Page 215 - Offshore Electrical Engineering Manual

202 CHAPTER 1 Notes on Design Project Organization and Documentation

4. Electrical load list: As with any project where electrical power will be required,
a continuous review of the projected loading is necessary. This is particularly
important where the electrical system is isolated and dependent on its own
power sources to support the load. The preparation of an accurate load list often
becomes a priority early in the project, as the less accurate the system load fig-
ures are the more the risk involved in purchasing suitable generators. In any case
a good margin should be kept over estimated loadings if generator outputs are not
already restricted by weight and space limitations on the installation. The sched-
ule should indicate connected and diversified loads for all the system and genera-
tion operational states envisaged. A typical load list is shown in Fig. 3.1.12.

MATERIAL AND EQUIPMENT HANDLING AND STORAGE

Adequate, secure, warm and dry storage needs to be provided for equipment before
being called offshore. The storage facility should be local to the offshore supply base
if construction delays are to be avoided.
A goods inspection procedure is important, as it should detect damaged or incor-
rect items which can then be repaired or replaced before they are sent offshore. An
item or equipment whose damage or unsuitability remains undetected until it is being
installed can cause problems in the construction programme.
The contractors carrying out the installation work will need to store materials
offshore, so suitable containers will need to be located on the installation. The areas
where such containers are stored are known as laydown areas. Laydown areas need
to be adjacent to platform cranes so that containers and equipment can be off- and
onloaded easily from supply vessels. Crane operations need to be studied to ensure
that the risk of dropping or impacting equipment or containers on modules, particu-
larly those containing hazardous production equipment, is minimised.
Every item sent offshore should be clearly identified and marked with its gross
weight. This reduces the incidence of loads being dropped by overloaded cranes, or
mysterious packing cases arriving on some other oil company’s offshore installation
when the equipment inside is vital to the next stage of your client’s construction
programme.
Once equipment has reached the offshore installation, particularly if heavy struc-
tural work is going on, it must be protected from physical damage, shock, vibration,
ingress of dust, moisture, welding sparks and any other foreign matter until it is
permanently protected.
The manufacturer’s storage and preservation procedures must be adhered to if
warranties are to remain valid.

ERECTION PROCEDURE
An installation specification should have been produced in the design office and cop-
ies of this should be made available to those carrying out the installation and to the