date: '2026-10-19'
status: proposed_design_contract_not_implemented_or_hardware_validated
reference: docs/40_full_transfer_application.md
requirements_preserved:
  motor_nominal_voltage_V: 72
  max_hull_skin_draft_m: 0.53
  primary_drive: HPM_with_reduction_direction_only
  local_onboard_AI_required: true
  manual_priority: true
  fast_loops_and_hardware_protection_independent_of_AI: true
  generator_is_optional: true
  shore_power_required_for_operation: false
power_topology:
  traction_channels:
  - port
  - starboard
  DC_shared_or_sectioned: null
  shared_failure_domains_to_analyse:
  - battery
  - DC_bus
  - CAN
  - VCU_power
  - cooling
  - emergency_circuit
  BMS_is_supervision_and_protection_not_assumed_power_converter: true
physical_limits:
  battery_series_cells: null
  DC_Vmin_Vnom_Vmax_V:
    minimum: null
    nominal: 72
    maximum: null
  charge_current_limit_vs_SOC_temperature_A: null
  discharge_current_limit_vs_SOC_temperature_A: null
  regen_voltage_limit_V: null
  surge_voltage_V: null
  continuous_power_each_shaft_W: null
  DC_bus_capacitance_F: null
  precharge_resistance_ohm: null
  precharge_timeout_ms: null
  contactor_weld_detection_threshold: null
  cooling_derate_curve: null
  control_backup_energy_Wh: null
message_contract:
  required_fields:
  - source
  - value
  - unit
  - sign_convention
  - measurement_time
  - receive_time
  - sequence
  - validity
  - mode
  - protocol_version
  CAN_ids: null
  endianness: null
  message_periods_ms: null
  timeouts_ms: null
  NMEA2000_gateway_or_protocol_choice: null
  device_restart_and_replay_policy: null
  permitted_command_authorities:
  - manual_post
  - bounded_local_AI_via_VCU
  command_acknowledgement_and_completion_policy: null
candidate_states:
- 'OFF'
- PRECHECK
- PRECHARGE
- READY
- PROPULSION
- CHARGE
- HYDROGENERATION
- DEGRADED
- FAULT_ISOLATED
state_machine:
  transitions_and_guards: null
  hydrogeneration_enabled_by_default: false
  fault_response_by_operating_mode: null
  no_universal_shutdown_or_brake_action_assumed: true
  per_channel_and_energy_supervisor_state_composition: null
  simultaneous_PV_charge_and_propulsion_handling: define_from_power_balance_not_assumed_mutually_exclusive
control_constraints:
  respect_per_channel_and_total_battery_limits: true
  charge_and_discharge_permissions_are_distinct: true
  preserve_navigation_priority_power: true
  AI_output_requires_validation_before_actuation: true
  hydrogeneration_requires_accepted_energy_path_and_drag_calculation: true
  contactor_opening_requires_regen_and_rotating_motor_analysis: true
mass_and_energy_interfaces:
  installed_BOM_mass_kg: null
  CG_xyz_frame_and_units: null
  power_profile_W: null
  losses_and_heat_W: null
  mass_budget_existing_line: electrics_CAN_AI; replace identified allowance, do not
    blindly add a second full controller allowance
  feed_to:
  - energy_balance
  - cooling
  - Ship_Weight_LoadCondition_after_physical_inputs
acceptance_work:
  energy_balance_and_sign_conventions: null
  power_allocation_and_manoeuvring: null
  BMS_and_inverter_communication_loss: null
  AI_failure_and_manual_override: null
  precharge_and_welded_contactor: null
  channel_fault_isolation_and_common_causes: null
  full_battery_or_cold_charge_rejection: null
  EMC_corrosion_environmental_trials: null
  stand_tests_and_sea_trials: null
instrument_telemetry:
  contract: calculations/navigation/open-boat-projects/data-contract.yaml
  SignalK_battery_current_positive: charging
  instrument_network_not_assumed_same_as_traction_CAN: true
  stale_data_must_not_gain_fresh_measurement_timestamp: true
  physical_power_and_isolation_to_select: true