Evidence
11 evidence entries recorded; each entry has a stable permalink (#ev-1 … #ev-11).
-
[1]research packet 930-packet.md [other_primary]
- Finding type
- vessel_history
- Finding
- Identity packet verdict: PHANTOM
- Verification
- verified
- Role
- negative_finding
- Documentation level
- ship_specific
- Evidence ID
- uss-pc-721-pc721-pkt-930-packet-md
-
[2]NavSource Online Submarine Chaser Photo Archive, SC-721 ex-PC-721 page (build/service timeline, specifications, dual US/Soviet service) [other_primary]
- Locator
- navsource.net/archives/12/150721.htm - timeline block and specifications block
- Finding type
- vessel_history
- Finding
- NavSource timeline for this hull: laid down 16 November 1942 as PC-721 by Fisher Boat Works, Detroit, MI; launched 17 April 1943 and reclassified SC-721; commissioned USS SC-721 7 August 1943; transferred to the Soviet Union 27 September 1943 and reclassified BO-212; placed out of service 26 February 1948 and laid up; sunk 25 June 1956 off Kildinsky Reach by agreement with the United States. Specifications: 91 t; 110'10" x 17' x 6'6"; 21 kts; complement 28; one 40mm mount, two .50 cal, two Y-gun depth charge projectors, two depth charge tracks; two 1,540 bhp GM (Electro-Motive Div.) 16-184A diesels, two shafts. NavSource states 'There is no DANFS history available for SC-721.'
- Verification
- verified
- Role
- supporting
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- 1942-1956
- Population
- Fisher Boat Works construction trades 1942-43; commissioning crew August-September 1943 (design complement 28); Soviet crew 1943-1956
- Limitations
- NavSource is a volunteer-compiled naval-history archive drawing on Navy registers - the standard reference for small craft lacking DANFS entries, but not itself a government publication. Documents service history and specifications, not materials or asbestos content. Hull-page displacement (91 t) conflicts with the class/table figure (148 t) - carried in gaps. The sinking date (25 June 1956) conflicts with a Russian-language compilation (28-30 June 1956) - carried in gaps.
- Atlas source
- true
- Evidence ID
- ev-uss-pc-721-pc721-01
-
[3]uboat.net Allied Warships of WWII, USS SC-721 (SC-721) page [other_primary]
- Locator
- uboat.net ship page 8938 - facts table
- Finding type
- vessel_history
- Finding
- uboat.net record for this hull: SC-497-class submarine chaser built by Fisher Boat Works (Detroit, Michigan); ordered 16 February 1942; laid down 16 November 1942; launched 17 April 1943; commissioned 7 August 1943; end service 27 September 1943 - 'Transferred to the USSR on 27 September 1943.'
- Verification
- verified
- Role
- supporting
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- 1942-1943
- Population
- Commissioning crew August-September 1943
- Limitations
- Secondary scholarly compilation (Gudmundur Helgason's Allied Warships database) - corroborates, not originates, the build/service dates; adds the 16 February 1942 order date not present in NavSource. Contains no materials or asbestos information.
- Atlas source
- true
- Evidence ID
- ev-uss-pc-721-pc721-02
-
[4]Shipbuilding History (Colton), 'Sub Chasers PC SC PCE PCS WWII' build table - SC-721 row and adjacent Fisher Boat Works sisters [other_primary]
- Locator
- shipbuildinghistory.com/smallships/pc2.htm - SC block, rows SC-719 through SC-721
- Finding type
- vessel_history
- Finding
- Build-table entry for this hull: 'SC 721 | Fisher Boat Works | Detroit MI | 148 | 110 | 7-Aug-43 | To the USSR 1943 as BO-212' - corroborates builder, yard city, 7 August 1943 delivery/commissioning, and 1943 Lend-Lease transfer to the USSR as BO-212. Adjacent rows show the same pattern for Fisher-built sisters: SC-719 to the USSR 1943 (the table prints 'BO-1' - the WLB Seekrieg index gives the designation as BO-210 ex-SC 719) and SC-720 to the USSR 1943 as BO-211.
- Verification
- verified
- Role
- supporting
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- 1943
- Population
- Fisher Boat Works construction trades 1942-43
- Limitations
- Shipyard-history compilation (Tim Colton) - secondary, not a government record. Its companion Fisher yard page reads 'to the USSR 1945' for this hull where this table reads 1943 - internal inconsistency resolved toward 1943 by NavSource, uboat.net, Soviet-side compilations, and the NARA log end date (27 September 1943); noted in gaps. '148' is tons, conflicting with the NavSource hull-page 91 t - carried in gaps.
- Atlas source
- true
- Evidence ID
- ev-uss-pc-721-pc721-03
-
[5]NARA Special List #44, by Ship Numbers - 'Logbooks of U.S. Navy Ships, Stations and Units' holdings list, SC-721 row [other_primary]
- Locator
- sl-44-ship-number.pdf, SC block: 'SC-721 8/13/1943 9/27/1943'
- Finding type
- historical_record
- Finding
- NARA Special List 44 (ship-number sort) lists SC-721 deck logs covering 8/13/1943 through 9/27/1943 - the holdings begin six days after commissioning and end on the documented Soviet transfer date, corroborating the approximately seven-week U.S. commission and providing the only US-flag archival trail for the hull.
- Verification
- verified
- Role
- supporting
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- 1943
- Population
- Commissioning crew August-September 1943
- Limitations
- The list documents the existence and date span of logbook holdings, not their content - no page-level review was performed and the logs' informational content (materials, personnel) is unexamined. Does not establish anything about materials aboard.
- Atlas source
- true
- Evidence ID
- ev-uss-pc-721-pc721-04
-
[6]Wuerttemberg State Library, Seekrieg 1939-45 pennant-number index (B section) - 'BO-212 (ex-SC 721) (N)' [other_primary]
- Locator
- pn-b.htm, BO series entries (BO-210 through BO-212 block)
- Finding type
- historical_record
- Finding
- State-library-hosted Seekrieg (Rohwer chronology) pennant index lists 'BO-212 (ex-SC 721) (N)' - independently confirms the Soviet designation BO-212 for this hull and its assignment to the Soviet Northern Fleet.
- Verification
- verified
- Role
- context
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- 1943-1956
- Population
- Soviet Northern Fleet crew 1943-1948
- Limitations
- Index-level confirmation only - it establishes designation and fleet assignment, not operational detail. Russian-language secondary compilations add operational specifics (Polyarny arrival 24 November 1943; Barents/Kara/White Sea convoy protection December 1943-May 1945; Petsamo-Kirkenes operation October-November 1944; sinking 28-30 June 1956) that are carried as unverified leads in gaps, not asserted here.
- Atlas source
- true
- Evidence ID
- ev-uss-pc-721-pc721-05
-
[7]NavSource Submarine Chaser (SC) photo index - SC-497 class overview [other_primary]
- Locator
- navsource.net/archives/12/15idx.htm - class summary paragraph
- Finding type
- historical_record
- Finding
- Class-level framing for this hull's type: 'Five hundred eighty SC-497 Class wood-hulled, 110-foot Submarine Chasers (SC) were built during World War II, with 142 of these being used by our Allies under the Lend-Lease Program' - the program under which SC-721 went to the USSR as BO-212; the type was designed for offshore patrol and anti-submarine warfare.
- Verification
- verified
- Role
- context
- Documentation level
- class_or_era
- Accessed
- 2026-10-03
- Study period
- 1941-1945
- Limitations
- Class statistics describe the type, not this hull. The NavSource build count (580) conflicts with the Wikipedia class figure (438 completed of 475 planned) - class-count conflict carried in gaps; the Lend-Lease count (142) is the figure as published by NavSource.
- Atlas source
- true
- Evidence ID
- ev-uss-pc-721-pc721-06
-
[8]NavSource SC-497 page (class leader) - commissioned as USS PC-497, reclassified SC-497 April 1943 [other_primary]
- Locator
- navsource.net/archives/12/150497.htm - SC-497 timeline ('Commissioned USS PC-497, 15 April 1942; Reclassified SC-497 in April 1943')
- Finding type
- vessel_history
- Finding
- Corrects the upstream classification of this vessel as PC-461 class: the early boats of this type were ordered under PC numbers and reclassified SC at or before commissioning - class leader SC-497 was herself commissioned USS PC-497 on 15 April 1942 and reclassified SC-497 in April 1943. SC-721 is an SC-497-class 110-foot wooden submarine chaser laid down as PC-721 and reclassified at launch, not a PC-461-class 173-foot steel patrol craft; the vessel never served under the PC-721 designation.
- Verification
- verified
- Role
- correction
- Documentation level
- class_or_era
- Accessed
- 2026-10-03
- Study period
- 1942-1943
- Limitations
- The correction concerns classification only; the PC-721 ordering number is genuine (documented by NavSource 'laid down ... as PC-721') and explains the file slug. Does not document materials or asbestos.
- Atlas source
- true
- Evidence ID
- ev-uss-pc-721-pc721-07
-
[9]NavSource SC-721 specifications block (diesel-only plant, wooden hull) + class/era material conventions [other_primary]
- Locator
- NavSource specifications block (propulsion line); era-standard application list
- Finding type
- asbestos_application
- Finding
- Era inference for this hull's asbestos profile: a 1942-43-built wooden-hulled submarine chaser with a diesel-only plant (two GM 16-184A diesels - no boilers, no steam system) would have carried era-standard asbestos applications appropriate to a small diesel combatant - exhaust insulation, gaskets and packing, electrical insulation, winch/windlass brake linings, and deck coverings - but not the boiler and steam-line lagging that dominated asbestos loading on steam ships.
- Verification
- inferred
- Role
- supporting
- Documentation level
- class_or_era
- Accessed
- 2026-10-03
- Study period
- 1942-1943
- Population
- Fisher Boat Works construction trades 1942-43; commissioning crew August-September 1943
- Limitations
- Class/era inference only - NOT a hull-specific finding. No primary source documents asbestos products aboard this hull; the inference cannot establish quantity, location, condition, or any individual's exposure, and cannot establish that asbestos was or was not present.
- Atlas source
- true
- Evidence ID
- ev-uss-pc-721-pc721-08
-
[10]Batch-8095 search ledger (this record): NHHC DANFS (404 - no entry exists); NavSource vessel and class pages; NARA Special List 44; Shipbuilding History build table; uboat.net; WLB Seekrieg index; Atlas shipyards.json; CourtListener opinion and RECAP queries [other_primary]
- Locator
- search_ledger rows sl-uss-pc-721-pc721-01 through sl-uss-pc-721-pc721-13
- Finding type
- historical_record
- Finding
- No qualifying ship-specific asbestos record located for SC-721/PC-721: no asbestos survey, abatement record, hazmat disclosure, or docketed asbestos case naming either designation was found in the public sources searched (see search_ledger). All four CourtListener base queries completed: 'SC-721' opinion (12 hits), 'SC-721' docket (14 hits), 'PC-721' opinion (2 hits), 'PC-721' docket (34 hits) - every hit is a docket-number or metadata string collision (state court case numbers, PACER IDs); none is asbestos litigation and none names the vessel. No DANFS entry exists for this hull. Fisher Boat Works does not appear in the Atlas shipyards dataset.
- 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 during construction or service - the ~7-week U.S. commission and 1943 foreign transfer leave a thin US archival trail, and Soviet-era material history is not accessible in the sources searched. Does not establish or defeat any claim of exposure or legal eligibility.
- Atlas source
- true
- Evidence ID
- ev-uss-pc-721-pc721-09
-
[11]NHHC DANFS (history.navy.mil) - no SC-721 entry exists (HTTP 404, verified live 2026-10-03); NavSource states 'There is no DANFS history available for SC-721' [nhhc_danfs]
- Locator
- history.navy.mil DANFS URL (404 on fetch); navsource.net/archives/12/150721.htm ('no DANFS history' notice)
- Finding type
- historical_record
- Finding
- Corrects the batch brief's attribution of the 7 August 1943 commission date to DANFS: no DANFS entry exists for SC-721 - the NHHC URL returns 404 and NavSource explicitly states no DANFS history is available. The commission date is documented instead by NavSource and corroborated by uboat.net and the Shipbuilding History build table.
- Verification
- verified
- Role
- correction
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- 2026-10-03
- Limitations
- A DANFS absence is not an absence of Navy records - NARA holds the hull's deck logs for the commissioned period (ev-04). The correction concerns source attribution only; the underlying date is unchanged and independently confirmed.
- Atlas source
- true
- Evidence ID
- ev-uss-pc-721-pc721-10