Section 7 Launch and recovery appliances for manned small watercraft

7.1 General

7.1.1 This Section covers the design requirements for the launch and recovery appliances for manned tender boats.

7.1.2 In general, the launching and recovery of tender boats with persons aboard is considered a higher risk activity than the launching and recovering of unmanned tender boats.

7.1.3 The requirements of Ch 4, 2 Shipboard cranes are also to be complied with unless specified differently within this Section.

7.1.4 The requirements of Ch 4, 6 Handling of personnel and Ch 9, 4 Machinery engaged in handling of personnel are also to be complied with unless specified differently within this Section.

7.1.5 The requirements of this Section are considered appropriate for launch and recovery operations carried out under the following conditions:

the mothership supporting the appliance shall be stationary;
operations are conducted in harbour or sheltered water conditions;
operating temperature is higher than -50°C and lower than +45°C;
minimum design temperature is higher than -40°C (see Ch 11, 1.2 General material requirements 1.2.4);
wind speeds do not exceed 4 m/s;
heel and trim of the mothership do not exceed 5° and 2° respectively;
significant wave height does not exceed 1,0 m;
daylight visibility or equivalent;
Operator of the appliance has continuous direct means of communication with the personnel to be lifted or direct line of sight with the personnel to be lifted;
crew embarks at the lowest possible location above the water line; and
the number of persons aboard the tender boat during hoisting and lowering are limited to those essential crew members required for safe operation and preparation of the tender boat for launch and recovery.

7.1.6 The scope of this Section does not include:

lifting, handling and erection of the appliance or its components;
transport of appliances and/or their components;
collision loads, e.g. collision of the tender boat with the hull of the mothership or with an object in the water, etc.;
assembling or disassembling of the appliance and/or its components;
scrapping or disabling of the appliance and/or its components;
appliances for life-saving; and
appliances installed on naval vessels.

7.1.7 The designer shall evaluate any additional arrangement requirements based on the operational profile of the appliance. The operational profile shall be decided in collaboration with the Owner/Operator, such that it is fully understood by all parties. The operational profile and any additional requirements are to be communicated to LR for consideration.

7.1.8 The responsible National Authorities and Flag States may have additional requirements which need to be adhered to. In case of any conflict arising between these requirements and those of the National Authorities and Flag States, the requirements of the National Authorities and Flag States take precedence.

7.2 Terms and definitions

7.2.1 Machinery is defined as mechanical, electrotechnical or hydraulic systems (and their combinations) used to move the appliance, its components and/or its load.

7.2.2 Mothership is defined as the ship which carries the small watercraft and its launch and recovery appliance.

7.2.3 Safe Working Load (SWL). The general definition of the SWL of a lifting appliance is included in Ch 1, 2.1 Safe Working Load (SWL) of a lifting appliance. Within the context of this Section, the maximum static load for appliances used for the launch and/or recovery of manned small watercraft is defined as the fully laden weight of the small watercraft, including the crew required to handle the manned small watercraft.

7.2.4 Significant wave height (H_1/3) is defined as the average of the one third highest waves (measured from trough to crest) in a short term wave measurement record.

7.2.5 Manned small watercraft is defined as a tender boat or workboat which is carried on the mothership for the purposes of transferring crew, passengers or other personnell; and which are both manned while being handled.

7.3 Loads and design factors

7.3.1 A risk coefficient, γ_n, shall be applied to the SWL of the appliance to account for the increased risk associated with personnel handling. The risk coefficient shall be taken as follows:

for h ≤ 3 m: γ_n = 1,20;
for h ≥ 10 m: γ_n = 1,70;
for 3 m < h < 10 m: γ_n = .

where

h = lifting height as measured between the waterline of the mothership and the bottom of the keel of the manned small watercraft (in metres).

A risk coefficient, γ_n.DL, shall be applied to the dead load of the appliance to account for the increased risk associated with personnel handling. The risk coefficient shall be taken as follows:

for h ≤ 3 m: γ_n.DL = 1,05;
for h ≥ 10 m: γ_n.DL = 1,50;
for 3 m < h < 10 m: γ_n.DL = .

Proposals for the application of alternative risk factors will be specially considered.

7.3.2 In case of the absence of actual dynamic factors, the hoisting factor shall be taken as follows:

for H_1/3 ≤ 0,6 m: F_h = 1,30;
for H_1/3 ≤ 1,0 m: F_h = 1,45.

Values for hoisting factors between H_1/3 of 0,6 m and 1,0 m may be linearly interpolated.

The application of lower hosting factors will be specially considered if supported by an acceptable technical justification. H_1/3 is generally limited to 1,0 m. The hoisting factor for H_1/3 beyond 1,0 m will be specially considered. The application of higher dynamic factors, other than those given above, shall be considered if required by design implications and/or environmental circumstances.

7.3.3 The duty factor shall be determined in accordance with the requirements of Ch 4, 2.3 Duty factor.

7.3.4 The heel and trim angles of the mothership shall be taken as 5° and 2° respectively. The heel and trim angles shall be applied to the dead weight of the appliance and the SWL. The heel and trim angles for values of H_1/3 above 1,0 m will be specially considered.

7.3.5 In cases where H_1/3 ≥ 1,0 m, the mothership accelerations are to be taken into consideration.

7.3.6 The offlead and sidelead angles (which are to be applied to the SWL) are both taken to be a minimum of 3° unless environmental or other conditions require higher angles to be applied. The offlead and sidelead angles are to be applied in addition to the heel and trim angles of the mothership. Consideration will be given to lower angles if it can be demonstrated that such angles can be effectively restricted. The offlead and sidelead angles for H_1/3 above 1,0 m will be specially considered.

7.3.7 If necessary, bow-lines (painters) and bowsing-lines should be used in order to stabilise the tender boat and in order to avoid swinging of the tender boat.

7.3.8 Effects of wind on tender boats shall be considered. The design wind speeds and force coefficients shall be determined in accordance with the requirements of Ch 4, 2.12 Wind loading.

7.3.9 Any loads arising from stowage of the manned small watercraft due to storing on the launch and recovery appliance are to be taken into consideration (e.g. small watercraft hanging from or resting on the appliance).

7.4 Machinery

7.4.1 The appliance’s hoisting and luffing winches (where fitted) are to be approved by LR for personnel handling and details of the winches are to be submitted for appraisal.

7.4.2 The appliance’s hoisting and luffing winches (where fitted) are to be fitted with primary automatic type brakes. These are to be of the interlocking type, where a failure in the brake system, including loss of power, will cause the brake to be applied automatically.

7.4.3 The hoisting and luffing winches (where fitted) are to be equipped with mechanically and operationally independent secondary braking systems. The control system for these secondary brakes shall be independent of the primary brake. Both primary and secondary brakes are to be automatically applied in case of the emergency stop being activated or in the event of a failure in the brake system.

7.4.4 The secondary brake system shall operate directly on the winch drum or drum shaft. Other proposals (e.g. a fully independent load path) will be specially considered.

7.4.5 Each winch brake shall be fitted with an override and means are to be provided to enable the recovery of the tender boat to safety from any position in the event of a failure of the brake system or other emergency situations. The override shall be protected against inadvertent activation. The emergency recovery concept, shall be submitted for appraisal.

7.4.6 The length of the steel wire rope shall be such that a minimum of three wraps remains on the winch drum at all times. End terminations (for the drum and elsewhere in the reeving system) shall adequately secure the rope to the winch drum in accordance with the rope manufacturer’s recommendations. Reference is made to the requirements of Ch 8, 6.4 Splicing and terminal connections.

7.4.7 The minimum number of wraps necessary for fibre ropes installed on winch drums will be specially considered. End terminations (for the drum and elsewhere in the reeving system) shall adequately secure the fibre rope to the winch drum (and other dead ends in the reeving system) in accordance with the rope manufacturer’s recommendations. Reference is made to the requirements of Ch 8, 7.3 Splicing and terminal connections.

7.4.8 Winch drum connections and end terminations for wire and fibre ropes shall be of an approved type.

7.4.9 Where hydraulic cylinders are used for luffing, folding or telescoping, they are to be fitted with pilot-operated non-return valves at both inlet and outlet manifolds to ensure that the cylinders remain in position in the event of a hydraulic failure. The required pilot-operated non-return valves are to be fitted directly to the cylinder ports. Other valves, which provide a similar and sufficient level of safety and functionality to pilot-operated non-return valves, will be specially considered.

7.4.10 The accumulated number of operating load cycles shall be recorded in order to ensure that the design lifetime of any part of the appliance (e.g. rope, winch gear, structure, etc.) is not exceeded during the service life of the appliance. This information is to be made available to the attending Surveyor.

7.4.11 For the design of machinery items the risk coefficient (see Ch 4, 7.3 Loads and design factors 7.3.1) shall be multiplied with the dynamic load (see Ch 4, 7.3 Loads and design factors 7.3.2 and Ch 4, 7.3 Loads and design factors 7.3.3). The risk coefficient need not be applied to establish the required brake torque and dimensioning of the motor or gearing.

7.5 Ropes and loose gear

7.5.1 The wire rope safety factor shall be determined in accordance with the requirements of Ch 4, 3.9 Rope safety factors and this safety factor shall be a minimum of 5. The derived rope safety factor shall further be multiplied by the risk coefficient as defined in Ch 4, 7.3 Loads and design factors 7.3.1. Rope safety factors for significant wave heights beyond 1,0 m will be specially considered.

7.5.2 The man-made fibre rope safety factor shall be determined in accordance with the requirements of Ch 4, 7.5 Ropes and loose gear 7.5.1 and shall be multiplied by a factor of 1,25. The instructions for use issued by the fibre rope manufacturer and any requirements, pre-cautions and limitations stated therein are to be complied with. These instructions are to be made available to the attending Surveyor.

7.5.3 The maximum number of guaranteed load cycles for the fibre rope (as stated by the fibre rope manufacturer) shall be divided by the risk coefficient as defined in Ch 4, 7.3 Loads and design factors 7.3.1. The actual load cycles the reeving system is subjected to shall be recorded and compared with the number of guaranteed load cycles for the fibre rope divided by the risk coefficient.

7.5.4 The hook is to have a safety factor of γ_n × 5 against the ultimate tensile strength of the materials used. The derived safety factor shall be a minimum of 6.

7.5.5 The hook block is to comply with the requirements of Ch 8, 3.5 Hook blocks. With respect to Ch 8, 3.5 Hook blocks 3.5.1.(a) the required safety factor against the ultimate tensile strength is generally set to γ_n × 5 and this safety factor shall be a minimum of 6. With respect to Ch 8, 3.5 Hook blocks 3.5.1.(b), the risk coefficient γ_n shall be applied to the dead load and SWL.

7.5.6 Loose gear items are to have a safety factor of γ_n × 5 against the ultimate tensile strength of the materials used. The derived safety factor shall be a minimum of 6.

7.5.7 Spreaders and lifting beams are to comply with Ch 8, 4 Spreaders and lifting beams. The risk coefficient γ_n shall be applied to the SWL of the spreader and lifting beam. The risk coefficient γ_n.DL shall be applied to the dead load of the spreader and lifting beam.

7.5.8 Loose gear items (including hook and hook block) are to have a safety factor of γ_n × 5 against the ultimate tensile strength of the materials used. The minimum safety factor shall be 6.

7.5.9 Hooks are to be designed for the purpose of lifting manned tender boats. The manufacturer of the hooks shall specify that the hooks are suitable for the purposes of launching and recovery of manned tender boats.

7.5.10 Hooks shall incorporate a means to prevent inadvertent opening or other accidental loss of the load (i.e. the manned tender boat). The arrangement shall be submitted for consideration and the effectiveness shall be demonstrated to the attending Surveyor.

7.5.11 Hooks are to be forged. Special consideration will be given to alternative proposals.

7.5.12 Where the appliance is equipped with more than one reeving system (e.g. two beams, each with a separate reeving system), details of the arrangements to prevent unequal lowering or hoisting of the tender boat are to be submitted for consideration and the effectiveness shall be demonstrated to the attending Surveyor.

7.6 Instructions for use

7.6.1 Instructions for use and the maintenance manual are required to be provided. The instructions for use shall cover all operational and emergency procedures, including any conditions, pre-cautions and limitations for manned tender boat launching and recovery operations.

7.7 Risk assessment

7.7.1 In case it is intended to deviate from the requirements as stipulated in this Section, it is required to prepare a risk-based justification in line with LR’s ShipRight Procedure for Risk Based Certification (RBC). The RBC process requires the manufacturer to carry out a suitable and sufficient risk assessment based on own information and experience and information received from the Owners and/or Operators.

7.7.2 The manufacturer shall prepare a Safety Statement in line with the RBC process which, as a minimum, shall describe:

the boundary of the system intended to be assessed;
the risk management process intended to be followed;
the risk assessment tools intended to be used; and
the acceptance criteria that will be used to determine if a risk is tolerable.

7.7.3 It shall be ensured that the boundaries of the risk assessment are set wide enough to suitably and sufficiently assess the system which is defined as the appliance and its components embedded in its environmental situation (e.g. mothership, environmental conditions such as wind/H_1/3/heel/trim, etc.). The system is required to be assessed in its entirety, and the boundaries are to be shifted until there are no parts or components having any influence on the appliances and vice versa.

7.7.4 It is the responsibility of the manufacturer to ensure the intended process and acceptance criteria meet the requirements of LR as given in the RBC. It is further required that the intended process and acceptance criteria are acceptable to the National Authority who may have requirements in addition to the methodology given in this Section and/or the RBC process.

7.7.5 The risk assessment shall clearly set out the boundary of the system to be assessed. As a minimum, it should consider the safety of the system during normal operation, during emergency conditions and while the system is out-of-service. As a minimum, the assessment is required to:

demonstrate the system meets the performance requirements;
demonstrate the appliance meets the performance requirements;
demonstrate the components of the appliance meet the performance requirements;
take into account the interfaces between the appliance and the mothership;
identify the potential hazards to the safety and integrity of the system and appliance and specifically quantify and rank these risks in terms of their consequence and frequency;
identify those risks that are unacceptable in relation to the defined performance requirements;
identify what prevention and/or mitigation actions are to be taken in order to reduce the risks that are unacceptable to a level tolerable to LR and the National Authority;
identify parts and/or components of the appliance and the system that are critical in relation to the management of the identified risks and hazards; and
clearly identify the hazards that may threaten the safety or integrity of the system and/or the appliance, or otherwise endanger the crew and other persons.

7.7.6 Suitable protective measures and safety features shall be introduced as a consequence of the risk assessment.

7.7.7 The instructions for use of the appliance shall be compiled based upon the findings of the risk assessment.

7.7.8 The manufacturer is responsible for communicating the output of the assessment to the Owner and/or Operator.

7.7.9 The manufacturer is responsible for implementing any mitigation measures relevant to the design of the appliance. The Owner and/or Operator is responsible for implementing any mitigation measures relevant to the operation of the appliance. One of the outcomes of the risk assessment shall be who is responsible for which mitigation measures and the definition of the interfaces between the manufacturer and the Owner and/or Operator.

7.7.10 The risk assessment should be carried out in accordance with relevant and recognised National and International Standards. In particular, the following standards shall be taken into consideration:

ISO 31000 Risk management;
ISO 31010 Risk management – Risk assessment techniques;
ISO Guide 73 Risk management – Vocabulary; and
ISO 12100 Safety of machinery — General principles for design — Risk assessment and risk reduction.

7.7.11 Whilst the manufacturer may use specialised support to produce the risk assessment, they remain accountable for the production of the risk assessment and demonstrating that deviating from the prescribed requirements does not lead to an increase in risk.

7.7.12 It is, in general, recommended to carry out a risk assessment for the appliance under due consideration of the conditions of the system (e.g. mothership, environmental) the appliance will be installed in and the interfaces between the appliance and the mothership. The risk assessment shall be carried out taking into account the methodology as given in Ch 4, 7.7 Risk assessment.

7.8 Testing, marking and surveys requirements

7.8.1 The testing, marking and survey of the appliance is to be carried out in accordance with the requirements of Ch 12 Testing, Marking and Surveys as applicable.

7.9 Inspection before use

7.9.1 Before any launching or recovery operation commences, an inspection/examination of the appliance and associated gear/equipment/components is required prior to each individual manned use. The manned small watercraft shall first be lowered and hoisted for a few meters without persons on board in order to ascertain that the arrangement operates safely and correctly. The inspection/examination shall be documented and shall be made available to the attending Surveyor.