Tight Radius System (TR31)

Work Securely and Safely

The Tight Radius rail and trolley system is designed to work as a moveable anchorage point for fall restraint applications.

Rails are composed of straight and curved sections that change direction in both horizontal and vertical planes, allowing trolleys to run exceptionally smoothly around very tight radii and joints.

The system is independently tested and is compliant with EN795.2012 Type D, meets ANSI Z359 and is OHSA compliant.

How Does it Work?

The TR31 continuous rail and trolley system allows a fully-harnessed crew member, safely tethered to the trolley, to move freely along the rail during inspection and maintenance, or when assisting in pilot transfer.

Rails can be either surface or stanchion mounted and are designed so the user never has to unhook and rehook the tether as he moves around the deck.


Trolley Design

Strong: tested to 1200 kg (2645 lb) complies with 2 x MCA requirements

Compact: minimum intrusion on narrow deck and restricted work areas

Multidirectional load bearing

Anodized for maximum corrosion resistance

rail design

Rail Design

Vertical and horizontal operating planes

1.3 m unsupported span

200 mm radiused sections are standard. Straight track can be bent to a 350 mm radius or larger.

High-strength, marine grade 6061-T6 aluminum rail

Anodized for maximum protection

Countersunk M10 fasteners for flush fitting

rail design


Trolleys and rail are available in black or clear-anodized finishes for maximum corrosion protection.


delrin roller bearings

Delrin® Roller Bearings

No lubrication required

Low friction

Smooth movement

Roller fully supported on both ends

Brake Trolley Design

Screwpin on trolley keeps it in position when not in use

Installation and Maintenance

The system can be installed either at initial build or as a retrofit. Flush clean with fresh water and mild detergent. It is important to clean the trolley. Excessive build-up of grease, dirt, and salt will affect trolley movement.

Rail Bends:200 mm Radius

Part No.

Horizontal Bend

Part No.

Vertical outside bend 

IN203.CLEAR* IN206.CLEAR* 30º bend
IN205.CLEAR* IN208.CLEAR* 45º bend
IN204.CLEAR* IN207.CLEAR* 60º bend
IN201.CLEAR* IN202.CLEAR* 90º bend

*To order in black hardcoat-anodized aluminium, remove “.CLR or .CLEAR” from end of part number.

TR31 Rail & Accessories

Description Bend Information Bend Radius Arc Length** Weight Fasteners
mm ft/in m lb g mm
IN209.3M.CLEAR* Straight rail section Straight 200 9′ 10 1/16″ 3 8.47 3840 M10
IN213.3M.CLEAR* Straight rail section without holes Straight 200 9′ 10 1/16″ 3 8.49 3850
IN203.CLEAR* Corner track Horizontal 30° 200 6 11/16″ 0.17 0.57 260 M10
IN205.CLEAR* Corner track Horizontal 45° 200 8 11/16″ 0.22 0.77 350      M10
IN204.CLEAR* Corner track Horizontal 60° 200 10 5/8″ 0.27 0.98 440 M10
IN201.CLEAR* Corner track Horizontal 90° 200 14 3/16″ 0.36 1.39 630 M10
IN206.CLEAR* Corner track Vertical 30° 200 7 1/16″ 0.18 0.60 270 M10
IN208.CLEAR* Corner track Vertical 45° 200 9 1/16″ 0.23 0.81 370 M10
IN207.CLEAR* Corner track Vertical 60° 200 11″ 0.28 1.03 470 M10
IN202.CLEAR* Corner track Vertical 90° 200 15 5/16″ 0.39 1.46 660 M10
548 Endstop set (2.83″/71.8 mm) 0.13 60
IN211 Splice link 0.50 230

*To order black hardcoat-anodized, remove .CLEAR from end of part number. ** Arc length is to the inside of the radius.

TR31 Trolleys

Description Length Width Weight
in mm in mm lb g
IN210.CLEAR* Trolley 2.63 66.8 2.06 52.32 0.56 254
IN212.CLEAR* Brake Trolley 2.73 69.2 2.6 66.04 0.60 270

*To order black hardcoat-anodized, remove .CLEAR from end of part number.

Contact Harken Industrial

If you would like further information on this product, please contact us: info@harkenindustrial.com or +44 (0)1590 689122.


Delrin is a registered trademark of E.I du Pont de Nemours and Company or its affiliates.

Product Video

Q: I already work with a rail system. Do I need additional training to work with the Harken Industrial TR31?

A: Skills learned for use with alternative rail systems are transferable. However, a short training session to familiarize yourself with the Harken Industrial system is required to ensure safe installation and working practice.

Q: Can the Harken Industrial Tight Radius System be fitted retrospectively?

A: Yes. The simplicity of the system means it can easily be installed at a later date. We recommend a complete site analysis be conducted by a professional engineer or qualified person in fall protection, prior to installation.

Q: What benefits can the Harken Industrial TR31 System provide over other rail systems?

A: The construction and materials used in the Tight Radius rail and trolley system create a stronger system with a smoother linear motion. The system is made of anodized, one-piece aluminum components with machined corners, reducing the chance of snagging and bending of cars. The design of the corrosion resistance system also ensures long life while providing low maintenance.

Q: How does it work?

A: The TR31 is designed as a continuous rail system around the vessel or structure. Once the operator is clipped to the trolley, they are able to move freely along the rail with fall-restraint security. The rail is designed to mount on fixed stanchions or securing points with the rail spanned between them. The operator does not need to adjust their attachment along the rail.

Q: What does it do?

A: The Tight Radius rail and car system is designed for use as an adjustable anchorage point for fall restraint and fall arrest in the Marine and Commercial Marine industries.

Q: Is the Harken Industrial TR31 covered by any industry legislation?

A: Yes, the Harken Industrial TR31 rail system is independently tested and is compliant with EN795.2012 Type D. It also meets ANSI Z359 and is OHSA compliant.

Q: I already work with a rail system do I need additional training to Install the Harken Industrial Tight Radius system?

A: Yes. Harken Industrial has a duty of care to ensure that the system is installed by competent persons and operates an Approved Installer Training Course, this is FOC. An installation manual is provided and the Installer has a responsibility to supply the user manual and training (where possible) to end users.

Q: How is it made?

A: The TR31 track is made by using an extruding process and the trolleys are made from one solid piece of aluminium.

Q: What is it made from?

A: The car is made from 6061-T6 aluminium with Delrin rollers and stainless steel shackles, the track is made from 6061-T6 aluminium.

Q: What are the fixing centres for the TR31?

A: Currently installation for Fall Arrest to EN795:2012 is a maximum span of 1.3m between fixings.

Q: What size/type of fixings do you have to use for installations and do Harken Industrial supply them?

A: The minimum specification for fixings is M10 A2-70 bolts. It is the responsibility of the installer (designer & engineer) to ensure that the anchorage structure and fixing method is suitable to withstand the dynamic forces that the system could be subjected to. Please contact your Harken Industrial Technical Sales Engineer to discuss anchors in further detail.

Q: In what orientation can the TR31 be fitted?

A: The TR31 can be mounted to vertical and horizontal surfaces and in a vertical and horizontal plane within one system (See Installation Manual). Please note that the TR31 is NOT suitable for use solely as a Vertical Fall Arrest device.

Q: What is the smallest radius the TR31 can follow?

A: The minimum bending radius for machined parts is 200mm. A straight section of track can be formed to a curve, Factory forming is recommended for best results. Larger radius bends can be manually formed in the field; however precautions should be taken to ensure bending is consistent and the rail is not damaged, which could lead to impaired performance.

Q: Can Harken Industrial supply compound bends with the TR31 rail?

A: Yes, but we need a detailed drawing to work from to confirm the compound bends are within the manufacturing limits.

Q: How many users can work from the TR31 System?

A: 1 user per 1.3m span between fixings/anchors.

Q: Do I need to consider expansion of the TR31 when fitted to a structure, are there any
problems or is there a guide to work from?

A: Typical expansion gaps of 3mm are recommended between track lengths to allow for vibration or thermal expansion. The working temperature range and mounting structure should be evaluated on the basis of each individual installation. Please contact us to discuss exceptional temperature range installations.

Q: Which is the correct trolley to use?

A: We supply two types of trolleys, the IN210 without the screw pin-stop and the IN211 with the screw pin-stop (recommended for positioning and parking trolley(s).

Q: Can the roller bearings be changed due to wear and tear?

A: No, damaged or worn trolleys should be replaced.

Q: Is there insulation between the stainless steel shackle pin and the aluminium trolley

A: No, this is due to the hard anodizing.

Q: How often should the TR31 be inspected?

A: Pre-use inspections should be completed before each use by the user. Competent person inspections are required at intervals of 12 months or less, as per EN 795, where a certificate will be issued. All inspections should be logged in the systems log book.

Q: Do I need to clean the Tight Radius system, if so how and how often?

A: Yes. The TR31 rail system is manufactured from anodised aluminium, stainless steel and polymer rollers, requiring no lubrication. It does however need to be periodically cleaned and is dependent on the installation location, environment and orientation of the system. Washing the cars and rail with clean water is recommended. In extreme conditions, a non-abrasive brush or cloth wipe may be required to effectively remove debris from the access rail sections.

Q: Can Harken Industrial provide system engineering support?

A: Yes. As the manufacturer and a member of your team, Harken Industrial can provide test results, documentation, and application engineering advice on best installation practices for our TR31 Rail System. Harken Industrial can recommend qualified consultants, who specialize in fall protection systems, for you to contact. The final design and installation of the TR31 Rail System, all of the associated components, compliance with safety standards and certification is the responsibility of the installer/dealer and their engineering team.

Q: What kind of post-installation support is available for the Tight Radius System?

A: All component parts of the TR31 Rail System are manufactured in the US and stocked in warehouse locations around the world for immediate availability. In addition, our technical service reps are available to conduct site visits, as well as provide remote support. Contact your local Harken Industrial representative for more details on parts availability and other available tech resources.

Q: How long has Harken Industrial been manufacturing the Tight Radius System?

A: Harken Industrial has been in business manufacturing light-weight load handling systems for the sailing industry since 1967. The TR31 system is a direct result of that experience and has been available to the Marine and Commercial industry since 2016.

Q: Can you direct me to a qualified Harken Industrial Installer/Dealer?

A: Yes. Harken Industrial is creating a worldwide network of installers/dealers who are experienced in providing fall protection solutions, are experts in all of the codes and regulations in their location, and are factory authorized to install and service Harken Industrial products. Contact your Harken Industrial representative for more information.

Q: What industry standards does it meet?

A: Tested and conforms to EN795:2012 Type B/D. Also tested to Excised MCA requirements.

Q: How is this product different from the competitors?

A: It is simple to install at initial build or retrofit, easy to maintain, uses high strength and marine grade aluminium rail on vertical or horizontal planes, and is anodized for maximum protection. It also has pre-bent rail sections for faster lead time and carries Harken's World Wide Limited warranty. For full details on the warranty please see the product manual.

Q: Are AutoCad and 3D Solidworks drawings available?

A: Yes, please contact your Harken Industrial representative to discuss this.

Harken Industrial Exception - This product can NOT be used for human suspension.

Warnings and Instructions - You must carefully read, understand, and follow all of the warnings and instructions in the manual provided by Harken Industrial in order to avoid an accident.