USS Interdictor (AGR-13)

Evidence

22 evidence entries recorded; each entry has a stable permalink (#ev-1 … #ev-22).

This record consolidates retired designation record uss-interdictor-yagr13 (redesignation of the same hull); entries carried over keep their original evidence ids and show the retired id as Source vessel.

1. [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 USMC operating 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 the Z-EC2-S-C5 boxed-aircraft-transport variant of the EC2 design (MARAD type; DANFS stat line 'T. Z-EC2-S-C5'), built to emergency USMC specifications during the period when the federal government had reserved asbestos supply for shipbuilding; the -C5 variant shared the standard EC2 machinery plant (2 oil-fired boilers, triple-expansion engine, ~2,500 ihp).

   Verification

   inferred

   Role

   supporting

   Documentation level

   class_or_era

   Accessed

   2026-09-20

   Study period

   1945

   Population

   Construction trades (J. A. Jones, Panama City, 1945); merchant engine crew (1945); Navy crew (1958-1965)

   Limitations

   Class/design documentation, not a hull record - the manual names the EC2-S-C1 type, not this vessel or the -C5 variant, and does not itself state 'asbestos' content (magnesia lagging of the era was typically asbestos-fiber-reinforced, but the manual text is silent on fiber). Asbestos presence aboard this hull is era inference, not ship-proven. Does not establish quantity, present-day presence, individual exposure, or causation.

   Atlas source

   true

   Evidence ID

   ev-uss-interdictor-agr13-01

2. [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 EC2-S-C5 hull was built (laid down 1945-05-18, delivered 1945-07-27) - 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 the EC2 type and does not establish that asbestos was or remains aboard this hull, nor quantity, location, condition, exposure, or causation.

   Atlas source

   true

   Evidence ID

   ev-uss-interdictor-agr13-02

3. [3]DANFS / NHHC, 'Interdictor' (YAGR-13/AGR-13) entry - live URL 404s as of 2026-09-20; text verified via Wayback Machine capture 2024-05-25 and hazegray DANFS transcription mirror [nhhc_danfs]

   Locator

   DANFS entry full text; Wayback http://web.archive.org/web/20240525212502/https://www.history.navy.mil/research/histories/ship-histories/danfs/i/interdictor.html ; mirror https://losthistory.net/hazegray/danfs/yard/yagr13.htm

   Finding type

   vessel_history

   Finding

   DANFS: launched as Liberty Ship Edwin H. Duff by J. A. Jones Construction Company, Inc., Panama City, Fla., 29 June 1945; sponsored by Mrs. Edwin H. Duff; delivered to McCormack Steamship Co. 27 July 1945. Carried aircraft until entering the National Defense Reserve Fleet, James River, Va., 17 October 1945; except for brief cargo service remained there until acquired by the Navy 10 May 1957. Renamed Interdictor and converted to Navy use at Charleston Naval Shipyard; commissioned 7 April 1958, Lt. Comdr. J. P. Dordahl in command. Shakedown in the Caribbean from 2 May 1958; departed Charleston 18 July; arrived new home port San Francisco 13 August; served as ocean radar station ship for the Continental Air Defense Command, three-to-four-week Pacific cruises with weather-reporting duties. Hull classification changed to AGR-13 on 28 September 1958. Decommissioned 5 August 1965; struck from the Navy List 1 September 1965 and transferred to the Maritime Administration for lay-up at Suisun Bay. Stat line: dp. 10,760 (f.); l. 441'6"; b. 56'11"; dr. 24'; s. 11 k.; cpl. 149; cl. Guardian; T. Z-EC2-S-C5.

   Verification

   verified

   Role

   supporting

   Documentation level

   ship_specific

   Accessed

   2026-09-20

   Study period

   1945-1965 (DANFS text predates 1974 disposal)

   Population

   Navy crew (1958-1965, cpl. 149 per DANFS)

   Limitations

   Authoritative Navy history for identity, dates, and service; contains no asbestos, materials, or condition-survey information - supports no asbestos claim. DANFS entry text ends with 'where she remains' (Suisun Bay), stale relative to the 1974 sale documented by MARAD - see correction row ev-uss-interdictor-agr13-07. NHHC live URL returns 404 (documented NHHC link-rot standing defect); Wayback capture 2024-05-25 carries the canonical text. DANFS internally inconsistent on merchant name spelling ('Edwin S. Duff' in launch sentence vs sponsor 'Mrs. Edwin H. Duff'); MARAD vessel name history confirms EDWIN H. DUFF.

   Atlas source

   true

   Evidence ID

   ev-uss-interdictor-agr13-03

4. [4]U.S. Maritime Administration, ShipHistory database - INTERDICTOR (AGR-13), Ship History Detail 2302, and EDWIN H. DUFF, Ship History Detail 7749 (same hull, Official No. 248131) [marad_nrc]

   Locator

   ShipHistory Detail 2302 milestone table + status-card slot; Detail 7749 (EDWIN H. DUFF) document slot

   Finding type

   vessel_history

   Finding

   MARAD ShipHistory records for this hull under both names: U.S. Official No. 248131; type Z-EC2-S-C5; built 1945 by J. A. Jones Construction Company; length 441.5 ft, beam 56.8 ft, 7,176 gross tons. Milestones (Detail 2302): NDRF entry/acquisition 1945-10-17 (ex-EDWIN H. DUFF); disposition/withdrawal 1974-06-21; fate 'Sold -NTU' (non-transportation use). A digitized status card (2302_4291AF.jpg / 1Z5_01.png) and one document file (EDWIN H. DUFF.pdf) exist on the records but were not OCR-retrieved this pass.

   Verification

   verified

   Role

   supporting

   Documentation level

   ship_specific

   Accessed

   2026-09-20

   Study period

   1945-1974

   Limitations

   Authoritative for government custody milestones and disposal; contains no asbestos, materials, or condition-survey information - supports no asbestos claim. Status card and attached PDF not text-reviewed; contents unknown beyond the milestone table. MARAD milestone dates are custody events, not necessarily contract dates - the 1974-06-21 withdrawal postdates the 1974-06-13 sale date given in secondary compilations.

   Atlas source

   true

   Evidence ID

   ev-uss-interdictor-agr13-04

5. [5]DANFS / NHHC, 'Guardian' (YAGR-1/AGR-1) entry - class lead ship (hazegray DANFS transcription mirror) [nhhc_danfs]

   Locator

   DANFS Guardian entry full text (hazegray mirror); class count per secondary compilations

   Finding type

   vessel_history

   Finding

   Guardian-class context: DANFS records Guardian (YAGR-1) - ex-Liberty ship James Squires, likewise built by J. A. Jones, Panama City - as the first ocean radar station ship put into service by the Navy, converted at Charleston Navy Yard and commissioned 1 February 1955, with 'sister ships' standing 3-4-week radar picket patrols for the Continental Air Defense Command; the class-wide YAGR-to-AGR redesignation occurred 28 September 1958. Secondary compilations (Wikipedia class roster, yagrs.org) count 16 Liberty-hull conversions 1954-1959, eight homeported at Treasure Island/San Francisco and eight at Davisville, RI - consistent with this hull's documented San Francisco homeport.

   Verification

   verified

   Role

   context

   Documentation level

   class_or_era

   Accessed

   2026-09-20

   Study period

   1954-1965 program era

   Population

   Navy crews of the Guardian-class conversions (class context)

   Limitations

   Class-program context only - establishes that the conversion program and mission existed, not any condition aboard this specific hull. The 16-ship count and homeport split derive from secondary compilations, not the DANFS text itself. Contains no asbestos information.

   Atlas source

   true

   Evidence ID

   ev-uss-interdictor-agr13-05

6. [6]DANFS / NHHC, 'Interdictor' entry - conversion event (via Wayback capture 2024-05-25; live URL 404s) [nhhc_danfs]

   Locator

   DANFS Interdictor entry, acquisition/conversion sentence

   Finding type

   vessel_history

   Finding

   Ship-specific yard event: the Navy acquired this hull 10 May 1957 and converted it to a radar picket ship at Charleston Naval Shipyard, Charleston, SC (1957-1958), commissioning as YAGR-13 on 7 April 1958. A major naval-yard conversion on a 1945 hull - reconfiguration of cargo spaces into berthing, electronics, and radar spaces - is the documented disturbance/installation pathway relevant to era insulation materials.

   Verification

   verified

   Role

   supporting

   Documentation level

   ship_specific

   Accessed

   2026-09-20

   Study period

   1957-1958

   Population

   Charleston Naval Shipyard conversion workforce (1957-58); Navy crew (1958-1965)

   Limitations

   The conversion event is ship-specific and documented; its asbestos scope is NOT documented - no materials list, work package, or abatement record for the conversion was located in public sources. Any statement that conversion work removed or installed asbestos aboard this hull is era inference, not ship-proven. Acquisition date conflicts: DANFS 1957-05-10 vs NavSource 1957-06-05 (secondary); DANFS carried.

   Atlas source

   true

   Evidence ID

   ev-uss-interdictor-agr13-06

7. [7]MARAD ShipHistory Detail 2302 milestones vs. DANFS closing sentence [marad_nrc]

   Locator

   MARAD Detail 2302 milestone table; DANFS Interdictor entry final sentence

   Finding type

   vessel_history

   Finding

   DANFS ends 'transferred to the Maritime Administration for lay-up in the Suisun Bay River Defense Reserve Fleet ... where she remains.' That text is stale: MARAD ShipHistory records disposition and withdrawal 1974-06-21 with fate 'Sold -NTU' (non-transportation use); secondary compilations (NavSource, mariners-l, yagrs.org) date the sale 13 June 1974 to a Portland, OR buyer, fate thereafter unknown.

   Verification

   verified

   Role

   correction

   Documentation level

   ship_specific

   Accessed

   2026-09-20

   Study period

   1965-1974

   Population

   NDRF caretaker crews (1965-1974); any post-sale dismantling workforce (undocumented)

   Limitations

   Corrects DANFS's 'where she remains' framing against MARAD custody records. Sale-date discrepancy (contract vs withdrawal, 06-13 vs 06-21) unresolved but immaterial to exposure history. Post-sale condition, use, and dismantling undocumented - no disposal-yard asbestos record exists or was located.

   Atlas source

   true

   Evidence ID

   ev-uss-interdictor-agr13-07

8. [8]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)

   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, acting through general agents such as this hull's 1945 operator) that ran this ship in merchant service. Claims against the government were barred on discretionary-function grounds - the fleet's characteristic litigation posture.

   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. Reporter citation confirmed 2026-09-14 in batch-01 work: 891 F.2d 31.

   Atlas source

   true

   Evidence ID

   ev-uss-interdictor-agr13-08

9. [9]Batch-749 search ledger (this record): NHHC DANFS live + Wayback; hazegray mirror; MARAD ShipHistory 2302/7749; NVR; CourtListener API v4 + web UI + site-indexed search; NavSource/yagrs.org lead check; NARA record-group guides [other_primary]

   Locator

   search_ledger rows sl-uss-interdictor-agr13-01 through -10

   Finding type

   historical_record

   Finding

   No qualifying ship-specific asbestos record located: no asbestos survey, abatement contract, hazmat disclosure, or docketed case naming Interdictor, YAGR-13, AGR-13, or Edwin H. Duff was found in the public sources searched (see search_ledger). CourtListener coverage is incomplete this pass - API v4 throttled at the 125/day cap (HTTP 429, ~20,450s reset) and the web UI returned 403; a site-indexed search returned only a name-collision result (an Arizona HIDTA drug-interdiction document, not the vessel).

   Verification

   verified

   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 1945 hull extensively reworked at a 1957-58 navy yard is era-consistent with asbestos-containing materials both original and conversion-installed. The litigation sweep is incomplete (CourtListener blocked); ship-name litigation may also run under operator or shipyard names not yet searched. Does not establish presence or absence; does not establish or defeat any exposure claim or legal eligibility.

   Atlas source

   true

   Evidence ID

   ev-uss-interdictor-agr13-09

10. [10]NARA Guide to Federal Records: RG 24 (Navy deck logs), RG 181 (naval shore establishment records - Charleston Naval Shipyard), RG 178 (U.S. Maritime Commission), RG 26 (USCG merchant-vessel logbooks) [other_primary]

    Locator

    archives.gov/research/guide-fed-records/groups/24.html, /181.html, /178.html; archives.gov/research/military/logbooks

    Finding type

    historical_record

    Finding

    Archival leads (not retrieved - require research-room or reproduction orders; no spend authorized): NARA RG 24 holds Navy deck logs covering this hull's 1958-1965 commission (command/operations-level detail, materials unlikely but possible); RG 181 Charleston Naval Shipyard industrial records (NARA Atlanta region) may hold the 1957-58 conversion work packages - the strongest candidate for any materials scope; RG 178 Construction Division records may hold MCE hull 3142 construction/outfitting records (Southeast/Gulf region for Panama City builds); merchant logbooks for the 1945 service period are in RG 26 distributed by port of submission.

    Verification

    unverified

    Role

    archival_lead

    Documentation level

    context_only

    Accessed

    2026-09-20

    Study period

    1945-1965 records

    Limitations

    Record-group mapping only - no box-level retrieval performed; existence of asbestos-specific documents for this hull or its conversion is unknown until surveyed in person. Nothing in this row is an asbestos finding.

    Atlas source

    true

    Evidence ID

    ev-uss-interdictor-agr13-10

11. [11]research packet 1018-packet.md [other_primary]

    Finding type

    vessel_history

    Finding

    Identity packet verdict: VERIFIED

    Verification

    verified

    Role

    supporting

    Documentation level

    ship_specific

    Evidence ID

    uss-interdictor-yagr13-pkt-1018-packet-md

    Source vessel

    uss-interdictor-yagr13

12. [12]DANFS, Interdictor (YAGR-13) - NHHC ship-history page (published 2015-07-22; live URL returns 404 as of 2026-10-04 - archived copy cited via Wayback Machine snapshot 2024-08-09) [nhhc_danfs]

    Locator

    DANFS entry spec block and service narrative (archived snapshot 2024-08-09)

    Finding type

    vessel_history

    Finding

    Documented for this hull (verbatim; footnote markers and spacing normalized): 'Interdictor (YAGR-13: dp. 10,760; l. 441'6"; b. 56'11"; dr. 24'; s. 11 k.; cpl. 149; cl. Guardian; T. Z-EC2-S-C5) One who prohibits. Interdictor (YAGR-13) was launched as Liberty Ship Edwin S. Duff [sic - MARAD records EDWIN H. DUFF] by J. A. Jones Construction Company, Inc., Panama City, Fla. 29 June 1945; sponsored by Mrs. Edwin H. Duff; and delivered to McCormack Steamship Co. 27 July 1945. She carried aircraft until entering the National Defense Reserve Fleet, James River, Va., 17 October 1945, and except for brief cargo service remained there until being acquired by the Navy 10 May 1957. Renamed Interdictor and converted to Navy use at Charleston Naval Shipyard, she commissioned 7 April 1958, Lt. Comdr. J. P. Dordahl in command.' Sailed 2 May 1958 for Caribbean shakedown; departed Charleston 18 July for new home port San Francisco, arriving 13 August; ocean radar station ship in the early-warning system, supplementing land-based radar and controlling interceptor aircraft; weather reporting on three-to-four-week Pacific cruises. 'Interdictor's hull classification was changed 28 September 1958 to AGR-13. She continued on radar picket patrols for the Continental Air Defense Command out of San Francisco until decommissioned 5 August 1965. Her name was struck from the Navy List 1 September 1965 when she transferred to the Maritime Administration for lay-up in the Suisun Bay ... Reserve Fleet.'

    Verification

    verified

    Role

    supporting

    Documentation level

    ship_specific

    Accessed

    2026-10-04

    Study period

    1945-1965

    Population

    J.A. Jones construction trades (1945); merchant crew (1945-46, brief reactivations); conversion yard trades, Charleston Naval Shipyard (1957-58); crew (1958-65)

    Limitations

    Ship-specific history only; contains no asbestos, insulation-material, or industrial-hygiene content. DANFS prints 'Edwin S. Duff' once in the launch line against sponsor 'Mrs. Edwin H. Duff' and MARAD's authoritative EDWIN H. DUFF - carried here as a typographic variant, flagged in gaps. DANFS dates Navy acquisition to 10 May 1957 vs NavSource 5 June 1957 and shipscribe 7 May 1957 (unresolved). Live NHHC page 404s (standing link-rot defect); archived copy used and labeled.

    Atlas source

    true

    Evidence ID

    ev-uss-interdictor-yagr13-01

    Source vessel

    uss-interdictor-yagr13

13. [13]U.S. Maritime Administration, ShipHistory database - INTERDICTOR (AGR-13), Ship History Detail 2302 [marad_nrc]

    Locator

    ShipHistory Detail 2302 - vessel summary fields, Vessel Name History, Milestones table, Status Cards/Documents tabs (empty)

    Finding type

    vessel_history

    Finding

    MARAD record for this hull: Year built 1945; U.S. Official Number 248131; shipyard 'J. A. Jones Construction Company'; type Z-EC2-S-C5; length 441.50 ft, beam 56.80 ft; gross 7,176 tons / net 4,380 tons; cargo capacity 500,000 sq ft; fate 'Sold -NTU' (non-transportation use). Vessel name history: EDWIN H. DUFF -> INTERDICTOR (AGR-13). Milestones: Entry 10/17/1945; Acquisition 10/17/1945 'ex-EDWIN H. DUFF'; Disposition 6/21/1974 'ex-EDWIN H. DUFF'; Withdrawal 6/21/1974. No historical narrative, documents, status cards, imagery, or plans digitized for this vessel.

    Verification

    verified

    Role

    supporting

    Documentation level

    ship_specific

    Accessed

    2026-10-04

    Study period

    1945-1974

    Limitations

    Authoritative for merchant identity, government custody milestones, and disposal date; the milestone table records NDRF entry (1945) and final withdrawal (1974) but not the 1957 Navy acquisition - custody events between merchant and naval service are absent from the digitized summary. Status cards exist in the record schema but are NOT digitized for this hull - the McCormack-vs-Waterman operator conflict and the 1957 acquisition-date conflict cannot be resolved from this source as published. No asbestos, materials, or condition-survey information.

    Atlas source

    true

    Evidence ID

    ev-uss-interdictor-yagr13-02

    Source vessel

    uss-interdictor-yagr13

14. [14]NavSource Online: Service Ship Photo Archive, USS Interdictor (AGR-13) ex USS Interdictor (YAGR-13) - designation timeline, specifications, commanding officers, final disposition (navsource.net, verified live 2026-10-04) [other_primary]

    Locator

    NavSource 09/62/6213.htm header block, Guardian-class timeline, Specifications block, Commanding Officers table

    Finding type

    vessel_history

    Finding

    NavSource timeline for this hull: laid down 18 May 1945 as SS Edwin H. Duff, MC type Z-EC2-S-C5, MCE hull 3142, at J. A. Jones Construction Co., Panama City, FL; launched 29 June 1945; delivered 27 July 1945 to the Maritime Commission/WSA 'to be operated by Waterman Steamship Corp, under contract' (conflicts with DANFS's McCormack Steamship Co. - see gaps); returned to the Maritime Commission 1947 for NDRF lay-up; reactivated 1951 for commercial service; returned to MARAD 25 August 1953; 'Acquired by the Navy, 5 June 1957' (vs DANFS 10 May / shipscribe 7 May 1957); converted at Charleston Naval Shipyard; commissioned 7 April 1958, LCDR Joseph P. Dordahl USNR; redesignated AGR-13 28 September 1958; decommissioned 5 August 1965; struck 1 September 1965 and transferred to the Maritime Commission, NDRF Suisun Bay; final disposition 13 June 1974, sold for non-transportation use to a Portland, OR buyer, fate unknown. Specs: 11,365 t (fl); 441' x 59' x 22'; 11 kts; complement 13 officers + 138 enlisted; two 3"/50 guns; propulsion two 220-psi boilers, Filer & Stowell three-cylinder triple-expansion engine, single 18'6" 4-blade propeller, 2,500 shp, two electric generators. Four commanding officers listed (Dordahl Apr 1958 - Nov 1959; Allison - Jan 1963; Henry - Feb 1965; Creighton - Aug 1965). Ribbon bar: National Defense Service Medal.

    Verification

    verified

    Role

    supporting

    Documentation level

    ship_specific

    Accessed

    2026-10-04

    Study period

    1945-1974

    Population

    Merchant crews (1945-53 reserve-fleet intervals); conversion trades, CNSY (1957-58); crew 1958-65 (~149 per DANFS)

    Limitations

    NavSource is a volunteer secondary compilation, not a primary registry - its milestones generally track NVR/DANFS but it is the dissenting source on the 1945 operator (Waterman vs McCormack) and acquisition date (5 June vs 10/7 May 1957); the digitized MARAD status card that would resolve both is not published. Specs differ from DANFS and shipscribe on displacement, beam, draft, and complement. Contains no asbestos content.

    Atlas source

    true

    Evidence ID

    ev-uss-interdictor-yagr13-03

    Source vessel

    uss-interdictor-yagr13

15. [15]shipscribe.com, 'USS Guardian (YAGR/AGR 1, Z-EC2-S-C5) Class' - compilation of U.S. Navy vessel register and Ship Characteristics Board data (class data, per-hull construction/disposition lines, class notes) [other_primary]

    Locator

    shipscribe AGR01.html - class Design/Specifications block, Construction table row 13, Disposition table row 13, Class Notes (YAGR->AGR redesignation narrative; YAGR 13-15 approval date; 1961 name-change request)

    Finding type

    vessel_history

    Finding

    Class and per-hull data for this vessel: Guardian class was designed under 'SCB Project No. 126, conversion of MC Z-EC2-S-C5'; class specs 8,760 light / 10,760 full displacement, 442' oa x 57' e x 27' max nav, two 3"/50, accommodations 13 officers + 124 enlisted, 11 kts, 2,500 hp 'steam triple expansion reciprocating, 2 boilers (220psi/450deg), 1 screw'. Per-hull line: 'INTERDICTOR 3142 FY 1958. (ex-YAGR 13) (ex-EDWIN H DUFF, compl. 27 Jul 1945). Converted at NSY Charleston, S.C. Renamed 19 Dec 1957 as YAGR. Served in the North Pacific. To MA custody 5 Aug 1965. To buyer 1 Jul 1974.' Acquisition column: 7 May 1957. Class notes document the YAGR->AGR redesignation: on 29 May 1958 Commander YAGR Division 21 asked CNO to change designator YAGR to AGR because the 'Y' (service craft) prefix 'had a subtle but definite adverse effect on the morale, the manning, and the supply of the ships'; name and classification for YAGR 13-15 (INTERDICTOR, INTERPRETER, INTERRUPTER) were approved 19 December 1957; on 5 April 1961 Interdictor's CO requested a name change because of confusion with INTERPRETER and INTERCEPTOR - not pursued.

    Verification

    verified

    Role

    supporting

    Documentation level

    ship_specific

    Accessed

    2026-10-04

    Study period

    1957-1974

    Population

    Conversion trades, NSY Charleston (1957-58); crew 1958-65

    Limitations

    Private but rigorous secondary compilation of official U.S. Navy register/SCB data, not a government publication itself - treated here as the nearest available transcription of NVR/SCB-126 figures for a hull absent from the live NVR. The acquisition date it carries (7 May 1957) conflicts with DANFS (10 May) and NavSource (5 Jun); 'to buyer 1 Jul 1974' vs NavSource sale 13 Jun and MARAD withdrawal 21 Jun 1974. Contains no asbestos content - conversion-scope asbestos claims are inference only.

    Atlas source

    true

    Evidence ID

    ev-uss-interdictor-yagr13-04

    Source vessel

    uss-interdictor-yagr13

16. [16]Capt. J. A. Brown, USN, 'Ocean Radar Station Ship - A Page from the New Navy,' U.S. Naval Institute Proceedings 84/8/666 (August 1958) [reputable_press]

    Locator

    USNI Proceedings August 1958, 'Ocean Radar Station Ship' - opening paragraphs, 'major characteristics retained' table, ballasting and command-arrangement sections

    Finding type

    historical_record

    Finding

    Contemporary professional-journal description naming this hull: 'The USS Interdictor (YAGR-13) is the first of four Ocean Radar Station Ships authorized in the 1958 Shipbuilding and Conversion Program and was the 13th ship of the Class when she was commissioned on April 7, 1958. The Navy's Ocean Radar Station Ship program is based on the conversion of World War II Liberty Ships with a minimum of rearrangement and alterations.' Retained from the original ship: hull dimensions 441' x 57' and 'Triple Expansion Reciprocating Engines, Single Screw,' 2,500 SHP; full-load displacement 10,800 tons (~3,400 tons under the original Liberty maximum); drafts 24' aft / 20' forward. Conversion changes: two additional main bulkheads (two-compartment standard), bulkheads subdividing usable spaces, masts and antenna supports, facilities to house and feed the enlarged crew; YAGR-5 through -16 carried no topside ballast, instead 4,700 tons of locked-water ballast tanked high in the hull. Operational arrangement: administratively assigned to Sea Frontier commanders; at sea under Continental Air Defense Command (an Air Force general via Commander Naval Forces, CONAD).

    Verification

    verified

    Role

    context

    Documentation level

    ship_specific

    Accessed

    2026-10-04

    Study period

    1957-1958

    Population

    Conversion trades (CNSY); crew 1958-65

    Limitations

    Ship-named contemporary description of conversion scope - the strongest single source that the 1957-58 conversion retained the 1945 hull and machinery largely intact ('minimum of rearrangement'). It does NOT mention insulation or asbestos; any asbestos-relevance (retained 1945-era materials vs new-construction insulation installed during conversion) is inference drawn from scope, not documented fact. A trade/professional journal, not a government record. Direct fetch returned HTTP 403; full text extracted via firecrawl rendering of the live page.

    Atlas source

    true

    Evidence ID

    ev-uss-interdictor-yagr13-05

    Source vessel

    uss-interdictor-yagr13

17. [17]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, verified live 2026-10-04) [other_primary]

    Locator

    Mirrored excerpt, engine-cylinder insulation section; NavSource Z-EC2-S-C5 hull-type caption (same hull form as EC2-S-C1); shipscribe class machinery line

    Finding type

    asbestos_application

    Finding

    The USMC operating 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 - the boxed-aircraft-carrier Liberty variant that shared the EC2-S-C1 hull form and the same 2,500-shp triple-expansion steam plant (NavSource hull-type caption; shipscribe machinery line; USNI 'retained' characteristics), so the type's insulation description applies at design-family level. Typical applications for the type: boiler and steam-drum insulation; steam-line lagging between boiler room and engine room; valve and flange gaskets; machinery packing; insulation in accommodation spaces and around the galley; brake linings on winches and windlass.

    Verification

    inferred

    Role

    supporting

    Documentation level

    class_or_era

    Accessed

    2026-10-04

    Study period

    1945; 1958-1965

    Population

    J.A. Jones construction trades (1945); merchant engine crew; Navy engine-room crew (1958-65)

    Limitations

    Design-family documentation, not a hull record: the manual names the EC2-S-C1 type, not this vessel nor the Z-EC2-S-C5 variant, and does not itself state 'asbestos' content (magnesia lagging of the era was typically asbestos-fiber-reinforced, but the manual text is silent on fiber). The Z-EC2-S-C5 shared hull form and machinery family - the inference is reasonable but a step removed. Does not establish quantity, present-day presence, individual exposure, or causation, and says nothing about materials added during the 1957-58 naval conversion.

    Atlas source

    true

    Evidence ID

    ev-uss-interdictor-yagr13-06

    Source vessel

    uss-interdictor-yagr13

18. [18]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 Maritime Commission emergency program under which this Z-EC2-S-C5 hull was mass-produced at J.A. Jones, Panama City - and that wartime demand drove unprecedented asbestos utilization aboard merchant-type hulls.

    Verification

    verified

    Role

    context

    Documentation level

    class_or_era

    Accessed

    2026-10-04

    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, the Z-EC2-S-C5 type, or J.A. Jones Panama City and does not establish that asbestos was or remains aboard this hull, nor quantity, location, condition, exposure, or causation.

    Atlas source

    true

    Evidence ID

    ev-uss-interdictor-yagr13-07

    Source vessel

    uss-interdictor-yagr13

19. [19]GAO, Navy Efforts To Protect Workers From Asbestos Exposure, HRD-80-2 (Oct 18, 1979) [gao]

    Locator

    GAO product page HRD-80-2 (full text blocked, HTTP 403)

    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 - spanning this hull's Charleston Naval Shipyard conversion (1957-58), her entire commissioned service (1958-65), and her Suisun Bay lay-up and 1974 disposal.

    Verification

    verified

    Role

    context

    Documentation level

    class_or_era

    Accessed

    2026-10-04

    Study period

    1979 (report); era 1940s-1970s

    Population

    Navy shipyard workers and crews (program context)

    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, confirmed 2026-10-04) - content via product-page description. Does not establish that the conversion installed asbestos, only that era insulation materials in naval service were commonly asbestos-containing.

    Atlas source

    true

    Evidence ID

    ev-uss-interdictor-yagr13-08

    Source vessel

    uss-interdictor-yagr13

20. [20]National Archives Catalog, deck-log file units 'Interdictor (YAGR-13)' / 'Interdictor (AGR-13)' - VA Navy Deck Log (NDL) digitization batches, National Archives at College Park (e.g., NAID 216411626 April 1958; NAID 216412188 September 1958; NAID 212613362 August 1965; ~350+ cataloged monthly file units spanning the entire commissioned life April 1958 - August 1965) [other_primary]

    Locator

    catalog.archives.gov searches 'Interdictor (YAGR-13)' / 'Interdictor (AGR-13)' - monthly file units Apr 1958 - Aug 1965 (NDL Batch series, College Park - Textual Reference); title sequence YAGR-13 Apr-Aug 1958 -> AGR-13 Sep 1958-Aug 1965

    Finding type

    historical_record

    Finding

    NARA holds digitized deck logs for this hull covering her entire commissioned life: cataloged monthly file units run April 1958 (commissioning month) through August 1965 (decommissioning month) in the VA Navy Deck Log digitization batches at National Archives at College Park. The cataloged titles themselves mirror the designation reconciliation: units are styled 'Interdictor (YAGR-13)' April through August 1958 and 'Interdictor (AGR-13)' September 1958 onward - consistent with the 28 September 1958 redesignation. Deck logs record underway periods, port visits, yard availabilities, and remarks entries - the open primary lead for documenting her radar-picket station cycles and any Charleston or other shipyard availabilities during which era insulation would have been disturbed or installed.

    Verification

    partial

    Role

    archival_lead

    Documentation level

    ship_specific

    Accessed

    2026-10-04

    Study period

    1958-1965

    Population

    Crew 1958-65 (log subjects); future researchers

    Limitations

    Archival lead only: the catalog record set was enumerated via the catalog API; log images were not individually reviewed, and no asbestos-specific entry is asserted. Deck logs document movements and events, not materials - any insulation-work inference would still require yard work-package records (undigitized). RG 24 logbooks for her 1945-53 merchant/reserve periods and any conversion-period records are separate undigitized series.

    Atlas source

    true

    Evidence ID

    ev-uss-interdictor-yagr13-09

    Source vessel

    uss-interdictor-yagr13

21. [21]Designation-error check across secondary sources: Wikipedia USS Interdictor article intro; DANFS; NavSource; shipscribe; asbestos-ships.com marketing page (excluded source, consulted for error-checking only) [other_primary]

    Locator

    Wikipedia USS Interdictor intro vs DANFS narrative, shipscribe class table acquisition column, USNI command-arrangement paragraph

    Finding type

    historical_record

    Finding

    CORRECTION of two circulating secondary-source errors: (1) Wikipedia's intro states the ship was 'acquired by the US Navy in 1954' - every primary/official-source candidate carries 1957 (DANFS 10 May, shipscribe 7 May, NavSource 5 June; Guardian-class acquisition began 1954 with YAGR-1, a class-program fact misapplied to this hull). (2) Wikipedia's intro assigns her to 'radar picket duty in the North Pacific Ocean as part of the Distant Early Warning Line' - primary sources place her as an ocean radar station ship on radar picket patrols for the Continental Air Defense Command out of San Francisco (DANFS) / 'served in the North Pacific' (shipscribe); the ocean radar station ships were the seaward maritime complement to, not components of, the northern continental DEW Line chain.

    Verification

    partial

    Role

    correction

    Documentation level

    ship_specific

    Accessed

    2026-10-04

    Study period

    1954-1965 (designation window)

    Limitations

    Corrects secondary-source framing, not a material claim. The DEW-line label is an imprecision common in secondary literature (the CONAD-controlled ocean barrier was related to but operationally distinct from the DEW Line proper). The 1954 acquisition year is flatly wrong for this hull. No asbestos content.

    Atlas source

    true

    Evidence ID

    ev-uss-interdictor-yagr13-10

    Source vessel

    uss-interdictor-yagr13

22. [22]Batch-8714 search ledger (this record): archived NHHC DANFS; MARAD ShipHistory Detail 2302; NavSource 09/62/6213; shipscribe Guardian-class data; USNI Proceedings (Aug 1958); NARA deck-log catalog; NVR (not digitized); USMC EC2 manual mirror; GAO product page (blocked); CourtListener (see ledger); YAGRs Association page; secondary litigation sweep [other_primary]

    Locator

    search_ledger rows sl-uss-interdictor-yagr13-01 through -14

    Finding type

    historical_record

    Finding

    No qualifying ship-specific asbestos record located: no asbestos survey, abatement contract, hazmat disclosure, or docketed/published case naming USS Interdictor (YAGR-13/AGR-13) or SS Edwin H. Duff was found in the public sources searched (see search_ledger). CourtListener was queried on all identifiers through the authenticated helper (opinion and docket indexes): 'Interdictor' opinions returned 3 hits, all word-usage name collisions (interdiction/court-appointed 'interdictor' usages); 'Interdictor' dockets returned 21 hits, all name collisions; '"YAGR-13"' opinions returned zero; '"AGR-13"' dockets returned only tokenized name collisions with no vessel-related caption. Secondary web sweep surfaced only banned-source marketing pages. No qualifying asbestos litigation located - a searched negative, not an unsearched gap.

    Verification

    verified

    Role

    negative_finding

    Documentation level

    ship_specific

    Accessed

    2026-10-04

    Study period

    2026-10-04

    Limitations

    Absence of a located public record does not prove absence of asbestos aboard - a 1945 hull retaining much original fabric through a 'minimum-rearrangement' conversion is era-consistent with retained asbestos-containing materials, and 1957-58 naval-yard work occurred inside the documented Navy asbestos-use era. Does not establish presence or absence aboard; does not establish or defeat any claim of exposure or legal eligibility.

    Atlas source

    true

    Evidence ID

    ev-uss-interdictor-yagr13-11

    Source vessel

    uss-interdictor-yagr13