dynamic positioning

Automatic station keeping

Record whether feedback automatically commands thrust to maintain position and heading, and identify any dependence on external restraints.

1. What evidence demonstrates automatic position and heading control rather than heading-only or manual control? definition
2. Does the assessed capability depend on anchors, mooring lines or another positioning system, and where is that interface bounded? boundary

Reference point and tolerance

Record the controlled vessel point, coordinate conventions, target motion and permitted position and heading deviations.

1. Which vessel point and reference frame define the setpoint, and how are sensor offsets transformed to that point? measurement
2. What excursion and heading limits apply at the operation's critical point, including during setpoint changes? boundary

Accepted reference basis

Identify selected inputs, their operating constraints and the evidence supporting their acceptance by the control system.

1. Which position, heading and motion inputs are selected, and what are their uncertainty, update rate and data age? measurement
2. Which inputs share corrections, targets, power or communications such that one fault could corrupt several together? boundary

Mode and feedback response

Record the active mode, commissioned control settings and defined response when references disagree or disappear.

1. What commissioning or trial evidence supports the control settings for this vessel configuration and operating mode? provenance
2. What approved response applies when references disagree, become stale or leave the controller without trustworthy position feedback? action

Thrust allocation envelope

Record which thrusters can contribute in each direction, including derating, forbidden sectors and interaction effects.

1. What force and yaw moment can the enabled thrusters deliver at the current draught and configuration? measurement
2. Which azimuth restrictions, interaction losses or task constraints reduce the thrust available to the DP controller? boundary

Configuration-specific capability

Link power availability and environmental capability evidence to a stated heading, equipment configuration and failure condition.

1. What power remains available for DP after competing loads and the assessed equipment failure are accounted for? measurement
2. Which calculation or trial supports the environmental envelope, and how closely does its configuration match the present one? provenance

Worst-case failure basis

Record the failure modes and effects analysis, redundancy groups and the failure used to assess remaining capability.

1. Which failure defines the assessed worst-case loss of DP capability, and what equipment remains available afterward? definition
2. What shared power, cooling, network, software or compartment dependencies could defeat the assumed separation? boundary

Applicable assurance evidence

Record applicable flag and class requirements, trials, acceptance documents and changes requiring reassessment. IMO guidance applicability depends in part on construction date; see [USCG regulatory guidance](https://www.dco.uscg.mil/OCSNCOE/DP/Regulatory-Guidance/).

1. Which issuing bodies, document editions and acceptance records support the claimed equipment class for this installation? provenance
2. Which repairs, software changes, overdue tests or outstanding defects require restrictions or renewed verification before DP service? action

Activity-specific permission

Record the applicable operating guidance, readiness evidence, human control authority and dependencies on other operations.

1. Which approved activity-specific limits and configuration requirements govern entering or continuing this DP operation? boundary
2. What checks and responsible-person decisions are required before engaging DP or changing its operating configuration? action

Loss-of-position response

Record response triggers for uncontrolled drift or unintended powered movement, including task termination and escape interfaces.

1. How do detection delay, excursion rate and task shutdown or disconnect time compare with the time remaining before a critical boundary is reached? measurement
2. Which approved actions, control transfers and notifications apply, and what evidence is required before resuming DP operations? action

Check these first

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these check these first hold for the sense of dynamic positioning this model covers, and on what evidence? provenance

Kinds and varieties

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these kinds and varieties hold for the sense of dynamic positioning this model covers, and on what evidence? provenance

Standards and regulation

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these standards and regulation hold for the sense of dynamic positioning this model covers, and on what evidence? provenance

Real-world use

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these real-world use hold for the sense of dynamic positioning 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.

1. Which of these failure modes and hazards hold for the sense of dynamic positioning this model covers, and on what evidence? provenance

Regional variation

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these regional variation hold for the sense of dynamic positioning 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.

1. Which of these neighbouring kinds and how to tell them apart hold for the sense of dynamic positioning this model covers, and on what evidence? provenance