CEN/TR 15151-3:2026
(Main)Mountaineering equipment - Braking devices - Part 3: Braking devices with amplified braking
- Abstract
This European Standard specifies safety requirements and test methods for braking devices with amplified braking used in mountaineering, climbing and related activities for belaying, with amplified braking function, to protect against falls from a height and/or for abseiling with speed regulation.
This European Standard applies to braking devices which are loaded with one person and which use mountaineering ropes according to EN 892. In case of abseiling and lowering down, this standard also applies to braking devices, used with low stretch kernmantel ropes are in accordance with EN 1891. It does not apply to manual braking devices and braking devices with assisted locking which are addressed in EN 15151-1:2012 and EN 15151-2:2012, nor to fully automatic fixed installations.
- Status
- Published
- Publication Date
- 07-Apr-2026
- Technical Committee
- CEN/TC 136 - Sports, playground and other recreational equipment
- Drafting Committee
- CEN/TC 136/WG 5 - Mountaineering and climbing equipment
- Current Stage
- 6060 - Definitive text made available (DAV) - Publishing
- Start Date
- 08-Apr-2026
- Completion Date
- 08-Apr-2026
CEN/TR 15151-3:2026 is a CEN Technical Report on mountaineering equipment braking devices with amplified braking. It summarizes the work on manual braking devices with partially assisted locking used for belaying and abseiling in mountaineering, climbing and related activities, and it records the test methods, classifications and safety observations studied for those devices. The report is aimed at manufacturers, test laboratories, and others who need to understand how rope type, rope condition and device design affect performance.
What does CEN/TR 15151-3:2026 specify?
CEN/TR 15151-3:2026 covers manual braking devices with partially assisted locking used to protect against falls from a height and/or for abseiling with speed regulation. It applies to one-person devices used with mountaineering ropes according to EN 892, and for abseiling and lowering down it also applies to use with low stretch kernmantel ropes according to EN 1891.
CEN/TR 15151-3:2026 is organized as a short front matter, then clauses on scope, normative references, terms and definitions, classification, test variables, static performance testing, dynamic testing, conclusions and observations. Annex A gives background information on the braking devices used in the work.
| Annex | What it covers |
|---|---|
| Annex A | Informative information on the braking devices used, including their permitted rope diameters and classification used in the report |
The report also notes the device types studied in Clause 4. Type 9 and Type 10 are for devices without a belay anchor function, while Type 11 and Type 12 are for devices with a belay anchor function. That distinction matters because the intended use and anchoring arrangement change how the device is handled in practice.
What are the key technical points of CEN/TR 15151-3:2026?
CEN/TR 15151-3:2026 is mainly about how the behavior of these braking devices changes with rope and user variables, and why a single simple classification test was difficult to make repeatable. The most useful points are the classification, the test set-ups, and the observations about rope-dependent performance.
Classification in Clause 4
CEN/TR 15151-3:2026 classifies manual braking devices with partially assisted locking into four types. Types 9 and 10 are for abseiling only, or for belaying and abseiling, without a belay anchor function; Types 11 and 12 add a belay anchor function. In practice, this tells a buyer or engineer whether the device is intended only for descent control or also for belaying, and whether anchoring is part of its use.
Test variables in Clause 5
CEN/TR 15151-3:2026 identifies the main variables that influence performance: rope diameter, linear density, construction, coatings and treatments, rope condition, braking device design, rope bearing carabiner geometry, brake rope angle and brake rope tension. In practical terms, the report shows that device behavior is not determined by rope diameter alone, so compatibility decisions need more than one rope parameter.
Static performance testing in Clause 6
CEN/TR 15151-3:2026 describes a quasi-static method in which the rope is conditioned, a new rope section is used for each test, and the device is tested at 23 ± 5 °C with a tensile machine pulling at 500 mm/min. The apparatus uses a pulley, a brake hand mass and a load cell to measure the force needed for rope slippage. For a test lab, this is the repeatable laboratory arrangement used to compare holding force.
The report’s static studies show three important effects. Brake hand force changes holding force, rope linear density can strongly influence partially assisted locking devices, and brake rope angle can change performance sharply in some designs. In practice, that means a device that works well at one hand position or with one rope may behave differently with another rope or another angle.
Residual holding force in Clause 6.6
CEN/TR 15151-3:2026 examines residual holding force by locking the device with a 4 kg brake rope mass at a 60° brake rope angle, then removing the brake hand mass and measuring what holding force remains. This was intended to distinguish partially assisted locking devices from manual braking devices. The report concludes that rope characteristics influence the result too strongly for this metric to serve as a clean classification method on its own.
Dynamic testing in Clause 7
CEN/TR 15151-3:2026 then moves to dynamic tests because slow static loading did not reflect real use well enough. One method starts with the device already locked and measures how the rope slips after brake hand tension is removed; another starts from an unlocked condition and judges the device by how much rope slips within 10 seconds.
These dynamic studies found very different behaviors, from no slippage to creeping to fast, accelerating slippage. The report also found poor repeatability and conflicting outcomes between laboratories and rope models. In practice, this is the key message for designers and buyers: the device response is highly sensitive to rope characteristics and test details.
Observations in Clause 9
CEN/TR 15151-3:2026 closes with observations on safer design, markings and manufacturer’s information. It recommends attention to attachment point geometry, smooth edges, resistance to unintended rope removal, clear rope diameter marking, and user information about the dependence on rope model, diameter, linear density, slipperiness, wetness and interconnecting components. For manufacturers, this section is the most directly practical part of the report.
What terms does CEN/TR 15151-3:2026 define?
CEN/TR 15151-3:2026 uses a small set of core terms to describe the device and how it is tested.
- Braking device - a mechanical device that generates forces on the rope to oppose rope movement through the device.
- Manual braking device with partially assisted locking - a hand-controlled device that produces an amplified holding force in the live rope and retains part of that force when brake rope force drops to zero.
- Attachment point - the system intended by the manufacturer for attaching a connector.
- Brake rope - the rope section leading into the belay device that the user controls.
- Live rope - the rope section leading from the braking device to the climber or anchor.
- Brake rope angle - the angle between the brake rope and the live rope at the belay device.
- Holding force - the force needed to make rope slip through the braking device.
- Residual holding force - the force needed to make rope slip after the device is locked and no force is applied to the brake rope.
Who uses CEN/TR 15151-3:2026?
CEN/TR 15151-3:2026 is used by manufacturers designing belay and abseil devices, test laboratories setting up performance tests, and technical committees working on equipment safety. Quality managers and buyers use it to understand what influences device performance and what rope information needs to be controlled or checked.
It is also relevant to certification and conformity assessment bodies, because the report explains why rope diameter alone is not enough to characterize these devices. In practice, anyone selecting or evaluating a braking device for mountaineering, climbing or related activities can use the report to understand the device’s intended use and the sensitivity of its performance to rope and connector choices.
Which standards are used with CEN/TR 15151-3:2026?
CEN/TR 15151-3:2026 is used together with the following referenced standards and companion documents:
- EN 15151-1 - provides the related framework for braking devices with manually assisted locking and supplies shared terms and definitions.
- EN 15151-2 - covers manual braking devices and supplies the other comparison class used throughout the report.
- EN 892:2012+A3:2023 - defines dynamic mountaineering ropes and the rope diameter and conditioning concepts used in the testing.
- EN 1891 - covers low stretch kernmantel ropes used for abseiling and lowering down.
- EN 567 - provides the rope clamp used in the test apparatus.
- ISO 7000:2019 - supplies the graphical symbol referenced for user information on the device.
What does the CEN/TR 15151-3:2026 document contain?
CEN/TR 15151-3:2026 contains the background work behind the attempted classification of manual braking devices with partially assisted locking. It includes the test variables considered, the static and dynamic test methods, and the discussion of why those methods gave inconsistent or non-repeatable results.
The document also includes several apparatus figures and two result tables for the dynamic tests. Figure 1 shows the classification logic, Figures 2, 6, 9 and 10 show test set-ups, and Figures 3 to 8 and Table 1 and Table 2 summarize measured behavior. Annex A lists the anonymized braking devices used, their rope diameter ranges and the classification used in the study.
Finally, the report contains observations on safer device design, markings and manufacturer instructions. For an engineer or buyer, those pages are useful because they explain what the device should communicate to the user and why rope model, rope diameter and interconnecting components all matter in actual use.
Frequently Asked Questions
CEN/TR 15151-3:2026 is a technical report published by the European Committee for Standardization (CEN). Its full title is "Mountaineering equipment - Braking devices - Part 3: Braking devices with amplified braking". This standard covers: This European Standard specifies safety requirements and test methods for braking devices with amplified braking used in mountaineering, climbing and related activities for belaying, with amplified braking function, to protect against falls from a height and/or for abseiling with speed regulation. This European Standard applies to braking devices which are loaded with one person and which use mountaineering ropes according to EN 892. In case of abseiling and lowering down, this standard also applies to braking devices, used with low stretch kernmantel ropes are in accordance with EN 1891. It does not apply to manual braking devices and braking devices with assisted locking which are addressed in EN 15151-1:2012 and EN 15151-2:2012, nor to fully automatic fixed installations.
This European Standard specifies safety requirements and test methods for braking devices with amplified braking used in mountaineering, climbing and related activities for belaying, with amplified braking function, to protect against falls from a height and/or for abseiling with speed regulation. This European Standard applies to braking devices which are loaded with one person and which use mountaineering ropes according to EN 892. In case of abseiling and lowering down, this standard also applies to braking devices, used with low stretch kernmantel ropes are in accordance with EN 1891. It does not apply to manual braking devices and braking devices with assisted locking which are addressed in EN 15151-1:2012 and EN 15151-2:2012, nor to fully automatic fixed installations.
CEN/TR 15151-3:2026 is classified under the following ICS (International Classification for Standards) categories: 97.220.40 - Outdoor and water sports equipment. The ICS classification helps identify the subject area and facilitates finding related standards.
CEN/TR 15151-3:2026 is associated with the following European legislation: EU Directives/Regulations: 2016/425; Standardization Mandates: M/031. When a standard is cited in the Official Journal of the European Union, products manufactured in conformity with it benefit from a presumption of conformity with the essential requirements of the corresponding EU directive or regulation.
CEN/TR 15151-3:2026 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-julij-2026
Gorniška oprema - Naprave za zaviranje - 3. del: Naprave za zaviranje z ojačanim
zaviranjem
Mountaineering equipment - Braking devices - Part 3: Braking devices with amplified
braking
Bergsteigerausrüstung - Bremsgeräte - Teil 3: Bremsgerät mit teilweiser
Verriegelungsunterstützung
Matériel d’alpinisme et d’escalade - Dispositifs de freinage - Partie 3 : Dispositif de
freinage avec assistance partielle au verrouillage
Ta slovenski standard je istoveten z: CEN/TR 15151-3:2026
ICS:
97.220.40 Oprema za športe na Outdoor and water sports
prostem in vodne športe equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
CEN/TR 15151-3
TECHNICAL REPORT
RAPPORT TECHNIQUE
April 2026
TECHNISCHER REPORT
ICS 97.220.40
English Version
Mountaineering equipment - Braking devices - Part 3:
Braking devices with amplified braking
Matériel d'alpinisme et d'escalade - Dispositifs de Bergsteigerausrüstung - Bremsgeräte - Teil 3:
freinage - Partie 3 : Dispositif de freinage avec Bremsgerät mit teilweiser Verriegelungsunterstützung
assistance partielle au verrouillage
This Technical Report was approved by CEN on 27 March 2026. It has been drawn up by the Technical Committee CEN/TC 136.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 15151-3:2026 E
worldwide for CEN national Members.
Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Classification. 7
5 Test Variables . 8
5.1 General. 8
5.2 Rope . 8
5.2.1 Diameter . 8
5.2.2 Linear Density . 8
5.2.3 Construction . 8
5.2.4 Coatings and treatments . 8
5.2.5 Condition . 8
5.3 Braking Device . 8
5.3.1 Braking device design . 8
5.3.2 Rope bearing carabiner . 8
5.4 User . 9
5.4.1 Brake rope angle . 9
5.4.2 Brake rope tension . 9
6 Static Performance Testing . 9
6.1 General. 9
6.2 Static Performance Test Procedure . 9
6.3 Brake Hand Force Study . 10
6.3.1 Introduction . 10
6.3.2 Brake Hand Force Results . 11
6.3.3 Brake Hand Force Discussion . 11
6.4 Rope Linear Density Study . 12
6.4.1 General. 12
6.4.2 Rope Linear Density Results . 13
6.4.3 Rope Linear Density Discussion . 13
6.5 Brake Rope Angle Study . 14
6.5.1 General. 14
6.5.2 Brake Hand Angle Results . 15
6.5.3 Brake Hand Angle Discussion . 15
6.6 Residual Holding Force Study . 16
6.6.1 General. 16
6.6.2 Residual Holding Force Results . 18
6.6.3 Residual Holding Force Discussion . 19
6.7 Static Performance Testing Conclusion . 20
7 Dynamic Testing . 20
7.1 General. 20
7.2 Dynamic Residual Performance . 20
7.2.1 General . 20
7.2.2 Dynamic Residual Performance Test Method . 20
7.2.3 Dynamic Residual Performance Test Results . 22
7.2.4 Dynamic Residual Performance Discussion . 23
7.3 Dynamic Response Study . 24
7.3.1 General . 24
7.3.2 Dynamic Response Test Method . 24
7.3.3 Dynamic Response Results . 26
7.3.4 Dynamic Response Discussion . 26
7.4 Dynamic Testing Conclusion . 26
8 Conclusion . 26
9 Observations . 27
9.1 General . 27
9.2 General Safety Improvements . 27
9.3 Markings . 28
9.4 Manufacturer’s instructions and information . 28
Annex A (informative) Information on the braking devices used . 30
Bibliography . 31
European foreword
This document (CEN/TR 15151-3:2026) has been prepared by Technical Committee CEN/TC 136
“Sports, playground and other recreational facilities and equipment”, the secretariat of which is held by
DIN.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
Introduction
This document summarizes the collection of work that was performed with the intention of forming an
EN standard for manual braking devices with partially assisted braking used in mountaineering, climbing
and related activities. Many different tests and test methods were conducted with the aim of finding a
repeatable process that could be used to classify the performance of this type of device. However, since
no repeatable data could be gained, after several years of work, it was not possible to write a complete a
standard.
In order to save all of the valuable studies and findings, the CEN/TC 136/WG 5 decided to move from
draft standard to technical report.
1 Scope
This document applies to manual braking devices with partially assisted locking used in mountaineering,
climbing and related activities for belaying, to protect against falls from a height and/or for abseiling with
speed regulation. These are for use with mountaineering ropes according to EN 892:2012+A3:2023. In
case of abseiling and lowering down, this also applies to braking devices used with low stretch
kernmantel ropes in accordance with EN 1891.
It does not apply to manual braking devices and braking devices with assisted locking which are
addressed in EN 15151-1 and EN 15151-2, nor to fully automatic fixed installations.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 15151-1, Mountaineering equipment - Braking devices - Part 1: Braking devices with manually assisted
locking, safety requirements and test methods
EN 15151-2, Mountaineering equipment - Braking devices - Part 2: Manual braking devices, safety
requirements and test methods
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 15151-1, EN 15151-2 and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
3.1
braking device
mechanical device, which generates forces on the rope to oppose movement of the rope through the
device
[SOURCE: EN 15151-1:2012, 3.1]
3.2
manual braking device with partially assisted locking
device controlled by hand force applied to the brake rope, in a specified range of positions, that produces
an amplified holding force in the live rope such that when the force in the brake the rope is reduced to
zero the amplified holding force is partially maintained
3.3
attachment point
system which is required and intended for the attachment of a connector according to the information
supplied by the manufacturer
3.4
brake rope
section of rope leading into the belay device, that is controlled by the user
3.5
live rope
section of rope leading from the braking device to the climber or anchor
3.6
brake rope angle
angle between the brake rope and the live rope about the belay device
3.7
holding force
force required to cause slippage of rope through the braking device
3.8
residual holding force
force required to cause slippage of rope through the braking device, after the device is locked and when
no force is applied in the brake rope
3.9
rope bearing carabiner
connector used with the braking device that the rope is in contact with
4 Classification
For classification of braking devices see Figure 1.
Key
A abseiling
B belaying
Figure 1 — Classification of braking devices
4.1 Manual braking device with partially assisted locking.
4.1.1 Type 9: devices for abseiling without a belay anchor function.
4.1.2 Type 10: devices for belaying and abseiling without a belay anchor function.
4.1.3 Type 11: devices for abseiling with a belay anchor function.
4.1.4 Type 12: devices for belaying and abseiling with a belay anchor function.
5 Test Variables
5.1 General
The following is a non-exhaustive list of variables that were considered when performing tests to evaluate
the performance of a braking device.
5.2 Rope
5.2.1 Diameter
The diameter of the rope (mm), where the method of measuring and expressing this diameter is specified
in EN 892:2012+A3:2023. EN 892:2012+A3:2023 permits the diameter stated in the information
supplied by the manufacturer and on the product markings to be within ± 0,2 mm of the measured value.
5.2.2 Linear Density
This is the mass per unit length (g/m) of the rope, where the method of measuring and expressing this is
specified in EN 892:2012+A3:2023.
5.2.3 Construction
EN 892:2012+A3:2023 and EN 1891 require the ropes to be of a kernmantle construction, where the rope
comprises a sheath and core. The proportions and composition of both can lead to a wide variety of
characteristics that can interact with each braking device design differently.
5.2.4 Coatings and treatments
A variety of coatings and treatments can be applied to the rope, or the fibres, to improve certain
properties of the rope (e.g. water repellence), however the interaction with the braking device can be
affected.
5.2.5 Condition
The condition of the rope could include a wide variety of factors such as: humidity, dirt, wear/damage,
and prior loading/elongation. Each of these factors can affect the performance of the braking device.
5.3 Braking Device
5.3.1 Braking device design
The design and mechanism for generating friction within a braking device can vary significantly. An
anonymised list of the braking devices used in this report, their permitted rope diameters (as specified
in the manufacturer’s instructions), and the classification (as defined in Clause 4), is shown in Annex A.
5.3.2 Rope bearing carabiner
For some braking devices the rope runs around an interconnecting carabiner, of which the geometry and
condition can alter the performance of the braking device.
5.4 User
5.4.1 Brake rope angle
The angle that the brake rope approaches the braking device can affect its performance. It is typical for
the user to reduce the angle of the brake rope to feed rope through the braking device more easily and
increase the brake rope angle to produce more holding force in the braking device.
5.4.2 Brake rope tension
The user can modulate the tension applied to the brake rope strand, which might affect both the response
and the performance of the device.
6 Static Performance Testing
6.1 General
A series of quasi-static tests were performed to better understand the impact of some variables (listed in
Clause 5) on the performance of the braking devices. These tests were designed to measure the force
required to cause slippage of rope through the braking device.
The test variance and repeatability were examined, with further Round-Robin testing performed. The
test procedure was improved until the results were proven to be repeatable and reproducible.
6.2 Static Performance Test Procedure
The test was carried out in an environment at a temperature of (23 ± 5) °C.
The rope was conditioned according to EN 892:2012+A3:2023.
A new section of rope was used for each test.
The test apparatus was set up according to Figure 2.
An EN 567 rope clamp was connected to the outgoing live rope, then with a connector it was connected
to the load cell on the moving head of the tensile test machine.
The braking device was connected to the rope using the connector specified in the manufacturer’s
instructions and information. This assembly was then connected directly to the fixed anchor located
below the load cell.
The brake rope passed through a pulley with a sheave diameter of (50 ± 10) mm, which was attached to
a rigid anchor point in such a way that the pulley axle remains fixed during testing. The pulley was
positioned to provide the required brake rope angle when the braking device is in its highest friction
position.
A mass was suspended from the brake rope via another EN 567 rope clamp, where the combined mass of
the rope clamp, connector, and the mass corresponds to the required brake hand mass. This was placed
at a distance of (500 ± 150) mm from the pulley.
Excess slack rope was removed from the system, and the braking device aligned in its lowest friction
position.
With the tensile tester operating at a speed of 500 mm/min, the live rope was then pulled through the
device, and the force measured at the load cell was recorded.
From the recorded results, the region where force readings become steady, due to rope slippage, was
identified. The average force was then calculated over a minimum of 100 mm of rope slippage.
Key
1 moving head of tensile test machine 6 fixed axle pulley
2 load Cell 7 rope baring carabiner
3 rope clamp 8 fixed anchor
4 rope 9 brake hand mass
5 braking device
Figure 2 — Apparatus for static performance testing
6.3 Brake Hand Force Study
6.3.1 Introduction
A study of the effects of brake hand force was performed using the test method described in 6.2. A small
selection of braking devices were tested, using one model of rope (⌀ 9,8 mm), at a brake rope angle of
150°. A mass was used to generate a tension force in the brake rope and was increased in increments of
5 kg, up to 25 kg. It becomes difficult for a typical user’s hand to produce beyond 25 kgf on a single strand
of rope.
6.3.2 Brake Hand Force Results
Key
X brake rope mass (kg)
Y holding force (kgf)
braking device H
braking device F
braking device E
braking device B
braking device A
Figure 3 — Results of holding force measurements with increasing brake rope mass
6.3.3 Brake Hand Force Discussion
The results in Figure 3 show manual braking devices (braking device A) exhibit a linear and proportional
response to brake hand force. Manual braking devices with partially assisted locking display a different
response – depending upon the design and model – that is typically non-proportional, so, they still
provide a level of holding force even with no brake hand force, and the holding force is generally less
dependent on brake hand force.
Without any tension in the brake rope it becomes more difficult to maintain a consistent brake hand
angle.
For further testing it was agreed a brake hand mass of 4 kg would be used.
6.4 Rope Linear Density Study
6.4.1 General
As shown in 5.2 there are several factors related to the model of rope used that can affect the performance
of a braking device. Of the five main factors identified in 5.2 only the diameter and linear density are
easily measurable and comparable. The method for measuring and expressing both is defined in
EN 892:2012+A3:2023 and these figures are made publicly available by the manufacturer of the rope in
the product’s instructions.
The relationship between rope diameter and the performance of a braking device is fairly well
understood and it has previously been established in EN 15151-1:2012 and EN 15151-2:2012 that
testing on the braking devices is performed on the minimum and maximum diameter specified by the
manufacturer. However, the relationship between linear density of the rope and the performance of
braking devices is less well understood.
A study on the effects of linear density was performed using the test method described in 6.2. The brake
rope angle used was 150° and the brake hand mass was 4 kg. A selection of four braking devices were
tested, of which one was a manual braking device (braking device A). Seven different models of ropes of
the same stated diameter (9,8 mm) were tested in the braking devices. These had a range of linear
densities from 60 g/m to 68 g/m. It is worth noting the ropes were sourced from five different
manufacturers and are known to have different constructions and treatments applied to them.
6.4.2 Rope Linear Density Results
Key
X combination braking device and rope
Y holding Force (kgf)
A braking device A
B braking device H
C braking device F
D braking device E
rope 1 60 g/m (9,8 mm)
rope 2 60 g/m (9,8 mm)
rope 3 61 g/m (9,8 mm)
rope 4 62 g/m (9,8 mm)
rope 5 62 g/m (9,8 mm)
rope 6 67 g/m (9,8 mm)
rope 7 68 g/m (9,8 mm)
Figure 4 — Results of holding force measurements when increasing linear density of the rope
6.4.3 Rope Linear Density Discussion
The results in Figure 4 show that for manual braking devices (braking device A) no strong influence of
linear density upon holding force can be seen.
For the other braking devices (braking device H, F and E) there is a clear trend that increasing the linear
density of the rope will increase the holding force of the device. The greatest increase in holding force for
each braking device H, F and E is 42 %, 63 % and 66 % respectively.
It is understood that the manual braking devices with partially assisted locking typically use designs that
feature an aperture that contracts under load, through which the rope has to squeeze. This pinching
action is used to increase holding force. A more densely packed rope would logically be more resistant to
being crushed and pulled through the aperture in the braking device. Manual braking devices of a basic
tube design simply rely on belt friction to generate the holding force, as the rope is bent around bollards
and there is no pinching action. This form of friction is less sensitive to how densely packed the rope is.
In addition to the linear density, the effects of other characteristics of the rope, such as the construction,
treatments, coatings and condition have not been isolated in these tests, and it is possible that these might
also contribute in some way to the results.
These results suggest that using rope diameter as the only metric for informing which ropes are suitable
for meeting the performance requirements, when used in this type of braking devices, is not sufficient.
6.5 Brake Rope Angle Study
6.5.1 General
A study on the effects of brake rope angle was performed using the test method described in 6.2. A
selection of braking devices where tested, including one manual braking (braking device A) and two
braking devices with manually assisted locking (braking device J & K). One model of rope (⌀ 9,8 mm) and
a brake hand mass of 4 kg was used for all tests. The pulley was repositioned so that tests with a brake
rope angle of 150°, 120°, 90°, 60°, 30° and 10° can be performed on each device.
6.5.2 Brake Hand Angle Results
Key
X brake rope angle (°)
Y holding force (kgf)
braking device A
braking device B
braking device C
braking device E
braking device F
braking device G
braking device H
braking device I
braking device J
braking device K
Figure 5 — Results of holding force measurements when changing brake rope angle
6.5.3 Brake Hand Angle Discussion
Figure 5 shows a varied response to brake rope angle and will depend upon the design of the braking
device. Some braking devices displayed a fairly consistent performance across a range of brake rope
angles. Some braking devices saw a steady drop in performance as the brake rope angle became smaller,
similar to the manual braking devices. Several braking devices exhibit a sharp drop off in performance at
angles lower than 60°. The braking
...