Tight Radius System (TR31)


The Tight Radius rail-and-trolley system is designed to work as an adjustable anchorage point for fall restraint on marine vessels.

Rails are composed of straight and sections 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 independantly tested and conforms to EN795.2012 B/D

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

Trolley Design

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

Compact: minimum intrusion on narrow deck and restricted work areas

Multidirectional load bearings

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

Counter sunk M8 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



Part No. Description
IN209.3M.CLEAR Straight rail section
IN211 Slice link
548 Endstops
IN210.CLEAR Trolley
IN212.CLEAR Brake trolley

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

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 anodized aluminium, remove “.CLR or .CLEAR” from end of part number.

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 car.
Excessive build-up of grease, dirt, and salt will restrict car movement.

If you would like to discuss this product further please register your interest by contacting 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 TR31?
A: Skills learned for use with alternative rail systems are transferable. However, a short training session to familiarize yourself with the Harken system is required to ensure safe installation and working practice.

Q: Can the Harken TR31 be retrofitted?
A: Yes. The simplicity of the system means it can easily be installed at a later date.

Q: What benefits can the Harken TR31 System offer me 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 up of anodized, one-piece aluminum components, ensuring long life with low maintenance and corrosion resistance.

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, he is 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 industries.

Q: Is the Harken TR31 covered by any industry legislation?
A: Yes, the Harken TR31 rail system is CE certified and tested under EN795.2012 Type B/D

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

A: Yes. Harken 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 User Manual and training (where
possible) to end users.

Q: Can the Harken 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 Tight Radius System offer me over other rail systems

A: Smoother running system, the system is made of anodized one-piece aluminium components
with machined corners reducing the chance of snagging and bending of car, ensuring long life
while providing low maintenance and corrosion resistance.

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: Car is 6061-T6 aluminium with Delrin rollers and S/S shackle, track is 6061-T6 aluminium

Q: What are the fixing centres for the TR31?
A: Currently installation for Fall Arrest to EN795:2012 is a maximum 1.3m span between fixings.

Q: What size/type of fixings do we have to use for installations & do you 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 Technical Sales Engineer to discuss anchors in further detail.

Q: In what orientation can the TR31 be fitted?
A: The TR31 is 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 impaired performance.

Q: Can you 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 a per installation basis. Please contact Harken to discuss exceptional temperature
range installations.

Q: Which is the correct trolley to use?
A: We supply two types of Trolleys, the IN210 without screw pin-stop and the IN211 with 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
Inspection 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 &
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 can provide test results,
documentation and application engineering advice on best installation practices for our TR31
Rail System to insure your success. 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 should the need arise. 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 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 installer/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 the 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 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 plane, and is anodized for maximum
protection. Has pre-bent rail sections for faster lead time and carries Harkens 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 EXCEPTION: This product can not be used for human suspension.

You must carefully read, understand, and follow all of the warnings and instructions in the manual provided by Harken in order to avoid an accident. Never, under any circumstances, exceed the maximum rated load.