ROSON-ST for safe and fast CPTs

Safe and efficient offshore operations with the ROSON-ST

The ROSON-ST is a compact, electrically powered Cone Penetration Testing (CPT) system that is deployed directly on the seabed. It has been specifically developed for CPT investigations, a geotechnical testing method that provides detailed insight into subsurface soil conditions.

What truly sets the ROSON-ST apart is its fully autonomous operation. Unlike traditional CPT systems, no external support of the CPT string is required. Thanks to its innovative design with integrated SingleTwist™ rods, the system delivers straight and continuous CPTs while operating more safely, faster, and with significantly reduced manual intervention.

The advantages at a glance

The ROSON-ST has been developed to make offshore Cone Penetration Testing (CPT) safer, more efficient, and more reliable. Its key advantages include:

• Operational safety
  The ROSON-ST eliminates the need for external support and handling of the CPT string, significantly reducing risks during offshore operations.

• Rapid deployment
  The system can be deployed quickly from virtually any vessel and increases production output by more than 30%.

• Continuous CPTs
  Ø 40 mm CPT rods ensure straight, stable, and continuous penetration of the seabed, even at great depths or in hard soil layers.

• Flexible deployment
  Designed for use on a wide range of vessels, including vessels of opportunity. No dedicated vessel modifications or fixed installations are required.

• CPT capacity

• The ROSON-ST supports CPT depths from 0 to 80 meters, making it suitable for a broad range of geotechnical applications.

• Deepwater capability
  The system operates reliably in water depths of up to 4,000 meters.

• Robust design for harsh environments
  Engineered for durability and reliability under extreme offshore conditions, the ROSON-ST is ideal for long-term use, even in severe weather.

• FO interface for data and integration
  An integrated fiber-optic (FO) interface provides a fast and stable 1,000 Mb Ethernet connection, enabling seamless integration of additional equipment such as cameras, beacons, and sensors, and offering ample expansion possibilities for future applications.

ST-rods: the rollable CPT string

The patented SingleTwist™ technology forms the heart of the ROSON-ST system. ST-rods are designed to operate in two states:

• Loose (relaxed): In the loose state, the rods behave like a string of pearls. This allows them to be easily rolled up and stored on a reel, enabling compact handling and fast deployment.

• Fixed (twisted): In the fixed state, the rods form a strong, rigid sounding string comparable to conventional AR tubes, providing the stiffness required for accurate and continuous CPTs.

The transition between the loose and fixed states is achieved through a short rotation using a self-aligning bayonet thread mechanism. This allows the rods to connect smoothly and lock securely with just one turn. The name SingleTwist™ directly refers to this smart and efficient locking principle.

The ROSON-ST system consists of three intelligent core components:

• Folder – smoothly unrolls and rolls up the ST-rods.

• Sprocket – ensures correct positioning and synchronization of the rods.

• Twister – locks the rods together with a single turn, creating a rigid CPT string ready for precise and reliable testing.

Together, these components enable fast, safe, and continuous CPT operations on the seabed.

Easy operation

The system is operated intuitively via a single touchscreen interface and is fully compatible with the versatile Icone data acquisition system. It supports the complete range of 5, 10, and 15 cm² CPT cones, including the 10 cm² pressure-compensated deepwater cone, as well as all click-on modules for Seismic, Vane, Conductivity, and Magneto testing.

Specifications ROSON-ST

The ROSON-ST is available in two versions:

• ROSON-2D-ST – Standard version with 140 kN pushing force, suitable for most offshore projects.

• ROSON-3D-ST –Heavy-duty version with 200 kN pushing force, for projects with high soil resistance or requirements for deeper CPTs.

Standard delivery
The ROSON-2D-ST and ROSON-3D-ST come standard with:

• Lifting frame

• Service unit

• Sheave block

• Umbilical

• Control box

• Winch

Optional equipment

• Guiding mast, available in lengths of 3.4, 6, and 10 m.

• Various ballast options, skirt also possible.

• Seismic version.

ROSON-ST in the spotlight