Tight Radius System (TR31) Installed on S-RIBS Custom Boatbuilding Vessel

Market: Commercial marine

Location: Russia, Black Sea

Project Description: S-RIBS Custom Boatbuilding specializes in commercial craft and custom boatbuilding, using the latest high-tech marine materials.  Operating from their headquarters in Russia, the company works with clients and customers all around the globe and cooperates with a wide range of world-leading companies.

S-RIBS Custom Boatbuilding needed a secure system on one of their multi-purpose commercial vessels, so that crew and pilots could tether to the boat and avoid falling overboard.

The proposed system had to look professional when installed, as well as be safe and reliable, without restricting the existing space available on the boat. In order to maximize safety, the system was required to go around the sides and the bow of the vessel to give crew full and secure access when onboard.

A further challenge was to complete the installation without obstructing the pilot’s view when the vessel was in operation.

Solution/Equipment Used:

With a strong heritage in the sailing world, Harken Industrial™ constantly builds on this knowledge to design and manufacture products for the commercial marine and industrial industries.

To help S-RIBS Custom Boatbuilding resolve their requirements noted above, Harken Industrial suggested the Tight Radius System (TR31) as the perfect solution. This moveable anchorage point, designed for fall arrest applications, was chosen for a number of reasons, including:

  • Rails can be bent up to a 350 mm (13.8") radius in a vertical or horizontal plane to accommodate the directional changes needed at the bow of the vessel.
  • Trolleys are strong and durable: tested to 1200 kg (2645 lb).
  • Rails and Trolleys are made of high-strength marine grade 6061-T6 aluminum.
  • Pre-bent sections come in 30°, 45°, 60° and 90° bends, in both vertical and horizontal planes.
  • The design of the trolley and rail allows for minimum intrusion on narrow decks and restricted work areas on the boat.
  • Delrin® roller bearings offer low friction and smooth movement when users are tethered to the trolley.
  • The solution is CE certified under EN795.2012, meets ANSI Z359 and is OSHA compliant

Countersunk M10 fasteners were used for a flush fit, with the rail installed to the lower section of the bow so the pilot’s vision isn’t obstructed.

Attachment of the TR31 to the boat is achieved by using custom mounting brackets, with an unsupported rail span of up to 1.3 m between anchorage brackets in this configuration.

Client Testimonial:

“The TR31 system proposed to us by Harken Industrial ensures that crew and pilots can tether to the vessel and safely move around the boat without having to worry about falling in the water. The equipment is incredibly easy to use, is strong, plus it doesn’t restrict access around the boat or the pilot’s view when in operation.”

“This practical and efficient innovation can make all the difference when it comes to keeping crew safe. Installation was easy to achieve and the service from Harken Industrial in order to meet our needs and expectations has been excellent.”

Artashes Uliyanov, project manager, S-RIBS Custom Boatbuilding


Due to its strength and the ease of movement when tethered to the equipment, the TR31 is a popular choice for many operating on workboats and pilot vessels in the commercial marine industry.

The ability for this solution to accommodate corners and directional changes makes the system versatile and ensures that the equipment isn’t restricted to one type of vessel.