ANNEX VISupplementary provisions
ANNEX VI Requirements applying to roll-over protection structures (dynamic testing) A. GENERAL PROVISION 1. The Union requirements applying to roll-over protection structures (dynamic testing) are set out in point B. B. REQUIREMENTS APPLYING TO ROLL-OVER PROTECTION STRUCTURES (DYNAMIC TESTING) ( 1 ) 1. Definitions 1.1. [Not applicable] 1.2. Rolling Over Protective Structure (ROPS) Roll-over protective structure (protective cab or frame), hereinafter called ‘protective structure’, means the structure on a tractor the essential purpose of which is to avoid or limit risks to the driver resulting from roll-over of the tractor during normal use. The roll-over protective structure is characterized by the provision of space for a clearance zone large enough to protect the driver when seated either inside the envelope of the structure or within a space bounded by a series of straight lines from the outer edges of the structure to any part of the tractor that might come into contact with flat ground and that is capable of supporting the tractor in that position if the tractor overturns. 1.3. Track 1.3.1. Preliminary definition: median plane of the wheel The median plane of the wheel is equidistant from the two planes containing the periphery of the rims at their outer edges. 1.3.2. Definition of track The vertical plane through the wheel axis intersects its median plane along a straight line which meets the supporting surface at one point. If A and B are the two points thus defined for the wheels on the same axle of the tractor, then the track width is the distance between points A and B. The track may be thus defined for both front and rear wheels. Where there are twin wheels, the track is the distance between two planes each being the median plane of the pairs of wheels. For track-laying tractors, the track is the distance between the median planes of the tracks. 1.3.3. Additional definition: median plane of the tractor Take the extreme positions of points A and B for the tractor rear axle, which gives the maximum possible value for the track. The vertical plane at right angles to the line AB at its centre point is the median plane of the tractor. 1.4. Wheelbase The distance between the vertical planes passing through the two lines AB as defined above, one for the front wheels and one for the rear-wheels. 1.5. Determination of seat index point; Seat location and adjustment for test 1.5.1. Seat Index Point (SIP) ( 2 ) The seat index point shall be determined in accordance with ISO 5353:1995. 1.5.2. Seat location and adjustment for test 1.5.2.1. Where the inclination of the backrest and seat pan is adjustable, these must be adjusted so that the Seat Index Point is in its rear uppermost position; 1.5.2.2. Where the seat is equipped with suspension, the latter must be blocked at mid-travel, unless this is contrary to the instructions clearly laid down by the seat manufacturer; 1.5.2.3. Where the position of the seat is adjustable only lengthwise and vertically, the longitudinal axis passing through the Seat Index Point shall be parallel with the vertical longitudinal plane of the tractor passing through the centre of the steering wheel and not more than 100 mm from that plane. 1.6. Clearance zone 1.6.1. Reference plane The clearance zone is illustrated in Figures 3.8 to 3.10 and Table 3.3. The zone is defined in relation to the reference plane and the Seat Index Point. The reference plane is a vertical plane, generally longitudinal to the tractor and passing through the Seat Index Point and the centre of the steering wheel. Normally the reference plane coincides with the longitudinal median plane of the tractor. This reference plane shall be assumed to move horizontally with the seat and steering wheel during loading but to remain perpendicular to the tractor or the floor of the roll-over protective structure. The clearance zone shall be defined on the basis of sub clauses 1.6.2 and 1.6.3. 1.6.2. Determination of clearance zone for tractors with a non-reversible seat The clearance zone for tractors with a non-reversible seat is defined in 1.6.2.1 to 1.6.2.10 below and is bounded by the following planes, the tractor being on a horizontal surface, the seat, where adjustable, adjusted to its rear uppermost position ( 2 ) , and the steering wheel, where adjustable, adjusted to the mid position for seated driving: 1.6.2.1. a horizontal plane A1 B1 B2 A2, (810 + av) mm above the seat index point (SIP) with line B1B2 located (ah – 10) mm behind the SIP; 1.6.2.2. an inclined plane G1 G2 I2 I1, perpendicular to the reference plane, including both a point 150 mm behind line B1B2 and the rearmost point of the seat backrest; 1.6.2.3. a cylindrical surface A1 A2 I2 I1 perpendicular to the reference plane, having a radius of 120 mm, tangential to the planes defined in 1.6.2.1 and 1.6.2.2 above; 1.6.2.4. a cylindrical surface B1 C1 C2 B2, perpendicular to the reference plane, having a radius of 900 mm extending forward for 400 mm and tangential to the plane defined in 1.6.2.1 above along line B1B2; 1.6.2.5. an inclined plane C1 D1 D2 C2, perpendicular to the reference plane, joining the surface defined in 1.6.2.4 above and passing 40 mm from the forward external edge of the steering wheel. In the case of a high steering wheel position, this plane extends forward from line B1B2 tangentially to the surface defined in 1.6.2.4 above; 1.6.2.6. a vertical plane D1 E1 E2 D2 perpendicular to the reference plane 40 mm forward of the external edge of the steering wheel; 1.6.2.7. a horizontal plane E1 F1 F2 E2 passing through a point (90 – av) mm below the seat index point (SIP); 1.6.2.8. a surface G1 F1 F2 G2, if necessary curved from the bottom limit of the plane defined in 1.6.2.2 above to the horizontal plane defined in 1.6.2.7 above, perpendicular to the reference plane, and in contact with the seat backrest throughout its length; 1.6.2.9. vertical planes J1 E1 F1 G1 H1 and J2 E2 F2 G2 H2. These vertical planes shall extend upwards from plane E1 F1 F2 E2 for 300 mm; the distances E1 E0 and E2 E0 shall be 250 mm; 1.6.2.10. parallel planes A1 B1 C1 D1 J1 H1 I1 and A2 B2 C2 D2 J2 H2 I2 inclined so that the upper edge of the plane on the side on which the force is applied is at least 100 mm from the vertical reference plane. 1.6.3. Determination of clearance zone for tractors with a reversible driver’s position For tractors with a reversible driver’s position (reversible seat and steering wheel), the clearance zone is the envelope of the two clearance zones defined by the two different positions of the steering wheel and the seat. 1.6.4. Optional seats 1.6.4.1. In case of tractors that could be fitted with optional seats, the envelope comprising the seat index points of all options offered shall be used during the tests. The protective structure shall not enter the larger clearance zone which takes account of these different seat index points. 1.6.4.2. In the case where a new seat option is offered after the test has been performed, a determination shall be made to see whether the clearance zone around the new SIP falls within the envelope previously established. If it does not, a new test must be performed. 1.6.4.3. Optional seat does not include a seat for a person in addition to the driver and from where the tractor cannot be controlled. The SIP shall not be determined because the definition of the clearance zone is in relation to the driver seat. 1.7. Unballasted mass The mass of the tractor without ballasting devices and, in the case of tractors with pneumatic tyres, without liquid ballast in the tyres. The tractor shall be in running order with tanks, circuits and radiator full, protective structure with cladding and any track equipment or additional front wheel drive components required for normal use. The operator is not included. 1.8. Permissible measurement tolerances Distance ± 0,5 mm Force ± 0,1 % (of the sensor full scale) Mass ± 0,2 % (of the sensor full scale) Tyre pressure ± 5,0 % Angle ± 0,1° 1.9. Symbols a h (mm) Half of the horizontal seat adjustment a v (mm) Half of the vertical seat adjustment E (J) Energy input during test F (N) Static load force H (mm) Height of lift of the centre of gravity of the pendulum block I (kg.m 2 ) Moment of inertia about rear axle, excluding wheels used for calculating rear impact energy L (mm) Wheelbase used for calculating rear impact energy M (kg) Mass used for calculating energy and crushing forces 2. Field of application 2.1. This Annex is applicable to tractors having at least two axles for pneumatic tyred wheels with or without track attachments and with an unballasted tractor mass greater than 600 kg but generally less than 6 000 kg. 2.2. The minimum track width of the rear-wheels should generally be greater than 1 150 mm. It is recognised that there may be designs of tractors, for example, lawn mowers, narrow vineyard tractors, low profile tractors used in buildings with limited overhead clearance or in orchards, high-clearance tractors and special forestry machines, such as forwarders and skidders, for which this Annex is not applicable. 3. Rules and directions 3.1. General regulations 3.1.1. The protective structure may be manufactured either by the tractor manufacturer or by an independent firm. In either case a test is only valid for the model of tractor on which it is carried out. The protective structure must be retested for each model of tractor to which it is to be fitted. However, testing stations may certify that the strength tests are also valid for tractor models derived from the original model by modifications to the engine, transmission and steering and front suspension (see below 3.6: Extension to other tractor models) . On the other hand, more than one protective structure may be tested for any one model of tractor. 3.1.2. The protective structure submitted for dynamic test must be supplied attached in the normal manner to the tractor model in connection with which it is being tested. The tractor submitted shall be complete and in running order. 3.1.3. Where a ‘tandem’ tractor is concerned, the mass of the standard version of that part to which the protective structure is fitted is to be used. 3.1.4. A protective structure may be designed solely to protect the driver in the event of the tractor overturning. Onto this structure it may be possible to fit weather protection for the driver, of a more or less temporary nature. The driver will usually remove this in warm weather. There are protective structures however, in which the cladding is permanent and warm weather ventilation provided by windows or flaps. As the cladding may add to the strength of the structure and if removable may well be absent when an accident occurs, all parts that can be so taken away by the driver will be removed for the purpose of the test. Doors, roof hatch and windows that can be opened shall be either removed or fixed in the open position for the test, so that they do not add to the strength of the protective structure. It shall be noted whether, in this position, they would create a hazard for the driver in the event of overturning. Throughout the remainder of these rules, reference will only be made to testing the protective structure. It must be understood that this includes cladding not of a temporary nature. A description of any temporary cladding supplied is to be included in the specifications. All glass or similar brittle material shall be removed prior to the test. Tractor and protective structure components which might sustain needless damage during the test and which do not affect the strength of the protective structure or its dimensions may be removed prior to the test if the manufacturer wishes. No repairs or adjustment may be carried out during the test. 3.1.5. Any component of the tractor contributing to the strength of the protective structure such as mud-guards, which has been reinforced by the manufacturer, should be described and its measurements given in the test report. 3.2. Apparatus and test conditions 3.2.1. The structure shall be struck by a block acting as a pendulum and submit to a front and a rear crushing test. 3.2.2. The mass of the pendulum bloc (Figure 3.1) shall be 2 000 kg. Its impact face shall have dimensions 680 × 680 mm ± 20. It shall be made in such a way that the position of its centre of gravity is constant (for example with iron bars bound in concrete). It shall be suspended from a pivot point about 6 m above the floor in such a way that the height of the pendulum may be conveniently and safely adjusted. 3.2.3. For tractors with less than 50 % of their mass on the front wheels, the first blow shall be at the rear of the structure. This shall be followed by a crushing test also at the rear of the structure. The second blow shall be at the front and the third at the side. Finally, there shall be a second crushing test at the front. For tractors with 50 % or more of their mass on the front wheels, the first blow shall be at the front and the second blow at the side. This shall be followed by the two crushing tests, firstly at the rear and secondly at the front. 3.2.4. For tractors with a reversible driver’s position (reversible seat and steering wheel), the first blow shall be longitudinal at the heavier end (with more than 50 % of the mass of the tractor). This shall be followed by a crushing test on the same end. The second blow shall be at the other end, and the third at the side. Finally, there shall be a second crushing test at the lighter end. 3.2.5. A track width setting for the rear-wheels shall be chosen such that the structure is in no way supported by the tyres during the test. This provision may be disregarded if such support is given when the wheels are in their widest alternative track setting. 3.2.6. The side of the tractor from which the side blow is struck shall be that which, in the opinion of the testing station, is likely to give the greatest distortion. The rear blow shall be on the corner opposite the side blow and the front blow on the corner nearer the side blow. The rear blow shall be administered at two-thirds the distance from the median plane of the tractor to the vertical plane touching the outside extremity of the structure. However, if a curve in the back of the structure starts at less than two-thirds of the distance from the centre, the blow shall be struck at the beginning of the curve, i.e. at the point where this curve is tangential to a line at right angles to the median plane of the tractor. 3.2.7. If, during the test, any lashings, props or blocks move or break, the test must be repeated. 3.3. Impact tests 3.3.1. Impact at the rear (Figures 3.2.a and 3.2.b) 3.3.1.1. The rear impact is not required on tractors having 50 % or more of their mass (as defined above) on the front wheels. 3.3.1.2. The tractor shall be placed in relation to the pendulum so that this will strike the structure when the striking face and the supporting chains are at an angle of 20° to the vertical unless the structure at the point of contact has, during deflection, a greater angle with the vertical. In this case the striking face shall be adjusted parallel to the side of the structure at the point of contact at the moment of maximum deflection by an additional support, the supporting chains remaining at an angle of 20° to the vertical. The point of impact shall be that part of the structure likely to hit the ground first in a rearward overturning accident, normally the upper edge. The height of the pendulum will be so adjusted that it has no tendency to turn about the point of contact. 3.3.1.3. The tractor will be lashed down. The points of attachment of the lashings shall be approximately 2 m behind the rear axle and 1,5 m in front of the front axle. There shall be two lashings on each axle, one on each side of the median plane of the tractor. The lashings shall be steel cable of 12,5 to 15 mm diameter, tensile strength 1 100-1 260 MPa. The tyres of the tractor shall be inflated, and the lashings tightened to give tyre pressures and deflections, as shown in the Table 3.1, below. After the lashings have been tightened a wood beam 150 × 150 mm shall be clamped in front of the rear-wheels, driven tight against them. 3.3.1.4. The pendulum shall be pulled back so that the height H of its centre of gravity above that at the point of impact is given by one of the following formulae at the option of the manufacturer: or 3.3.1.5. The pendulum shall be released and allowed to crash against the structure. The quick release mechanism must be so positioned that it does not tilt the weight in relation to the chains supporting it at the moment of release. Table 3.1 Tyre Pressures Tyre pressures kPa ( *1 ) Deflection mm Four-wheel drive tractors with front and rear wheels of the same size: Front 100 25 Rear 100 25 Four-wheel drive tractors with front wheels smaller than rear wheels: Front 150 20 Rear 100 25 Two-wheel drive tractors: Front 200 15 Rear 100 25 3.3.2. Impact at the front (Figures 3.3.a and 3.3.b) 3.3.2.1. This shall be carried out in the same way as the impact at the rear. The lashings shall be the same but the wooden beam shall be behind the rear-wheels. The height of fall of the centre of gravity of the pendulum shall be given by the following formula: 3.3.2.2. The point of impact shall be that part of the structure that would hit the ground first when turning over sideways while travelling forward, normally the top of the front corner. 3.3.3. Impact at the side (Figure 3.4) 3.3.3.1. The tractor shall be placed in relation to the pendulum so that this will strike the structure when the striking face and the supporting chains are vertical unless the structure at the point of contact is, during deflection, other than vertical. In this case the striking face shall be adjusted so that it is approximately parallel to the structure at the point of contact at the moment of maximum deflection. This adjustment shall be made by an additional support, the supporting chains remaining vertical at the moment of impact. The point of impact shall be that part of the structure likely to hit the ground first in a sideways overturning accident, normally the upper edge. 3.3.3.2. Unless it is certain that any other part of this edge would hit the ground first, the point of impact shall be in the plane at right angles to the median plane of the tractor and passing 60 mm in front of the seat index point, the seat being at its mid-point of longitudinal adjustment. The height of the pendulum will be so adjusted that it has no tendency to turn about the point of contact. 3.3.3.3. For tractors with a reversible driver’s position, the point of impact shall be in the plane at right angles to the median plane of the tractor and at the mid-point between the two seat index points. 3.3.3.4. The rear-wheel of the tractor on the side to be struck shall be lashed down. The tension in the lashings shall be determined as for the impact at the rear. After lashing, a beam 150 × 150 mm shall be clamped against the side of the rear-wheel opposite the blow, and driven hard against the tyre. A beam shall be placed as a prop against this wheel and secured on the floor so that it is held tight against the wheel during impact. The length of this beam shall be chosen so that when in position against the wheel it makes an angle of 25 to 40° with the horizontal. Furthermore its length shall be 20 to 25 times its thickness and its width 2 to 3 times its thickness. 3.3.3.5. The pendulum shall be pulled back as in the previous tests so that the height H of its centre of gravity above that at the moment of impact is determined by the following formula: 3.3.3.6. During the side impact test the difference between the maximum momentary deflection and the permanent deflection at a height of (810 + a v ) mm above the seat index point shall be recorded. This may be done with a device on which a moving friction collar shall be fitted on a horizontal rod. One end of the rod shall be attached to the top member of the structure and the other will pass through a hole in a vertical bar attached to tractor chassis. The collar will be positioned against the vertical bar attached to tractor chassis before the blow and its distance from it after the blow will give the difference between the maximum momentary deflection and the permanent deflection. 3.4. Crushing tests It may be necessary to hold down the front of the tractor when carrying out the test at the rear. Blocks will be placed under the axles so that the tyres do not bear crushing force. The cross beam used shall have a width of approximately 250 mm and shall be connected to the load applying mechanism by universal joints (Figure 3.5). 3.4.1. Crushing at the rear (Figures 3.6.a and 3.6.b) 3.4.1.1. The crushing beam shall be positioned across the rear uppermost structural members so that the resultant of the crushing forces is located in the vertical reference plane of the tractor. The crushing force (F) shall be applied where: F = 20 M This force shall be maintained for 5 seconds after cessation of any visually detectable movement of the protective structure. 3.4.1.2. Where the rear part of the protective structure roof will not sustain the full crushing force (Figures 3.7.a and 3.7.b), the force shall be applied until the roof is deflected to coincide with the plane joining the upper part of the protective structure with that part of the rear of the tractor capable of supporting the tractor when overturned. The force shall then be removed and the crushing beam repositioned over that part of the protective structure that would support the tractor when completely overturned. The crushing force F shall be applied. 3.4.2. Crushing at the front (Figures 3.6.a and 3.6.b) 3.4.2.1. The crushing beam shall be positioned across the front uppermost structural members so that the resultant of the crushing forces is located in the vertical reference plane of the tractor. The crushing force (F) shall be applied where: F = 20 M This force shall be maintained for 5 seconds after cessation of any visually detectable movement of the protective structure. 3.4.2.2. When the front part of the roof of the protective structure will not sustain the full crushing force (Figures 3.7.a and 3.7.b), the force shall be applied until the roof is deflected to coincide with the plane joining the upper part of the protective structure with that part of the front of the tractor capable of supporting the tractor when overturned. The force shall then be removed and the crushing beam repositioned over that part of the protective structure that would support the tractor when completely overturned. The crushing force F shall then be applied. 3.5. Conditions for acceptance 3.5.1. The structure and tractor shall be visually examined for cracks and tears after each part of the test. For the structure to pass the test the following conditions shall be complied with: 3.5.1.1. there shall be no cracks in structural members, mounting components or tractor parts contributing to the strength of the protective structure (except as covered by 3.5.1.3 below); 3.5.1.2. there shall be no cracks in welds contributing to the strength of the protective structure or its mounting components. Spot or tack welding used for the attachment of cladding panels shall normally be excluded from this condition; 3.5.1.3. energy-absorbing tears in sheet metal structures are acceptable, providing that they are judged by the testing station to have not significantly reduced the resistance to deflection of the protective structure. Tears in sheet metal components caused by edges of the pendulum weight shall be ignored; 3.5.1.4. the required force must be sustained in both crushing tests; 3.5.1.5. the difference between the maximum momentary deflection and the permanent deflection in the side impact test must not exceed 250 mm (Figure 3.11); 3.5.1.6. no part shall enter the clearance zone during any part of the tests. No part may strike the seat during the tests. Furthermore, the clearance zone shall not be outside the protection of the protective structure. For this purpose, it shall be considered to be outside the protection of the structure if any part of it would come in contact with flat ground if the tractor overturned towards the direction from which the test load is applied. For estimating this, the tyres and track width setting shall be the smallest standard fitting specified by the manufacturer. 3.5.1.7. for the articulated tractors, the median planes of the two parts shall be assumed to be in line. 3.5.2. After the final crushing test, the permanent deformation of the protective structure shall be recorded. For this purpose, before the start of the test, the position of the main members in relation to the seat index point must be recorded. Then any movement of the members struck in the tests and any change of the height of the front and back members of the roof shall be recorded. 3.6. Extension to other tractor models 3.6.1. [Not applicable] 3.6.2. Technical extension When technical modifications occur on the tractor, the protective structure or the method of attachment of the protective structure to the tractor, the testing station that has carried out the original test can issue a ‘technical extension report’ in the following cases: 3.6.2.1. Extension of the structural test results to other models of tractors The impact and crushing tests need not be carried out on each model of tractor, provided that the protective structure and tractor comply with the conditions referred to hereunder 3.6.2.1.1 to 3.6.2.1.5. 3.6.2.1.1. The structure shall be identical to the one tested; 3.6.2.1.2. The required energy shall not exceed the energy calculated for the original test by more than 5 %. The 5 % limit shall also apply to extensions in the case of substituting tracks for wheels on the same tractor; 3.6.2.1.3. The method of attachment and the tractor components to which the attachment is made shall be identical; 3.6.2.1.4. Any components such as mud-guards and bonnet that may provide support for the protective structure shall be identical; 3.6.2.1.5. The position and critical dimensions of the seat in the protective structure and the relative position of the protective structure on the tractor shall be such that the clearance zone would have remained within the protection of the deflected structure throughout all tests (this shall be checked by using the same reference of clearance zone as in the original test report, respectively Seat Reference Point [SRP] or Seat Index Point [SIP]). 3.6.2.2. Extension of the structural test results to modified models of the protective structure This procedure has to be followed when the provisions of paragraph 3.6.2.1 are not fulfilled, it may not be used when the method of attachment of the protective structure to the tractor does not remain of the same principle (e.g. rubber supports replaced by a suspension device): 3.6.2.2.1. Modifications having no impact on the results of the initial test (e.g. weld attachment of the mounting plate of an accessory in a non-critical location on the structure), addition of seats with different SIP location in the protective structure (subject to checking that the new clearance zone(s) remain(s) within the protection of the deflected structure throughout all tests); 3.6.2.2.2. Modifications having a possible impact on the results of the original test without calling into question the acceptability of the protective structure (e.g. modification of a structural component, modification of the method of attachment of the protective structure to the tractor). A validation test can be carried out and the test results will be drafted in the extension report. The following limits for this type extension are fixed: 3.6.2.2.2.1. No more than 5 extensions may be accepted without a validation test; 3.6.2.2.2.2. The results of the validation test will be accepted for extension if all the acceptance conditions of this Annex are fulfilled and if the deflection measured after each impact test does not deviate from the deflection measured after each impact test in the original test report by more than ± 7 %; 3.6.2.2.2.3. More than one protective structure modifications may be included in a single extension report if they represent different options of the same protective structure, but only one validation test can be accepted in a single extension report. The options not tested shall be described in a specific section of the extension report. 3.6.2.2.3. Increase of the reference mass declared by the manufacturer for a protective structure already tested. If the manufacturer wants to keep the same approval number it is possible to issue an extension report after having carried out a validation test (the limits of ± 7 % specified in 3.6.2.2.2.2 are not applicable in such a case). 3.7. [Not applicable] 3.8. Cold weather performance of protective structures 3.8.1. If the protective structure is claimed to have properties resistant to cold weather embrittlement, the manufacturer shall give details that shall be included in the report. 3.8.2. The following requirements and procedures are intended to provide strength and resistance to brittle fracture at reduced temperatures. It is suggested that the following minimum material requirements shall be met in judging the protective structure’s suitability at reduced operating temperatures in those countries requiring this additional operating protection. Table 3.2 Minimum Charpy V-notch impact energies Specimen size Energy at Energy at – 30 °C – 20 °C mm J J ( 2 ) 10 × 10 ( 1 ) 11 27,5 10 × 9 10 25 10 × 8 9,5 24 10 × 7,5 ( 1 ) 9,5 24 10 × 7 9 22,5 10 × 6,7 8,5 21 10 × 6 8 20 10 × 5 ( 1 ) 7,5 19 10 × 4 7 17,5 10 × 3,5 6 15 10 × 3 6 15 10 × 2,5 ( 1 ) 5,5 14 3.8.2.1. Bolts and nuts used to attach the protective structure to the tractor and used to connect structural parts of the protective structure shall exhibit suitable controlled reduced temperature toughness properties. 3.8.2.2. All welding electrodes used in the fabrication of structural members and mounts shall be compatible with the protective structure material as given in 3.8.2.3 below. 3.8.2.3. Steel materials for structural members of the protective structure shall be of controlled toughness material exhibiting minimum Charpy V-Notch impact energy requirements as shown in Table 3.2. Steel grade and quality shall be specified in accordance with ISO 630:1995; Amd1:2003. Steel with an as-rolled thickness less than 2,5 mm and with a carbon content less than 0,2 % is considered to meet this requirement. Structural members of the protective structure made from materials other than steel shall have equivalent low temperature impact resistance. 3.8.2.4. When testing the Charpy V-Notch impact energy requirements, the specimen size shall be no less than the largest of the sizes stated in Table 3.2 that the material will permit. 3.8.2.5. The Charpy V-Notch tests shall be made in accordance with the procedure in ASTM A 370-1979, except for specimen sizes that shall be in accordance with the dimensions given in Table 3.2. 3.8.2.6. Alternatives to this procedure are the use of killed or semi-killed steel for which an adequate specification shall be provided. Steel grade and quality shall be specified in accordance with ISO 630:1995; Amd1:2003. 3.8.2.7. Specimens are to be longitudinal and taken from flat stock, tubular or structural sections before forming or welding for use in the protective structure. Specimens from tubular or structural sections are to be taken from the middle of the side of greatest dimension and shall not include welds. 3.9. [Not applicable] Figure 3.1 Pendulum block and its suspending chains or wire ropes (Dimensions in mm) Figure 3.2 Method of impact from rear Figure 3.2.a Protective cab Figure 3.2.b Rear roll bar frame Figure 3.3 Method of impact from front Figure 3.3.a Protective cab Figure 3.3.b Rear roll bar frame Figure 3.4 Method of impact from side Figure 3.5 Example of an arrangement for crushing tests Figure 3.6 Position of beam for front and rear crushing tests Figure 3.6.a Protective cab Figure 3.6.b Rear roll bar frame Figure 3.7 Position of beam for front crushing test when full crushing force not sustained in front Figure 3.7.a Protective cab Figure 3.7.b Rear roll bar frame Table 3.3 Dimensions of the clearance zone Dimensions mm Remarks A 1 A 0 100 minimum B 1 B 0 100 minimum F 1 F 0 250 minimum F 2 F 0 250 minimum G 1 G 0 250 minimum G 2 G 0 250 minimum H 1 H 0 250 minimum H 2 H 0 250 minimum J 1 J 0 250 minimum J 2 J 0 250 minimum E 1 E 0 250 minimum E 2 E 0 250 minimum D 0 E 0 300 minimum J 0 E 0 300 minimum A 1 A 2 500 minimum B 1 B 2 500 minimum C 1 C 2 500 minimum D 1 D 2 500 minimum I 1 I 2 500 minimum F 0 G 0 — I 0 G 0 — depending on C 0 D 0 — the tractor E 0 F 0 — Figure 3.8 Clearance zone Note: for dimensions, see Table 3.3 above; Figure 3.9 Clearance zone Figure 3.9.a Side view section in reference plane Figure 3.9.b Rear or front view 1 – Seat index point 2 – Force 3 – Vertical reference plane Figure 3.10 Clearance zone for tractor with reversible seat and steering wheel Figure 3.10.a Protective cab Figure 3.10.b Rear roll bar frame Figure 3.11 Example of apparatus for measuring elastic deflection Explanatory notes to Annex VI ( 1 ) Unless otherwise stated, the text of the requirements and the numbering set out in point B are identical with the text and numbering of the OECD standard code for the official testing of protective structures on agricultural and forestry tractors (dynamic test), OECD Code 3, Edition 2015 of July 2014. ( 2 ) Users are reminded that the seat index point is determined according to ISO 5353 and is a fixed point with respect to the tractor that does not move as the seat is adjusted away from the mid-position. For purposes of determining the clearance zone, the seat shall be placed in the rear and uppermost position. ( *1 ) No water ballast is to be used. ( 1 ) Indicates preferred size. Specimen size shall be no less than largest preferred size that the material permits. ( 2 ) The energy requirement at – 20 °C is 2,5 times the value specified for – 30 °C. Other factors affect impact energy strength, i.e. direction of rolling, yield strength, grain orientation and welding. These factors shall be considered when selecting and using steel.