Ever wondered what offshore support vessels are and what they do? If yes, this blog is for you. 

What are Offshore Support Vessels or OSVs?

Offshore support vessels or offshore supply vessels, as they are also known as, are ships specifically designed to perform many different operations. Be it working for construction and maintenance, anchor handling or platform support, these vessels provide efficient support out on the high seas. That’s, of course, the quick answer to ‘what are offshore support vessels’, but as you can imagine there’s way more to learn more about these versatile ships. So, keep reading to know more about OSVs, their way of working, applications, and position in the global maritime market.

The Types of Offshore Support Vessels 

An offshore vessel is one that serves a specific purpose such as undertaking construction work or provide assistance in oil exploration. While the term “offshore vessels” collectively denotes the class of ships that are employed for operating in the high seas, they have evolved and their operations have diversified dramatically. So today, we have several types of offshore vessels that do a lot more than just drilling and exploration. You can engage them in sending critical supplies to construction units and excavation sites on the high seas. They also allow crew personnel from offshore operational areas to be transitioned and relieved as per the necessity.

That said, OSVs can be broadly be classified into the following types:

  • Seismic survey ships
  • PSVs, or Platform Supply Vessels
  • Anchor Handling Tug Supply Vessels (AHTS)
  • Offshore Construction Vessels
  • Diving Support Vessels
  • Vessels for inspection, repair, and maintenance purposes
  • ROV Support Vessels

A Closer Look at Some OSV Types and How They Work

One of the most common OSVs is offshore supply vessels. They transport people, materials, and other important supplies between the land and ships and rigs. 

Platform Supply Vessel (PSV) is a type of offshore vessel that commonly finds application in offshore drilling as they get deployed for carrying various items such as food, stores, spare parts, equipment, and anything else that an offshore rig may need for regular operations.

A PSV starts its journey by loading up at shore. Liquid cargo is stored in double bottom tanks while special pneumatic pressure tanks hold dry cargo. Large items such as drill pipes and other drilling equipment are placed on the deck. A rig crane helps in moving deck cargo while liquid and powder cargo is loaded on to the rigs through pumps. In a typical voyage, half the time is spent in loading and unloading. Working aboard a PSV is not only challenging but also dangerous as it involves use of heavy machinery amidst difficult sea conditions.

Anchor Handling Tug Supply Vessels or AHTS perform multiple functions and can be used to assist drilling rigs in handling supply platforms, towing rigs, anchors, and mooring chains. High bollard pull is an essential feature for performing this kind of work and this is duly reflected in the vessel’s hull shape, power requirements, and propeller size. It is extremely important for this offshore support vessel type to remain stable. They must also have ample space for storing equipment and chains. Anchors and wires are passed over the stern using a stern roller to ease the operations.

Offshore Construction Vessels typically feature vast, open areas on the deck and spacious accommodations. They are built for working on large projects and are capable of remaining at the site for extended periods. The vessels are fitted with heavy lift cranes and can support both underwater as well as surface installations. Also known as Construction Support Vessels (CSV), these can be deployed for IRM – inspection, repair, and maintenance – projects too. Well-stimulation and maintenance are key responsibilities of an IRM with these OSV offshore support vessels often being remotely operated for supply operations.

Diving Support Vessel (DSV) is another of the offshore support vessel types that undertakes inspection of pipelines, wells, and platforms along with underwater maintenance activities. There are one or more holes, known as a moon pool, in the middle of the vessels through which ROVs, equipment, and divers go down into the water. While CSVs are required to hold their position to facilitate proper constructions, staying still is absolutely imperative for DSVs. The vessels come fitted with a dynamic positioning system that holds them in place through all conditions and operations.

An offshore support vessel can also be used as an escort vessel to support disabled ships through an emergency. You can also employ them for cleaning up oil spills from the ocean. Another type is the Fast Supply Intervention Vessel (FSIV) which is a smaller, faster remake of the original OSV and can be used in emergency response services or for making urgent deliveries.

There are also Seismic Survey Vessels which are specifically built for conducting seismic surveys out in the ocean. These unique carriers help identify the best areas where oil can be drilled while causing minimum disturbance to marine life. They determine the suitability of an area for drilling by shooting seismic waves and measuring the time interval between their return. Their special design often gives them an unconventional look compared to any standard OSV or ship. Seismic Vessels can also be used to study ocean geology such as trenches, rocks, and other underwater structures using sensitive equipment that are available onboard.

A Peek into the Offshore Support Vehicle Market

Given the diversity of OSVs, they not only play an integral role in the maritime industry, but their importance is ever-increasing. As of 2020, the offshore support vessel market had a valuation of around $19.4Bn that is expected to grow to $28Bn by 2027 at a CAGR of roughly 4.5% between 2022 and 2027.

However, the offshore support vessel market isn’t without its downturns. As with practically every other industry on the planet, the OSV market too faced slowdowns due to the COVID-19 pandemic with offshore drilling contracts being reduced or cancelled altogether. Nevertheless, the demand for deep-water gas and oil drilling projects is picking up pace and is expected to revive growth for the offshore support vessel industry as the projects become more viable. 

Final Words

With the need for exploring and harnessing the potentials from the high seas ever-increasing, demand for various types of offshore vessels has also been on the rise alongside. Add to that the advantages brought forth by technological research and all associated developments, and the modern global fleet of offshore supply vessels starts mirroring the huge strides that have been made across the maritime sector in recent years.