20
LNG
INDUSTRY
SEPTEMBER
2014
Samsung C&T was awarded the contract to build an
additional 180 000 m
3
LNG tank at the terminal. In July 2011,
the company was again selected – this time to build the
terminal’s secondary berth and enhanced works order to
expand its facilities to increase its send-out capacity from
3.5 million tpy to 6 million tpy.
The project’s requirements necessitated engineering,
procurement, multi-discipline (mechanical, piping,
electrical) construction and other works to be performed
simultaneously. Therefore, it required an EPC firm with
sufficient expertise and experience in the related field.
Samsung C&T is experienced in building LNG terminals and
tanks in South Korea. The company combined the advanced
cryogenic tank construction expertise it had gained through
these projects with advanced planning, simulation, and
precision process management techniques to complete the
Singapore LNG terminal project on time and within budget.
The single most important process in building an LNG
terminal is the construction of tanks for storing LNG in a
cryogenic state. These tanks consist of an inner wall and an
outer wall. The outer wall is made up of 75 cm thick
reinforced concrete. The wall was constructed by using
‘jump forming’, requiring a total of 10 ‘lifts’ of the formwork
followed by 10 concrete pours. One of the most important
processes in building the outer wall is the installation of the
tank roof.
For the Singapore LNG terminal project, Samsung C&T
chose to apply a technique known as air-raising, which
involves fabricating the top inside the tank and raising the
1060 t structure to the top of the tank by introducing air into
the internals of the tank. The company first sealed all the
space between the roof and the side walls of the tank and
introduced air at a pressure of around 205 mmAq using a
blower. It then pushed the roof from the bottom to the top,
a process that took 3 hours, moving 200 mm per minute.
Another key factor when raising the roof was that it should
remain horizontal during the entire process. Thus, during
construction the company installed a weight to maintain
balance and set up a levelling wire system in approximately
30 places in order to maintain the right level.
The inner walls of the tanks were made using a special
alloy that can withstand cryogenic temperatures down to
-196°C. The alloy is 9% nickel steel, and Samsung C&T
utilised its quality management and schedule management
expertise to prevent the material from coming into contact
with moisture, magnets, and other metals throughout the
entire construction process. Stiffeners were also utilised
when installing the inner plates to prevent them from
warping and to minimise the amount of welding required,
enabling faster completion. The opening, used as the
access point for materials and manpower, was located in
the first ‘lift’ of the outer wall. Conventionally located in the
second ‘lift’, this change further enhanced the construction
efficiency and safety.
Samsung C&T commissioned the third tank and the
secondary berth independently. The company
systematically managed tasks and document handover to
Singapore LNG Corp. (SLNG), the owner of the project, for
each commissioning system using a programme developed
by the project staff.
Figure 1.
Overall view of the terminal (from the primary jetty).
Figure 2.
View of the terminal (from the secondary jetty).
Figure 3.
Panoramic view of the terminal (from the tertiary jetty).
