engineering

Offshore construction

Offshore construction is a engineering topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Offshore construction rather than just read about it. In short: Offshore construction is the installation of structures and facilities in a marine environment, usually for the production and transmission of electricity, oil, gas and other resources. It is also called maritime engineering.

Key takeaways

Offshore construction belongs to engineering; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Offshore construction to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Offshore construction from memory before moving on to harder problems.

Reference excerpt

Offshore construction is the installation of structures and facilities in a marine environment, usually for the production and transmission of electricity, oil, gas and other resources. It is also called maritime engineering. Construction and pre-commissioning is typically performed as much as possible onshore. To optimize the costs and risks of installing large offshore platforms, different construction strategies have been developed. One strategy is to fully construct the offshore facility onshore, and tow the installation to site floating on its own buoyancy. Bottom founded structure are lowered to the seabed by de-ballasting (see for instance Condeep or Cranefree), whilst floating structures are held in position with substantial mooring systems. The size of offshore lifts can be reduced by making the construction modular, with each module being constructed onshore and then lifted using a crane vessel into place onto the platform. A number of very large crane vessels were built in the 1970s which allow very large single modules weighing up to 14,000 tonnes to be fabricated and then lifted into place. Specialist floating hotel vessels known as flotels or accommodation rigs are used to accommodate workers during the construction and hook-up phases. This is a high cost activity due to the limited space and access to materials. Oil platforms are key fixed installations from which drilling and production activity is carried out. Drilling rigs are either floating vessels for deeper water or jack-up designs which are a barge with liftable legs. Both of these types of vessel are constructed in marine yards but are often involved during the construction phase to pre-drill some production wells. Other key factors in offshore construction are the weather windows which define periods of relatively light weather during which continuous construction or other offshore activity can take place. Safety of personnel is another key construction parameter, an obvious hazard being a fall into the sea from which speedy recovery in cold waters is essential. Environmental issues are also often a major concern, and environmental impact assessment may be required during planning. The main types of vessels used for pipe laying are the "derrick barge (DB)", the "pipelay barge (LB)" and the "derrick/lay barge (DLB)" combination. Closed diving bells in offshore construction are mainly used for saturation diving in water depths greater than 120 feet (40 m), less than that, the surface oriented divers are transported through the water in a wet bell or diving stage (basket), a suspended platform deployed from a launch and recovery system (LARS, or "A" frame) on the deck of the rig or a diving support vessel. The basket is lowered to the working depth and recovered at a controlled rate for decompression. Closed bells can go to 1,500 feet (460 m), but are normally used at 400 to 800 feet (120 to 240 m). Offshore construction includes foundations engineering, structural design, construction, and/or repair of offshore structures, both commercial and military.

Outline Mariculture Offshore aquaculture Offshore windfarm Floating solar Offshore platform Spar (platform) Tension leg platform Floating production storage and offloading (FPSOs) Oil platform Semi-submersible platform Sea fort Accommodation platform Offshore embedded anchors Offshore geotechnical engineering Offshore drilling Land reclamation Artificial island Subsea Submarine pipelines Underwater habitat

See also Commercial offshore diving – Professional diving in support of the oil and gas industry Fluid mechanics – Branch of physics Hydraulic engineering – Sub-discipline of civil engineering Hydrology – Science of the movement, distribution, and quality of water on Earth Maritime archaeology – Archaeological study of human interaction with the sea Marine biology – Scientific study of ocean life Oceanography – Scientific study of the ocean Offshore (disambiguation) Offshore geotechnical engineering – Sub-field of engineering concerned with human-made structures in the sea Offshore survey – Discipline of hydrographic survey largely concerned with the oil industry Rheology – Study of the flow of matter, primarily in a fluid state Very large floating structure – Artificial islands used as infrastructure in aquatic environments Artificial island – Island constructed by people Underwater habitat – Human habitable underwater enclosure filled with breathable gas Ocean development – Establishing of human activities at sea and use of the ocean Ocean colonization – Type of ocean claim Ring crane – Type of construction crane Underground construction – Field of engineering for the design and construction of structures below the ground Wind turbine installation vessel – Type of vessel

References

Illustrations

Worked examples

Example 1 — a first encounter with Offshore construction

Start with the simplest possible case. Write down what Offshore construction claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In engineering, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Offshore construction before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Offshore construction ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Offshore construction

In research: Offshore construction appears in engineering research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Offshore construction in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Offshore construction is common in secondary-school and first-year university syllabi. It links to neighbouring topics Coastal construction, Offshore engineering, so understanding it makes those chapters shorter.
In everyday life: Look for Offshore construction outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Offshore construction in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Offshore construction means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Offshore construction out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Offshore construction in simple terms?

Why does Offshore construction matter?

Because it connects several engineering ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Offshore construction?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Offshore construction.