This document was published on 30 May 2023 and will be effective from 1 June 2023.
A Wind Assisted Propulsion System (WAPS) is a mechanical means able to convert the kinetic energy of the wind into thrust or electrical power for the propulsion of a ship.
It helps reduce fuel consumption and greenhouse gas emissions from internal combustion engines. The WAPS is considered an additional propulsion system that is not essential for the safety and navigation of the ship.
The class notation WAPS is assigned to ships equipped with a wind-assisted propulsion system, according to Pt F, Ch 13, Sec 46.
The WAPS notation depends on the available effective power of the system.
The following notations are assigned based on the percentage of the WAPS power compared to the propulsion power:
WAPS-A (Auxiliary) when the available effective power of the WAPS is equal to or less than 15% of the propulsion power.
WAPS-H (Hybrid) when the available effective power of the WAPS is more than 15% and equal to or less than 60% of the propulsion power.
WAPS-M (Main) when the available effective power of the WAPS is more than 60% of the propulsion power.
The WAPS can be based on different technologies, such as sails, wing-sails, kite-sails, flettner rotors, or wind turbines.
The WAPS notation can be completed with the commercial denomination of the technology, identifying the type of installation.
Examples of technology denominations include "Ventifoil," "Rotor," or "Dyna Rigg."
Annual, Intermediate, and Renewal Surveys
Annual and intermediate surveys:
During these surveys, the following tests and inspections are to be performed:
a) Availability of an approved operating manual, including procedures for emergency operation and allowable weather conditions for the use of WAPS.
b) Availability of an approved Operating and Maintenance Manual (OMM), including a corrosion protection plan for WAPS elements.
c) Availability of a Risk Assessment Report (HAZID, FMECA, or HAZOP).
d) Availability of additional guidance for the operation of wind assistance equipment, included in the stability book.
e) Availability of a rig booklet for WAPS with rigging.
f) Checking the control, monitoring, and safety system.
g) Checking the automatic release systems to avoid wind overload on the WAPS system.
h) Checking the winches and clutches.
i) Checking the rigging elements and their connection to the hull structure and/or hull stiffening, as applicable.
j) Checking loose gear and confirming their test mark, as applicable.
k) Checking the transfer ballast system foreseen for stability purposes.
l) Checking critical machinery items, like drive and safety systems, needed for the safe control or emergency operation of WAPS as identified during the risk assessment.
m) Checking hydraulic power units and actuating units.
n) Checking securing and locking arrangements for retracted or tilted WAPS elements, together with their interlock system.
o) Confirming that the hydraulic system for securing and locking devices is isolated from other hydraulic circuits when the WAPS is in a tilted or retracted position.
p) Checking electrical power supplies and actuating units.
q) Checking electrical installation in hazardous areas, if any.
r) Confirming proper earth connection.
s) Checking automatic control, alarm, and safety functions provided for the wind propulsion system.
t) Performing functional tests, as far as practicable, of the whole system, including its monitoring, alarm, and safety systems.
During renewal surveys, in addition to the tests and inspections performed during annual and intermediate surveys, the following additional tests and inspections are to be conducted:
a) Thorough examination of rigging for the mast, including shroud and stays, with relevant connections to the hull structure and/or stiffening, as applicable.
b) Testing of the alarm and control system.
c) Functional tests, as far as practicable, of the whole system under working conditions, including its monitoring, alarm, and safety systems.
These renewal surveys ensure that the WAPS and its associated components are thoroughly examined, tested, and inspected to maintain their operational effectiveness and safety.
By conducting these surveys, the ship can ensure the proper functioning and maintenance of the wind-assisted propulsion system.