Evidence
11 evidence entries recorded; each entry has a stable permalink (#ev-1 … #ev-11).
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[1]research packet 898-packet.md (2 sources cited) [other_primary]
- Finding type
- vessel_history
- Finding
- Identity packet verdict: VERIFIED
- Verification
- verified
- Role
- supporting
- Documentation level
- ship_specific
- Evidence ID
- uss-pc-500-pc500-pkt-898-packet-md
-
[2]NavSource Online: Submarine Chaser Photo Archive, SC-500 ex-PC-500 (designation timeline, specifications, Soviet-service disposition; live page verified 2026-10-03) [other_primary]
- Locator
- NavSource 12/150500.htm header block, specifications block, and DANFS-availability note
- Finding type
- vessel_history
- Finding
- NavSource record for this hull: laid down 27 February 1942 by the Fisher Boat Works, Detroit, MI; launched 11 October 1942; commissioned USS PC-500, 31 March 1943; reclassified SC-500 in April 1943; transferred to the Soviet Union 9 June 1945 and reclassified BO-319; placed in Soviet service 9 June 1945, assigned to the Pacific Fleet; placed out of service 25 June 1956 and sunk in the Strait of Tartary off the island of Sakhalin by agreement with the U.S. Specifications: 148 t., 110'10" length, 17' beam, 6'6" draft, 21 kts, complement 28; one 40mm gun mount, two .50 cal. machine guns, two Y-gun depth-charge projectors, two depth-charge tracks; two 1,540 bhp General Motors (Electro-Motive Div.) 16-184A diesel engines, two shafts. Page states 'There is no DANFS history available for SC-500.'
- Verification
- verified
- Role
- context
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- 1941-1956
- Population
- Fisher Boat Works construction trades (1941-42); USN crew (1942-45); Soviet crew (1945-56)
- Limitations
- NavSource is a volunteer secondary compilation, not a primary registry. Its construction/commissioning years (laid down 1942, launched 1942, commissioned 1943) conflict one-for-one with uboat.net, navypedia, jounin.jp, the shipbuildinghistory Fisher yard table, and this batch's VERIFY data, all of which read one year earlier (1941/1941/1942) - carried as a documented conflict in gaps; the one-year-later NavSource dates are treated here as the outlier. No asbestos content.
- Atlas source
- true
- Evidence ID
- ev-uss-pc-500-pc500-01
-
[3]uboat.net Allied Warships, USS SC-500 (SC-500), SC-497-class submarine chaser (build dates, commissioning, end-of-service, commanding-officer roster; live page verified 2026-10-03) [other_primary]
- Locator
- uboat.net Allied Warships ship page 8806 (data table + 'Commands listed' roster)
- Finding type
- vessel_history
- Finding
- uboat.net Allied Warships database record for this hull: ordered 14 January 1941; laid down 27 February 1941; launched 11 October 1941; commissioned 31 March 1942; end of U.S. service 9 June 1945; transferred to the USSR 9 June 1945; built by Fisher Boat Works, Detroit, Michigan. Commanding-officer roster begins with Lt.(jg) Arthur E. H. Bernhard, USNR, from 31 March 1942 - the roster's start date independently corroborates a 31 March 1942 commissioning.
- Verification
- verified
- Role
- context
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- 1941-1945
- Population
- Fisher Boat Works construction trades (1941); USN crew (1942-45), incl. listed USNR officers
- Limitations
- Secondary compiled database (Guðmundur Helgason's Allied Warships), not a primary registry; its 1941/1942 dates agree with navypedia, jounin.jp, the shipbuildinghistory yard table, and batch VERIFY data against NavSource's one-year-later variant. The 'ordered 14 Jan 1941' date is single-source. No asbestos content.
- Atlas source
- true
- Evidence ID
- ev-uss-pc-500-pc500-02
-
[4]Richard A. Russell, Project Hula: Secret Soviet-American Cooperation in the War Against Japan (Naval Historical Center, U.S. Navy in the Modern World Series No. 4, Washington, 1997) - Appendix, 'U.S. Navy Combatant Ships Transferred to the USSR Under Project HULA, May-September 1945' [other_primary]
- Locator
- Russell, Project Hula (NHC 1997), Appendix table 'U.S. Navy Combatant Ships Transferred to the USSR', printed page 40 (PDF p.45), row 'SC500 / B0-319 / 10 June / 1956-destroyed'
- Finding type
- historical_record
- Finding
- Official Naval Historical Center publication documents this hull's end state: the appendix table reads 'SC500 | B0-319 | 10 June | 1956-destroyed' - SC-500 transferred to the USSR 10 June 1945 as Soviet BO-319, disposition 'destroyed' in 1956. Program context documented in the same source: Project Hula transferred 149 ships and craft at Cold Bay, Territory of Alaska, between April and September 1945, including 32 submarine chasers; SC-500 appears in the appendix among the five-boat SC group transferred 10 June 1945 (with SC-634, SC-675, SC-1295, SC-1324). The book's narrative records the program routing plan for small vessels such as subchasers: Cold Bay through Unimak Pass, coastwise along the northern Aleutian chain to Adak for servicing (they could not make a nonstop passage), then to the Petropavlovsk Naval Base (program-level routing, not a hull-specific itinerary).
- Verification
- verified
- Role
- supporting
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- 1945-1956
- Population
- USN crew through transfer (June 1945); Soviet crew of BO-319 (1945-56)
- Limitations
- Establishes transfer date and Soviet disposition only - not U.S. striking date, not asbestos or material content. The 10 June transfer date conflicts by one day with NavSource/uboat.net (9 June decommission/transfer; Wikipedia text likewise 9 June, infobox 10 June) - carried in gaps; a 9 June U.S. decommissioning followed by a 10 June Soviet transfer ceremony is the most consistent reading but is not stated as such by any source.
- Atlas source
- true
- Evidence ID
- ev-uss-pc-500-pc500-03
-
[5]shipbuildinghistory.com (Tim Colton), 'Fisher Boat Works, Detroit MI' emergency-small-yards production table (Wayback capture 2019-03-05; live mirror shipbuildinghistory.njscuba.net returned HTTP 500 on 2026-10-03) - ARCHIVED COPY [other_primary]
- Locator
- Wayback capture 20190305194436 of shipbuildinghistory.com/shipyards/emergencysmall/fisher.htm, production table row 'SC 500'
- Finding type
- vessel_history
- Finding
- Builder's-yard production table documents this hull: 'SC 500 | US Navy | Sub Chaser | 136 tons | 110 ft | Delivery 31-Mar-42 | To the USSR 1945 as BO 319' - delivery date corroborates the 31 March 1942 commissioning against NavSource's 1943 variant. Yard context: Fisher Boat Works began as Russell J. Pouliot Boat Works in the early 1930s, was acquired by William P. Fisher in 1937, and closed after the war; it built the SC-497-class prototype SC-453 (delivered 12 Aug 1941) and sister boats SC-499 (18 Mar 1942), SC-662, SC-663, SC-712 through SC-721, and SC-1347-1349.
- Verification
- verified
- Role
- context
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- 1941-1942
- Population
- Fisher Boat Works construction trades (1941-42)
- Limitations
- Secondary yard-history compilation, not a primary registry - its 'Delivery' column corroborates but does not by itself prove the commissioning date. Cited via Wayback capture because the live mirror returned HTTP 500; archive URL is labeled as such. Contains no asbestos or material content.
- Atlas source
- true
- Evidence ID
- ev-uss-pc-500-pc500-04
-
[6]DANFS, Racer II (IX-100) - verbatim transcription carried on the NavSource SC-501 page (SC-501's own history documents the class-wide PC-to-SC reclassification event of April 1943) [nhhc_danfs]
- Locator
- NavSource 12/150501.htm 'Dictionary of American Naval Fighting Ships History' block (DANFS Racer II text); NavSource 12/150497.htm header block
- Finding type
- vessel_history
- Finding
- Sibling-hull DANFS entry documents the reclassification program this hull went through: 'The second Racer (IX-100) was laid down 29 April 1941 as PC-501 by Seabrook Yacht Corp., Houston, Tex.; launched 24 January 1942; changed to SC-501 8 April 1943...' Sister SC-497 (NavSource page 12/150497.htm) shows the same pattern - commissioned USS PC-497 15 April 1942, reclassified SC-497 April 1943. The early SC-497-class boats commissioned under PC designations in 1942 and were reclassified to SC in a class-wide action in April 1943 - the same event NavSource records for this hull ('Reclassified SC-500 in April 1943').
- Verification
- verified
- Role
- context
- Documentation level
- class_or_era
- Accessed
- 2026-10-03
- Study period
- 1942-1943
- Population
- crews of SC-497-class boats commissioned as PCs, 1942-43
- Limitations
- Sibling-hull documentation, not a record for SC-500 itself - establishes the April 1943 PC-to-SC reclassification as a class-wide administrative event, corroborating (not independently proving) SC-500's own reclassification month. Live NHHC DANFS page for Racer not located (404s); verbatim text carried on NavSource SC-501 page. No asbestos content.
- Atlas source
- true
- Evidence ID
- ev-uss-pc-500-pc500-05
-
[7]HyperWar, 'Ships of the U.S. Navy, 1940-1945: Submarine Chasers' (compiled tabulation of USN PC/SC commissionings and dispositions, incl. SC-497-class spec block; live page verified 2026-10-03) [other_primary]
- Locator
- ships-sc.html - PC-461-class table (PC-496 -> PC-542 gap) and SC-497-class table row 'SC-500'
- Finding type
- vessel_history
- Finding
- USN compilation table lists SC-500 in commission '1942-44', noted 'Lend-Lease to USSR' - a commissioning-era window consistent with 1942, not 1943. Structural evidence on the same page resolves the designation question: the steel-hull PC-461-class table runs PC-461 through PC-496 then jumps to PC-542, meaning hull numbers 497-541 were never assigned to steel PC-461-class boats - those numbers belonged to the wooden SC-497-class group that briefly held PC designations. The only vessel ever designated PC-500 is this 110-foot wooden chaser. Class spec block (SC-497 class): displacement 98 tons, length 110'10", beam 17', draft 6'6", speed 20 knots, armament one 3"/50 + 2x2 .50-cal machine guns, complement 2 officers + 20 enlisted, diesel twin screws 1,200 shp.
- Verification
- verified
- Role
- context
- Documentation level
- class_or_era
- Accessed
- 2026-10-03
- Study period
- 1940-1945
- Population
- USN crew (1942-44 per table window)
- Limitations
- Compiled tabulation (Patrick Clancey/HyperWar from official lists), not a per-ship record; its commission column gives an era window ('1942-44'), not an exact date. Class spec block values (98 t, 20 kt, 22 crew, 3"/50 armament) differ from the NavSource per-hull spec block (148 t, 21 kt, 28 crew, 40mm) - both are era/class specifications of uncertain per-hull applicability; no asbestos content.
- Atlas source
- true
- Evidence ID
- ev-uss-pc-500-pc500-06
-
[8]Era inference built on: wooden hull construction at a small commercial boat yard (Fisher Boat Works); diesel propulsion (NavSource: 2 x GM EMD 16-184A; class-standard fit: GM 8-268A) - no boilers, no steam plant, no steam piping; 1941 build year inside the Navy's documented asbestos-use era [other_primary]
- Locator
- ev-01/ev-02 specifications (diesel plant, wooden hull, 1941 build); class-standard SC-497-class specifications (ev-06)
- Finding type
- asbestos_application
- Finding
- A 110-foot wooden-hulled submarine chaser built February-October 1941 sits inside the Navy's documented asbestos-use era, but its exposure profile is narrow: wooden hull construction eliminates the steel-hull insulation scope, and a diesel plant eliminates the boiler/turbine lagging and steam-line insulation that dominate asbestos findings on larger combatants. Era-standard asbestos applications consistent with this platform are diesel-exhaust lagging around engine exhaust runs, machinery gaskets and valve packing in the engine room, electrical insulation aboard, and possibly minor fireproofing or adhesive products - all as era inference. At roughly 28 crew aboard a 110-foot hull, any installed ACM would concentrate in the engine space.
- Verification
- inferred
- Role
- supporting
- Documentation level
- class_or_era
- Accessed
- 2026-10-03
- Study period
- 1941-1956
- Population
- Fisher Boat Works construction trades (1941-42); USN crew (1942-45); Soviet crew (1945-56)
- Limitations
- Class/era inference only - no hull-specific insulation manifest, plan, work package, or survey was located for SC-500, and none may ever have existed in public records for a boat this size. Names plausible era-standard applications, not confirmed installed materials; no quantity, no manufacturer attribution. Even the direction of inference is uncertain: wooden-hull diesel chasers may have carried substantially less ACM than steel steam vessels of the same era.
- Atlas source
- true
- Evidence ID
- ev-uss-pc-500-pc500-07
-
[9]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 entire construction (1941) and U.S. service era (1942-45).
- Verification
- verified
- Role
- context
- Documentation level
- class_or_era
- Accessed
- 2026-10-03
- Study period
- 1979
- Population
- Navy shipyard workers; asbestos program review
- Limitations
- Program-level documentation; supports era context only, not any fact specific to this hull. The GAO record addresses Navy ship insulation generally - its relevance to a 110-foot wooden diesel boat is weaker than to steam combatants. Full text not retrieved (gao.gov blocks automated fetch, HTTP 403 - access gap carried in ledger); content via product-page description.
- Atlas source
- true
- Evidence ID
- ev-uss-pc-500-pc500-08
-
[10]Batch-7875 search ledger (this record): NavSource SC-500 page; uboat.net Allied Warships; NHC Project Hula PDF appendix; shipbuildinghistory Fisher yard table (Wayback); HyperWar ships-sc compilation; NavSource SC-497/SC-501 sibling pages; DANFS availability check; NVR check; NARA catalog; CourtListener API v4 (type=o and type=r); secondary web litigation sweep [other_primary]
- Locator
- search_ledger rows sl-uss-pc-500-pc500-01 through -10
- Finding type
- historical_record
- Finding
- No qualifying ship-specific asbestos record located for this hull: no asbestos survey, abatement contract, hazmat disclosure, museum record (hull sunk in Soviet service 1956 - no surviving artifact), or verified litigation naming PC-500 or SC-500 was found in the public sources searched. The CourtListener exact-name opinion query returned 27 hits, all classified as name collisions or non-qualifying litigation (asbestos cases name other vessels; remaining hits are 'PC 500' product/statute collisions); the other three required base queries (exact-name docket, hull-number opinion, hull-number docket) could not be run - the fleet pacing budget was spent throughout the session (logged blocked, not a negative result). A secondary-web sweep surfaced only law-firm marketing content listing patrol craft/subchasers generically as asbestos-bearing without primary sourcing - excluded by source policy. There is no DANFS entry for this hull (NavSource states none exists), and the Naval Vessel Register holds no entry (vessel left Navy custody 1945, decades before NVR coverage).
- 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 - only that no public ship-specific document was found. Wooden diesel chasers are a low-asbestos-profile platform, which is consistent with (but does not confirm) the null result. NARA RG 24 deck logs and any BuShips/BuOrd material records for this hull are undigitized leads.
- Atlas source
- true
- Evidence ID
- ev-uss-pc-500-pc500-09
-
[11]Designation cross-check: HyperWar ships-sc compilation (PC-461-class table skips hull numbers 497-541; SC-497-class table lists SC-500 'Lend-Lease to USSR'); NavSource SC index (SC-497 ex-PC-497, SC-501 ex-PC-501, SC-503/504 ex-PC, etc. - 'SC-454 to SC-496 hull numbers not used'); NavSource SC-500 page ('ex-PC-500') [other_primary]
- Locator
- ships-sc.html PC-461-class table (PC-496 -> PC-542 numbering gap); NavSource 12/15idx.htm SC index (ex-PC notations); NavSource 12/150500.htm; uboat.net ship 8806; shipbuildinghistory Fisher table (Wayback)
- Finding type
- vessel_history
- Finding
- CORRECTION to the intake record, which listed this hull as PC-461 class: PC-500 was never a PC-461-class 173-foot steel patrol craft. The steel PC-461-class number series skips 497-541 entirely (HyperWar PC table runs PC-496 to PC-542); those hull numbers belonged to wooden SC-497-class boats, several of which commissioned under PC designations in 1942 and were reclassified to SC in April 1943. This hull commissioned as USS PC-500 (31 Mar 1942), was reclassified SC-500 (April 1943), and spent most of her U.S. career as SC-500 - the PC-461-class attribution in intake data is structurally impossible. Separately, NavSource's build/commission dates (laid 27 Feb 1942, launched 11 Oct 1942, commissioned 31 Mar 1943) conflict with uboat.net, navypedia, jounin.jp, the shipbuildinghistory yard table, and VERIFY data (27 Feb 1941, 11 Oct 1941, 31 Mar 1942); the one-year-earlier dates are carried per the majority of sources and internal sibling-yard sequence (Fisher delivered SC-499 18 Mar 1942 and SC-500 31 Mar 1942).
- Verification
- verified
- Role
- correction
- Documentation level
- ship_specific
- Accessed
- 2026-10-03
- Study period
- 1941-1943
- Limitations
- Corrects a class attribution and flags a date conflict; neither establishes any material or asbestos fact. The commission-date conflict is a documented disagreement between secondary compilations, not a resolved question - 1942 is carried on weight of sources, but NavSource has not been shown wrong by a primary document.
- Atlas source
- true
- Evidence ID
- ev-uss-pc-500-pc500-10