Blue Queen (Kasteelborg)

New name: Kasteelborg. Originally delivered as a medium-sized platform supply vessel of the PX121 design, the vessel has been converted to a Walk-to-Work emergency response and rescue vessel, W2W ERRV, for the inspection and maintenance of unmanned platforms.

Vessel type

Platform supply



Built by

Ulstein Verft AS



Yard number


Designed by

Ulstein Design & Solutions AS

Ordered by

Blue Ship Invest

Operated by

Wagenborg Offshore

IMO Number


Principal dimensions

83.4 m
18.0 m
Dead weight:
4065 tonnes
6.69 m
15.8 kn
22 people
Deck area:
850 sqm

Note: Subject to selected variant configuration


Fuel oil:
1461 cbm
Fresh water:
1061 cbm
Ballast water/drill water:
1664 cbm
Liquid mud (,8t/m3):
1293 cbm
Brine (,5t/m3):
1293 cbm
Cement (4 tanks):
254 cbm
LFL* (4 tanks):
155 cbm
Base oil:
254 cbm
1015 cbm


  • DNV 1A1
  • Offshore Service Vessel Supply
  • SF
  • EO
  • COMF-V(3)C(3)
  • LFL*
  • DK(+)
  • HL(2.8)
  • ICE-C

Featured solutions

Ship history

In total, 30 vessels of this design have been contracted by different ship owners for construction at various shipyards world-wide. ‘Blue Queen’ was the 9th being constructed at Ulstein Verft, and is the sister vessel to 'Blue King'.

Named at Ulstein Verft, lady sponsor Dagny Wærdahl.

In 2015, the vessel received the highest ESI (Environmental Ship Index) score of 100 points from the World Port Climate Initiative (WPCI).

2017: Entered into a 6-year contract for Wagenborg Offshore, to support the Nederlandse Aardolie Maatschappij (NAM) and SHELL UK Exploration & Production (Shell UK) with their offshore maintenance operations in the Southern North Sea. Ulstein Design & Solutions AS performed weight estimates based on ship's data and data for the new components including the accommodation block, the Motion-compensated crane and the Motion-compensated gangway, and also carried out stability calculations, motion analysis and heel test.

December 2017:
The vessel arrived at the shipyard Royal Niestern Sander, Holland for conversion from a standard platform supply vessel to a walk to work emergency response and rescue vessel: W2W ERRV.

7 March 2018: The converted vessel was put into service. After conversion, the vessel has had the accommodation facilities expanded by installing an additional accommodation and emergency response unit on deck. A motion compensated gangway system, a heave compensated crane and a daughter craft and fast rescue craft have been installed, as well as hose reels for chemical transport. Kasteelborg will support the offshore activities on the southern North Sea under a 6-year contract with the Nederlandse Aardolie Maatschappij (NAM) and SHELL UK Exploration & Production (Shell UK). The so-called 'Walk-to-Work Emergency Response and Rescue Vessel' (W2W ERRV) provides maintenance services for unmanned platforms in the Southern North Sea.

25 October 2018: Naming of the 'Kasteelborg' by Mrs. Marjan van Loon, CEO Shell Netherlands. Using walk-to-work vessels for their maintenance operations allows Shell and NAM to 'decomplex' their infrastructure, reducing their overall costs of producing hydrocarbons from the Southern North Sea.

Please contact us for more information

Ulstein Shipping AS

P. O. Box 158,
NO-6067 Ulsteinvik

Tel: +47 7000 8000