{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.jack-post","code":"thing-q2313763","url":"https://ver.cy/models/thing/q2313763/","name":"jack post","alternateNames":["Acrow prop"],"kind":"thing","status":"published","version":"0.2.0-wave.4","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 jack post, also called an adjustable steel prop or, by the trade name, an Acrow prop, is a telescopic vertical support used in construction to hold up floors, beams or formwork temporarily or, in shorter basement versions, permanently, adjusted to length by a threaded collar and pin; props must be correctly sized, plumb, on firm bearing and not overloaded, and misuse or removing props too early can cause dangerous collapse, so temporary works should be designed and inspected by competent people.","purpose":"Let an agent explain jack posts, relay their use, adjustment and safety from construction sources, note the Acrow trade name, route temporary-works safety, and distinguish jack posts from permanent columns, scaffolding, shoring and jacks used for lifting.","scope":{"in":[],"out":[],"boundaries":[]},"distinguishingFeatures":["Telescopic steel prop","Adjustable length","Temporary or basement use","Load-rated"],"structure":{"bundles":[{"id":"understand","name":"Understand","description":"What a jack post is.","layers":[{"id":"definition","name":"Definition","description":"Definition.","findings":[{"id":"definition-finding","name":"Definition","description":"Definition.","questions":[{"text":"Is a prop supporting a load, in which case it must be correctly sized, plumb and not removed early, with temporary works designed and inspected by competent people?","kind":"boundary"},{"text":"What is a jack post, and how does it differ from permanent columns, scaffolding, shoring and lifting jacks?","kind":"definition"}]}]},{"id":"trade","name":"Trade name","description":"Acrow prop.","findings":[{"id":"trade-finding","name":"Trade name","description":"Trade name.","questions":[{"text":"Why is Acrow prop used as a generic term?","kind":"definition"},{"text":"Which entry fits Acrow?","kind":"action"}]}]}]},{"id":"use","name":"Use","description":"Use.","layers":[{"id":"adjustment","name":"Adjustment","description":"Adjustment.","findings":[{"id":"adjustment-finding","name":"Adjustment","description":"Adjustment.","questions":[{"text":"How are jack posts adjusted to length and locked?","kind":"provenance"},{"text":"Which references are standard?","kind":"provenance"}]}]},{"id":"applications","name":"Applications","description":"Applications.","findings":[{"id":"applications-finding","name":"Applications","description":"Applications.","questions":[{"text":"Where are props used in construction and basements?","kind":"provenance"},{"text":"Which sources are cited?","kind":"provenance"}]}]}]},{"id":"safety","name":"Safety","description":"Safety.","layers":[{"id":"loading","name":"Loading","description":"Load limits.","findings":[{"id":"loading-finding","name":"Loading","description":"Loading.","questions":[{"text":"Why must props not be overloaded and be on firm bearing?","kind":"provenance"},{"text":"Is the information current?","kind":"boundary"}]}]},{"id":"temporaryworks","name":"Temporary works","description":"Temporary works.","findings":[{"id":"temporaryworks-finding","name":"Temporary works","description":"Temporary works.","questions":[{"text":"Why should temporary works be designed and inspected?","kind":"provenance"},{"text":"Which entry fits temporary works?","kind":"action"}]}]}]},{"id":"context","name":"Context","description":"Standards.","layers":[{"id":"standards","name":"Standards","description":"Prop standards.","findings":[{"id":"standards-finding","name":"Standards","description":"Standards.","questions":[{"text":"What standards govern adjustable props?","kind":"provenance"},{"text":"Is the information accurate?","kind":"boundary"}]}]},{"id":"formwork","name":"Formwork","description":"Formwork support.","findings":[{"id":"formwork-finding","name":"Formwork","description":"Formwork.","questions":[{"text":"How are props used to support formwork during concreting?","kind":"provenance"},{"text":"Which entry fits formwork?","kind":"action"}]}]}]}]},"agentConduct":{"may":["Check a jack post's rated load and condition against its marking or manufacturer data.","Report props that are bent, corroded, not plumb or standing on soft ground."],"mustNot":["Load a jack post beyond its rating or with an extended length it is not rated for.","Remove or adjust temporary props before the structure is able to stand without them.","Use a jack post as a lifting jack.","Leave a temporary prop as a permanent support without engineering approval."],"requiresHuman":["Deciding when temporary propping can be struck.","Using props to support a structure that has already moved or cracked."]},"ethics":{"considerations":["A failed prop can bring down a floor on workers and occupants.","Shortcuts under time pressure are a common cause of collapse."],"affectedParties":["Construction workers","Occupants","Passers-by"]},"owners":{"steward":"The contractor in charge of temporary works on site; the engineer answers for the propping design.","roles":[],"masterSystems":[]},"relations":[{"target":"Q811430","type":"parent","note":"registry parent class"},{"target":"structural support","type":"related","note":"in registry terms"},{"target":"column","type":"related"},{"target":"scaffolding","type":"related"},{"target":"jack (device)","type":"related"}],"interaction":{"identity":{"applicability":"required","items":["Vercy registry: vr.tr.jack-post","Wikidata: Q2313763 (https://www.wikidata.org/wiki/Q2313763)"]},"properties":{"applicability":"required","items":["adjustment: threaded collar and pin note","Acrow: a trade name note - often used generically","registry parent: fixed construction note"]},"recognition":{"applicability":"required","items":["Adjustable steel prop supporting loads","Acrow prop","Permanent columns are fixed structure; scaffolding provides access; shoring supports excavations; lifting jacks raise loads rather than hold them","A telescopic steel tube with a threaded adjustment collar and base and head plates."]},"capabilities":{"applicability":"required","items":["explain use and adjustment","relay safety","note the trade name","distinguish related supports"]},"hazards":{"applicability":"required","items":["Collapse from overloading or early removal","Buckling if not plumb or on firm bearing","Confusing props with lifting jacks"]},"interfaces":{"applicability":"required","items":["Standards for adjustable props such as EN 1065","Temporary works design and inspection rules"]},"context":{"applicability":"required","items":["Temporary or adjustable vertical structural support.","temporary props","permanent basement jack posts","formwork props"]}},"sources":[{"title":"Wikidata item Q2313763: jack post","url":"https://www.wikidata.org/wiki/Q2313763","note":"identity and sense of the item"},{"title":"Wikipedia: Jack post","url":"https://en.wikipedia.org/wiki/Jack_post","note":"general description of the item"}],"openQuestions":["Should permanent basement jack posts be a separate entry?","How should temporary works standards be linked?","Should the Acrow trade name be noted as generic?"],"resources":{"spec":"/models/things/publications/thing-q2313763/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q2313763/spec.json"],"providers":["Claude"],"researchStatus":"unreviewed","generatedAt":"2026-09-14T02:35:30Z","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 2026-10-06T19:51:57+00:00: completeness 1.00; sense: Wikidata description; 2 live sources; review by codex: pass"},"score":1.0}}