UN R13 Supplement 18 (11 series) · UNECE Regulation No. 13 (ECE R13) — Uniform provisions concerning the approval of vehicles of categories M, N and O with regard to braking.
UN R13 — Supplement 18 to the 11 series of amendments
Supplement 17 → 18
- What changed
- New definitions and special requirements cover towing trailers, dollies and link-trailers (paras. 2.43. to 2.43.2. and 5.2.2.24. to 5.2.2.25.2.).
- Power-driven vehicles authorised to tow more than one trailer of Category O3 or O4 must have a pneumatic and an electric control line (para. 5.2.1.34.1.).
- New paragraph 5.1.2.4. sets endurance braking requirements, with special requirements for systems incorporating electric regenerative braking (para. 5.1.2.4.3.).
- Why
- UN Regulation No. 13 only defined requirements for single-trailer combinations, but combinations with more than one trailer are used in many countries.
- Germany understood from GRVA discussions that the endurance braking test is an economic burden for battery electric vehicles with electric regenerative braking.
- Germany's proposal also puts the endurance braking requirements into paragraph 5 of the Regulation, to make the specification more transparent.
Q1What changed166 changes
Towing trailer, dolly and link-trailer: definitions (paras. 2.43. to 2.43.2.), scope (para. 1.2.4.) and special requirements (paras. 5.2.2.24.11., 5.2.2.24.12.)
New paragraph 2.43. defines a “Towing trailer” as a trailer which is equipped to tow another trailer. A “Dolly” is a towing trailer designed for the sole purpose to tow a semi-trailer; it may have a rigid or a hinged drawbar. A “Link-trailer” is a semi-trailer with a fifth wheel in its rear end, so that a second semi-trailer can be towed (para. 2.43.2.). New paragraph 1.2.4. adds the hinged drawbar dolly to the list of what this Regulation does not cover. For Annex 4, para. 3. and Annex 10, para. 5., a rigid drawbar dolly counts as a centre axle trailer, a link-trailer as a semi-trailer.
Special requirements for towing trailers and the trailers they tow (paras. 5.2.2.12.1., 5.2.2.24. to 5.2.2.25.2.)
New paragraph 5.2.2.24. sets special requirements for towing trailers of Category O3 or O4 able to tow another trailer of Category O3 or O4. Towing trailers must have pneumatic control/supply lines, an electric control line as in paragraph 5.1.3.1.2. and a message routing function (paras. 5.2.2.24.1. and 5.2.2.24.2.). A towing trailer may only be operated with a power-driven vehicle that has at least a pneumatic and an electric control line (para. 5.2.2.24.6.3.). If the towed trailer's brakes fail, the towing trailer must be able to brake with at least 50 per cent of prescribed service brake performance. Applying the parking braking system of the towing trailer must also brake the towed trailer (para. 5.2.2.24.10.2.). Under paragraph 5.2.2.25.1., other O3 or O4 trailers authorized to be coupled to a towing trailer need a pneumatic and an electric control line.
Connections and control lines between vehicles in a combination (paras. 5.1.3. to 5.1.3.9., 5.2.2.15.2.1., 5.2.2.17.)
Paragraph 5.1.3. now covers compressed-air connections between vehicles within a combination, instead of between power-driven vehicles and trailers. A towing trailer connected to a trailer, both with electric control lines, must detect a continuous failure (> 40 ms) in the line at its rear. A trailer must use the control line signalling from the vehicle that first generates it, the power-driven vehicle or a towing trailer (para. 5.1.3.6.4.). Flexible hoses and cables between a towing vehicle and its following semi-trailer must now be part of the towing vehicle, not only for tractors. Under paragraph 5.2.2.15.2.1., the failure information that trailers give when service braking performance can no longer be ensured now also covers the yellow warning signal. If a trailer's electric control line is longer than ISO 11992-1:2003 permits, a repeater must split it into two segments that each meet that length.
Power-driven vehicle wording and trailer warning signals (paras. 5.2.1.15. to 5.2.1.34.1.)
Several paragraphs of 5.2.1. now say “power-driven vehicle” instead of “towing vehicle”, for example paragraphs 5.2.1.15., 5.2.1.18.2. and 5.2.1.28.1. Under paragraph 5.2.1.29.2., the trailer activates the yellow warning signal through pin 5 (or an automated connector's equivalent pin) and an amber warning request. The trailer uses the amber warning request whenever it provides corresponding failure information through the data communications part of the electric control line. The amber warning request may only carry information equivalent to that defined for pin 5 of the ISO 7638:2003 connector. The red warning signal of paragraph 5.2.1.29.2.1. now also applies when a towing trailer transmits the red warning signal request from any succeeding towed trailer. New paragraph 5.2.1.34.1. requires a pneumatic and an electric control line on power-driven vehicles authorised to tow more than one O3 or O4 trailer.
Endurance braking system requirements (paras. 5.1.2.4. to 5.1.2.4.2., 5.1.2.4.3.3.)
New paragraph 5.1.2.4. requires the endurance braking system to make it possible to keep a constant downhill speed for a long time without friction brakes. For vehicles in Annex 4, paragraph 1.8.1., it must hold an average 30 km/h on a seven per cent down-gradient for at least 12 min. For vehicles that absorb the energy by the braking action of the engine alone, the tolerance of Annex 4, paragraph 1.8.2.3. applies. These requirements are deemed satisfied if the relevant test requirements of Annex 4, paragraph 1.8. are met. If endurance braking is solely based on electric regenerative braking, the driver must be informed before its braking force can no longer be provided.
Electric regenerative braking: endurance braking options, driver warning and Annex 4 tests (paras. 2.42., 5.1.2.4.3., 5.2.1.29.7.)
Paragraph 5.1.2.4.3.1. deems systems incorporating electric regenerative braking compliant if the vehicle can store and/or dissipate the energy of the maximum negative vertical height difference. This energy is limited to the level needed for paragraphs 5.1.2.4.1. and 5.1.2.4.2., and the current electric state of charge is considered. Paragraph 5.1.2.4.3.2. gives an alternative: the service braking system must meet Annex 4, paragraph 1.8.2.5., and a brake performance estimator must warn the driver. Paragraph 5.2.1.29.7. covers Category A or B regenerative braking vehicles using the service brakes only when a high state of charge prevents energy storage. These vehicles must warn the driver at the latest when service braking performance falls below the minimum values of Annex 4, paragraphs 1.6.3. and 2.2.1. New Annex 4, paragraph 1.8.2.5. sets two tests where the service braking system is used only because the maximum battery state of charge is reached.
Approval form items and annex tests (Annexes 2, 4, 6, 7, 17 and 21)
New Annex 2 items 9.4.6., 14.16. and 14.17. state whether a vehicle is authorised for combinations with more than one trailer or a towing trailer. Annex 4, paragraph 2.3.2. now also covers multiple trailers; the parking brake must hold the laden combination stationary on a 12 per cent gradient. New Annex 4, paragraphs 1.6.5. and 1.8.2.4. limit the regenerative braking force at the test start to the minimum guaranteed by the system design. New Annex 6, paragraph 4. sets how to measure the towing trailer control line response time, with a simulator replacing the power-driven vehicle. New Annex 17, paragraph 4.3. adds towing trailer checks, such as control line signalling and warning messages sent from the rear to the front connection. Annex 21, paragraph 2.2.2. adds item (b): the ability for a towing trailer to brake the towed trailer for vehicle/combination stabilization.
Q2Why it changed
- Proposed by
- Expert from the International Organization of Motor Vehicle Manufacturers (modular vehicle combinations); expert from Germany (endurance braking systems)
- Working party
- GRVA, 7th session (September 2020)
Reasons
UN Regulation No. 13 only defined requirements for vehicle combinations with a single trailer. In many countries, combinations with more than one trailer, or a dolly and a semi-trailer, are used without uniform braking provisions. The proposal specifies uniform requirements for trailers and motor vehicles that may be used in a combination with multiple trailers.
Sources (3)
“UN Regulation No. 13 only defines requirements for vehicle combinations which include a single trailer.”
“in many countries, vehicle combinations, which include more than one trailer or a combination of a dolly and semi-trailer are used, while no uniform provisions with respect to braking are applied”
“specifies uniform requirements for trailers and motor vehicles which may be used in a combination with multiple trailers”
Germany understood from earlier GRVA discussions that the endurance braking test (Type-IIA) is an economic burden for battery electric vehicles with electric regenerative braking systems. Its proposal aims to help find a practical and safe solution for this challenge.
Sources (3)
“Germany understands from previous discussions at GRVA that the current endurance braking performance test in UN-Regulation No. 13 (Type-IIA)”
“poses to be an economical burden to battery electric vehicles incorporating electric regenerative braking systems”
“in order to contribute to the ambition in finding a practical and safe solution for the described challenge”
Germany's approach was to take the requirements for endurance braking systems from the existing endurance braking performance test in Annex 4, paragraph 1.8. It puts them also into paragraph 5 of the Regulation, to make the endurance brake specification more transparent.
Sources (2)
“requirements for endurance braking systems from the existing endurance braking performance test (paragraph 1.8. in Annex 4)”
“This proposal only suggests to additionally introduce the requirements into paragraph 5 of the Regulation, with the intention to make the endurance brake specification (in general) more transparent.”
For battery electric vehicles with electric regenerative braking, the proposal gave two alternatives. One takes into account the position of the vehicle and the topography around it. The other allows friction brakes for endurance braking if a too high battery state of charge prevents recuperation. If friction brakes are used, at least 5.0 m/s² of brake deceleration must remain after the endurance braking. A brake estimator then alerts the driver if brake efficiency falls below the Type-II hot performance test, for additional safety.
Sources (5)
“introduces a new requirement to take the position of the vehicle and topography of its surrounding into account”
“introduces a new requirement allowing the usage of friction brakes for endurance braking, if recuperation is prevented in case of a too high battery state of charge of the traction battery”
“If friction brakes are used, it is always necessary that the remaining available brake deceleration after fulfilling the endurance brake requirements is still ≥ 5.0 m/s².”
“vehicles using the friction brakes shall be equipped with a brake estimator alerting the driver in case the efficiency of the brakes falls below the Type-II hot performance test”
“This is intended to provide additional safety”
Document trail
- 2020-07ProposalECE/TRANS/WP.29/GRVA/2020/30Proposal on modular vehicle combinations by the expert from the International Organization of Motor Vehicle Manufacturers
- 2020-07ProposalECE/TRANS/WP.29/GRVA/2020/36Proposal on endurance braking systems by the expert from Germany
- —Amended in sessionGRVA-07-71Amendments to ECE/TRANS/WP.29/GRVA/2020/30 by the expert from OICA
- —Amended in sessionGRVA-07-73-Rev.1Amendments to ECE/TRANS/WP.29/GRVA/2020/36
- —Working party adoptsECE/TRANS/WP.29/GRVA/7GRVA session report, paras. 62 and 69
- —Sent to WP.29ECE/TRANS/WP.29/2021/12Text that GRVA sent to WP.29 and AC.1
- —Working party adoptsECE/TRANS/WP.29/GRVA/8GRVA session report, para. 48: square brackets removed from the WP.29 document
- 2021-03WP.29 adoptsECE/TRANS/WP.29/1157Adopted at the 183rd session (session report, para. 137)
- 2021-09-30In forceC.N.308.2021.TREATIES-XI.B.16.13UN depositary notification
Q3Who is affected
Vehicle manufacturer
- Fit pneumatic and electric control lines to power-driven vehicles authorised to tow more than one O3 or O4 trailer.
- For O3 or O4 towing trailers, meet the special requirements of paragraphs 5.2.2.24. to 5.2.2.24.12., including the message routing function.
- For endurance braking systems with electric regenerative braking, check whether to use the option of paragraph 5.1.2.4.3.1. or 5.1.2.4.3.2.
- For vehicles under paragraph 5.2.1.29.7., describe the service braking performance assessment method with the Annex 18 documentation package.
- If endurance braking relies solely on electric regenerative braking, make sure the driver is informed before its braking force ends.
Component supplier
- Check that towing trailer braking equipment supports the message routing function defined in ISO 11992-2:2014 (para. 5.2.2.24.2.).
- Check that the amber warning request carries only information equivalent to pin 5 of the ISO 7638:2003 connector (para. 5.2.1.29.2.).
- Be ready for repeater devices where a trailer's electric control line is longer than ISO 11992-1:2003 permits (para. 5.2.2.17.3.).
Technical service / Approval authority
- Check the 0.4 second limit for the control line response time of towing trailers in Annex 6, paragraph 4.1.4.1.
- Check towing trailers with the new Annex 17, paragraph 4.3. checks, such as warning message transmission from rear to front.
- For the alternative of paragraph 5.1.2.4.3.2., check both tests of Annex 4, paragraph 1.8.2.5.
- Check the battery condition at the start of the Annex 4 tests in paragraphs 1.6.5. and 1.8.2.4.
- Check that the option of paragraph 5.1.2.4.3.1. is demonstrated to your satisfaction.
See every change side by side
RegVault customers compare every version of UN regulations, read the consolidated text and download the PDF.
ⓘ This report gives advice only. It is not legal or type-approval advice.
More UN R13 change reports
- 15 series — Supplement 3
- 15 series — Supplement 2
- 15 series — Supplement 1
- 15 series — Base text
- 14 series — Supplement 4
- 14 series — Supplement 3
- 14 series — Supplement 2
- 14 series — Supplement 1
- 14 series — Base text
- 13 series — Supplement 7
- 13 series — Supplement 6
- 13 series — Supplement 5
- 13 series — Supplement 4
- 13 series — Supplement 3
- 13 series — Supplement 2
- 13 series — Supplement 1
- 13 series — Base text
- 12 series — Supplement 9
- 12 series — Supplement 8
- 12 series — Supplement 7
- 12 series — Supplement 6
- 12 series — Supplement 5
- 12 series — Supplement 4
- 12 series — Supplement 3
- 12 series — Supplement 2
- 12 series — Supplement 1
- 12 series — Base text
- 11 series — Supplement 23
- 11 series — Supplement 22
- 11 series — Supplement 21
- 11 series — Supplement 20
- 11 series — Supplement 19
- 11 series — Supplement 17
- 11 series — Supplement 16