Makai offers submarine cable planning services to assist cable owners and planners in the preliminary stages of cable route planning. Makai uses GIS software, MakaiPlan, to integrate all available GIS data into detailed maps in order to investigate cable route options. The route position list (RPL) and cable assembly/single line diagram (SLD), are prepared and can be provided to cable manufacturers for preliminary cost estimates. The GIS data can be made available to the customer in a variety of different formats for use in GeoMedia or ArcGIS. Makai can also provide specifications for the bathymetric survey that will need to be completed prior to the final cable design. Makai engineers can act as owner representatives onboard the survey vessel during at-sea operations to be certain that the data collected matches the specifications of the contract. Makai has the software tools necessary to process the survey data files and assess the quality of the data collected. Makai engineers have also acted as expert witnesses during environmental impact study hearings and press conferences for new submarine cable projects.
Desktop Studies & Route Selection
Makai conducts desktop studies for preliminary submarine cable route selection. These studies provide an understanding of the technical and economic feasibility and risk factors of the project prior to investing in large offshore surveys or detailed engineering designs. During a typical study, Makai conducts a search for available data for a particular site, including bathymetric data, meta-ocean data, GIS spatial data, and nautical charts. Using all the available data and Makai’s experience in submarine cable route design, constraint maps are created and potential route options are selected. The final report typically consists of multiple sections including: route description, which includes RPLs, depth and slope profiles; bathymetry; geology; fisheries; environmental conditions; hazards and obstructions, and landing sites. Results can be presented as GIS databases and custom high-quality offshore charts that can be used in later stages of the project.
Landing Site Surveys
Makai conducts shore landing site surveys for submarine telecommunications and power cables. The purpose of the site survey is to locate a suitable exit site for horizontal directional drilling operations. Depending on the seafloor characteristics of the site, a diver may be towed over an area defined by preliminary results from the desktop study. At the exit point, the goal is to locate a sand channel which has unencumbered access to deep water for the cable to follow and possibly be buried. The site is documented by pictures, videos, and the depth of the sand up to two feet.
Situations arise that necessitate a change in the cable path after the cable has been manufactured. Makai can make changes to the cable route after the cable has been manufactured by using a special “fixed cable mode” in MakaiPlan which allows changes to the position of the route and slack without changing the length of the cable segments. This is important when the cable has already been manufactured and changes to its length cannot be made.
Cable Assembly Design
Makai can design the cable assembly to be installed on a selected cable route. In the design of the cable assembly, Makai will consider constraints such as changing the cable type based on depth and bottom roughness, changing bottom slack based on terrain roughness, and planning the landing of the repeaters in reasonably flat portions of the route. At the end of this work, Makai will produce a Single Line Diagram (SLD) with all the cable type lengths, cable transitions and in-line bodies.
In general, the Cable assembly design is completed simultaneously with the cable route planning, especially during initial stages before the cable is manufactured. At the end, a Route Position List (RPL) that combines the route as well as cable assembly information will be created.
Preliminary Cost Estimates
The MakaiPlan software is equipped with a feature that can produce a preliminary cost estimate for the cable and the installation process. This estimate will be based on the unit costs of cable, repeaters, daily ship rates for installation and burial, and other parameters affecting the installation time and laying speeds. Upon client request, Makai can run the MakaiPlan software to produce such an estimate for a given cable route. While these estimates are very preliminary, they can used to perform initial cost-benefit analyses on various design options in the project planning phase.