{ "url": "https://openlegislation.uk/eu-regulation-2015-68/annex-II/appendix-1", "json_url": "https://openlegislation.uk/eu-regulation-2015-68/annex-II/appendix-1.json", "legislation": "eur/2015/68", "legislation_title": "Commission Delegated Regulation (EU) 2015/68 of 15 October 2014 supplementing Regulation (EU) No 167/2013 of the European Parliament and of the Council with regard to vehicle braking requirements for the approval of agricultural and forestry vehicles (Text with EEA relevance)", "legislation_url": "https://openlegislation.uk/eu-regulation-2015-68", "path": "annex/II/appendix/1", "kind": "appendix", "number": "1", "heading": null, "text": "Distribution of braking among the axles of vehicles and requirements for compatibility between tractor and towed vehicle\n1.\nGeneral requirements\n1.1.\nVehicles of categories T, C, R and S\n1.1.1.\nVehicles of categories Ta, Ca, R2a, R3a, R4a and S2a with a maximum design speed exceeding 30 km/h shall fulfil the following requirements of this Appendix:\n1.1.1.1. the compatibility requirements associated with diagrams 2 and 3, as appropriate, if a special device is used, this shall operate automatically. In the case of trailers with electronically controlled brake force distribution, the requirements of this appendix shall only apply when the trailer is electrically connected to the tractor by the ISO 7638:2003 connector.\n1.1.1.2. in the event of a failure of the control of the special device the braking performance specified in point 5 shall be fulfilled for the relevant vehicle.\n1.1.1.3. the marking requirements laid down in point 6.\n1.1.2.\nVehicles of categories Tb, R2b, R3b, R4b and S2b shall meet the relevant requirements of this Appendix. If a special device is used, this shall operate automatically.\n1.1.3.\nHowever, vehicles of the categories mentioned in point 1.1.1 and in point 1.1.2 both equipped with an anti-lock braking system of category 1 or 2 (tractors) and category A or B (towed vehicles) fulfilling the relevant requirements of Annex XI shall also fulfil all the relevant requirements of this Appendix with the following exceptions or conditions:\n1.1.3.1. compliance with the adhesion utilisation requirements associated with diagram 1 is not required;\n1.1.3.2. in the case of tractors and towed vehicles, compliance with the unladen compatibility requirements associated with diagrams 2 and 3 as appropriate, is not required. However, for all load conditions, a braking rate shall be developed between a pressure of 20 kPa and 100 kPa (pneumatic braking systems) and 350 to 1 800 kPa (hydraulic braking systems) or the equivalent digital demand value at the coupling head of the control line(s);\n1.1.3.3. vehicles equipped with a special device which automatically controls the distribution of braking among the axles or automatically regulates the braking force according to the load on the axle(s) the requirements of points 5 and 6 shall apply.\n1.1.4.\nWhere the vehicle is installed with an endurance braking system, the retarding force shall not be taken into consideration when determining the vehicle performance with respect to the provisions of this Appendix.\n1.1.5.\nThe requirements of this Appendix apply to the braking equipment fitted with the largest diameter tyres intended by the manufacturer for that vehicle type.\n1.1.6.\nCompliance with the adhesion utilisation and compatibility requirements associated with diagrams 1, 2 and 3 of this Appendix shall be demonstrated by calculation.\n1.2.\nThe requirements relating to the diagrams specified in points 3.1.6.1, 4.1 and 4.2, are valid for vehicles with a pneumatic and electrical control line according to point 2.1.4 of Annex I or a hydraulic control line according to point 2.1.5 of Annex I. In all cases, the reference value (abscissa of the diagrams) will be the value of the transmitted pressure or electrical signal respectively in the control line:\n1.2.1. For vehicles equipped according to point 2.1.4.1.1 of Annex I, this value will be the actual pneumatic pressure in the control line (pm);\n1.2.2. For vehicles equipped according to point 2.1.4.1.2 or 2.1.4.1.3 of Annex I, this value will be the pressure corresponding to the transmitted digital demand value in the electric control line, according to ISO 11992:2003 including ISO 11992-2:2003 and its Amd.1:2007.\nVehicles equipped according to point 2.1.4.1.2 of Annex I (with both pneumatic and electric control lines) shall satisfy the requirements of the diagrams related to both control lines. However, identical braking characteristic curves related to both control lines are not required.\n1.2.3. For vehicles equipped according to point 2.1.5.1 of Annex I, this value shall be the actual hydraulic pressure in the control line (pm).\n1.3.\nValidation of the development of braking force.\n1.3.1.\nAt the time of type-approval it shall be checked that the development of braking on an axle of each independent axle group shall be within the following pressure ranges:\n1.3.1.1. Laden vehicles:\nAt least one axle shall commence to develop a braking force when the pressure at the coupling head is within the pressure range 20 to 100 kPa (pneumatic braking systems) and 350 to 1 800 kPa (hydraulic braking systems) respectively or equivalent digital demand value.\nAt least one axle of every other axle group shall commence to develop a braking force when the coupling head is at a pressure ≤ 120 kPa (pneumatic braking systems) and 2 100 kPa (hydraulic braking systems) respectively or equivalent digital demand value.\n1.3.1.2. Unladen vehicles:\nAt least one axle shall commence to develop a braking force when the pressure at the coupling head is within the pressure range 20 to 100 kPa (pneumatic braking systems) and 350 to 1 800 kPa (hydraulic braking systems) respectively or equivalent digital demand value.\n1.3.1.3. With the wheel(s) of the axle(s) raised off and free to rotate, apply an increasing brake demand and measure the coupling head pressure corresponding to when the wheel(s) can no longer be rotated by hand. In the case of tractors of category C an alternative procedure may be used for the validation of the development of braking force (e.g. by removing the tracks). This condition determines the development of the braking force.\n2.\nSymbols\ni axle index (i = 1, front axle; i = 2, second axle; etc.)\nE wheelbase\nER distance between coupling point and centre of axle of rigid drawbar towed vehicle and of centre-axle towed vehicle\nfi Ti/Ni, adhesion utilised by axle i\nFi normal reaction of road surface on axle i under static conditions\nFM total normal static reaction of road surface on wheels of tractor\ng acceleration due to gravity: g = 9,81 m/s2\nh height above ground of centre of gravity specified by the manufacturer and agreed by the Technical Services conducting the approval test;\nJ deceleration of vehicle\nk theoretical coefficient of adhesion between tyre and road\nP mass of vehicle\nNi normal reaction of road surface on axle i under braking\npm pressure at coupling head of control line\nFR total normal static reaction of road surface on all wheels of towed vehicle\nFRmax value of FR at maximum mass of towed vehicle\nTi force exerted by the brakes on axle i under normal braking conditions on the road\nTM sum of braking forces at the periphery of all wheels of tractors\nTR sum of braking forces Ti at periphery of all wheels of towed vehicle\nz braking rate of vehicle = J/g\n3.\nRequirements for tractors of category T\n3.1.\nTwo-axle tractors\n3.1.1.\nFor k values between 0,2 and 0,8:\nz ≥ 0,10 + 0,85 (k-0,20)\nThe provisions laid down in this point do not affect the requirements of Annex II relating to the braking performance. However, if, in tests made under the provisions of this point, braking performances are obtained which are higher than those prescribed in Annex II, the provisions relating to the adhesion utilization curves shall be applied within the areas of diagram 1 defined by the straight lines k = 0,8 and z = 0,8.\n3.1.2.\nFor all braking rates between 0,15 and 0,30:\n3.1.2.1.\nThe adhesion utilization curves for each axle are situated between two lines parallel to the line of ideal adhesion utilization given by the equation k = z +/–0,08 as shown in diagram 1 and the adhesion utilization curve for the rear axle for braking rates z > 0,3 complies with the relation:\nz ≥ 0,3 + 0,74 (k − 0,38).\n3.1.3.\nFor tractors authorised to tow vehicles of category R3b, R4b and S2b fitted with compressed-air braking systems:\n3.1.3.1.\nWhen tested with the energy source stopped, the supply line blocked off, a reservoir of 0,5 litre capacity connected to the pneumatic control line and the system at cut-in and cut-out pressures, the pressure at full application of the braking control device shall be between 650 and 850 kPa at the coupling heads of the supply line and the pneumatic control line, irrespective of the load condition of the vehicle.\n3.1.3.2.\nFor vehicles equipped with an electric control line, a full application of the control device of the service braking system shall provide a digital demand value corresponding to a pressure between 650 and 850 kPa (see ISO 11992:2003 including ISO 11992-2:2003 and its Amd.1:2007).\n3.1.3.3.\nThese values shall be demonstrably present in the tractor when the latter is uncoupled from the towed vehicle. The compatibility bands in the diagrams specified in points 3.1.6, 4.1 and 4.2, should not be extended beyond 750 kPa and/or the corresponding digital demand value (see ISO 11992:2003 including ISO 11992-2:2003 and its Amd.1:2007).\n3.1.3.4.\nIt shall be ensured that at the coupling head of the supply line, a pressure of at least 700 kPa is available when the system is at cut-in pressure. This pressure shall be demonstrated without applying the service brakes.\n3.1.4.\nFor tractors authorised to tow vehicles of category R3b, R4b and S2b fitted with hydraulic braking systems:\n3.1.4.1.\nWhen tested with the energy source at idling speed and of 2/3 of maximum engine speed, a control line of the towed vehicle simulator (point 3.6 of Annex III) connected to the hydraulic control line. At full application of the braking control device the pressures shall be between 11 500 and 15 000 kPa at the hydraulic control and shall be between 1 500 and 3 500 kPa at the supplementary line, irrespective of the load condition of the vehicle.\n3.1.4.2.\nThese values shall be demonstrably present in the tractor when uncoupled from the towed vehicle. The compatibility bands in the diagrams specified in points 3.1.6, 4.1 and 4.2, should not be extended beyond 13 300 kPa.\n3.1.5.\nVerification of the requirements of points 3.1.1 and 3.1.2\n3.1.5.1.\nIn order to verify the requirements of points 3.1.1 and 3.1.2, the manufacturer shall provide the adhesion utilisation curves for the front and rear axles calculated by the formulae:\nf1 = T1 N1 = T1 F1 + z × h E × P × g\nf2 = T2 N2 = T2 F2 − z × h E × P × g\nThe curves shall be plotted for both the following load conditions:\n3.1.5.1.1.\nUnladen, not exceeding the minimum mass declared by the manufacturer in the information document;\n3.1.5.1.2.\nLaden; where provision is made for several possibilities of load distribution, the one whereby the front axle is the most heavily laden shall be the one considered.\n3.1.5.2.\nSpecial requirements in the case of tractors where all axles are permanently rigidly connected (100 % locking rate) by the all-wheel drive or are automatically connected during braking by the all-wheel drive (100 % locking rate)\n3.1.5.2.1.\nThe mathematical verification pursuant to point 3.1.5.1 is not required.\n3.1.5.3.\nTractors with permanent all-wheel drive other than covered by point 3.1.5.2.\n3.1.5.3.1.\nIf it is not possible, for vehicles with permanent all-wheel drive or in the condition when the all-wheel drive is connected during braking, to carry out the mathematical verification pursuant to point 3.1.5.1, the manufacturer may instead verify by means of a wheel lock sequence test that, lockup of the front wheels occurs either simultaneously with or before the lockup of the rear wheels.\n3.1.5.4.\nHowever, for tractors which automatically apply the all-wheel drive when the braking is initiated above a vehicle speed of 20 km/h but not automatically connect the all-wheel drive when the service braking system is applied at speeds not exceeding 20 km/h, then it is not required to show compliance with point 3.1.5.1 for the condition when the all-wheel drive is not connected during braking.\n3.1.5.5.\nProcedure to verify the requirements set out in point 3.1.5.3\n3.1.5.5.1.\nThe wheel lock sequence test shall be conducted with the laden and the unladen vehicle on road surfaces having an adhesion level such that wheel locking on the first axle occurs at braking rates between 0,55 and 0,8 from the initial test speed specified in point 3.1.5.5.2.\n3.1.5.5.2.\nTest speed:\n0,9 vmax, but not exceeding 60 km/h.\n3.1.5.5.3.\nThe pedal force applied may exceed the permissible actuation forces pursuant to point 3.1.1 of Annex II.\n3.1.5.5.4.\nPedal force is applied and increased such that the second wheel on the vehicle shall reach lockup between 0,5 and 1 s after initiating the brake application, until lockup of both wheels on one axle occurs (additional wheels may also lock during the test, e.g. in the case of simultaneous lockup).\n3.1.5.5.4.1.\nIf it is not possible during the laden test to reach lockup of the second wheel within a period of 1 s, this test may be omitted under the condition that wheel-locking under the conditions as prescribed in point 3.1.5.5.4 can be demonstrated during the unladen test.\nIf also in the unladen test it is not possible to reach lockup of the second wheel within a period of 1 s, a third, decisive test shall be carried out on road surfaces with a coefficient of adhesion of not more than 0,3 from a test speed of 0,8 vmax km/h, but not exceeding 60 km/h.\n3.1.5.5.4.2.\nFor the purpose of the tests according to point 3.1.5.5, a simultaneous lockup of the front and rear wheels refers to the conditions when the time interval between the first occurrence of lockup of the last (second) wheel on the rear axle and the first occurrence of lockup of the last (second) wheel on the front axle does not exceed 0,3 second.\n3.1.6.\nTractors authorized to draw towed vehicles\n3.1.6.1.\nThe permissible relationship between the braking rate T M /F M and the pressure p m shall lie within the areas shown on diagram 2 for all pressures between 20 and 750 kPa (in the case of compressed air braking system) and 350 and 13 300 kPa (in the case of hydraulic braking system).\n3.2.\nTractors with more than two axles\nThe requirements of point 3.1 shall apply to vehicles with more than two axles. The requirements of point 3.1.2 with respect to wheel lock sequence shall be considered to be met if, in the case of braking rates between 0,15 and 0,30, the adhesion utilised by at least one of the front axles is greater than that utilised by at least one of the rear axles.\n4.\nRequirements for towed vehicles\n4.1.\nFor drawbar towed vehicles fitted with compressed-air and hydraulic braking systems:\n4.1.1. For drawbar towed vehicles with two axles the following requirements apply:\n4.1.1.1. For k values between 0,2 and 0,8:\nz ≥ 0,1 + 0,85 (k – 0,2)\nThe provisions of point 3.1.1. do not affect the requirements of Annex II relating to the braking performance. However, if, in tests made under the provisions of point 3.1.1, braking performances are obtained which are higher than those prescribed in Annex II, the provisions relating to the adhesion utilisation curves shall be applied within the areas of diagrams 1 of this Annex defined by the straight lines k = 0,8 and z = 0,8.\n4.1.1.2. For all states of load of the vehicle, the adhesion utilisation curve of the rear axle shall not be situated above that for the front axle for all braking rates between 0,15 and 0,30. This condition is also considered satisfied if, for braking rates between 0,15 and 0,30, the following two conditions are satisfied:\n4.1.1.2.1. the adhesion utilisation curves for each axle are situated between two lines parallel to the line of ideal adhesion utilisation given by the equations k = z + 0,08 and k = z – 0,08 as shown in diagram 1\nand\n4.1.1.2.2. the adhesion utilisation curve for the rear axle for braking rates z ≥ 0,3 complies with the relation z ≥ 0,3 + 0,74 (k – 0,38).\n4.1.1.3. For the verification of the requirements of points 4.1.1.1 and 4.1.1.2 the procedure should be as that in the provisions of point 3.1.5.\n4.1.2. For drawbar towed vehicles with more than two axles the requirements of point 4.1.1 shall apply. The requirements of point 4.1.1 with respect to wheel lock sequence shall be considered to be met if, in the case of braking rates between 0,15 and 0,30, the adhesion utilised by at least one of the front axles is greater than that utilised by at least one of the rear axles.\n4.1.3. The permissible relationship between the braking rate TR/FR and the pressure pm shall lie within the designated areas in diagram 3 for all pressures between 20 and 750 kPa (pneumatic) and 350 and 13 300 kPa (hydraulic) respectively, in both the laden and unladen states of load.\n4.2.\nFor rigid drawbar towed vehicles and centre-axle towed vehicles fitted with compressed-air and hydraulic braking systems:\n4.2.1. The permissible relationship between the braking rate TR/FR and the pressure pm shall lie within two areas derived from diagram 3, by multiplying the vertical scale by 0,95. This requirement shall be met at all pressures between 20 and 750 kPa (pneumatic) and 350 and 13 300 kPa (hydraulic) respectively, in both the laden and unladen states of load.\n4.3.\nFor drawbar towed vehicles with inertia braking system\n4.3.1.\nThe requirements according to point 4.1.1 apply also for drawbar towed vehicles with inertia braking system.\n4.3.2.\nFor drawbar towed vehicles with inertia braking system and with more than two axles the requirements according to point 4.1.2 of this Appendix apply.\n4.3.3.\nFor the calculation to verify the compliance with the provisions of point 4.1.1.3 the influence of the permissible drawbar force D* (point 10.3.1. of Annex VIII) can be ignored.\n5.\nRequirements to be met in case of failure of the braking distribution system\nWhen the requirements of this Appendix are fulfilled by means of a special device (e.g. controlled mechanically by the suspension of the vehicle), it shall be possible, in the event of the failure of its control, to stop the vehicle under the conditions specified for secondary braking in the case of tractors; tractors authorised to tow a vehicle fitted with compressed-air or hydraulic braking systems, it shall be possible to achieve a pressure at the coupling head of the control line within the range specified in points 3.1.3 and 3.1.4 In the event of failure of the control of the device on towed vehicles, a service braking performance of at least 30 % of that prescribed for the vehicle in question shall be attained.\n6.\nMarkings\n6.1\nVehicles which meet the requirements of this Appendix by means of a device mechanically controlled by the suspension of the vehicle shall be marked in accordance with the requirements laid down in Article 24 of Delegated Regulation (EU) 2015/208 and with the appropriate data to show the useful travel of the device between the positions corresponding to vehicle unladen and laden states, respectively, and any further information to enable the setting of the device to be checked.\n6.1.1.\nWhen a brake load sensing device is controlled via the suspension of the vehicle by any other means, the vehicle shall be marked with information to enable the setting of the device to be checked.\n6.2.\nWhen the requirements of this Appendix are met by means of a device which modulates the air or hydraulic pressure in the brake transmission, the vehicle shall be marked to show the axle loads at the ground, the nominal outlet pressures of the device and an inlet pressure of not less than 80 per cent of the maximum design inlet pressure, as declared by the vehicle manufacturer, for the following states of load:\n6.2.1. Technically permissible maximum axle load for the axle(s) which control(s) the device;\n6.2.2. Axle load(s) corresponding to the unladen mass of the vehicle in running order as stated in the test report for the braking requirements approval;\n6.2.3. The axle load(s) designated by the manufacturer to enable the setting of the device to be checked in service if this is (these are) different from the loads specified in points 6.2.1 to 6.2.2.\n6.3.\nThe markings referred to in points 6.1 and 6.2 shall be affixed in a visible position in indelible form. An example of the markings for a mechanically controlled device in a vehicle fitted with compressed-air or hydraulic braking system is provided in accordance with the requirements laid down in Article 5 of Commisison Implementing Regulation (EU) 2015/504 .\n6.4.\nElectronically controlled brake force distribution systems that cannot fulfil the requirements of points 6.1, 6.2 and 6.3 shall have a self-checking procedure of the functions which influence brake force distribution. In addition, when the vehicle is stationary, it shall be possible to carry out the checks laid down in point 1.3.1, by generating the nominal demand pressure associated with the commencement of braking for both the laden and unladen conditions.\n7.\nVehicle testing\nAt the time of type-approval, the technical service shall verify conformity with the requirements contained within this Appendix and carry out any further tests considered necessary to this end. The report of any further tests shall be appended to the type-approval report.\nDiagram 1\nTractors of category Tb and drawbar towed vehicles of categories R3b, R4b and S2b\n(see points 3.1.2.1 and 4.1.1.2)\nNote: The lower limit k = z – 0,08 is not applicable for the adhesion utilisation of the rear axle.\nDiagram 2\nPermissible relationship between braking rate T M /F M and the coupling head pressure pm for tractors of categories T and C with compressed air or hydraulic braking systems\nDiagram 3\nPermissible relationship between braking rate TR/FR and the coupling head pressure pm for towed vehicles of categories S2, R3 and R4 with compressed air or hydraulic braking systems", "extent": "E+W+S+N.I.", "status": null, "version": "current", "annotations": [ { "type": "F", "label": "F1", "text": "Substituted by Commission Delegated Regulation (EU) 2016/1788 of 14 July 2016 amending Regulation (EU) No 167/2013 of the European Parliament and of the Council as regards the list of requirements for vehicle EU type-approval, and amending and correcting Commission Delegated Regulations (EU) No 1322/2014, (EU) 2015/96, (EU) 2015/68 and (EU) 2015/208 with regard to vehicle construction and general requirements, to environmental and propulsion unit performance requirements, to vehicle braking requirements and to vehicle functional safety requirements (Text with EEA relevance)." }, { "type": "F", "label": "F2", "text": "Inserted by Commission Delegated Regulation (EU) 2016/1788 of 14 July 2016 amending Regulation (EU) No 167/2013 of the European Parliament and of the Council as regards the list of requirements for vehicle EU type-approval, and amending and correcting Commission Delegated Regulations (EU) No 1322/2014, (EU) 2015/96, (EU) 2015/68 and (EU) 2015/208 with regard to vehicle construction and general requirements, to environmental and propulsion unit performance requirements, to vehicle braking requirements and to vehicle functional safety requirements (Text with EEA relevance)." }, { "type": "footnote", "label": "f1", "text": "Commission Implementing Regulation (EU) 2015/504 of 11 March 2015 implementing Regulation (EU) No 167/2013 of the European Parliament and of the Council with regard to the administrative requirements for the approval and market surveillance of agricultural and forestry vehicles ( OJ L 85, 28.3.2015, p. 1 .)." } ], "outstanding_effects": [], "provenance": { "source": "legislation.gov.uk", "source_url": "https://www.legislation.gov.uk/eur/2015/68/annex/II/appendix/1", "retrieved_at": "2026-11-01T14:46:56.586941+00:00" }, "licence": "Open Government Licence v3.0", "licence_url": "https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/", "attribution": "Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives." }