CEMA comments on EU COM Draft „Tcat_RVBR_v2_0“

Amendments compared to CEMA Working Document

„131113_CEMA_Draft_EU_Braking_Regulation“

CEMA response to EU COM comments in green font

Chapter I: Article 2 Definitions:

- 1 (CEMA): Definition of “maximum design speed” not carried over from CEMA proposal

Since on certain tractors the maximum design speed in the rearward direction is higher than

the maximum design speed in the forward direction, this definition clarifies that for the

various test requirements specified in RVBR, ''maximum design speed' means refers always to

the maximum design speed in the forward direction of travel.

In order to avoid any confusion CEMA proposes to add this definition to Article 2.

- 10: Definition of “electrical brake“

Was deleted in RVBR_v2. CEMA proposes to keep this definition to show the differences of the

different braking systems which are necessary for the understanding of the relevant braking

requirements.

It is essential that persons applying this Regulation do understand the differences between the

braking systems.

CEMA response: Delete in RVBR

- 11: Definition of “fluid brake”

This definition does not refer to braking systems with a hydraulic or pneumatic transmission.

E. g. endurance braking systems like retarders are considered to be a fluid brake.

- 13: Definition of parking brake

CEMA proposes to replace “parking brake” by “parking braking system”

- 20 (CEMA): Definition of “Hydraulic or pneumatic braking system with stored energy”

This definition has been moved in RVBR_v2 to Annex IV (below the heading of this annex).

CEMA prefers to have this definition in the general definition section since it is neither specific to Part

A or Part C of Annex IV nor has any relevance to Part B of Annex IV.CEMA response: From our point

of view the general definition section is still the preferred place. If due to legal reasons necessary,

placing to Annex IV could be accepted

- 25: Definition of “rigid draw bar towed vehicle”:

In RVBR_v2 the wording "The coupling to be used for a vehicle combination shall not consist

of a king pin and a fifth wheel." was changed to "The coupling to be used for a vehicle

combination shall not consist of a king pin and a fifth wheel and shall permit slight vertical

movement e.g. due to suspension movements".

CEMA is of the opinion that this amendment is wrong. Here, a "may-provision" has been

wrongly turned into a "shall-requirement".

Thus CEMA proposes to leave this definition unchanged (including the informative 'Note').

Notes:

1. Some slight vertical movement may occur at a rigid drawbar e.g. due to suspension

movements.

2. A hydraulically adjustable articulated drawbar is considered to be a rigid drawbar.

The “Notes”above are an additional explanation to the definition of the rigid draw bar, not a

requirement. CEMA strongly recommends to keep the “Notes” here in the definition section and to

do not move to the requirements.

The requirement in RVBR_v2 “…shall permit slight vertical movement e.g. due to suspension movements.” Must be removed.

- 26: Definition of “Control configurations for endurance braking systems”

The simplified definition in RVBR_v2 does not define the differences of the different control

configurations for endurance braking systems which are necessary for the understanding of

the relevant braking requirements.

It is essential that persons applying this Regulation do understand the different control

configurations for endurance braking systems.

Therefore, to delete these definitions (information) is seen as not appropriate.

Placing one specific control configuration ('integrated endurance braking system') under the

heading of the ABS Annex XI is seen as arbitrary since general requirements as to the

endurance braking systems are also in Annex I, Annex II, Annex II, Appendix I, Annex V, and

Annex VII.

Thus, CEMA proposes to keep the well known definitions of ECE R13 and Directive

71/320/EEC.

“Independent endurance braking system” means an endurance braking system whose control device

is separated from that of the service and other braking systems,

“Integrated endurance braking system” means an endurance braking system whose control device is

integrated with that of the service braking system in such a way that both endurance and service

braking systems are applied simultaneously or suitably phased by operation of the combined control

device,

“Combined endurance braking system” means an integrated endurance braking system, which in

addition has a cut-out device, which allows the combined control to apply the service braking

system alone.

The term “Integrated endurance braking system” is a subcategory of the term “endurance braking system”.

Therefore CEMA fears that it will cause confusion, if this defintion is dissolved from a common definition. The

context is needed to understand the different configurations of an endurance braking system. We see a big risk

that later many people have big problems of understanding the different control configurations for the

endurance braking systems and will have problems in interpreting the RVBR correctly.

The generic term “endurance braking system” is used in several Annexes in the RVBR and therefore

not specific to Annex XI..

- 28 (CEMA): Definition of „point-to-point“ was not carried over from CEMA proposal

In RVBR_v2 under the number (38) the definition "Data communication" is inserted into

Article 2.Closely related to this definition is the definition of "Point-to-point" Therefore

CEMA proposes to add this definition also to Article 2 and not to Annex XII.

This definition was moved by CEMA to Annex I, together with the amendment for Annex XII. Now it is

specific for Annex I and only mentioned there

- 32 (CEMA): Definition of “coupling force control” and 33 (CEMA) “nominal demand value”

In RVBR_v2 these definitions were moved to Annex I. Although these terms are not

expressively used in Appendix 1 of Annex II, requirements concerning coupling force control

are also indirectly laid down in this Appendix 1 (see e.g. compatibility Diagram 2 and

paragraph 6.2 of Appendix 1).

Thus, CEMA proposes to have these definitions in Article 2.

CEMA agrees that these two terms can only be found in Annex I. However, it was chosen to move

these only two left-over defintions to Article 2 out of the following reasons:

- Both definition are very closely< related to the compatibility requirements of Annex II,

therefore the definition are not specific to Annex I

- No European braking Regulation defines the parameters which have to be considered when

the characteristic lines of the

"Permissible relationship between braking rate TM/FM or TR/FR and the coupling head pressure

pm..."is established. One of these parameters is the "Nominal demand value".

Out of this reason the parameter "Nominal demand value" is not specific to Annex I.

- 34 (CEMA): Definition of „braking signal“

In RVBR_v1 this definition is left in Annex XII.

However, the definition for the "Braking signal" is not specific to Annex XII.

Additionally, there are also for this braking signal "may-requirements" not related to EBS

vehicles.

Since this signal is only required in the case of "EBS vehicles" this definition was previously

added to the definition sector of Annex XII. Thus, CEMA is in favour to move this definition to

the general definition section of Article 2.

This definition was moved by CEMA to Annex I, together with the amendment for Annex XII. Now it is

specific for Annex I and only mentioned there

- 35 (CEMA): Definition of “subject towed vehicle”

In RVBR_v2 this definition is placed in Annex VII.

CEMA is of the opinion that this definition should be placed in Article 2 and not in Annex VII

since this term is not specific to Annex VII (although it is currently only used there). This will

be obvious should the agricultural "RAR" also accept Test Reports as to ECE R13.

Note:The GRRF has only recently moved the definition of "Subject trailer" from the special

Annex 20 of to the general definition section of the body of ECE R13.

- 36 (CEMA): Definition of „axle group“

In RVBR_v2 this definition is located in Annex II below its heading.

This definition of "Axle group" is not seen as specific to Annex II (in particular when the

agricultural RAR also accepts Test Reports according to ECE R13). As done with the

definition (35) "Subject towed vehicle", this definition was also recently added to the general

part of ECE R13. CEMA proposes to move this definition to Article 2.

- 38 (CEMA): Definition of „brake factor“

This definition was not carried over to RVBR_v2. CEMA is of the opinion that for the time

being this definition should stay in article 2 of the agricultural braking Regulation as a

reminder. This definition was recently amended by the GRRF since this definition was

wrongly applied in ECE R13.

When the Commission presents the first draft of the new RAR this definition may be moved to

the RAR.

- Definitions (33) to (37):

CEMA prefers not to move the following definitions (33) to (37) of Article 2 in RVBR_v2 from

their respective special annexes. In our opinion these definition are specific to corresponding

annex. It is assumed that braking experts expect to find these definitions in the special annexes

as it is the case with other international regulations.

(33) „spring compression chamber“ move to Annex V

(34) „hydrostatic drive“ move to Annex IX

(35) „complex electronic systems“ move to Annex X

(36) „anti-lock-systems“ move to Annex XI

(37) „directly controlled wheels“ move to Annex XI

(39) „hydraulic connection of single conduit type“ move to Annex XIII

Chapter II: Article 16 & Chapter III, Article 17

After further detailed internal discussion and discussion with Member States, CEMA came to the

conclusion that the transitional period of 10 years for the hydraulic connection of the single conduit

type as proposed in „131113_CEMA_Draft_EU_Braking_Regulation“ is not appropriate. Therefore

CEMA proposes to amend Chapter II, Article 16 and Chapter III, Article 17 of RVBR as follows:

Article 16

Requirements for hydraulic connections of the single-conduit type and trailer braking couplings

The performance requirements applying to vehicles fitted with hydraulic connections of the

single-conduit type of braking devices and with trailer braking couplings referred to in line

No 3 of Annex I to Regulation (EU) No 167/2013 are laid down in Annex XIII to this

Regulation.

Vehicle manufacturers may fit such device to new types of vehicles of category T and C

until 31 December 2019 and to new vehicles of these categories until 31 December 2020.

Article 17

Type-approval of vehicles, systems, components and separate technical units

Pursuant to Article 6(2) of Regulation (EU) 167/2013, with effect from 1 January 2016,

approval authorities shall grant EU type-approval to agricultural and forestry vehicle types

which comply with the requirements of this regulation.

With effect from 1 January 2020 and in accordance with Article 6(2) of Regulation (EU)

167/2013 and Article 16 of this Regulation, type approval authorities shall refuse to grant

type-approval to vehicle types of categories T and C fitted with hydraulic connections of the

single-conduit type of braking devices set out in Article 16.

….

With effect from 1 January 2021, for new vehicles fitted with hydraulic connections of the

single-conduit type, national authorities shall consider certificates of conformity to be no

longer valid for the purposes of Article 38 (1) of Regulation (EU) No 167/2013 and shall

prohibit the making available on the market, registration, or entry into service of such

vehicles.

Annex I:

2.1.1.5 Towed vehicles fitted with braking systems and designed to have more than

one loading condition shall will be equipped with an automatic load sensing

device, if the ratio of technically permissible maximum laden mass to unladen

mass exceeds … […]

To add a payload ratio is impossible, as it has not influence on the intention of this paragraph. Please change back to the original CEMA proposal. The intention of this paragraph is to allow manual load sensing devices in the case of strong reason that due to insufficient spring travel automatic load sensing devices cannot be used. Then it is permissible to use brake load regulators with a manual adjusting device with at least three settings. All requirements regarding distribution of braking and compatibility requirements are prescribed in Annex II. To fulfill those requirements it is allowed to use load sensing devices, but it is not mandatory. The requirements of Annex II must be fulfilled, no matter with or without load sensing. To demand for mandatory load sensing here in this paragraph would be design restrictive.

This first sentence of Annex I, 2.1.1.5 of RVBR_v2 demands for mandatory

fitting of load sensing devices on all vehicles of category R and S with more

than one load condition. This sentence must be deleted. The original intention

of this paragraph is to allow load sensing devices other than automatic systems

for vehicles < 30 km/h (e.g. by a lever with two or three positions) .A

mandatory fitting of towed vehicles with load sensing having more than one

loading condition is wrong, as there may be vehicles which may have only a

small pay load and do not need load sensing to fulfill the requirements of

Annex II.

CEMA proposal for 2.1.1.5:

2.1.1.5 If a towed vehicle with a maximum design speed not exceeding 30 km/h

cannot be equipped for technical reasons with an automatic load sensing

device, it may be equipped with a device having at least three discrete settings

for the control of the braking forces.

In the special case that a towed vehicle allows by design that only two discrete

loading conditions “unladen” and “laden” can be realized then the vehicle may

have only two discrete settings for the control of the braking forces.

__________________________________________________________________________________

2.1.4.1.3 One pneumatic supply line and one electric control line. Until uniform

technical standards have been agreed, which ensure compatibility and safety,

connections between tractors and trailers conforming to the provisions of this

paragraph shall not be permitted.

This paragraph is carried over from ECE-R13. The way as ECE-R13 is drafted assumes that the configuration of “one electric control line only” really exists. Therefore the corresponding

requirements in the Annexes are given. With the footnote this option is not allowed for the time being. But in practice, all current systems are designed as if this option would be allowed. This ensures that beginning from the point in time the footnote is deleted, all the existing and the new EBS systems are compatible to each other. If it is now written explicitly in the main body of the regulation that this option is forbidden (therefore not exists), why should then all the according requirements be kept in the regulation? Please check our justification Part B to see a list of all the paragraphs covering provisions for the “electric control line only” requirements.

The text in red font is intended by CEMA to be in a footnote and not in the main text

of the regulation. In RVBR_v2 the Commission has removed the footnote3 and added

this footnote directly into the text of paragraph 2.1.4.1.3. This is not desirable for the

following reasons:

It is currently prohibited for a towing vehicle or trailer to be approved with only an

electric control line. However, it is possible that the legislator will delete at some

time this footnote. In this case, forward and downward compatibility of the EBS must

be ensured for all vehicles (old and new) connected by "an only electric control

line". Thus, there are more than ten EBS requirements in this Regulation which deal

with this possible configuration where only "one pneumatic supply line and one

electric control line" is fitted. Even as this configuration is today forbidden by this

'famous' and well-know footnote3, all EBS vehicles today have also to comply with

these specific "electric control line only" requirements. By taking away this

footnote3, the configuration of paragraph 1.1.4.1.3 is for the setup of the agricultural

braking Regulation is not an option anymore.

CEMA is of the opinion that it is much more practical and simpler to leave this

footnote in the agricultural braking Regulation than to look into the aforementioned

"electric control line only" requirements throughout the Regulation and to suggest

amendments as necessary.

__________________________________________________________________________________

2.1.5.1.1 With the engine running and the parking brake of the tractor fully applied:

- a pressure of 0+100

kPa is present on the supplementary line and

- the pressure generated on the control line shall either be 0+100

kPa, or between

11500 and 15000 kPa.

It seems that this paragraph was changed due to a comment from UK. This

means that the supplementary line must always be evacuated when the parking

brake is fully applied.

The CEMA proposal as provided in

„131113_CEMA_Draft_EU_Braking_Regulation“:

1.1.5.1.1 With the engine running and the parking brake of the tractor fully applied:

- a pressure of 0+100 kPa is present on the supplementary line and/or

- a pressure between 11.500 kPa and 15.000 kPa is generated on the control

line

provides 3 options when the parking brake of the tractor is fully applied:

1st) supplementary line pressure 0 kPa (irrespective of the pressure in the

control line)

2nd) control line pressure between 11.500 kPa and 15.000 kPa (irrespective of

the pressure in the supplementary line)

3rd) supplementary line pressure 0 kPa and control line pressure between

11.500 kPa and 15.000 kPa

The UK proposal does not allow the 2nd option and demands that always both

the supplementary line pressure and the control line pressure must be of

certain prescribed pressure conditions. In this respect the UK proposal is

regarded to be very design restrictive and unacceptable from CEMA side:

o Compared to the pneumatics the parking brake performance is only allowed

to be achieved by 0 kPa on the supplementary line. The option to only

pressurize the control line is not given.

o It is taken away the possibility that when the parking brake is used as a

secondary braking system on the tractor, the towed vehicle can control its

braking action by the ABS if it is fitted with this system. To do not allow this

safety feature is not acceptable.

Further we see the proposed condition “the pressure generated on the control

line shall either be 0+100

kPa, or between 11500 and 15000 kPa” as confusing

and not applicable for towed vehicle manufacturers. How should the towed

vehicle know, which pressure the tractor will deliver (low or high)? As usual

for type approval, only worst case situation will be considered, that means 0

kPa. The allowed additional pressure range from 11500 to 15000 kPa might be

useless.

The intention of this paragraph is to ensure a defined braking action on the towed vehicle, when the parking braking system on the tractor is fully applied. (performance requirement). To fulfil this requirement, 3 options are possible. Starting point for this consideration is the tractor with the engine running and the control of the service braking system on the tractor fully released. That means a pressure of 0 kPa on the control line and a pressure between 1500-3500 kPa on the supplementary line (this pressure is necessary to open the spring on the towed vehicle, that means no brake applied) The 3 options to brake the towed vehicle are:

1. Evacuation of the supplementary line (= 0 kPa).The spring comes into action to brake the towed vehicle.

2. Pressurizing the control line with a pressure between 11500 and 15000 kPa. This pressure range ensures full service braking performance on the towed vehicle. Therefore a pressure below 11500 kPa is not accepted. The supplementary line is allowed to be between 0-3500 kPa

3. Evacuation of the supplementary line (=0kPa) and pressurizing the control line to a pressure of 11500 to 15000 kPa.This can be considered as doubled the options 1. And 2., but it leads to a safe condition and we see no reason to prohibit this option.

The UK proposal does not allow the 2nd option, which could be a pressure of 11500-15000 kPa on the control line and a pressure of 1500-3500 kPa on the supplementary line. This condition would mean, that the braking performance is achieved by the control line pressure only, the spring is fully opened via the supplementary pressure. This condition is considered as absolutely safe.

But only this condition(actuation of the service braking system of the towed vehicle only) makes it possible to control the braking action with an ABS when the braking is performed dynamically during driving. If the spring would come into by evacuation of the supplementary line, this could not be controlled by an ABS. If there is an emergency on the tractor and the secondary braking system must be applied during driving, also the towed vehicle must be braked. In most cases, the control of the parking braking system is used for this action. To have the option to control this braking action on the towed vehicle with an ABS would be a big safety gain __________________________________________________________________________________

2.1.8.1.2. In a braking system which incorporates a device that modulates the air or

hydraulic pressure in the brake transmission, located in the pressure line

upstream and downstream of this device at the closest accessible position.

At the moment for road vehicles one test point before and after a load sensing

device is required whereas now it is required for any device that modulates the

air or hydraulic pressure in the whole brake transmission.

Even if this requirement should not make a substantial differences to current

braking systems it should not be accepted since no one knows today which

detrimental effect it may have for future developments. Therefore CEMA

prefers the proposal from „131113_CEMA_Draft_EU_Braking_Regulation“

which refers only to load sensing devices:

2.1.8.1.2. In a braking system which incorporates a pressure modulation device as

referred to in paragraph 6.2. of Appendix I of Annex II, located in the pressure

line upstream and downstream of this device at the closest accessible position.

_________________________________________________________________________

2.2.1.9 The service, secondary and the parking braking systems shall act on braking

surfaces permanently connected to the wheels through components of adequate

strength. It shall not be possible to disconnect a braking surface from the

wheels; however, such disconnection shall be permitted in the case of the

parking braking system, provided that it is controlled exclusively by the driver

from his driving seat by a system which cannot be actuated by a leak. When

more than one axle is normally subject to braking in the case of vehicles of

categories T and C with a maximum design speed not exceeding 40 km/h, one

axle may be decoupled provided that activation of the service braking system

automatically re-couples this axle and that, in the case of a failure in the energy

supply or a failure in the control transmission of the re-coupling control device,

then automatic re-coupling shall be ensured.

CEMA propose 60 km/h as an appropriate speed limit for this requirement. It must be

allowed that tractors with design speed > 40 km/h using brakes on the rear-axle only

are allowed to disengage the All-wheel-drive during driving. In RVBR_v2 the speed

limit of 40 km/h was not changed to 60 km/h as agreed during the meeting with COM,

CLEPA and CEMA on 21st Nov 2013.

_________________________________________________________________________________

2.2.1.17.1: Deleted in „131113_CEMA_Draft_EU_Braking_Regulation“

This paragraph was deleted as already covered by 2.2.1.16.3. Further CEMA is of the

opinion that the requirement of the graduable braking action is appropriate for Tb

tractors only. Old 2.2.1.17.1 would have demanded this requirement for all categories

of tractors. Thus, it is in contradiction to 2.2.16.2.

__________________________________________________________________________________

2.2.1.19.1 Editorial amendment:

By way of derogation from paragraph 2.2.1.19, in order to improve the driving

behaviour of the vehicle combination by modifying the coupling force between

the tractor and towed vehicle, it is permissible to apply by automatic means the

towed vehicle brakes up to a time of 5 s without the operation of the service,

secondary or parking braking system of the tractor.

CEMA proposes to replace the word "reducing" by the word "modifying" due

to the fact that by applying the trailer brakes the coupling force (due to

different braking ratios of the individual vehicles) may also increase under

transient conditions resulting from the vehicle/road dynamics.

Annex II:

2.1.3.4. On tractors to which the coupling of towed vehicles is authorised, the parking

braking system of the tractor shall be capable of holding the vehicle combination, at

the maximum permissible mass as specified by the tractor manufacturer, stationary

on a 12 % up or down gradient.

In the case that this requirement cannot be met due to physical limitations (e.g.

limited available tyre/road adhesion for the tractor to generate sufficient braking

forces) this requirement is deemed to be fulfilled when the alternative requirement of

paragraph 2.1.3.4.1 in connection with paragraph 2.2.1.20 of Annex I is complied

with. By way of derogation from paragrapah 1.2.1.19, in order to improve the driving

behaviour of the vehicle combination by modifying the coupling force between the

tractor and the towed vehicle, it is permissible that towed vehicle brakes are applied

automatically up to a time of 5 s without the operation of the service, secondary or

parking braking system of the tractor.

Delete the crossed out sentence. This was a typing mistake in the CEMA document

and is totally wrong in this context.

This requirement still exists in paragraph 2.2.1.19.1 of Annex I.

Annex II, Appendix 1:

2. Symbols: COM remark is correct. PR must be exchanged by FR as done in

„131113_CEMA_Draft_EU_Braking_Regulation“

Annex III:

1.1 COM question:

Editorial amendment:

"of the least efficient brake cylinder" replaced by "of the least favourably placed brake". To

clarify with CEMA

This editorial amendment was done by CEMA to align the wording "least efficient brake

cylinder" with the current ECE R13 wording and the wording of some other paragraphs of

RVBR using the expression: "least favourably", compare paragraphs AI/2.1.8.1.1,

AI/2.1.8.1.3, AII/2.3.1.1, AIV/2.4.1

__________________________________________________________________________________

3.6.2: CEMA prefers to replace “displacement volume” by “displaced volume”

Appendix 2: CEMA prefers to replace “displacement” by “displaced volume” in the

diagram

Annex IX:

CEMA proposal for new additional paragraph 5.4.3. was not carried over into RVBR_v2:

5.4.3. As an alternative to the procedure with continuous braking defined by paragraphs

5.4.1 and 5.4.2 above, the test procedure defined in Annex II, paragraph 1.3.1 with repeated

braking may also be used.

The possibility to do the Type-I test with repeated braking is an important alternative for slow

and very heavy tractors. To pull very heavy tractors for this test, even bigger tractors for this

test only are necessary. This is seen as not justifiable burden for manufacturers which can be

avoided by allowing the repeated braking test as an alternative.

Annex X:

CEMA proposes to delete the complete version of Annex X as in current draft RVBR_v2 and

only have here the definition of the complex electronic systems and the reference to ECE-R13.

Adaption of some references throughout the regulation would be necessary, see document

provided by CLEPA “Draft proposal to amend RVBR Annex X”

All complex electronic vehicle control systems, as defined by UN(ECE)

Regulation No. 13, shall comply with the provisions of Annex 18 of that

Regulation.

Annex XI:

CEMA proposes the following amendments in the definition section to this Annex:

1. Integrated endurance braking system: Not specific to this Annex. CEMA proposes to move

to the general defintion of this regulation.

2. Indirectly controlled wheels: doubled. Remove one sentence (editorial)

3. In the case of towed vehicles with… : should move to 4.7 as proposed by CEMA

See our comment as to Article 2, Definition 26 1.3: COM question: This paragraph is useful, as it

is allowed to install ABS as an option also for vehicles with a design speed below 40 km/h.

_________________________________________________________________________________

3.5.3. The anti-lock braking system shall automatically be reconnected/returned to on-road mode

when the ignition (start) device is again set to the ‘on’ (run) position or the vehicle speed

exceeds 30 km/h;

EU COM comment: UK proposal to delete this point.

CEMA response:

Automatic reconnection of the ABS system when the ignition is set to the run position again is of

paramount importance for the safety of the driver. It cannot not be ensured that the driver will do this

manually when going on-road again. The speed limit for automatic reconnection should also remain,

as with ABS it is not required to fulfil the requirements of adhesion and distribution of braking. In

contrast to ECE-R13 it is not required to fulfil these requirements when ABS is switched off. CEMA

could agree to change this speed limit to 40 km/h to increase driving behaviour on loose grounds with

off-road mode engaged.

Annex XIII:

Annex XIII as proposed in „131113_CEMA_Draft_EU_Braking_Regulation“does only

consider the current French type hydraulic trailer braking system as prescribed in 2009/144

EC. After further detailed internal discussion and discussion with Member States, CEMA

came to the conclusion that the existing CUNA system from Italy must also be considered

here to ensure compatibility with existing for a transitional period. Therefore CEMA proposes

to amend Annex XIII as follows:

Hydraulic connections of the single-conduit type

1. General

1.1 In addition to at least one type of connection as defined in paragraph 2.1.4 or

the types of connections as defined in paragraph 2.1.5.1 a) to c) of Annex I of

this regulation a hydraulic connection of the single conduit type may be

installed on the towing vehicle.

1.2 The service braking system of the towing vehicle shall be so designed that if

the towed vehicle braking system should fail, or the control line between the

towing vehicle and towed vehicle should break, it will still be possible to brake

the towing vehicle with the effectiveness prescribed for the secondary braking

system as defined in Annex II of this regulation.

CEMA proposes to have here a clear reference to the requirements for the secondary braking performance as laid down in Annex II

2. Hydraulic connections of the single-conduit type between tractors and towed

vehicles with hydraulic braking system shall fulfil the following requirements:

2.1 Type of connection: hydraulic control line with the male connector on the

tractor and the female connector on the towing vehicle. The connectors shall

comply with ISO 5676:1983

2.2 With the engine running and the control of the service braking system of the

tractor fully applied a pressure between 10000 kPa and 15000 kPa shall be

generated on the control line.

2.3 The response time requirements of Annex III of this regulation do not apply to

this type of connection.

2.4 The compatibility requirements according to Appendix 1 of Annex II of this

regulation do not apply to this type of connection.

2.5 In addition to the requirements as defined in paragraphs 2.1 to 2.4 of this

Annex, either the requirements from the following paragraph 2.5.1 or from

both paragraphs 2.5.2 and 2.5.3 shall be fulfilled:

These 3 paragraphs do not exist in Annex II. Only specific to those single line systems.

2.5.1 With the engine running and no brake control on the tractor applied (driving or

stand-by condition), the pressure supplied at the coupling head of the control

line shall be 0+200 kPa.

2.5.2 With the engine running and no brake control on the tractor applied (driving or

stand-by condition), the pressure supplied at the coupling head of the control

line shall be between 1000 and 1500 kPa.

2.5.3 With the parking brake of the tractor fully applied and/or the engine not

running, the pressure supplied at the coupling head of the control line

shall be 0 kPa.