Evidence
6 evidence entries recorded; each entry has a stable permalink (#ev-1 … #ev-6).
-
[1]Naval History and Heritage Command, Dictionary of American Naval Fighting Ships, 'Chilkat (YTB-510)' [nhhc_danfs]
- Locator
- Complete short vessel entry, published 2024-08-15
- Finding type
- vessel_history
- Finding
- DANFS identifies Chilkat as YTB-510, a tug built by Commercial Iron Works at Portland in 1944-45 and assigned to the 11th Naval District. It records reserve placement in August 1947 and return to 'in service' status in April 1961.
- Verification
- verified
- Role
- supporting
- Documentation level
- ship_specific
- Accessed
- 2026-09-24
- Study period
- 1944-1961
- Limitations
- The entry does not give a delivery date, crew figure, final disposal, machinery specifications, or any asbestos finding; 'in service' is the Navy's status wording for this tug.
- Atlas source
- true
- Evidence ID
- ev-uss-chilkat-ytb510-01
-
[2]U.S. Maritime Administration, National Register Eligibility Assessment: Tug TD-66, ex-Chilkat (YTB-510), ex-YTM-773 (2023-02-02) [marad_nrc]
- Locator
- PDF pp. 1-5, Vessel History; Description/Characteristics; Eligibility Statement
- Finding type
- vessel_history
- Finding
- MARAD's 2023 assessment identifies TD-66 as former Chilkat YTB-510/YTM-773. It records an August 1945 launch, March 1946 delivery at San Diego, 11th Naval District service, reserve placement in August 1947, reactivation in 1961, redesignation YTM-773 in March 1967, transfer to MARAD on 1977-05-01, and Suisun Bay Reserve Fleet tug service until 1995. It describes diesel, single-screw propulsion at 1,250 horsepower and finds the tug ineligible for the National Register on 2023-02-02.
- Verification
- verified
- Role
- supporting
- Documentation level
- ship_specific
- Accessed
- 2026-09-24
- Study period
- 1945-2023
- Limitations
- Assessment's engine-model discussion is phrased for the class, so only its explicit TD-66 diesel/single-screw/horsepower entries are carried as hull facts. It does not specify final Navy service or strike dates, asbestos content, or a material survey. Its 'Crew: 10' figure is not adopted because DANFS does not corroborate it.
- Atlas source
- true
- Evidence ID
- ev-uss-chilkat-ytb510-02
-
[3]U.S. Maritime Administration, ShipHistory Detail 12611, TD-66 [marad_nrc]
- Locator
- Identity table and Fate field; Milestones and Status Cards sections empty
- Finding type
- vessel_history
- Finding
- MARAD's TD-66 ShipHistory entry identifies Commercial Iron Works as builder and records the vessel's fate as 'Sold - Scrap.'
- Verification
- verified
- Role
- supporting
- Documentation level
- ship_specific
- Accessed
- 2026-09-24
- Study period
- 1945-present database record
- Limitations
- The database gives no sale date, recycler, delivery or completion certificate; 'Sold - Scrap' is a disposition label and does not by itself prove physical scrapping. It has no asbestos finding. Its 1945 year-built field conflicts with the assessment's 1946 year field; launch and delivery dates are stated separately.
- Atlas source
- true
- Evidence ID
- ev-uss-chilkat-ytb510-03
-
[4]Occupational Safety and Health Administration, Occupational Exposure to Asbestos, Federal Register final rule, 1994-08-10 [other_primary]
- Locator
- Shipbuilding and repairing—historical contact with asbestos in shipyard work, lines beginning 'Asbestos products were used extensively'
- Finding type
- asbestos_application
- Finding
- OSHA's 1994 rulemaking history reports extensive asbestos use on American ships from the early 1940s through the late 1970s in various shipboard systems and materials. This supplies construction-era research context for a Navy tug launched in 1945.
- Verification
- verified
- Role
- context
- Documentation level
- class_or_era
- Accessed
- 2026-09-24
- Study period
- Early 1940s-late 1970s
- Population
- American shipyard workers and ship crews generally
- Limitations
- This is era-wide evidence, not an inspection, plan, or material list for Chilkat or the Cholocco class. It does not establish that any listed application was installed on this diesel tug, survived conversion, or exposed any person; no ship-specific product is normalized from it.
- Atlas source
- true
- Evidence ID
- ev-uss-chilkat-ytb510-04
-
[5]National Archives, Ship Plan Index, CHILKAT YTB-510; Researching Asbestos aboard US Naval Vessel up through 1961 [other_primary]
- Locator
- CHILKAT YTB-510 index row, RG 19 Microfilm, ID 175668680; guide https://www.archives.gov/research/military/navy/guided-topics/asbestos, 'Ship Engineering Drawings'
- Finding type
- historical_record
- Finding
- NARA's Ship Plan Index lists CHILKAT YTB-510 in Record Group 19 Microfilm of Ship Engineering Drawings, catalog identifier 175668680. NARA's ship-asbestos research guide directs researchers to S39 insulation and lagging and S48 piping drawings, with microfilm often carrying more detail than paper drawings.
- Verification
- partial
- Role
- archival_lead
- Documentation level
- ship_specific
- Accessed
- 2026-09-24
- Study period
- 1945-1955 indexed drawing series
- Limitations
- The index proves an associated microfilm record exists, not which drawings it contains. The film was not obtained or inspected; no asbestos or insulation conclusion follows. S39/S48 are NARA's general research suggestions, not verified Chilkat sheet numbers.
- Atlas source
- true
- Evidence ID
- ev-uss-chilkat-ytb510-05
-
[6]This batch's review of NHHC DANFS Chilkat entry and MARAD TD-66 assessment and ShipHistory detail [other_primary]
- Locator
- Search ledger rows sl-uss-chilkat-ytb510-01 through -03; full text checked for asbestos, insulation, abatement, and survey
- Finding type
- historical_record
- Finding
- No Chilkat-specific asbestos identification was found in the retrieved DANFS entry, the full six-page MARAD TD-66 eligibility assessment, or MARAD ShipHistory Detail 12611.
- Verification
- verified
- Role
- negative_finding
- Documentation level
- ship_specific
- Accessed
- 2026-09-24
- Study period
- 2026-09-24 review
- Limitations
- This is a negative result limited to three public records, not proof that the tug lacked asbestos or that no other record exists. NARA's indexed microfilm was not inspected; litigation search status is recorded separately in the ledger.
- Atlas source
- true
- Evidence ID
- ev-uss-chilkat-ytb510-06