Allseas is an international offshore contractor specialising in the execution of large and complex projects, covering pipeline installation, platform installation and removal, and the installation of subsea infrastructure.
The company provides support to clients already in the conceptual design stage and offer services for project management, engineering, fabrication, procurement, installation and commissioning.

The Allseas Group is headquartered in Châtel-Saint-Denis, Switzerland.
Allseas Engineering B.V. with offices in Delft, Eindhoven and Enschede, the Netherlands, provides project management and engineering services to the group.
The company also operates project and engineering offices out of Australia, Brazil and the USA.

Allseas operates a versatile fleet of specialised heavy-lift, pipelay and subsea installation vessels designed and developed in-house.
The company has installed over 20,000 km of subsea pipeline worldwide using S-lay technology, with diameters ranging from 2” to 48”.
Allseas’ launched its first vessel Lorelay, the world's first pipelay vessel to operate on full dynamic positioning, in 1986.

In 1998, Allseas added the 300-metre (980 ft) Solitaire to its fleet.
The vessel has a pipe carrying capacity of 22,000 t and has achieved pipelay speeds in excess of 9 kilometres per day (5.6 mi/d).
In 2006, while working on the Atwater Valley and Independence Trail projects in the Gulf of Mexico, Solitaire set new depth records, laying 10-inch pipeline in 2775 m (9100 ft) water depth and 24-inch pipeline in 2550 m (8370 ft) water depth.

Allseas’ Pioneering Spirit is the world's largest construction vessel, designed for the single-lift installation and removal of large oil and gas platforms and the installation of record-weight pipelines.

Pioneering Spirit set a new offshore lift record with the single-lift removal of Shell's 24,200 t Brent Delta topsides in April 2017.
 For its first commercial job, the vessel removed the 13,500 t Yme mobile offshore production unit from Norwegian waters for Repsol in August 2016.
Pioneering Spirit’s started its first pipelay job, installation of the offshore section of the TurkStream pipeline in the Black Sea, in June 2017.

Allseas has committed to building an even larger version of the same design, Amazing Grace, which is scheduled to be delivered in 2022.
Allseas is an international offshore contractor specialising in the execution of large and complex projects, covering pipeline installation, platform installation and removal, and the installation of subsea infrastructure. The company provides support to clients already in the conceptual design stage and offer services for project management, engineering, fabrication, procurement, installation and commissioning.
The Allseas Group is headquartered in Châtel-Saint-Denis, Switzerland. Allseas Engineering B.V. with offices in Delft, Eindhoven and Enschede, the Netherlands, provides project management and engineering services to the group. The company also operates project and engineering offices out of Australia, Brazil and the USA.
Allseas operates a versatile fleet of specialised heavy-lift, pipelay and subsea installation vessels designed and developed in-house. The company has installed over 20,000 km of subsea pipeline worldwide using S-lay technology, with diameters ranging from 2” to 48”. Allseas’ launched its first vessel Lorelay, the world's first pipelay vessel to operate on full dynamic positioning, in 1986.
In 1998, Allseas added the 300-metre (980 ft) Solitaire to its fleet. The vessel has a pipe carrying capacity of 22,000 t and has achieved pipelay speeds in excess of 9 kilometres per day (5.6 mi/d). In 2006, while working on the Atwater Valley and Independence Trail projects in the Gulf of Mexico, Solitaire set new depth records, laying 10-inch pipeline in 2775 m (9100 ft) water depth and 24-inch pipeline in 2550 m (8370 ft) water depth.
Allseas’ Pioneering Spirit is the world's largest construction vessel, designed for the single-lift installation and removal of large oil and gas platforms and the installation of record-weight pipelines.
Pioneering Spirit set a new offshore lift record with the single-lift removal of Shell's 24,200 t Brent Delta topsides in April 2017.  For its first commercial job, the vessel removed the 13,500 t Yme mobile offshore production unit from Norwegian waters for Repsol in August 2016. Pioneering Spirit’s started its first pipelay job, installation of the offshore section of the TurkStream pipeline in the Black Sea, in June 2017.
Allseas has committed to building an even larger version of the same design, Amazing Grace, which is scheduled to be delivered in 2022.
Allseas