Review of Cabling Techniques and Environmental Effects Applicable
Review of Cabling Techniques and Environmental Effects Applicable
Review of Cabling Techniques and Environmental Effects Applicable
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Cable types <strong>and</strong> installation techniques<br />
Fronds are popular with environmental organisations as there is a perception<br />
that the indigenous substrate is being reinstated. However, experience has<br />
shown that situations such as storms, which create high energy situations on the<br />
seabed, have resulted in deposited materials around the fronds being stripped<br />
out.<br />
The installation procedure for the frond mattresses would be identical to that<br />
explained above for concrete mattresses.<br />
Uraduct<br />
Uraduct is manufactured using high performance polyurethane elastomer. The<br />
system comprises two cylindrical half shells which overlap <strong>and</strong> interlock to<br />
form close fitting protection around the core product such as cable, umbilical<br />
or flexible/rigid flowline. For ease <strong>of</strong> h<strong>and</strong>ling, the half shells are manufactured<br />
in lengths <strong>of</strong> up to 2.0 metres with flexing characteristics to suit the required<br />
minimum bend radius <strong>of</strong> the product or ancillary shipboard lay equipment.<br />
The half shells are secured in place using corrosion resistant b<strong>and</strong>ing located<br />
in recessed grooves to ensure a smooth external pr<strong>of</strong>ile. A range <strong>of</strong> sizes is<br />
available to support product outside diameters ranging from 15mm to 450mm<br />
<strong>and</strong> beyond.<br />
Uraduct comes in varying sizes <strong>and</strong> stiffnesses to resist different levels <strong>of</strong> impact<br />
<strong>and</strong> is <strong>of</strong> particular use at cable crossing points or in areas close to structures, such<br />
as <strong>of</strong>fshore wind turbine support structures or <strong>of</strong>fshore oil <strong>and</strong> gas installations,<br />
where the risk from dropped objects is high. Uraduct is not commonly used<br />
along longer sections <strong>of</strong> cable which has been inadvertently surface laid on the<br />
seabed as it does not <strong>of</strong>fer any further protection from trawling gear or anchors<br />
<strong>and</strong> only increases the target size.<br />
Articulated metal shell connectors<br />
Articulated metal shell connectors are typically used to provide cable sections<br />
with added mass <strong>and</strong> abrasion resistance in high energy environments such as<br />
a cable shore l<strong>and</strong>ings, which pass over rock outcrops <strong>and</strong> where other forms<br />
<strong>of</strong> cable burial are not possible. The articulated sections would be applied by<br />
surface divers in half sections which are then locked or bolted together to form<br />
a continuous pipe section.<br />
Directional drilling<br />
Directional drilling is employed by cable installation contractors when the<br />
topography <strong>of</strong> a l<strong>and</strong>fall site makes it difficult to achieve a conventional l<strong>and</strong>fall<br />
by trenching, or where there are environmental interest features that need to<br />
be avoided such as saltmarsh or chalk cliff. Directional drilling provides a very<br />
useful alternative, as it allows the cable installation to bypass the critical areas<br />
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