To allow the protection of the passenger, to consider the specific conditions of tractor design, its intended use and all risks including the risk of roll-over, the standard should satis
Location and mounting
4.1.1 Each seat shall be so placed that the passenger is in no danger and creates no impediment to driving the tractor
4.1.2 There shall be a vertical clearance of at least 920 mm above the surface of the passenger seat
A tractor that meets driver protection and seating requirements may have a reduced vertical clearance of 800 mm for the passenger if its design does not allow for greater height This reduction is permissible as long as sufficient padding is installed directly above the passenger seat at the roof level.
The vertical clearance for passengers is restricted at the rear and sides by a radius not exceeding 300 mm This clearance refers to the vertical space between the front edge of the seat and the tractor's roof.
4.1.3 The passenger seat shall not add to the overall width of the tractor
Each seat must be securely fixed and appropriately attached to a structural component of the tractor, such as the chassis, roll-over protective structure, or platform It is essential that the structural member is robust enough to support a fully loaded passenger seat.
Seat dimensions
4.2.1 Each seat shall be at least 400 mm wide and at least 300 mm deep
4.2.2 Each seat shall incorporate a lateral support for position-maintenance purposes and be fitted with a back rest that is at least 200 mm high
NOTE The lateral support and/or the backrest may also be provided by parts of the cab and/or the roll-over protective structure.
Seat cushion
The seat cushion shall be either padded or made from elastic materials (e.g plastics).
Seat belt
A restraint system shall be provided The restraint system shall be in accordance with the ISO 3776- series or other applicable standards.
Foot rest and handles
4.5.1 A suitable foot rest for the passenger's feet shall be provided
4.5.2 Suitable grab handles shall be provided in order to facilitate the access to the passenger seat and to help him to remain in position on it.
Roll-over protection
Passenger Deflection Limiting Volume (PDLV)
The passenger deflection limiting volume (PDLV) is established using the passenger seat index point (SIP p ), as defined in 3.2 according to the dimensions reported in Figure B.1
Front view Right side view
Figure B.1 — Passenger deflection limiting volume ( PDLV )
It is also allowed to rotate forward and rearward and to each side about the SIP p not more than 15° with respect to transversal and longitudinal reference planes (Figure B.2)
When rotating the PDLV to the side, the portion of the PDLV below the horizontal plane passing through
Front view Left side view
Figure B.2 — Rearward, forward and lateral rotation
The upper section of the PDLV can flex forward and backward up to a maximum of 15° relative to the transversal reference plane, as shown in Figure B.3 This flexion occurs around a designated flexion axis (FA) indicated in the same figure.
Figure B.3 — Rearward and forward flexion (right side view)
The side views in Figure B.4 illustrate the potential rearward and forward motions of the PDLV The PDLV can rotate in all directions—forward, rearward, and sideways—around the SIP point, as well as flex forward and backward at the FA during various tests.
The SIP p may move during the test due to deflection of the chassis If this occurs, the PDLV will continue to maintain its relationship with the SIP p
Key a rearward flexion b rearward rotation c forward flexion d forward rotation
Figure B.4 — Overall motions in rearward and forward directions (right side view)
Passenger seat index point (SIP p )
In order to apply the passenger deflection limiting volume it is necessary to define a passenger seat index point (SIP p ) For its definition, ISO 5353:1995 shall be applied.
Allowable interference
General
In the ROPS test for agricultural and forestry tractors, a maximum interference is permitted between the operator clearance zone (OCZ) and the passenger deflection limiting volume (PDLV) The OCZ, which is defined in relation to the operator seat index point (SIP o ), is categorized into three distinct interference zones.
— the first zone extends for 350 mm (plane a in Figure B.5) in longitudinal direction from the back of the operator clearance zone (point G in Figure B.5);
— the second zone is enclosed among the end of the previous one (plane a) and a transversal plane (plane b in Figure B.5) located at 400 mm from point B in longitudinal direction;
— the third zone extends from the end of the previous one (plane b) till the end of the operator clearance zone
Top view Left side view
For each of the interference zones previously defined a maximum allowable interference between OCZ and PDLV has been set
The reference interference zone is defined by the projection of SIP p onto the tractor's longitudinal median plane If this projection aligns with one of the division planes (either a or b), the reference interference zone can be considered as either of the two zones that share the division plane.
With reference to Figure B.6 a minimum horizontal distance (A) between SIP p and SIP o shall be evaluated
The horizontal distance between SIP p and SIP o is measured on a vertical plane that is orthogonal to the longitudinal median plane of the tractor passing through SIP p Additionally, the vertical distance between SIP p and SIP o is also measured on this vertical plane The angular deflection, denoted as α, is measured between the vertical median plane of the tractor and the vertical median plane of PDLV.
Figure B.6 — Nomenclature for interference determination - Rear view (on the left) and top view
Interference evaluation procedure
The interference evaluation procedure is defined as follows:
— determination of the operator seat index point (SIP o );
— determination of the passenger seat index point (SIP p );
— determination of the three interference zones on the operator clearance zone (see Figure B.5);
— determination of the reference interference zone by the projection of the SIP p on the longitudinal median plane of tractor;
— determination of the angular deflection (α) of the passenger seat with respect to the moving direction of the tractor;
— measurement of the vertical distance (h) between SIP o and SIP p ;
— measurement of the transversal distance (A) between SIP o and SIP p during all the ROPS test;
— comparison and verification of the value of A, determined at previous step, with respect to the values reported in the following Tables B.1, B.2 and B.3
Table B.1 —Minimum distance ( A ) for the zone I h [mm] A [mm]
Table B.2 —Minimum distance ( A ) for the zone II h [mm]
Table B.3 —Minimum distance ( A ) for the zone III h [mm] A [mm]
A tolerance of 5 % should be applied to all dimensions reported in Tables B.1, B.2 and B.3
Reference interference zone, angular deflection (α) and vertical distance (h) measured at the beginning shall be considered constant during any part of the tests.
Reversible driver’s position
For tractors equipped with a reversible driver's position, it is essential to conduct the interference evaluation procedure for the rearward-facing seat position, following the guidelines outlined in section B.3.2 for the forward-facing seat position.
Operator clearance zone for rearward ( R ) facing seat position Operator clearance zone for forward ( F ) facing seat position
Figure B.7 — Interference zone in case of reversible driver's position (left side view)
The OCZ for the reward-facing seat position exhibits distinct interference zones, vertical distance (h), and transversal distance (A) compared to the OCZ for the forward-facing seat position However, the angular deflection (α) remains consistent across both seat configurations, as it is determined by the passenger seat and the tractor's longitudinal median plane.
Applying the interference evaluation procedure to both driver seat positions, the four cases reported in Table B.4 may present
Table B.4 — Possible cases of combined interference evaluation procedure for reversible driver's position CASE Forward facing OCZ test Rearward facing OCZ test
3 Not allowable interference Allowable interference
— Case 1: the PDLV has an allowable interference for both operator seat positions and can be used in both working condition without any restriction
The passenger seat is only usable when the operator seat is in a forward-facing position If the operator seat is in a rearward position, the use of the passenger seat should be avoided, or the tractor's rearward functionality must be restricted.
In Case 3, the passenger seat is only usable when the operator seat is in a rearward-facing position If the operator seat is in a forward position, the use of the passenger seat should be avoided, or the tractor's forward functionality must be restricted.
— Case 4: the PDLV has not allowable interference and then passenger seat shall not be installed.
ROPS test
General
The testing sequence must be based on the OECD code and adjusted as needed for the passenger seat position All guidelines outlined in Annex C should be followed, detailing the testing sequence, load application points, and acceptance criteria related to the passenger seat.
Sequence of tests
Tests shall be conducted in the following sequence:
For wheeled tractors with at least 50% of their mass on the rear axle and for track laying tractors, longitudinal loading must be applied from the rear In contrast, for other types of tractors, this loading should be applied from the front.
The first crushing test shall be applied at the same end of the protective structure as the longitudinal loading
The side loading shall be on the side most likely to lead to infringement of the passenger deflection limiting volume
The second crushing test will be conducted on the protective structure's end opposite to where the first longitudinal loading was applied For two-post designs, the second crush may occur at the same location as the first.
A second longitudinal loading shall be applied to tractors fitted with a folding (e.g two posts) or tiltable (e.g non-two posts) protective structure, if one or more of the following conditions exists:
— temporary folding for special operating conditions;
— structures designed to tilt for service, unless the tilt mechanism is independent from the structural integrity of the roll-over protective structure
For folding protective structures, if the first longitudinal loading was applied in the folding direction then a second longitudinal loading is not required.
Horizontal loading tests from the rear, front and side
The load on the protective structure must be uniformly distributed using a stiff beam positioned perpendicular to the load direction This beam should include a mechanism to prevent lateral movement The load application rate should be static, and both force and deflection must be continuously recorded for accuracy Once the load is initially applied, it must remain unchanged until the test concludes, and the applied force direction must adhere to specified limits.
— at start of test (no load): ± 2°;
— during test (under load): 10° above and 20° below the horizontal
The rate of load application shall be considered static if the rate of deflection under loading is not greater than 5 mm/s
If no structural cross member exists at the point of load application, a substitute test beam which does not add strength will be utilised
The load must be applied horizontally and parallel to the tractor's median plane When the load is applied from the rear, both longitudinal and lateral loads should be positioned on opposite sides of the median plane Conversely, if the longitudinal load is applied from the front, it should be on the same side as the lateral load.
The load shall be applied to the uppermost transverse structural member of the protective structure (i.e that part which would be likely to strike the ground first in an overturn)
The load application point must be positioned one-sixth of the width of the protective structure inward from the outer corner The width of the protective structure is defined as the distance between two lines parallel to the tractor's median plane, which touch the outer edges of the structure at the top of the highest transverse structural members.
The load distribution device must have a length that is at least one third of the width of the protective structure, with a maximum allowable length that exceeds this minimum by no more than 49 mm.
The longitudinal loading shall be stopped when:
— the energy absorbed by the protective structure is equal to or greater than the required energy input, E IL1 where:
— the protective structure infringes on the passenger deflection limiting volume or leaves it unprotected
Side loading must be applied horizontally at a 90° angle to the tractor's median plane This loading should be directed to the upper extremity of the protective structure, specifically at a point located (160 - a h) mm forward of the operator seat index point.
For tractors equipped with a reversible driver's position, the protective structure must be applied to the upper extremity at the midpoint between the two operator seat index points.
When a tractor is at risk of overturning sideways, the load should be applied at the point of the protective structure that will first contact the ground, ensuring uniform load distribution For a two-post protective structure, side loading must be applied to the uppermost structural member on the side, irrespective of the operator seat index position Additionally, the load distribution beam should be as long as possible, with a maximum length of 700 mm.
The side loading shall be stopped when:
— the energy absorbed by the protective structure is equal to or greater than the required energy, E IS , where:
— the protective structure infringes on the passenger deflection limiting volume or leaves it unprotected.
Crushing tests
The crushing beam must be placed across the uppermost structural members at the rear, ensuring that the resultant crushing forces align with the vertical reference plane Subsequently, a crushing force of \$F = 20 \, \text{M}\$ will be applied.
This force shall be maintained for 5 s after cessation of any visually detectable movement of the protective structure
In cases where the rear section of the protective structure roof cannot withstand the entire crushing force, the force should be applied until the roof is deflected to align with the plane connecting the upper part of the protective structure to the rear section of the tractor that can support it during an overturn After this, the force must be removed, and the crushing beam should be repositioned over the part of the protective structure that would support the tractor in a complete overturn Subsequently, the crushing force \( F_{20M} \) should be applied.
The crushing beam must be placed over the uppermost structural members to ensure that the resultant crushing forces align with the vertical reference plane Subsequently, a crushing force of F = 20 M will be applied.
This force shall be maintained for 5 s after cessation of any visually detectable movement of the protective structure
In cases where the front section of the roof of a protective structure cannot withstand the entire crushing force, the force should be applied until the roof is deflected to align with the plane connecting the upper part of the protective structure to the front section of the tractor that can support it during an overturn After this, the force must be removed, and the crushing beam should be repositioned over the part of the protective structure that would support the tractor when fully overturned Subsequently, the crushing force \( F_{20M} \) should be applied.
Second longitudinal loading test
The load shall be applied in the opposite direction to and at the corner farthest from the point of application of the first longitudinal load
The longitudinal loading shall be stopped when:
— the energy absorbed by the protective structure is equal to or greater than the required energy, E IL2 , where:
— the protective structure infringes on the passenger deflection limiting volume or leaves it unprotected.
Interference measuring apparatus
A device for measuring distance A during and after completion of the tests is needed in order to record the minimum value attained
For this measurement, an apparatus similar to that illustrated in Figure B.8 may be used
Conditions for acceptance
For the protective structure to be accepted it shall fulfil the following conditions at the beginning, during and after completion of the tests:
During testing, no component should intrude into the passenger deflection limiting volume, and no part may impact the passenger seat Additionally, only components relevant to the strength of the ROPS may be considered.
The passenger deflection limiting volume must remain within the protective structure's boundaries It is deemed outside protection if any part could touch the ground when the tractor tips over in the direction of the applied test load To assess this, the smallest standard tyre and track width settings specified by the manufacturer should be used.
— the minimum value of distance A attained during or after completion of the tests shall comply with Tables B.1, B.2 or B.3;
— for the articulated tractors, the median planes of the two parts shall be assumed to be in line;
After conducting the final crushing test, it is essential to document the permanent deflection of the protective structure Prior to the test, the positions of the main protective structure members relative to the operator seat index point must be recorded Subsequently, any displacements of these members due to the loading tests, as well as any changes in the height of the front and back members of the roof, should also be noted.
— at the point where the required energy absorption is met in each of the specified horizontal loading tests the force shall exceed 0,8 F max ;
An overload test is necessary if the applied force drops by more than 3% during the final 5% of deflection when the structure absorbs energy For a detailed description of the overload test, refer to section B.4.7.2.
— the required force shall be sustained in both crushing tests;
To ensure passenger safety during an overturning accident, it is crucial to eliminate any protruding components that could cause serious injury or potentially trap passengers, such as by their legs or feet, due to deformation.
— there shall be no other components presenting a serious hazard to the passenger
B.4.7.2 Description of the overload test
— An overload test shall consist of continuing the horizontal loading in increments of 5 % of the original required energy, up to a maximum of 20 % additional energy
The overload test is deemed successful if, after absorbing an additional 5%, 10%, or 15% of energy, the force decreases by less than 3% for each 5% increment while still exceeding 0.8 times the maximum force (0.8 F max) Alternatively, the test is also successful if, after absorbing 20% additional energy, the force remains above 0.8 F max.
During the overload test, additional cracks, tears, or breaches in the passenger deflection limiting volume due to elastic deformation are allowed However, once the load is removed, the protective structure must not encroach upon the passenger deflection limiting volume, which must remain fully protected.
General
NOTE The text herein reported refers to sections from 3.1 to 3.3 of OECD Code 4 edition July 2014 and includes additional statements for the passenger seat
Protective structures for tractors can be produced by either the tractor manufacturer or an independent firm, but tests are only valid for the specific tractor model tested Each model must undergo retesting for the protective structure to ensure compatibility Testing stations can certify that strength tests are applicable to modified tractor models that share components like the engine, transmission, steering, and front suspension Additionally, multiple protective structures can be tested for a single tractor model.
The protective structure intended for static testing must be securely attached to the tractor or its chassis It is essential that the tractor chassis is fully assembled, including all attaching brackets and components that could be influenced by the loads exerted on the protective structure.
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
A protective structure is primarily designed to safeguard the driver during a tractor overturn Temporary weather protection may be added, but drivers typically remove it in warm conditions Some structures feature permanent cladding with ventilation options like windows or flaps Since cladding can enhance structural strength, any removable components will be taken off for testing to ensure they do not contribute to the protective structure's integrity Doors, roof hatches, and operable windows will either be removed or secured in an open position during tests to prevent them from adding strength, while also assessing any potential hazards they may pose to passengers in the event of an overturn.
Throughout the remainder of these rules, reference will only be made to testing the protective structure It shall be understood that this includes cladding not of a temporary nature
The specifications must include a description of any temporary cladding provided Prior to testing, all glass or similar brittle materials should be removed Additionally, components of the tractor and protective structure that could incur unnecessary damage during the test, without impacting the strength or dimensions of the protective structure, may be removed at the manufacturer's discretion.
In addition parts mentioned in B.4.7.1 may also be removed at the request of the manufacturer, unless such parts are relevant for the strength of the ROPS
No repairs or adjustment may be carried out during the test
The test report must detail any tractor component that enhances the strength of the protective structure, including reinforced mudguards, along with their specific measurements.
Apparatus
The following shall be used in horizontal loading tests:
— material, equipment and means of attachment to ensure that the tractor chassis is firmly fixed to the ground and supported independently of the tyres;
— device for applying a horizontal force to the protective structure; provision shall be made so that the load can be uniformly distributed normal to the direction of loading:
For optimal performance, use a beam with a length ranging from 250 mm to 700 mm, in precise increments of 50 mm Additionally, ensure that the beam has a vertical dimension of 150 mm.
— the edges of the beam in contact with the protective structure shall be curved with a maximum radius of 50 mm;
Universal joints or their equivalents must be included to guarantee that the loading device does not restrict the protective structure's rotation or translation in any direction except for the loading direction.
When the straight line defined by the beam on the protective structure is not perpendicular to the load direction, it is essential to fill the space to ensure that the load is evenly distributed along the entire length.
For precise measurement of force and deflection in the load direction relative to the tractor chassis, it is essential to utilize equipment that provides continuous readings The measuring devices must be strategically positioned to accurately capture the force and deflection at the loading point and along the loading line.
The following shall be used in crushing tests:
— material, equipment and means of attachment to ensure that the tractor chassis is firmly fixed to the ground and supported independently of the tyres;
— device for applying a downward force to the protective structure, including a stiff beam with a width of 250 mm;
— equipment for measuring the total vertical force applied.
Test conditions
The protective structure shall be to production specifications and shall be fitted to the appropriate tractor model chassis in accordance with the manufacturer's declared method of attachment
The assembly must be firmly attached to the bedplate to prevent significant deflection of the connecting members in relation to the protective structure when under load Additionally, the assembly should rely solely on the initial attachment for support while under load.
An adjustable track width setting for the wheels, if present, shall be chosen such that no interference exists with the protective structure during the tests
The protective structure shall be instrumented with the necessary equipment to obtain the required force-deflection data
All tests shall be performed on the same protective structure No repairs or straightening of any
On completion of all tests, permanent deflections of the protective structure shall be measured and recorded.
Extension to other tractor models
General
If there are modifications to the make, denomination, or marketing features of the tested tractor or protective structure, the testing station that conducted the original test can provide an "administrative extension report." This report will reference the original test report.
When technical modifications are made to a tractor's protective structure or its attachment method, the original testing station can issue a "technical extension report" as outlined in sections C.4.2 and C.4.3.
Extension of the structural test results to other models of tractors
The loading and crushing tests need not be carried out on each model of tractor, provided that the protective structure and tractor comply with the following conditions:
— the structure shall be identical to the one tested;
The energy required must not exceed the energy calculated during the original test by more than 5% This 5% limit also applies to extensions when substituting tracks for wheels on the same tractor.
— the method of attachment and the tractor components to which the attachment is made shall be identical;
— any components such as mudguards and bonnet that may provide support for the protective structure shall be identical;
— the position and critical dimensions of the passenger seat in the protective structure, the position of
The SIP p in relation to SIP o, along with the positioning of the protective structure on the tractor, must ensure that the PDLV remains safeguarded within the deflected structure during all tests, considering the minimum horizontal distance (A).
Extension of the structural test results to modified models of the protective
This procedure should be implemented when the requirements of paragraph C.4.2 are not met It is not applicable if the attachment method of the protective structure to the tractor deviates from the original principle, such as replacing rubber supports with a suspension device.
Modifications that do not affect the results of the initial test include weld attachments of accessory mounting plates in non-critical areas of the structure Additionally, the inclusion of seats with different SIP o locations in the protective structure is permissible, provided that the minimum horizontal distance (A) from the new SIP o location adheres to the limits specified in Tables B.1, B.2, or B.3.
Modifications that may affect the results of the original test, while still maintaining the acceptability of the protective structure, include changes to structural components or the method of attachment to the tractor A validation test can be conducted, and the results will be documented in the extension report Specific limits for this type of extension are established.
— no more than 5 extensions may be accepted without a validation test;
The validation test results will be accepted for extension if all acceptance conditions are met Specifically, the force measured during the horizontal load tests must not deviate from the original test by more than ± 7%, and the deflection measured must also remain within a ± 7% range compared to the original test report.
An extension report may include multiple modifications of a protective structure if they represent different options; however, only one validation test is permissible per report Any untested options must be detailed in a specific section of the extension report.
Manufacturers can increase the reference mass of a previously tested protective structure while retaining the same approval number To do this, they must conduct a validation test and issue an extension report, as the ± 7% limits mentioned earlier do not apply in this scenario.
[1] Council Directive 77/536/EEC of 28 June 1977 on the approximation of the laws of the Member States relating to the roll-over protection structures of wheeled agricultural or forestry tractors
The Council Directive 79/622/EEC, established on June 25, 1979, focuses on harmonizing the laws of Member States regarding the static testing of roll-over protection structures for wheeled agricultural and forestry tractors.
[3] Council Directive 87/402/EEC of 25 June 1987 on roll- over protection structures mounted in front of the driver's seat on narrow-track wheeled agricultural and forestry tractors
[4] Council Directive 86/298/EEC of 26 May 1986 on rear- mounted roll-over protection structures of narrow-track wheeled agricultural and forestry tractors
[5] !OECD Code 4, July 2014 OECD standard code for the official testing of protective structures on agricultural and forestry tractors (static test)"