Onshore Energy Conference — Dubai Onshore Energy Conference — Dubai 02 | Page 36

CURRENT THOUGHT
HV UNDERGROUND CABLE INSTALLATIONS
W
e see HV underground cable
claims either as first party claims
as a result of damage caused
during erection or installation or as TPPD
claims. This note concerns the former.
HV Cables are generally laid in about
500 metre spans between substations with
joint bays making the connections to cover
the distance. The joint bay is usually a buried
concrete box enclosure. A 400kV cable with
a single conductor will weigh around 26
tons net of its drum, ie about 52kg/metre.
HV cable values are very high not least
because a significant part of the weight
is made up of the copper conductor.
When damage occurs, as often as not,
it is located somewhere in a span but
distant from an existing joint bay.
Unless there are local ground conditions
which prevent it, it should generally be possible
to consider jointing the cable at the damage
location using a single straight through joint.
However, it is invariably the case that the
construction contract does not
permit the insertion
36
By John Kidd
of an extra joint in a span that was not
designed to be there in the first place. As
a result the Contractor has to replace the
complete span from joint bay to joint bay.
The considerable cost involved in that
replacement becomes the Contractor’s
claim against the CAR/EAR policy.
The question Adjusters are faced with
in such circumstances is whether Insurers
should pay for the replacement span or
only for the notional joint repair cost?
Leaving aside the contractual obligations,
the Contractor will generally make the case
that an extra joint is a weak point to be
avoided. I am not particularly impressed with
that argument as in, for example, a 5 km route
there would already be 10 joints and in a 10
km route 20 joints. I am not convinced that one
extra joint in the route makes any difference.
I have yet to see a claim for a failed joint, so I
think the premise that a joint is a weak point
may be more illusory than real in practise.
Another aspect that is difficult to reconcile
is that we know that once a cable route
is taken over by the utility if,