BSI Rigging Introduces Hydraulic Sail Control Cylinder Range

Danish specialist BSI Rigging has announced that it will introduce a standard range of hydraulic cylinders at METSTRADE 2026. The company's 11 November announcement identifies four families of sail-control components, including single-acting rams, single-acting and double-acting vangs, and single-acting rams incorporating mechanical locks. The first product in the new range will be presented at the BSI Marine Equipment Group stand 12.740 at RAI Amsterdam from 17 to 19 November.

The development is particularly relevant to the custom sailing yacht industry because hydraulic sail controls require coordination between the rig designer, yacht builder, hydraulic equipment supplier and service organisation. BSI already supplies wire and rod rigging, and Ulf Josefsson, who works in its worldwide superyacht and custom sales activity, describes the cylinder range as an addition that its certified service centres, dealers and agents can now offer. The company has not published a complete technical catalogue, pricing or the specifications of individual completed installations in its announcement.

A hydraulic cylinder is part of a load-bearing system

Hydraulic actuation permits a relatively compact component to exert substantial force, making it useful in applications where large sails and highly loaded spars must be adjusted from a controlled operating position. A yacht's hydraulic system may be responsible for moving equipment that remains under considerable tension during manoeuvres. The cylinder, its attachments, hydraulic power source and control arrangements therefore need to be considered together with the rig and the structure that supports it.

The required force depends on the intended application, the geometry of the installation and the conditions under which the device is expected to operate. A cylinder's quoted capability cannot by itself establish whether the device is suitable for an individual yacht. The equipment designer must understand how the resulting loads are transmitted to the relevant spar and the yacht's structure, including the consequences of using the cylinder near the limits of its movement. BSI's announcement describes a range of components rather than a universal installation specification.

Understanding single-acting and double-acting arrangements

The new range includes single-acting rams and both single-acting and double-acting vangs. In general engineering terms, a single-acting cylinder uses hydraulic pressure to produce force in one direction, with return movement achieved through another force or arrangement. A double-acting cylinder can use hydraulic pressure to produce movement in both directions. The two configurations offer different possibilities for system design, and their suitability depends on the actual loads and control functions required.

A purchaser should establish the hydraulic pressures, fluid volumes, stroke lengths, response times and operating limitations of the specific component under consideration. The way the device interacts with other equipment also matters. A cylinder suitable for one sail-control application may not be suitable elsewhere on the same yacht. These requirements should be defined by the responsible engineers rather than inferred solely from broad categories in a supplier's product announcement.

The vang and the behaviour of the sailing rig

A vang is an important part of the arrangement for controlling a sailing yacht's boom. Its design and use depend on the rig configuration and the interaction between the sail, boom and other control systems. A component used for this purpose may experience changing loads as sail settings, wind conditions and yacht manoeuvres vary. The relevant attachment geometry influences the force required from the actuator and the forces transmitted into the surrounding structure.

For a yacht with a sophisticated custom rig, any proposal to replace or upgrade an existing vang should consider the whole load path. Changes in the dimensions of the hydraulic cylinder or in its available stroke may affect the positions that the boom can reach. Compatibility with existing fittings cannot be assumed without checking the actual installation and the approved design. BSI says its new range will include vangs in several designated sizes, but the announcement does not contain the detailed dimensional drawings needed to establish suitability for a particular vessel.

The place of a mechanical locking arrangement

BSI includes single-acting mechanical-lock rams within its standard range. A mechanical locking feature can serve a different function from maintaining hydraulic pressure alone. Depending on the equipment design, it may provide a means of retaining a defined position through mechanical engagement. The exact behaviour of a particular locking device must be established from the product's technical documentation and the way it is installed.

The crew will need to understand when the mechanism is intended to engage, how engagement is confirmed and what procedures apply if the system requires servicing. Designers should also investigate the consequences of a loss of hydraulic pressure or electrical control and establish the required safe behaviour of the equipment. The company's announcement does not describe the new rams' locking mechanism, holding-force ratings or release procedure in detail. Those matters are important specifications for a technical consultation, not features that can be assumed from the product name.

Incorporating new components into an existing yacht

Retrofitting a hydraulic sail-control cylinder is a different proposition from specifying one during the original design of a sailing yacht. An existing installation may have particular constraints on the available mounting space, service access, hose routes and compatibility with the hydraulic power unit. A replacement should be assessed against the original drawings and the current condition of the rig, including any modifications completed since delivery.

The technical team should also examine how the component can be safely accessed during installation and periodic maintenance. Changing the physical position of an attachment point, for example, may influence the loading of other components. An apparent benefit in cylinder packaging or actuation force should not be taken as evidence that a change is acceptable without the appropriate engineering assessment. This is especially relevant to large custom sailing yachts whose equipment may have been designed as part of an individual project rather than for interchangeable installation across an entire series.

Materials, corrosion and hydraulic maintenance

BSI describes the products as intended for demanding marine environments. Such an operating environment raises questions about surface protection, the compatibility of materials, the exclusion of contaminants and the accessibility of hydraulic connections. Equipment exposed on deck can be subjected to salt water, spray and substantial variations in temperature, while the yacht's motion can create additional mechanical demands.

Appropriate maintenance procedures need to be based on the manufacturer's instructions for the selected cylinder, together with the requirements of the complete system. Owners should establish the recommended inspection arrangements, availability of seals and other replacement parts, and the conditions under which a component should be removed for specialist servicing. A yacht undertaking extended voyages may benefit from knowing which services can be obtained in its intended cruising regions. The release does not supply individual maintenance intervals or make a quantified durability claim.

The commercial importance of the service network

The new range is intended to be available through BSI Rigging's existing certified service centres, agents and dealers. For a superyacht manager, such a network can be relevant to the lifetime cost of the equipment. A component that can be specified and purchased easily still requires appropriate support during the years that it remains in operation. Availability of drawings, technical advice, replacement parts and personnel familiar with the system can influence the practical value of a supplier relationship.

The introduction of a standard range may also simplify preliminary discussions about equipment selection. It does not remove the need to establish compatibility with a specific yacht, nor does it necessarily make every size immediately available in every region. Owners considering new sail-control packages should request written information about the product selected, the service arrangements and the responsibilities of the parties involved in installation and commissioning.

Technical discussions at METSTRADE

The manufacturer's announcement identifies four particular groups: single-acting rams designated from -6 to -60, single-acting vangs from -10 to -91, double-acting vangs from -40 to -91, and mechanical-lock single-acting rams from -12 to -91. The designations are reported as published by BSI and should not be interpreted as specific force or pressure ratings without the associated technical catalogue. Journalists can contact Lou Johnson at lou@boxpr.co.uk as identified in the official announcement.

The Amsterdam presentation provides an opportunity for rig designers, captains and management teams to discuss the product range with the supplier. For the superyacht market, the development expands the range of hydraulic equipment that an established rigging specialist intends to offer through its network. The significance of the individual products will depend on their technical specifications, integration and service capabilities when selected for an actual yacht. Those are the considerations that should guide any subsequent purchase or refit decision.

Primary source: BSI Rigging official METSTRADE announcement, 11 November 2026.

BSI Rigging service programme — official manufacturer illustration of existing rigging. Official source.