This low cost patented device has been developed to meet the requirements of the Offshore Oil and Gas Subsea Industry. Wherever remote structural connections are required the Spring-blok is available for attaching structural elements together in a simple, reliable and robust manner. Two basic configurations are available:

Both types of units may be arranged in singles, complimentary/opposing pairs or in multiple radial arrangements. The units are retractable allowing release of the unit. The units may be either self activated on mating of the male/female units or engaged on demand using ROV intervention. The status of the locking device is clearly visible at all stages. Each unit is driven using a load rated custom designed helical spring. This will drive the pin in any orientation but will also allow subsequent ROV release.


Spring-blok is an adaptable device suitable for any self activating latching application. Alternatively the Spring-blok may be activated via a simple ROV operation if the firing of the mechanism is required to be a controlled secondary operation. The units are intended for any attachment applications including PLET arms to fix rotating mudmats , articulation arms, structural sub-assembly attachment, submerged riser connections. A wide range of pin sizes are available in bar size from 30mm to 250 diameter rated to transfer pin shear from 5 Te to in excess of 1000 Te.

We have numerous ‘off the shelf’ designs available immediately plus customised designs that can be developed at very short notice.

Key features & advantages

The key benefit of this design is the speed with which the units are developed and produced. The units are task specific and address the most demanding of Purchasers’ requirements. The designs provide tailored functional performance and load transfer design. High strength offshore rated materials and fabrication specifications plus full FAT/SIT offers quality assured performance to ensure robust trouble-free offshore operations.

For the example shown the solution was developed from enquiry to arrival in the main yard in 5 weeks and deployed and activated in a further 2 weeks in over 1000m water depth.


The fabrications are carried out under a fully implemented BS EN ISO 9001 approved Quality Management System.

The units are checked and adjusted before a fully documented FAT is carried out. The functional tests address all aspects of offshore conditions and address tolerance aspects to ensure the unit performs precisely as intended once offshore.

The units are preserved and crated prior to shipment to the Purchasers main structural fabricator.

Design & documentation

Each device is supplied with full documentation that addresses the load function and resistance of the device to the preferred structural code. The default code is API RP2A/AISC but designs are available in other National Codes.

The Spring design calculations are supplied along with drawings of the components. A fully documented Fabrication Dossier is also supplied with material certificates, ITP, Certificate of Conformance, welding and NDE procedures, coating procedures and operator certificates.

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