Offshore Supply Vessels (OSVs): Overlooked Hazards & Worker Injuries

Offshore supply vessels (OSVs) play a fundamental role in the oil and gas industry, ensuring that offshore platforms—whether oil rigs, wind farms, or drilling sites—receive the supplies and support they need to operate around the clock. While these vessels may not command the same attention as drilling rigs or cargo ships, they play an essential role in keeping offshore operations running smoothly.

Here, we will take a closer look at the vital role of OSVs, the range of ship types that fall under this category, and the specific risks crew members encounter. Although these vessels are essential for exploration, production, and renewable energy work, it’s important to acknowledge—and address—the potential dangers that come with the territory.

Looking into the World of OSVs

According to the U.S. Coast Guard, an offshore supply vessel is a ship propelled by machinery other than steam, over 15 gross tons, that does not meet the definition of a passenger vessel. OSVs carry goods, supplies, and personnel in support of offshore mineral or energy resources. They’re versatile, nimble, and—by design—capable of handling specialized tasks in often unforgiving maritime environments.

While the origins of OSVs were simple—transporting equipment and workers to offshore facilities—they’ve evolved into complex, highly specialized vessels. Modern OSVs may boast dynamic positioning systems, large open decks for cargo, and powerful winches or cranes for anchor handling and towing operations. 

There are many types of OSVs, each tailored to support different aspects of offshore work:

Supply OSVs

• What They Do: Transport vital cargo—like drilling equipment, dry bulk, liquid mud, water, and fuel—to offshore rigs and platforms.
• Key Features: Often feature dynamic positioning for precise station-keeping, along with large open decks and below-deck tanks for liquids.

Support OSVs

• What They Do: Provide specialized services such as operating remotely operated vehicles (ROVs) and carrying out seabed tasks like riser or jumper connections.
• Key Features: Usually larger than basic supply vessels, equipped with advanced tech to manage complex underwater operations.

Anchor Handling Tug Supply (AHTS) Vessels

• What They Do: Towing and positioning mobile offshore drilling units or floating facilities, as well as laying mooring lines.
• Key Features: Strong winches, open decks for anchor equipment, and the capacity to handle standard OSV tasks when not performing anchor-handling.

Dive Support OSVs

• What They Do: Enable commercial dive operations for underwater maintenance, repairs, or inspections.
• Key Features: Dynamic positioning or mooring systems keep them stable while divers work below.

Accommodation OSVs

• What They Do: House additional personnel near offshore installations, essentially serving as “floating hotels.”
• Key Features: Deck modifications, living quarters, and sometimes dynamic positioning to maintain a steady position next to rigs.

Fracture/Stimulation OSVs

• What They Do: Equipped to perform well fracturing or stimulation services, increasing production in oil and gas wells.
• Key Features: Carry specialized pumps and chemicals under strict hazardous materials regulations.

Lift Boats

• What They Do: Position themselves by lowering retractable legs to the seafloor, creating a stable platform for construction, repair, or accommodation.
• Key Features: Limited by water depth, as the legs must fully extend for safe operation.

Crew Boats & Utility Vessels

• What They Do: Transport personnel, equipment, and sometimes light cargo.
• Key Features: Typically faster than larger OSVs, often built from aluminum, and capable of speedier runs between shore bases and offshore sites.

Standby Vessels

• What They Do: Assist offshore installations or rigs with emergency evacuations, rescue, and secondary lifesaving support.
• Key Features: Carry extra emergency gear and remain on standby to augment platform safety measures.

Large OSVs

• What They Do: Similar to standard OSVs but built on a much grander scale (6,000 gross tons or more), handling bigger, heavier loads.
• Key Features: Inspected under specific regulations, designed to manage massive cargo operations.

Crew Transfer Vessels (CTVs)

• What They Do: Carry technicians and personnel to offshore wind farms—an increasingly vital part of the energy sector.
• Key Features: Typically smaller, fast-moving vessels often constructed of aluminum and inspected under multiple categories.

While these vessels differ in form and function, they share one defining purpose: to maintain offshore operations. 

Common Hazards on Offshore Supply Vessels

Like any vessel, working on or being transported by an OSV may present risks. The motion of the ship, the handling of heavy cargo or equipment, and the challenges posed by unpredictable seas can lead to serious hazards. When shipowners and operators fail to put safety first, these hazards can result in accidents that leave crew members and passengers with serious injuries. Some OSV incidents are fatal. 

Offshore supply vessel accidents may involve:

• Deck Slips & Falls: Constantly moving decks—exposed to water, oil, and other slick substances—make OSVs high-risk zones for slip-and-fall accidents. This can result in a crew member falling overboard or suffering a severe injury on deck.
• Crane & Cargo-Handling Accidents: On many OSVs, cranes move oversized or oddly shaped equipment, often in rough waters. If these machines malfunction or if rigging procedures aren’t strictly followed, crew members can be struck by swinging loads, crushed by shifting cargo, or even swept off the deck.
• Hazardous Material Exposure: Fracture/stimulation vessels, as well as general supply OSVs, may carry chemicals, fuel, or other volatile substances. Poor storage, mishandling, or leakage can put the crew at risk of toxic fume inhalation, chemical burns, or catastrophic fires and explosions.
• Adverse Weather: OSVs often operate year-round, sometimes in storms, strong winds, or heavy seas. Severe weather can destabilize cargo, reduce visibility, and heighten the risk of collisions, grounding, or capsizing.
• Equipment Failures: From complex DP (dynamic positioning) systems to basic engine components, mechanical breakdowns can escalate into emergencies. If the OSV loses power or propulsion, crew members may find themselves adrift or powerless against the elements.

The Consequences for OSV Workers

When these hazards turn into incidents, the fallout can be devastating. Injuries sustained on OSVs often involve crushed limbs, head trauma, or severe burns—any of which can end a maritime career in an instant. Workers face not only the physical pain of recovery but also the emotional and financial toll of being temporarily or permanently sidelined. In worst-case scenarios, the offshore supply vessel becomes a scene of tragedy, leaving families grappling with the sudden loss of a loved one. 

Whether the cause is an improperly maintained crane, inadequate safety drills, or a slip on a wet deck, the aftermath can fundamentally change the course of a worker’s life—and that of their family.

Advocating for Safety

OSVs may differ in design and purpose, but they share a common, urgent need for strong safety practices. Regular maintenance, specialized training, and reliable communication systems can dramatically reduce the risks crew members face every day. Creating a culture of safety extends beyond meeting regulatory obligations. It involves real, on-the-ground changes—from updating safety gear to enforcing mandatory breaks that keep workers rested. Maritime employers who prioritize these measures not only prevent accidents but also cultivate trust among their crews—a factor that leads to smoother, more efficient operations overall. 

Employers must recognize the gravity of these hazards and act decisively—because no operational schedule or profit margin is worth the cost of a life.

##Arnold & Itkin is a nationally known maritime firm that has helped after every offshore disaster in the last 20 years. The firm’s attorneys represented one-third of the Deepwater Horizon crew after the rig exploded and sank in April of 2010, helped widows find justice after the El Faro was lost in Hurricane Joaquin in 2015, and has helped workers and families after all types of maritime incidents across the United States and in international waters. The firm has won more than $20 billion in verdicts and settlements by outworking and outthinking the largest corporations and their teams of attorneys.