multihull
Enable an agent to recognise a multihull vessel, assess its configuration and condition, and identify operations compatible with its structural, stability and propulsion limits.
Bundle → Layer → Finding → Questions Filled
6 bundles · 11 layers · 18 findings · 28 questions
Hull identity and arrangement Establishes which hull bodies comprise the craft and how their arrangement defines its multihull identity.
Hull membership
Identifies the bodies counted as hulls and the evidence that they form one vessel.
Distinct integrated hulls
Record each hull body and the basis for treating it as part of a single multihull craft.
- Which distinct external bodies count as hulls, and what definition supports that count? definition
- What distinguishes these bodies from internal compartments, auxiliary floats or separately operated vessels? boundary
Arrangement and hull roles
Describes relative positions, symmetry and buoyancy roles.
Configuration-specific geometry
Record hull arrangement and dimensions without assuming equal hull size or continuous immersion.
- What are the hull lengths, transverse spacing and overall beam in each supported configuration? measurement
- Which hulls carry normal displacement, and which principally provide stability when immersed? definition
Cross-hull structure Describes the connections and load paths that allow separated hulls to operate together.
Connecting load paths
Identifies crossbeams, decks and attachments that transfer forces between hulls.
Connection capacity and condition
Record connection construction, supporting design evidence and observed deterioration.
- Which members and attachments transmit bending and torsional loads between the hulls? definition
- Which drawings, assessments or inspections establish their capacity and current condition? provenance
Variable beam and handling
Addresses folding or demountable structures and external support during lifting or storage.
Approved structural configurations
Identify permitted configurations, locking requirements and hull support arrangements.
- Does the craft fold or demount, and which connection states permit afloat operation? boundary
- What documented locking, lifting-point and support checks are required before reconfiguration or lifting? action
Buoyancy, loading and stability Relates weight and buoyancy distribution across the hulls to trim, heel and loss-of-stability scenarios.
Displacement distribution
Connects loading positions to hull immersion and vessel attitude.
Loading by position
Record total loading and its longitudinal, transverse and vertical distribution.
- What displacement, centre of gravity and individual hull drafts describe the assessed loading condition? measurement
- Which limits govern unequal loading between hulls and concentration of weight near the ends or above the deck? provenance
Stability and flooding
Addresses intact stability, hull-specific flooding and documented recovery assumptions.
Loss-of-stability scenarios
Record evidence about transverse capsize, longitudinal overturning and asymmetric flooding where applicable.
- What vessel-specific evidence describes stability limits and the consequences of flooding one hull or compartment? provenance
- What actions and recovery provisions are documented for flooding, hull lift or capsize? action
Wave interaction and motion Captures behaviour arising from separated hulls and structures spanning the water between them.
Clearance and wave contact
Examines immersion and wave impacts beneath connecting structures.
Bridgedeck exposure
Record relevant clearances and evidence of wave contact where a bridgedeck or cross structure exists.
- What are the minimum underside clearances at the assessed loading condition, or why is this measure inapplicable? measurement
- What trials, operating records or damage reports document slamming beneath the connecting structure? provenance
Speed, heading and immersion
Relates operating choices to motions and changing hull immersion in waves.
Documented seaway response
Record supported constraints associated with bow immersion, hull emergence and wave encounter.
- Which speed, loading and wave-heading combinations have documented bow burial, excessive impacts or hull emergence? provenance
- What speed, heading or loading changes are prescribed when these conditions arise? action
Control and operating readiness Connects distributed propulsion, steering and configuration checks to permitted operation.
Distributed propulsion and steering
Maps control-producing components to hull positions and available operating modes.
Control authority and failures
Record propulsion and steering arrangements without assuming twin engines or a sailing rig.
- Where are propulsors, rudders and any sailing rig located relative to the hulls, and which can be controlled independently? definition
- Which manoeuvres and restrictions are documented after loss of propulsion or steering on one side? action
Inspection and applicable limits
Brings together vessel-specific evidence needed to judge readiness for an intended operation.
Multihull readiness evidence
Record the status of cross-hull connections, hull integrity and applicable loading or configuration restrictions.
- Which inspection records and issuing-body documents establish applicable structural, stability and operating requirements for this craft? provenance
- Which defects, expired checks or configuration mismatches require restriction, repair or further assessment before the intended operation? action
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Check these first
Recalled without web access and unsourced; every item is a lead to verify.
- Which of these check these first hold for the sense of multihull this model covers, and on what evidence? provenance
Kinds and varieties
Recalled without web access and unsourced; every item is a lead to verify.
- Which of these kinds and varieties hold for the sense of multihull this model covers, and on what evidence? provenance
Standards and regulation
Recalled without web access and unsourced; every item is a lead to verify.
- Which of these standards and regulation hold for the sense of multihull this model covers, and on what evidence? provenance
Real-world use
Recalled without web access and unsourced; every item is a lead to verify.
- Which of these real-world use hold for the sense of multihull this model covers, and on what evidence? provenance
Typical measurements
Recalled without web access and unsourced; every item is a lead to verify.
- Which of these typical measurements hold for the sense of multihull this model covers, and on what evidence? provenance
Failure modes and hazards
Recalled without web access and unsourced; every item is a lead to verify.
- Which of these failure modes and hazards hold for the sense of multihull this model covers, and on what evidence? provenance
Regional variation
Recalled without web access and unsourced; every item is a lead to verify.
- Which of these regional variation hold for the sense of multihull this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Recalled without web access and unsourced; every item is a lead to verify.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of multihull this model covers, and on what evidence? provenance
Classifiers Filled
- Family
- Thing Registry
- Category
- Physical world and living systems
- Entry kind
- thing
- Plane
- PHY
- Domain
- PHY.OBJ
- Other names and narrower kinds
- quadrimaran, pentamaran
What it is Filled
A multihull is a watercraft with two or more distinct hulls connected to operate as one vessel, with the hulls contributing buoyancy, stability, or both.
In scope
- Hull count, geometry, spacing and arrangement
- Connections that make separate hull bodies function as one vessel
- Buoyancy, loading, stability and behaviour in waves
- Propulsion and steering as integrated with the hull arrangement
- Multihull-specific inspection needs and operating limits
Out of scope
- Shipyard, manufacturer and commercial product-line identities
- Detailed models of engines, batteries, sails and other installed components
- Voyage planning, navigation rules and crew qualifications
- Floating platforms or independently operated vessels merely moored together
- Detailed cargo, passenger and port infrastructure models
Why it exists Filled
Enable an agent to recognise a multihull vessel, assess its configuration and condition, and identify operations compatible with its structural, stability and propulsion limits.
Distinguishing features Filled
- Identify multiple distinct hull bodies that participate in flotation or stability, rather than multiple compartments inside one external hull.
- Verify that the hull bodies are structurally integrated and operated as one craft rather than forming a convoy or tow.
- Distinguish a catamaran arrangement with two hulls from a trimaran arrangement with a central hull and two lateral hulls.
- Determine whether lateral bodies are hulls, stabilising outriggers or accessories; record uncertain classifications explicitly.
- Separate hull count from propulsion type: sails, engines or other propulsion do not by themselves establish that a craft is a multihull.
What robots and AI may and may not do Filled
Must not
- Take a multihull to sea beyond its design category or in forecast conditions it cannot handle.
- Ignore the risk of capsize, which a multihull may not recover from on its own.
- Operate the vessel without the skipper's authority or against collision rules.
- Disable safety equipment such as beacons, lifejackets or escape hatches.
Only with a human decision
- Deciding to put to sea or turn back in marginal weather.
- Calling for rescue or abandoning the vessel.
May
- Describe multihull types such as catamarans and trimarans and how they differ from monohulls.
- Monitor a vessel's position, weather and systems for its skipper when authorized.
- Report weather or sea conditions that exceed the vessel's design limits.
Moral aspects Filled
- A capsized multihull often stays inverted; crew safety depends on cautious handling.
- Vessels at sea affect other mariners and rescuers.
Who is affected
- Crew and passengers
- Other mariners
- Rescue services
Owners Filled
Steward
The registered owner and the skipper in command; the flag state registry records the vessel.
Master systems
- Flag state ship and small craft registers
Links to other meta-models Filled
parent
- Q17096141 - registry parent class
What else AI and robots need to interact with it Filled
Identity and identifiers required Filled
- Vercy registry: vr.tr.multihull
- Wikidata: Q1642862 (https://www.wikidata.org/wiki/Q1642862)
Direct properties required Filled
- Hull arrangement: catamaran; trimaran; other documented arrangement; unresolved
- Hull count: integer count, with the counting convention stated
- Principal dimensions: length, overall beam and draft in m, for a stated configuration and loading condition
- Transverse hull spacing: m between identified hull reference lines
- Hull connection arrangement: fixed crossbeams; bridgedeck; folding connections; demountable connections; other documented arrangement
- Loaded displacement and distribution: kg or t, with centre-of-gravity coordinates in m and a stated reference frame
- Bridgedeck clearance: m above the water surface at stated locations and loading condition; not applicable
- Buoyancy role by hull: continuously immersed; intermittently immersed; normally clear of water; configuration-dependent
- Propulsion and steering placement: links between installed propulsion or steering components and their hull positions
- Structural and watertight condition: assessed serviceable; restricted; damaged; unassessed, with inspection evidence
- Documented operating envelope: links to vessel-specific loading, speed, weather, configuration and stability limits
Recognition required Filled
- Two or more distinct hulls are connected by a shared deck, platform or crossbeams.
- A catamaran has two principal hulls arranged side by side.
- A trimaran has a central hull and a smaller hull on each side.
- Visible gaps between the hulls distinguish the arrangement from a single broad hull.
Capabilities and actions required Filled
- Classify the hull arrangement and flag ambiguous outrigger boundaries.
- Compare proposed loading with documented displacement, trim and stability limits.
- Check beam, draft and configuration against berth, channel and lifting arrangements.
- Identify connection, hull and watertight-integrity inspections needed before operation.
- Assess manoeuvring options after loss of a propulsion or steering component.
- Identify evidence and restrictions needed before changing folding, loading or sailing configuration.
Hazards and failure modes required Filled
- Capsize can leave some multihulls inverted with limited ability to recover without external assistance.
- Wave impacts and uneven loading can damage the structures connecting the hulls.
- Overloading can reduce clearance beneath the connecting deck and increase wave impact loads.
- The vessel's wide beam can increase collision risks in confined berths and channels.
Standards and interfaces required Filled
- International Regulations for Preventing Collisions at Sea (COLREGs), International Maritime Organization.
- ISO 12217-2, Small craft - Stability and buoyancy assessment and categorization, sailing boats, International Organization for Standardization.
Context of use required Filled
- Multihulls are used for passenger transport, recreation, racing and specialist marine operations.
- Their separated hulls provide configurations suited to broad decks and substantial initial stability, with performance depending on vessel design and loading.
Sources Filled
- Wikidata item Q1642862: multihull - identity and sense of the item
- Wikipedia: Multihull - general description of the item
Open questions
- Does the registry intend multihull to include outrigger craft, proas, small-waterplane-area twin-hull vessels and temporary modular craft, and what authoritative definition fixes those boundaries?
- Does an existing Vercy vessel or multihull world model already own this concept, requiring a registry link instead of a separate publication?
- Which primary naval-architecture sources substantiate the proposed stability, cross-structure and wave-interaction distinctions across different multihull arrangements?
- Which standards and issuing bodies apply to each intended size, use and jurisdiction, and which requirements are specific to multihulls?
- Which dimensions, capacities and operating limits can be supported for defined subtypes without presenting a misleading range for all multihulls?
Machine files
Provenance
thing registry research (pass 2) · unreviewed
Built from: models/things/publications/thing-q1642862/spec.json