Introduction to Offshore Structures - Offshore Structures: Design, Construction and Maintenance - page 14

Helideck
platform

FIGURE 1.5 Bridges connecting a helideck platform.

Heliport
The heliport is the landing area for a helicopter, so it must be large enough to
handle loading and unloading operations.
A square heliport has a side length of one and a half to two times the largest
helicopter

s expected length. The heliport landing surface should be designed
for a concentrated load of 75% of the gross weight. The impact load is two
times the gross weight for the largest helicopter, and this load must be sustained
in an area of 24

'

″ × 24 ″ anywhere in the heliport surface. Figure 1.5 shows a

heliport platform.

1.6 DIFFERENT TYPES OF OFFSHORE STRUCTURES
Different types of offshore structural systems have been developed over time
due to the requirements for obtaining oil and gas in locations that have a greater
water depth. These types of platforms are as follows.

Concrete Gravity Platform
The concrete gravity platform shown in Figure 1.6 is a concrete platform that
was constructed in 1997 for Shell.
Figure 1.7 illustrates a complex platform that consists of a production and
drilling platform connected by bridges.