Evidence
10 evidence entries recorded; each entry has a stable permalink (#ev-1 … #ev-10).
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[1]U.S. Maritime Commission, Instruction Manual for Operating and Maintaining 2500 H.P. Triple Expansion Marine Steam Engines, EC2-S-C1 Cargo Vessels (mirrored excerpt) [other_primary]
- Locator
- Mirrored excerpt, engine-cylinder insulation section
- Finding type
- asbestos_application
- Finding
- The U.S. Maritime Commission instruction manual for the EC2-S-C1 plant describes cylinder insulation of magnesia under sheet-iron lagging; insulation products of this era were commonly manufactured with asbestos fiber, and period steam-system gaskets, packing, and insulation felts commonly contained asbestos. This hull is a Z-EC2-S-C5 'boxed aircraft transport' - a hull-form variant of the EC2 emergency cargo design retaining the standard machinery plant (2 oil-fired boilers, 3-cylinder triple-expansion engine, 2,500 ihp). Liberty-type hulls were built to emergency USMC specifications during the period when the federal government had reserved asbestos supply for shipbuilding.
- Verification
- inferred
- Role
- supporting
- Documentation level
- class_or_era
- Accessed
- 2026-09-20
- Study period
- 1944-1965
- Population
- Construction trades (J.A. Jones, Panama City, 1944-45); merchant engine crew (1945-47); Navy engineering crew (1958-65)
- Limitations
- Class/design documentation, not a hull record - the manual names the EC2-S-C1 type, not this vessel or the Z-EC2-S-C5 variant by designation, and does not itself state 'asbestos' content. Application of the machinery-spec inference to this variant rests on the hull-form-variant relationship (propulsion plant unchanged). Asbestos presence aboard this hull is era inference, not ship-proven; does not establish quantity, present-day presence (hull scrapped ~2000), individual exposure, or causation.
- Atlas source
- true
- Evidence ID
- ev-uss-interrupter-agr15-01
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[2]Corn, Jacqueline Karnell, and Jennifer Starr, 'Historical perspective on asbestos: Policies and protective measures in World War II shipbuilding,' American Journal of Industrial Medicine 11(3):359-373 (1987) [other_primary]
- Locator
- Abstract and article, AJIM 11(3):359-373
- Finding type
- asbestos_application
- Finding
- Peer-reviewed historical study documents that asbestos was used extensively as a fireproofing and insulating material in U.S. shipbuilding during WWII - the era and emergency program under which this Liberty-type hull was mass-produced - and that wartime demand drove unprecedented asbestos utilization aboard merchant-type hulls.
- Verification
- verified
- Role
- context
- Documentation level
- class_or_era
- Accessed
- 2026-09-20
- Study period
- 1940s era documented; article 1987
- Population
- WWII shipyard workers and ship crews (class context)
- Limitations
- Program/era-level scholarly documentation of asbestos use in WWII shipbuilding generally; does not name this vessel or type and does not establish that asbestos was aboard this hull, nor quantity, location, condition, exposure, or causation.
- Atlas source
- true
- Evidence ID
- ev-uss-interrupter-agr15-02
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[3]NHHC, Dictionary of American Naval Fighting Ships, 'Tracer' (AGR-15) entry [nhhc_danfs]
- Locator
- DANFS Tracer entry, full text (canonical https://www.history.navy.mil/research/histories/ship-histories/danfs/t/tracer.html returned 404 on 2026-09-20 - standing NHHC link rot; Wayback capture of the official page used)
- Finding type
- vessel_history
- Finding
- DANFS (NHHC): William J. Riddle, a Liberty ship, was laid down under a Maritime Commission contract (MC hull E-2340) on 24 December 1944 at Panama City, Fla., by J.A. Jones Construction Co., Inc.; launched 31 January 1945; sponsored by Mrs. Marion Harders; delivered to the War Shipping Administration in early 1945. Operated with Moore-McCormack Lines and Waterman Steamship Corp. 1945-1947; at war's end she was steaming from Hawaii to the Philippines; converted to a cattle carrier in 1946; reverted to dry cargo by March 1947; laid up in the James River NDRF for ten years. Selected by the Navy in May 1957; conversion began at Charleston Naval Shipyard 24 May 1957; renamed Interrupter, classified AGR-15, commissioned at Charleston 16 October 1958, Lt. Comdr. George S. Harrison in command. Transited the Panama Canal 26 January 1959; arrived home port San Francisco 12 February 1959, sixth AGR to join Radar Picket Squadron 1; first barrier patrol 6 March 1959. Renamed Tracer 4 September 1959 to eliminate confusion with similarly named sister ships. Patrolled Western Contiguous Radar Line stations 1959-1965, earning awards for administrative and operational efficiency. Deactivated 1965; struck from the Navy list 1 September 1965; transferred to the Maritime Commission and laid up at Suisun Bay, Calif.
- Verification
- verified
- Role
- supporting
- Documentation level
- ship_specific
- Accessed
- 2026-09-20
- Study period
- 1944-1965
- Population
- Navy crew, complement 151 (DANFS)
- Limitations
- Authoritative for identity, construction, service, renaming, and disposal outline. Gives no decommissioning date (states only 'deactivated in 1965') and contains no asbestos, insulation-material, or industrial-hygiene information; supports no asbestos claim.
- Atlas source
- true
- Evidence ID
- ev-uss-interrupter-agr15-03
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[4]U.S. Maritime Administration, ShipHistory database - TRACER (AGR-15) Detail 4907 and WILLIAM J. RIDDLE Detail 5271, incl. digitized vessel status cards [marad_nrc]
- Locator
- ShipHistory Detail 4907 + Detail 5271 milestone tables; status card scans incl. Vessel Status Card O.N. 247202, Reserve Fleet Ship Particulars card (Form MA-383), and Record of Ship Sales card (Form MA-20, PD-X-979, contract MA-7460)
- Finding type
- vessel_history
- Finding
- MARAD ShipHistory database and digitized vessel status cards: U.S. Official No. 247202; built by J.A. Jones Construction Co. at Panama City, Fla.; completed 2-15-45; type Z-EC2-S-C5; MCE hull 2340, builder's no. 81. Card-documented custody chain: Moore-McCormack Lines (GAA, delivered Panama City 2-15-45); Wilmington NC Reserve Fleet entry 12-16-46; Waterman SS Corp. withdrawal for operation 1-29-47 (GAA/MC/BB deliveries at Wilmington, New York, Baltimore 1947); Reserve Fleet entry Lee Hall, James River 10-29-47; Navy Department title transfer at James River 5-21-57 ('Renamed "TRACER" (AGR-15)'); MARAD custody at Suisun Bay 8-16-65; permanent transfer to MARAD 2-4-66; sold 7-15-74 to Walco Vessels Ltd. for nontransportation use under PD-X-979 for $200,010.00; physically delivered/withdrawn 8-1-74 (12:45 PM PDT). The sale card (Form MA-20) records the hull was advertised under PD-X-979 dated 6-5-74, bids opened 7-9-74, under two conditions - (1) non-transportation use, (2) scrap hull in the U.S. - and was awarded under condition (1) NTU.
- Verification
- verified
- Role
- supporting
- Documentation level
- ship_specific
- Accessed
- 2026-09-20
- Study period
- 1945-1974
- Limitations
- Authoritative primary custody record for government ownership milestones and the 1974 disposal. Status-card handwriting partially legible (OCR-aided); the sales card's price field reads $200,010.10 vs $200,010.00 on the reserve-fleet card - trivial internal variance. Contains no asbestos, materials, or condition-survey information; supports no asbestos claim.
- Atlas source
- true
- Evidence ID
- ev-uss-interrupter-agr15-04
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[5]NHHC DANFS 'Tracer' entry (conversion start 24 May 1957 at Charleston Naval Shipyard; commissioning 16 October 1958); MARAD status card (Navy title transfer 5-21-57) [nhhc_danfs]
- Locator
- DANFS Tracer entry paragraphs 3-4; MARAD card custody line 'Navy Department - Title - James Riv - 5-21-57'
- Finding type
- vessel_history
- Finding
- Documented ship-specific yard event: the hull underwent conversion to a radar picket ship at Charleston Naval Shipyard, Charleston, S.C., from 24 May 1957 through commissioning on 16 October 1958 - an approximately 17-month naval shipyard period in which the merchant hull was reconfigured for the AGR role (DANFS dates; conversion-yard identity corroborated by MARAD custody record and class records).
- Verification
- verified
- Role
- supporting
- Documentation level
- ship_specific
- Accessed
- 2026-09-20
- Study period
- 1957-1958
- Population
- Charleston Naval Shipyard conversion workforce; ship's crew during post-conversion availability
- Limitations
- The conversion event, yard, and dates are ship-specific and documented. Any asbestos involvement in that conversion (insulation rip-out, refit materials, yard-trade exposure) is era/yard inference - no conversion work package, material schedule, or asbestos abatement record for this hull was located. Charleston Naval Shipyard is a documented asbestos-associated yard in the Atlas shipyards dataset; that is yard-level context, not a finding about this hull. Does not establish exposure, quantity, or causation.
- Atlas source
- true
- Evidence ID
- ev-uss-interrupter-agr15-05
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[6]MARAD ShipHistory Detail 4907/5271 and status cards (name-change milestone, sale card); NHHC DANFS 'Tracer' entry (rename sequence); NavSource AGR-15 page (price transcription, CO list); Wikipedia USS Tracer (internal inconsistency) [marad_nrc]
- Locator
- MARAD milestone tables + status cards; DANFS Tracer entry; https://navsource.org/archives/09/62/6215.htm; https://en.wikipedia.org/wiki/USS_Tracer
- Finding type
- historical_record
- Finding
- Source discrepancies resolved: (a) MARAD's milestone table and status card record the vessel name change as 'WILLIAM J. RIDDLE to TRACER' on 5-21-57 - a simplification; DANFS documents the Navy sequence as renamed Interrupter at the 1958 commissioning, then renamed Tracer on 4 September 1959 (to eliminate confusion with Interdictor AGR-13 and Interpreter AGR-14). MARAD recorded the final Navy name. (b) The Wikipedia article's body text erroneously states the ship was laid down as 'Dudley H. Thomas' - a copy-paste from the AGR-14 Interpreter article; its own infobox, DANFS, and MARAD all confirm William J. Riddle, MCE hull 2340. (c) Sale price: NavSource transcribes $210,010.00; the MARAD status cards read $200,010.00 (reserve-fleet card) and $200,010.10 (sales card) - the handwritten primary documents control. (d) MARAD's web 'MARAD Type' field reads EC2-S-C1, while the status cards show Z-EC2-S-C5 - the card (primary document) controls. (e) The YAGRS Association page gives decommissioned 1 September 1965, conflating the strike date; NavSource/Wikipedia give 7 July 1965 and DANFS only 'deactivated in 1965' - 7 July 1965 is used with the conflict flagged.
- Verification
- verified
- Role
- correction
- Documentation level
- ship_specific
- Accessed
- 2026-09-20
- Study period
- 1945-1974
- Limitations
- Resolves publication-level discrepancies in secondary sources and one database field-level simplification; does not affect identity or custody timeline materially. No asbestos content in any of these sources.
- Atlas source
- true
- Evidence ID
- ev-uss-interrupter-agr15-06
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[7]U.S. Naval History and Heritage Command photo NH 89309 (caption, via NavSource hosting); NavSource Online Service Ship Photo Archive, USS Tracer (AGR-15) page captions [other_primary]
- Locator
- NavSource AGR-15 page, commercial-service photo captions; NHHC photo no. NH 89309 as captioned
- Finding type
- historical_record
- Finding
- Post-Navy disposition detail: official NHHC photograph NH 89309 documents ex-Tracer in September 1974 after conversion to an 'Alaskan waters crab processing ship.' NavSource photo captions further document commercial service as the fish-processing vessel 'Unisea' at Unalaska, Alaska, and disposition 'towed to China in 2000' for scrapping.
- Verification
- partial
- Role
- context
- Documentation level
- ship_specific
- Accessed
- 2026-09-20
- Study period
- 1974-2000
- Population
- Fish-processing conversion crews (1974+); scrapping workforce (China, ~2000) - hypothetical populations only, not documented exposed persons
- Limitations
- The crab-processing conversion is supported by an official NHHC photo artifact; the 'Unisea' renaming and the 2000 China tow are documented only in NavSource contributor captions - secondary material not independently corroborated against a MARAD or registry source. No asbestos content; the NTU conversion and eventual foreign scrapping are the kind of events where hull ACM disposition would matter, but no abatement or survey record was located.
- Atlas source
- true
- Evidence ID
- ev-uss-interrupter-agr15-07
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[8]Batch-751 search ledger (this record): NHHC DANFS (via Wayback); MARAD ShipHistory 4907/5271 + status cards; NVR ship detail; CourtListener API v4 + web UI; general web search; NavSource/yagrs.org as leads [other_primary]
- Locator
- search_ledger rows sl-uss-interrupter-agr15-01 through sl-uss-interrupter-agr15-08
- Finding type
- historical_record
- Finding
- No qualifying ship-specific asbestos record located: no asbestos survey, abatement contract, hazmat disclosure, or docketed case naming Interrupter, Tracer, AGR-15, or William J. Riddle was found in the public sources searched. The litigation sweep is INCOMPLETE - CourtListener API v4 returned HTTP 429 (125/day limit exhausted, ~9h reset) and the HTML interface returned 403 at research time; a general web search surfaced only law-firm marketing pages (asbestos-ships.com, freeasbestostesting.com), which are banned sources and were excluded. See search_ledger.
- Verification
- partial
- Role
- negative_finding
- Documentation level
- ship_specific
- Accessed
- 2026-09-20
- Study period
- 2026-09-20
- Limitations
- Absence of a located public record does not prove absence of asbestos aboard - a 1944-45 Liberty-type hull retaining era materials through a 1957-58 conversion is era-consistent with asbestos-containing materials. Does not establish presence or absence; does not establish or defeat any exposure claim or legal eligibility. Marked 'partial' (not 'verified') because the CourtListener litigation index could not be queried - a hull-specific asbestos docket may exist that this sweep could not reach.
- Atlas source
- true
- Evidence ID
- ev-uss-interrupter-agr15-08
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[9]NARA Guide to Federal Records: RG 178 (US Maritime Commission), RG 248 (War Shipping Administration), RG 181 (Naval Districts and Shore Establishments); NARA deck-log and merchant-vessel logbook guidance [other_primary]
- Locator
- https://www.archives.gov/research/guide-fed-records/groups/178.html ; https://www.archives.gov/research/guide-fed-records/groups/248.html ; https://www.archives.gov/research/guide-fed-records/groups/181.html ; https://www.archives.gov/research/military/logbooks/merchant-vessels-pl.html
- Finding type
- historical_record
- Finding
- Archival leads (not retrieved - requires research-room or reproduction order; no spend authorized): NARA RG 178 (Records of the U.S. Maritime Commission) - Construction Division and Gulf Coast/East Coast Director files may hold J.A. Jones Panama City contract E-2340 construction and outfitting specifications; RG 248 (War Shipping Administration) holds vessel acquisition/operation files; RG 181 (Records of Naval Districts and Shore Establishments) holds Charleston Naval Shipyard records incl. potential 1957-58 conversion work packages; Navy deck logs for AGR-15 (1958-1965) are in NARA's deck-log holdings; merchant logbooks are in RG 26 (USCG), distributed regionally by port of submission.
- Verification
- unverified
- Role
- archival_lead
- Documentation level
- context_only
- Accessed
- 2026-09-20
- Study period
- 1944-1965 records
- Limitations
- Record-group mapping only - no box-level retrieval performed; existence of asbestos-specific documents for this hull (conversion work packages, outfitting specs) is unknown until surveyed in person. Nothing in this row is an asbestos finding.
- Atlas source
- true
- Evidence ID
- ev-uss-interrupter-agr15-09
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[10]In re Joint Eastern and Southern Districts Asbestos Litigation (Robinson v. United States), 891 F.2d 31 (2d Cir. 1989) [court_record]
- Locator
- Opinion, 891 F.2d 31 (No. 1547, docket 89-6109); reporter citation confirmed 2026-09-14 in Batch-01 (this repo)
- Finding type
- litigation_documented
- Finding
- Second Circuit ruling addressing mesothelioma claims by a mariner aboard War Shipping Administration vessels; the court considered jurisdiction over a personal-injury claim against the United States for asbestos exposure aboard the WWII government merchant fleet - the same operating agency (WSA, with Moore-McCormack Lines and Waterman Steamship Corp. as general agents) that ran this hull 1945-1947. Claims against the government were barred on discretionary-function grounds.
- Verification
- verified
- Role
- context
- Documentation level
- class_or_era
- Accessed
- 2026-09-20
- Study period
- 1989 (opinion); wartime exposure period
- Population
- WWII merchant mariners (class context)
- Limitations
- Fleet-level jurisdictional ruling; does not name this hull, does not find asbestos conditions aboard any specific vessel, and establishes only the litigation posture for WWII merchant-fleet claims. Carried as class context for the hull's WSA period only - says nothing about the Navy AGR period.
- Atlas source
- true
- Evidence ID
- ev-uss-interrupter-agr15-10