{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.pit-prop","code":"thing-q1550218","url":"https://ver.cy/models/thing/q1550218/","name":"Pit prop","alternateNames":[],"kind":"thing","status":"published","version":"0.2.0-wave.5","language":"en","classifiers":{"family":"Thing Registry","category":"Physical world and living systems","entryKind":"thing","plane":"PHY","domain":["PHY.BLT"],"industry":[],"navPath":"","tags":[],"facets":{}},"whatItIs":"A timber post used to support the roof of underground workings, especially in coal mines, typically a length of round softwood such as pine; largely replaced by steel and hydraulic supports.","purpose":"Let an agent describe pit props, their materials, use and history in mining, and point to mine safety rules.","scope":{"in":[],"out":[],"boundaries":[]},"distinguishingFeatures":["Some timber props creak or crack under load, historically valued as a warning, though warning is not guaranteed.","Steel arches, roof bolts and powered supports displaced much timber propping; timber remains in some applications.","Often pine or spruce; pit-prop timber was a major forestry trade, for example from Scandinavia to British coalfields."],"structure":{"bundles":[{"id":"prop","name":"Prop","description":"Which support.","layers":[{"id":"material","name":"Material","description":"Timber or steel.","findings":[{"id":"material","name":"Material","description":"Material and species.","questions":[{"text":"What material is it?","kind":"provenance"},{"text":"Which timber species?","kind":"provenance"}]}]},{"id":"dimensions","name":"Dimensions","description":"Size.","findings":[{"id":"dimensions","name":"Dimensions","description":"Length and diameter.","questions":[{"text":"What are its length and diameter?","kind":"measurement"},{"text":"For which seam height?","kind":"measurement"}]}]}]},{"id":"use","name":"Use","description":"In the mine.","layers":[{"id":"setting","name":"Setting","description":"Installation.","findings":[{"id":"installation","name":"Installation","description":"Method.","questions":[{"text":"How was it set?","kind":"provenance"},{"text":"With cap pieces or wedges?","kind":"provenance"}]}]},{"id":"support-plan","name":"Support plan","description":"Spacing.","findings":[{"id":"support-plan","name":"Support plan","description":"Spacing and rule.","questions":[{"text":"What spacing was required?","kind":"provenance"},{"text":"By which rule?","kind":"provenance"}]}]}]},{"id":"history","name":"History","description":"Trade and replacement.","layers":[{"id":"trade","name":"Trade","description":"Timber supply.","findings":[{"id":"trade","name":"Trade","description":"Source and period.","questions":[{"text":"Where did props come from?","kind":"provenance"},{"text":"When?","kind":"provenance"}]}]},{"id":"replacement","name":"Replacement","description":"Steel and hydraulic.","findings":[{"id":"replacement","name":"Replacement","description":"Technology and date.","questions":[{"text":"When were timber props replaced?","kind":"provenance"},{"text":"By what?","kind":"provenance"}]}]}]},{"id":"safety","name":"Safety","description":"Ground control.","layers":[{"id":"failure","name":"Failure","description":"Roof falls.","findings":[{"id":"failure","name":"Failure","description":"Event and cause.","questions":[{"text":"Which failures occurred?","kind":"provenance"},{"text":"Why?","kind":"provenance"}]}]},{"id":"rules","name":"Rules","description":"Regulation.","findings":[{"id":"rule","name":"Rule","description":"Law.","questions":[{"text":"Which ground support rules applied?","kind":"provenance"},{"text":"Who enforced them?","kind":"provenance"}]}]}]}]},"agentConduct":{"may":["describe props and history"],"mustNot":["encourage entering old mine workings"],"requiresHuman":["ground support design by qualified mining engineers"]},"ethics":{"considerations":["miner safety"],"affectedParties":["miners"]},"owners":{"steward":"the mine operator","roles":[],"masterSystems":[]},"relations":[{"target":"Q29052406","type":"parent","note":"registry parent class"},{"target":"mine support","type":"related","note":"mining"},{"target":"coal mine","type":"related","note":"setting"},{"target":"steel and hydraulic props and roof bolts","type":"related","note":"modern supports"},{"target":"timber","type":"related","note":"material"}],"interaction":{"identity":{"applicability":"required","items":["Vercy registry: vr.tr.pit-prop","Wikidata: Q1550218 (https://www.wikidata.org/wiki/Q1550218)"]},"properties":{"applicability":"required","items":["length: about 0.6-2.7 m - British peeled props, 1964 Forestry Commission guidance","diameter-to-length ratio: about 1:12 - historical rule of thumb"]},"recognition":{"applicability":"required","items":["Vertical timber posts in old mine tunnels","Round timber posts, often with a cap piece, set between floor and roof in mine workings."]},"capabilities":{"applicability":"required","items":["describe materials and dimensions","describe historical use and trade","explain replacement by steel and hydraulic supports","point to mine safety rules"]},"hazards":{"applicability":"required","items":["Roof falls when supports fail","Decay of timber in old workings"]},"interfaces":{"applicability":"required","items":["Mine safety regulations on ground support, by jurisdiction"]},"context":{"applicability":"required","items":["Supporting mine roofs to prevent falls of ground.","round timber props","peeled and unpeeled props"]}},"sources":[{"title":"Q1550218","url":"https://www.wikidata.org/wiki/Q1550218","note":"identity of the registry item, labels and sitelinks"},{"title":"Pit prop","url":"https://en.wikipedia.org/wiki/Pit_prop","note":"general description of the subject"},{"title":"Forestry Practice, Bulletin 14, eighth edition","url":"https://cdn.forestresearch.gov.uk/1964/03/fcbu014_8ed.pdf","note":"Round softwood mining timber, historical British dimensions, seasoning and variation in mine requirements."},{"title":"Props","url":"https://snl.no/props","note":"Timber supports, spruce use and substantial Norwegian exports to English mines."},{"title":"Forestry Commission Journal 32","url":"https://cdn.forestresearch.gov.uk/1963/03/fcjo032.pdf","note":"Historical importance of pit-prop timber and its perceived warning function."},{"title":"Fundamentals of Coal Mine Roof Support","url":"https://stacks.cdc.gov/view/cdc/206364","note":"Timber and other standing supports, roof bolts, loading conditions and structural performance properties."}],"openQuestions":[],"resources":{"spec":"/models/things/publications/thing-q1550218/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q1550218/spec.json"],"providers":["Claude"],"researchStatus":"unreviewed","generatedAt":"2026-10-21T21:31:16Z","builder":"tools/build_cards.py@1.0.0"},"completeness":{"sections":{"classifiers":"filled","whatItIs":"filled","purpose":"filled","distinguishingFeatures":"filled","structure":"filled","agentConduct":"filled","ethics":"filled","owners":"filled","relations":"filled","interaction.identity":"filled","interaction.properties":"filled","interaction.recognition":"filled","interaction.capabilities":"filled","interaction.hazards":"filled","interaction.interfaces":"filled","interaction.context":"filled","sources":"filled"},"notes":{"_gate":"Published through the thing publication gate 1.0 on 2026-10-22T10:59:04+00:00: completeness 1.00; sense: Wikidata description; 6 live sources; review by codex: pass"},"score":1.0}}