INGENIEUR
● Permit limitation – environmental approval and related local work permit without impacting the start of construction ; and
● Economic impact – to improve the overall execution plan and schedule .
It is clear that the adoption of modular plant construction concept is justified , given the project site ’ s logistic envelope constraints and the need to maximise modular fabrication to the extent possible .
MODULAR LNG CONSTRUCTION CONCEPT
The modularised LNG construction concept applies positive aspects of topside modules ( process or plant modules ) – pre-treatment , liquefaction and utility that include structural , equipment , piping , electrical and instrumentation systems , fire protection , ladders and platform . Optimisation of the process of the modular construction concept against site erection ( e . g . 60 % -70 % modularisation and 30 % -40 % site erection ) for land-based development projects is determined by the site ’ s local labour costs , limitations in marine transportation , site haulage and crane facilities , and other site preparations e . g . jetty , temporary ramp , temporary heavy-duty access road , piling work for foundations , LNG storage tanks and what is generally known as Offsite Battery Limit ( OSBL ) Area .
Admittedly , the modular project is relatively complex and unique considering the design , detailed engineering , operation and maintenance requirements when compared with a site erection project . However , the higher design and engineering costs spent for the modular project can be offset by minimising the number of equipment , piping , insulation , painting , electrical and instrumentation site erection and installation , which are costlier than the modular fabrication work .
Benefits of the modular concept are :
● Higher productivity due to a controlled shipyard environment ;
● Higher quality control resulting in a good product ;
● Better fabrication schedule and production ;
● Lower construction cost , less risk and improved safety performance , and
● Lower overall project cost .
In contrast , the modular concept may have several factors requiring extra consideration , such as the early design and engineering work of the project , among them piling work for the modular foundation . Potentially , weight of structural steel will be increased upon receiving the final vendor data and equipment layout or weight . Modular Design Factors are :
● Process Engineering ;
● Process Safety Study ;
● Equipment Selection ;
● Equipment Layout and Elevation ;
● Piping General Arrangement ;
● Electrical and Instrumentation Arrangement ;
● Insulation , Coating and Painting ;
● Module Size and Weight ;
● Module Lifting Study ; and
● Operation and Maintenance Philosophy . Modular Fabrication Requirements : The shipyard ’ s fabrication or construction engineering requirements include labour , equipment , materials , construction tools and special tools supervision , inspection , quality assurance and quality control , safety services and interface co-ordination to accomplish the fabrication and outfitting of the modular .
a ) Typical Modular Fabrication Scope
● Fabrication and installation of all equipment and materials ;
● Fabrication and installation of the modules and other topside structures and appurtenances , including platforms , access ways and stairs ;
● Fabrication and installation of all required piping , piping equipment and piping supports ;
● Pre-alignment and final alignment of equipment ;
● Fabrication and installation of all buildings , maintenance facilities , laboratory ( optional ),
● Installation of all electrical and utility services ;
● Installation and hook-up of all instrumentation and control system , telecommunication systems and navigation aid systems ;
66 VOL 84 OCTOBER-DECEMBER 2020