; DANFS final paragraph [other_primary]
- Locator
- NavSource disposal line; Shipscribe Disposition table row AG-521; DANFS final paragraph
- Finding type
- historical_record
- Finding
- CONFLICT: sources disagree on the disposal. NavSource: 'Sold for scrap 1 July 1978 by the Defense Reutilization and Marketing Service to Ampel Wrecking and Dismantling Corp.' Shipscribe Disposition table: '1 Jul 1978, Navy sale.' DANFS: 'In December of 1979, the former minesweeper was sold to the Ampol Corp. for scrapping.' The 1 July 1978 DRMS/DISPOSITION sale is the better-anchored date (two compilations agree); the December 1979 'Ampol Corp.' sentence likely reflects either a resale/completion event or a DANFS transcription variance ('Ampel' vs 'Ampol'). Carried here as unresolved rather than silently choosing one.
- Verification
- partial
- Role
- correction
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- 1978-1979
- Population
- Shipbreakers at the dismantling yard (1978-79 window)
- Limitations
- Corrects/documents a milestone conflict, not a material claim. 'Ampel Wrecking and Dismantling Corp.' vs 'Ampol Corp.' may be the same entity under variant transcription; no corporate record was verified. No asbestos content.
- Atlas source
- true
- Evidence ID
- ev-uss-assurance-mso521-10
-
[12]Designation cross-check: NavSource designation line (MSO-521 -> AG-521 only); DANFS entry header (MSO-521); Wikipedia USS Assurance (MSO-521) article (lead 'AM-521/MSO-521'; infobox 'Reclassified: MSO-510 to AG-521'); Shipscribe Ship Notes ('ex-MSO 521, ex-AM 520' printed against AG-521) [other_primary]
- Locator
- NavSource header; DANFS header; Wikipedia article lead and infobox; Shipscribe Ship Notes table
- Finding type
- historical_record
- Finding
- CORRECTION: secondary sources attach designation errors to this hull. (1) Wikipedia's lead styles her 'AM-521/MSO-521', but DANFS and NavSource carry only MSO-521 (the class was ordered under SCB Project 45B as MSOs on 26 October 1955, after the 1955 AM-to-MSO redesignation); Shipscribe's Ship Notes print 'ex-MSO 520, ex-AM 520' for AG-520 and 'ex-MSO 521, ex-AM 520' for AG-521 - the latter repeating AM-520, a visible slip (presumably for AM-521) - suggesting an ordering-era AM paperwork designation circulated but is inconsistently transcribed. The AM designation is not supported as officially held. (2) Wikipedia's infobox prints 'Reclassified: MSO-510 to AG-521' - MSO-510 is a different hull (Acme-class Advance); a clear typo for MSO-521. NavSource/DANFS sequence MSO-521 -> AG-521 (1 March 1973) is the documented line.
- Verification
- partial
- Role
- correction
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- 1955-1973 (designation window)
- Limitations
- Corrects circulating designation errors, not a material claim. Whether an ordering-era 'AM-521' paperwork designation ever officially applied is unresolved - DANFS and NavSource do not show it; Shipscribe's note contains an internal typo. No asbestos content.
- Atlas source
- true
- Evidence ID
- ev-uss-assurance-mso521-11
-
[13]NARA 'Navy Deck Logs Available in the National Archives Catalog' index (Vietnam-era digitization, Blue Water Navy Vietnam Veterans Act of 2019 pipeline) [other_primary]
- Locator
- NARA deck-log online index, 'A' section (Alacrity MSO-520 present 1961-69; Assurance absent)
- Finding type
- historical_record
- Finding
- Archival lead for this hull's primary records: Assurance does NOT appear in NARA's published index of fully-digitized Navy deck logs (checked 2026-10-03), while sister ship Alacrity (MSO-520) is listed with 1961-1969 logs online. Her deck logs exist in NARA's College Park holdings but are not publicly digitized; the logs would document exact availability dates, ports, and any onboard events for the 1958-1977 commissioned period.
- Verification
- partial
- Role
- archival_lead
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- 1958-1977 (logs' coverage)
- Limitations
- Archival lead only - establishes where the primary record sits, not its content. Absence from the digitized index does not mean the logs are unavailable at Archives II (textual reference, College Park); it means no online images. No asbestos content.
- Atlas source
- true
- Evidence ID
- ev-uss-assurance-mso521-12