IEEE 1120-2004 pdf download IEEE Guide for the Planning, Design, Installation, and Repair of Submarine Power Cable Systems
1. Overview
1.1 Scope
This guide provides a list of factors to consider when planning, designing, permitting, installing.commissioning, and repairing submarine power cable systems. While many factors are common to bothpower and communication cables, this guide focuses on power cables that cross seas, lakes. and rivers.
1.2 Purpose
The purpose of this guide is to assist engineers in developing knowledge and to assure that important itemsare not overlooked when dealing with submarine cable systems.
1.3 Preface
Submarine cables are installed in unique environments using specialized installation techniques. Someuncommon characteristics that may be encountered include:
A variety of environmental conditions, including the transitions between water and land
Challenges in gathering geophysical information
High installation and retrieval stresses on the cable
A potentially hostile marine environment during construction and repair
Human activities that do not normally threaten land cables
Even with these constraints ubmarine cables have successfully served the industry since the 1890s. Theysometimes offer a means of delivering energy and communications in a direct route that may providesuperior system benefits and higher reliability, and sometimes they cost less than other alternatives.
This guide is broken into a number of clauses that roughly follow the milestones that a submarine cableproject goes through.The milestones are commonly not sequential; for example, information will have tobe gathered so the route can be evaluated, but one must have chosen a prospective route before a surveycan be done.
2. Route selection
A number of factors must be considered when evaluating potential cable routes. Most of these factor*influence the cost,constructability, reliability, and reparability of the proposed cable system, and theyshould be weighed along with the electrical benefits to the power system.
2.1 Natural marine conditions
Below is a list of naturally occurring marine conditions that may influence the evaluation of a prospectivesubmarine cable route. Some of these conditions may vary considerably along the cable route, so anobservation at one location may not represent the entire route
2.1.1 Water depth
As the depth increases, cable-laying tensions will increase, which may influence the design of the cable andthe installation method. Route surveys may also be more difficult.
21.2 Rock and pinnacles
Laying a cable over a sharp object may kink the cable. Where the cable is suspended between two points onthe sea bottom, it may fatigue due to strumming (vortex-shedding vibration) induced by water currents.Where cable touches down, it may abrade on the bottom, especially if the bottom is hard.
2.1.3 Tidal, current, or surf action
Currents may carry silt or gravel that may abrade the cable. Strong tidal currents may wash the cable backand forth across the bottom, thus damaging it.
2.1.4 Shifting bottoms/scour
The soil under the cable may wash out, leaving the cable suspended and under high tension. Alternatively.
the cable may become deeply buried (which will affect its ampacity and its ability to be retrieved).
2.1.5 Soil structural stability
The soil composition and consistency affect the stability of the walls of cable trenches. The presence oflarge boulders, rock outcroppings, and reefs can impede the trenching, plowing, and jetting operations.
2.1.6 Marine slope stability
Underwater landslides can damage a cable system.
IEEE 1120-2004 pdf download
PS:Thank you for your support!
