Structural design and execution
General
Aquaculture facilities and their components must at all times have sufficient capacity to withstand loads and load combinations that may occur during the design service life and lifetime extension.
The design and execution of aquaculture facilities must ensure sufficient capacity, durability, and robustness under all relevant design situations.
Fire safety on floating aquaculture facilities must ensure that a fire does not lead to capacity being exceeded.
Structural design
All main components and auxiliary equipment shall be properly designed.
Execution
Execution must be in accordance with the design and as specified for the individual materials and components.
Reliability and control
Those who carry out the design or execution of additional equipment in reliability class 2 or main components in reliability class 2 or reliability class 3 shall perform self-control and peer control of such activities. An external company shall carry out an extended control of the design and execution of main components in reliability class 3.
Control of the design and execution of additional equipment must meet the requirements for reliability class 2.
The requirements for reliability class 3 apply to the control of design and execution of:
- enclosures and floaters if the number of fish in an enclosure exceeds 200,000 individuals
- floaters if the number of fish in common floats exceeds 200,000 individuals
- anchoring systems if the number of fish in a common positioning system exceeds 1,500,000 individuals
- main components in aquaculture facilities located at a site where the significant wave height can exceed 5 meters in a sea state with a return period of 50 years or more
Risk assessment
Risk assessment
A risk assessment of fish escape must be carried out in connection with the design of main components and auxiliary equipment. This should identify limit states and potential unwanted events and be used as a basis for ensuring robust and reliable design of main components and additional equipment.
The risk assessment must be included in the basis for the preparation of the user manual for main components and additional equipment.
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Materials
General
Materials to be used in or on aquaculture facilities must have properties that provide satisfactory capacity and durability for the aquaculture facility and its components throughout the entire design service life.
Material properties
Material properties that are included in the design must be documented. For example:
- strength
- capacity
- corrosion properties
- strain properties
- density
Material properties based on testing
If a material property is not documented, it must be determined through standardized tests under
defined conditions. Based on tests, characteristic values for use in sizing must be calculated.
Corrosion
Components in the splash zone are exposed to corrosive conditions. Corrosion protection in the splash zone will depend on maintenance philosophy and surrounding conditions. Galvanic corrosion can occur when metals with different potentials come into contact.
A plan must be prepared for the implementation of corrosion control of main components and
permanent additional equipment, where measures for increased corrosion or the need for replacement must be stated.
Structural system design
General
Components that are part of the aquaculture facility must be correctly assembled and adapted to each other in accordance with the facility certificate, requirements in NYTEK23, and user manuals.
The basic requirement is that components should not affect each other in such a way that the capacity of adjacent components will be exceeded.
Global analysis
For aquaculture facilities, a global analysis must be carried out. The global model must include geometry, stiffness, and mass from all main components and additional equipment, so that load effects can be determined.
Load effects from the global analysis are divided into two parts:
- One part concerns movements such as displacement, velocities, and accelerations, in addition to relative movements to assess wave impact and overtopping
- The other part concerns forces in the structure on main components and additional equipment as a basis for sizing
Loads, effects of loads and load carrying capacity
Loads
The aquaculture facility must be designed to withstand all loads that may occur during the design service life of the facility, for example:
- permanent loads
- variable functional loads
- deformation loads
- environmental loads
- accident loads
Local analysis
Local analysis must be carried out for main components and, in particular, connection points. The local analysis should be based on the design load effect from the global analysis combined with local effects.
Effects of loads
Main components, individual parts, or the joining of individual parts in main components must be designed to withstand the effects of influences from calculations with waves, wind, and currents in at least eight directional sectors.
Load carrying capacity
Based on forces from load effect analyses, the capacity of components in the aquaculture facility must be demonstrated. Design forces must be used with relevant load factors together with design capacity based on the material factor for the applicable material. This includes capacity against overtopping and requirements for freeboard.
Physical conditions and site survey
Site survey
For aquaculture facilities, a site survey must be carried out that includes mapping and quantification of the following conditions:
- physical conditions at the site, including seabed topography and seabed conditions, and
- environmental conditions at the site for the following parameters:
- tidal levels and high and low water levels
- currents
- wind
- waves
- ice and snow conditions, including icing, drifting ice, and freezing in
The site survey must be included in the basis for the design of the floating aquaculture facility.
Specific demands for main components, moorings and auxiliary
Components
In addition to the general requirements for planning, design, and execution, there are specific requirements for all components such as:
- Enclosure
- Floats
- Barge
- Anchoring and positioning
- Auxiliary equipment
User manual
The supplier of main components, structural parts, and additional equipment must, along with the product, provide a user manual with clear instructions for transport, storage, assembly, use, and maintenance of the product. The user manual must be available in electronic format.
The user manual must be based on a risk assessment and provide necessary and sufficient information about the component and its proper and safe use.