(a) Definitions. As used in this subpart—

Agricultural tractor means a two-or four-wheel drive type vehicle, or track vehicle, of more than 20 engine horsepower, designed to furnish the power to pull, carry, propel, or drive implements that are designed for agriculture. All self-propelled implements are excluded.

Low profile tractor means a wheeled tractor possessing the following characteristics:

(1) The front wheel spacing is equal to the rear wheel spacing, as measured from the centerline of each right wheel to the centerline of the corresponding left wheel.

(2) The clearance from the bottom of the tractor chassis to the ground does not exceed 18 inches.

(3) The highest point of the hood does not exceed 60 inches, and

(4) The tractor is designed so that the operator straddles the transmission when seated.

Tractor weight includes the protective frame or enclosure, all fuels, and other components required for normal use of the tractor. Ballast shall be added as necessary to achieve a minimum total weight of 110 lb. (50.0 kg.) per maximum power take-off horsepower at the rated engine speed or the maximum gross vehicle weight specified by the manufacturer, whichever is the greatest. Front end weight shall be at least 25 percent of the tractor test weight. In case power take-off horsepower is not available, 95 percent of net engine flywheel horsepower shall be used.

(b) General requirements. Agricultural tractors manufactured after October 25, 1976, shall meet the following requirements:

(1) Roll-over protective structures (ROPS). ROPS shall be provided by the employer for each tractor operated by an employee. Except as provided in paragraph (b)(5) of this section, a ROPS used on wheel-type tractors shall meet the test and performance requirements of 29 CFR 1928.52, 1928.53, or 1926.1002 as appropriate. A ROPS used on track-type tractors shall meet the test and performance requirements of 29 CFR 1926.1001.

(2) Seatbelts. (i) Where ROPS are required by this section, the employer shall:

(A) Provide each tractor with a seatbelt which meets the requirements of this paragraph;

(B) Ensure that each employee uses such seatbelt while the tractor is moving; and

(C) Ensure that each employee tightens the seatbelt sufficiently to confine the employee to the protected area provided by the ROPS.

(ii) Each seatbelt shall meet the requirements set forth in Society of Automotive Engineers Standard SAE J4C, 1965 Motor Vehicle Seat Belt Assemblies, 2 except as noted hereafter:

2 Copies may be obtained from the Society of Automotive Engineers, 400 Commonwealth Drive, Warrendale, PA 15096.

(A) Where a suspended seat is used, the seatbelt shall be fastened to the movable portion of the seat to accommodate a ride motion of the operator.

(B) The seatbelt anchorage shall be capable of withstanding a static tensile load of 1,000 pounds (453.6 kg) at 45 degrees to the horizontal equally divided between the anchorages. The seat mounting shall be capable of withstanding this load plus a load equal to four times the weight of all applicable seat components applied at 45 degrees to the horizontal in a forward and upward direction. In addition, the seat mounting shall be capable of withstanding a 500 pound (226.8 kg) belt load plus two times the weight of all applicable seat components both applied at 45 degrees to the horizontal in and upward and rearward direction. Floor and seat deformation is acceptable provided there is not structural failure or release of the seat adjusted mechanism or other locking device.

(C) The seatbelt webbing material shall have a resistance to acids, alkalies, mildew, aging, moisture, and sunlight equal to or better than that of untreated polyester fiber.

(3) Protection from spillage. Batteries, fuel tanks, oil reservoirs, and coolant systems shall be constructed and located or sealed to assure that spillage will not occur which may come in contact with the operator in the event of an upset.

(4) Protection from sharp surfaces. All sharp edges and corners at the operator's station shall be designed to minimize operator injury in the event of an upset.

(5) Exempted uses. Paragraphs (b)(1) and (b)(2) of this section do not apply to the following uses:

(i) Low profile tractors while they are used in orchards, vineyards or hop yards where the vertical clearance requirements would substantially interfere with normal operations, and while their use is incidental to the work performed therein.

(ii) Low profile tractors while used inside a farm building or greenhouse in which the vertical clearance is insufficient to allow a ROPS equipped tractor to operate, and while their use is incidental to the work performed therein.

(iii) Tractors while used with mounted equipment which is incompatible with ROPS (e.g. cornpickers, cotton strippers, vegetable pickers and fruit harvesters).

(6) Remounting. Where ROPS are removed for any reason, they shall be remounted so as to meet the requirements of this paragraph.

(c) Labeling. Each ROPS shall have a label, permanently affixed to the structure, which states:

(1) Manufacturer's or fabricator's name and address;

(2) ROPS model number, if any;

(3) Tractor makes, models, or series numbers that the structure is designed to fit; and

(4) That the ROPS model was tested in accordance with the requirements of this subpart.

(d) Operating instructions. Every employee who operates an agricultural tractor shall be informed of the operating practices contained in appendix A of this part and of any other practices dictated by the work environment. Such information shall be provided at the time of initial assignment and at least annually thereafter.

[40 FR 18257, Apr. 25, 1975, as amended at 61 FR 9255, Mar. 7, 1996; 69 FR 18803, Apr. 9, 2004; 70 FR 77003, Dec. 29, 2005]

(a) Purpose. The purpose of this section is to establish the test and performance requirements for a protective frame designed for wheel-type agricultural tractors to minimize the frequency and severity of operator injury resulting from accidental upsets. General requirements for the protection of operators are specified in 29 CFR 1928.51.

(b) Types of tests. All protective frames for wheel-type agricultural tractors shall be of a model that has been tested as follows:

(1) Laboratory test. A laboratory energy-absorption test, either static or dynamic, under repeatable and controlled loading, to permit analysis of the protective frame for compliance with the performance requirements of this standard.

(2) Field-upset test. A field-upset test under controlled conditions, both to the side and rear, to verify the effectiveness of the protective system under actual dynamic conditions. Such testing may be omitted when:

(i) The analysis of the protective-frame static-energy absorption test results indicates that both FERis and FERir (as defined in paragraph (d)(2)(ii) of this section) exceed 1.15; or

(ii) The analysis of the protective-frame dynamic-energy absorption test results indicates that the frame can withstand an impact of 15 percent greater than the impact it is required to withstand for the tractor weight as shown in Figure C-7.

(c) Descriptions—(1) Protective frame. A protective frame is a structure comprised of uprights mounted to the tractor, extending above the operator's seat. A typical two-post frame is shown in Figure C-1.

(2) Overhead weather shield. When an overhead weather shield is available for attachment to the protective frame, it may be in place during tests provided it does not contribute to the strength of the protective frame.

(3) Overhead falling object protection. When an overhead falling-object protection device is available for attachment to the protective frame, it may be in place during tests provided it does not contribute to the strength of the protective frame.

(d) Test procedures—(1) General. (i) The tractor weight used shall be that of the heaviest tractor model on which the protective frame is to be used.

(ii) Each test required under this section shall be performed on a new protective frame. Mounting connections of the same design shall be used during each such test.

(iii) Instantaneous deflection shall be measured and recorded for each segment of the test; see paragraph (e)(1)(i) of this section for permissible deflections.

(iv) The seat-reference point (“SRP”) in Figure C-3 is that point where the vertical line that is tangent to the most forward point at the longitudinal seat centerline of the seat back, and the horizontal line that is tangent to the highest point of the seat cushion, intersect in the longitudinal seat section. The seat-reference point shall be determined with the seat unloaded and adjusted to the highest and most rearward position provided for seated operation of the tractor.

(v) When the centerline of the seat is off the longitudinal center, the frame loading shall be on the side with the least space between the centerline of seat and the protective frame.

(vi) Low-temperature characteristics of the protective frame or its material shall be demonstrated as specified in paragraph (e)(1)(ii) of this section.

(vii) Rear input energy tests (static, dynamic, or field-upset) need not be performed on frames mounted to tractors having four driven wheels and more than one-half their unballasted weight on the front wheels.

(viii) Accuracy table:

(2) Static test procedure. (i) The following test conditions shall be met:

(A) The laboratory mounting base shall be the tractor chassis for which the protective frame is designed, or its equivalent;

(B) The protective frame shall be instrumented with the necessary equipment to obtain the required load-deflection data at the locations and directions specified in Figures C-2 and C-3; and

(C) When the protective frame is of a one- or two-upright design, mounting connections shall be instrumented with the necessary equipment to record the required force to be used in paragraph (d)(2)(iii)(E) and (J) of this section. Instrumentation shall be placed on mounting connections before installation load is applied.

(ii) The following definitions shall apply:

W = Tractor weight (see 29 CFR 1928.51(a)) in lb (W′ in kg); Eis = Energy input to be absorbed during side loading in ft-lb (E′is in J [joules]); Eis = 723 + 0.4 W (E′is = 100 + 0.12 W′); Eir = Energy input to be absorbed during rear loading in ft-lb (E′ir in J); Eir = 0.47 W (E′ir = 0.14 W′); L = Static load, lbf [pounds force], (N) [newtons]; D = Deflection under L, in. (mm); L-D = Static load-deflection diagram; Lmax = Maximum observed static load; Load Limit = Point on a continuous L-D curve where the observed static load is 0.8 Lmax on the down slope of the curve (see Figure C-5); Eu = Strain energy absorbed by the frame in ft-lb (J); area under the L-D curve; FER = Factor of energy ratio; FERis = EuEis; FERir = EuEir; Pb = Maximum observed force in mounting connection under a static load, L lbf (N); Pu = Ultimate force capacity of a mounting connection, lbf (N); FSB = Design margin for a mounting connection; and FSB = Pu/Pb

(iii) The test procedures shall be as follows:

(A) Apply the rear load according to Figure C-3, and record L and D simultaneously. Rear-load application shall be distributed uniformly on the frame over an area perpendicular to the direction of load application, no greater than 160 sq. in. (1,032 sq. cm) in size, with the largest dimension no greater than 27 in. (686 mm). The load shall be applied to the upper extremity of the frame at the point that is midway between the center of the frame and the inside of the frame upright. When no structural cross member exists at the rear of the frame, a substitute test beam that does not add strength to the frame may be used to complete this test procedure. The test shall be stopped when:

(1) The strain energy absorbed by the frame is equal to or greater than the required input energy Eir; or

(2) Deflection of the frame exceeds the allowable deflection (see paragraph (e)(1)(i) of this section); or

(3) Frame load limit occurs before the allowable deflection is reached in rear load (see Figure C-5).

(B) Using data obtained under paragraph (d)(2)(iii)(A) of this section, construct the L-D diagram shown in Figure C-5;

(C) Calculate Eir;

(D) Calculate FERir;

(E) Calculate FSB as required by paragraph (d)(2)(i)(C) of this section;

(F) Apply the side-load tests on the same frame, and record L and D simultaneously. Side-load application shall be at the upper extremity of the frame at a 90° angle to the centerline of the vehicle. The side load shall be applied to the longitudinal side farthest from the point of rear-load application. Apply side load L as shown in Figure C-2. The test shall be stopped when:

(1) The strain energy absorbed by the frame is equal to or greater than the required input energy Eis; or

(2) Deflection of the frame exceeds the allowable deflection (see paragraph (e)(1)(i) of this section); or

(3) Frame load limit occurs before the allowable deflection is reached in side load (see Figure C-5).

(G) Using data obtained in paragraph (d)(2)(iii)(F) of this section, construct the L-D diagram as shown in Figure C-5;

(H) Calculate Eis;

(I) Calculate FERis; and

(J) Calculate FSB as required by paragraph (d)(2)(i)(C) of this section.

(3) Dynamic test procedure. (i) The following test conditions shall be met:

(A) The protective frame and tractor shall be tested at the weight defined by 29 CFR 1928.51(a);

(B) The dynamic loading shall be accomplished by using a 4,410-lb (2,000-kg) weight acting as a pendulum. The impact face of the weight shall be 27 ±1 in. by 27 ±1 in. (686 ±25 mm by 686 ±25 mm), and shall be constructed so that its center of gravity is within 1.0 in. (25.4 mm) of its geometric center. The weight shall be suspended from a pivot point 18 to 22 ft (5.5 to 6.7 m) above the point of impact on the frame, and shall be conveniently and safely adjustable for height (see Figure C-6);

(C) For each phase of testing, the tractor shall be restrained from moving when the dynamic load is applied. The restraining members shall have strength no less than, and elasticity no greater than, that of 0.50-in. (12.7-mm) steel cable. Points of attachment for the restraining members shall be located an appropriate distance behind the rear axle and in front of the front axle to provide a 15° to 30° angle between a restraining cable and the horizontal. For impact from the rear, the restraining cables shall be located in the plane in which the center of gravity of the pendulum will swing, or alternatively, two sets of symmetrically located cables may be used at lateral locations on the tractor. For impact from the side, restraining cables shall be used as shown in Figures C-8 and C-9;

(D) The front and rear wheel-tread settings, when adjustable, shall be at the position nearest to halfway between the minimum and maximum settings obtainable on the vehicle. When only two settings are obtainable, the minimum setting shall be used. The tires shall have no liquid ballast, and shall be inflated to the maximum operating pressure recommended by the manufacturer. With the specified tire inflation, the restraining cable shall be tightened to provide tire deflection of 6 to 8 percent of the nominal tire-section width. After the vehicle is restrained properly, a wooden beam no less than 6-in. × 6-in. (150-mm × 150-mm) in cross section shall be driven tightly against the appropriate wheels and clamped. For the test to the side, an additional wooden beam shall be placed as a prop against the wheel nearest to the operator's station, and shall be secured to the base so that it is held tightly against the wheel rim during impact. The length of this beam shall be chosen so that it is at an angle of 25° to 40° to the horizontal when it is positioned against the wheel rim. It shall have a length 20 to 25 times its depth, and a width two to three times its depth (see Figures C-8 and C-9);

(E) Means shall be provided for indicating the maximum instantaneous deflection along the line of impact. A simple friction device is illustrated in Figure C-4;

(F) No repairs or adjustments shall be made during the test; and

(G) When any cables, props, or blocking shift or break during the test, the test shall be repeated.

(ii) H = Vertical height of the center of gravity of a 4,410-lb (2,000-kg) weight in in. (H′ in mm). The weight shall be pulled back so that the height of its center of gravity above the point of impact is: H = 4.92 + 0.00190 W (H′ = 125 ±0.170 W′) (see Figure C-7).

(iii) The test procedures shall be as follows:

(A) The frame shall be evaluated by imposing dynamic loading from the rear, followed by a load to the side on the same frame. The pendulum swinging from the height determined by paragraph (d)(3)(ii) of this section shall be used to impose the dynamic load. The position of the pendulum shall be so selected that the initial point of impact on the frame is in line with the arc of travel of the center of gravity of the pendulum. When a quick-release mechanism is used, it shall not influence the attitude of the block;

(B) Impact at rear. The tractor shall be restrained properly according to paragraphs (d)(3)(i)(C) and (d)(3)(i)(D) of this section. The tractor shall be positioned with respect to the pivot point of the pendulum so that the pendulum is 20° from the vertical prior to impact as shown in Figure C-8. The impact shall be applied to the upper extremity of the frame at the point that is midway between the centerline of the frame and the inside of the frame upright. When no structural cross member exists at the rear of the frame, a substitute test beam that does not add to the strength of the frame may be used to complete the test procedure; and

(C) Impact at side. The blocking and restraining shall conform to paragraphs (d)(3)(i)(C) and (d)(3)(i)(D) of this section. The center point of impact shall be at the upper extremity of the frame at a point most likely to hit the ground first, and at a 90° to the centerline of the vehicle (see Figure C-9). The side impact shall be applied to the longitudinal side farthest from the point of rear impact.

(4) Field-upset test procedure. (i) The following test conditions shall be met:

(A) The tractor shall be tested at the weight defined in 29 CFR 1928.51(a);

(B) The following provisions address soil bank test conditions.

(1) The test shall be conducted on a dry, firm soil bank. The soil in the impact area shall have an average cone index in the 0-in. to 6-in. (0-mm to 152-mm) layer of not less than 150. Cone index shall be determined according to American Society of Agricultural Engineers (“ASAE”) recommendation ASAE R313.1-1971 (“Soil cone penetrometer”), as reconfirmed in 1975, which is incorporated by reference. The incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. The path of vehicle travel shall be 12° ±2° to the top edge of the bank.

(2) ASAE recommendation R313.1-1971, as reconfirmed in 1975, appears in the 1977 Agricultural Engineers Yearbook, or it may be examined at: Any OSHA Regional Office; the OSHA Docket Office, U.S. Department of Labor, 200 Constitution Avenue, NW., Room N-2625, Washington, DC 20210 (telephone: (202) 693-2350 (TTY number: (877) 889-5627)); or the National Archives and Records Administration (“NARA”). (For information on the availability of this material at NARA, telephone (202) 741-6030 or access the NARA Web site at http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.) Copies may be purchased from the American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, MI 49085.

(C) An 18-in. (457-mm) high ramp (see Figure C-10) shall be used to assist in upsetting the vehicle to the side; and

(D) The front and rear wheel-tread settings, when adjustable, shall be at the position nearest to halfway between the minimum and maximum settings obtainable on the vehicle. When only two settings are obtainable, the minimum setting shall be used.

(ii) Field upsets shall be induced to the rear and side as follows:

(A) Rear upset shall be induced by engine power, with the tractor operating in gear to obtain 3 to 5 mph (4.8 to 8.0 kph) at maximum governed engine rpm by driving forward directly up a minimum slope of 60° ±5° as shown in Figure C-11, or by an alternative equivalent means. The engine clutch may be used to aid in inducing the upset; and

(B) To induce side upset, the tractor shall be driven under its own power along the specified path of travel at a minimum speed of 10 mph (16 kph), or at maximum vehicle speed when under 10 mph (16 kph), and over the ramp as described in paragraph (d)(4)(i)(C) of this section.

(e) Performance requirements—(1) General requirements. (i) The frame, overhead weather shield, fenders, or other parts in the operator area may be deformed in these tests, but shall not shatter or leave sharp edges exposed to the operator, or encroach on the dimensions shown in Figures C-2 and C-3, and specified as follows:

d = 2 in. (51 mm) inside of the frame upright to the vertical centerline of the seat; e = 30 in. (762 mm) at the longitudinal centerline; f = Not greater than 4 in. (102 mm) to the rear edge of the crossbar, measured forward of the seat-reference point (“SRP”); g = 24 in. (610 mm) minimum; and m = Not greater than 12 in. (305 mm), measured from the seat-reference point to the forward edge of the crossbar.

(ii) The protective structure and connecting fasteners must pass the static or dynamic tests described in paragraphs (d)(2), (d)(3), or (d)(4) of this section at a metal temperature of 0 °F (−18 °C) or below, or exhibit Charpy V-notch impact strengths as follows:

10-mm × 10-mm (0.394-in. × 0.394-in.) specimen: 8.0 ft-lb (10.8 J) at −20 °F (−30 °C); 10-mm × 7.5-mm (0.394-in. × 0.296-in.) specimen: 7.0 ft-lb (9.5 J) at −20 °F (−30 °C); 10-mm × 5-mm (0.394-in. × 0.197-in.) specimen: 5.5 ft-lb (7.5 J) at −20 °F (−30 °C); or 10-mm × 2.5-mm (0.394-in. × 0.098-in.) specimen: 4.0 ft-lb (5.5 J) at −20 °F (−30 °C). Specimens shall be longitudinal and taken from flat stock, tubular, or structural sections before forming or welding for use in the frame. Specimens from tubular or structural sections shall be taken from the middle of the side of greatest dimension, not to include welds.

(2) Static test-performance requirements. In addition to meeting the requirements of paragraph (e)(1) of this section for both side and rear loads, FERis and FERir, shall be greater than 1.0, and when the ROPS contains one or two upright frames only, FSB shall be greater than 1.3.

(3) Dynamic test-performance requirements. The structural requirements shall be met when the dimensions in paragraph (e)(1) of this section are used in both side and rear loads.

(4) Field-upset test performance requirements. The requirements of paragraph (e)(1) of this section shall be met for both side and rear upsets.

[70 FR 77004, Dec. 29, 2005]

(a) Purpose. The purpose of this section is to establish the test and performance requirements for a protective enclosure designed for wheel-type agricultural tractors to minimize the frequency and severity of operator injury resulting from accidental upset. General requirements for the protection of operators are specified in 29 CFR 1928.51.

(b) Types of tests. All protective enclosures for wheel-type agricultural tractors shall be of a model that has been tested as follows:

(1) Laboratory test. A laboratory energy-absorption test, either static or dynamic, under repeatable and controlled loading, to permit analysis of the protective enclosure for compliance with the performance requirements of this standard; and

(2) Field-upset test. A field-upset test under controlled conditions, both to the side and rear, to verify the effectiveness of the protective system under actual dynamic conditions. This test may be omitted when:

(i) The analysis of the protective-frame static-energy absorption test results indicates that both FERis and FERir (as defined in paragraph (d)(2)(ii) of this section) exceed 1.15; or

(ii) The analysis of the protective-frame dynamic-energy absorption test results indicates that the frame can withstand an impact 15 percent greater than the impact it is required to withstand for the tractor weight as shown in Figure C-7.

(c) Description. A protective enclosure is a structure comprising a frame and/or enclosure mounted to the tractor. A typical enclosure is shown in Figure C-12.

(d) Test procedures—(1) General. (i) The tractor weight used shall be that of the heaviest tractor model on which the protective enclosure is to be used.

(ii) Each test required under this section shall be performed on a protective enclosure with new structural members. Mounting connections of the same design shall be used during each test.

(iii) Instantaneous deflection shall be measured and recorded for each segment of the test; see paragraph (e)(1)(i) of this section for permissible deflections.

(iv) The seat-reference point (“SRP”) in Figure C-14 is that point where the vertical line that is tangent to the most forward point at the longitudinal seat centerline of the seat back, and the horizontal line that is tangent to the highest point of the seat cushion, intersect in the longitudinal seat section. The seat-reference point shall be determined with the seat unloaded and adjusted to the highest and most rearward position provided for seated operations of the tractor.

(v) When the centerline of the seat is off the longitudinal center, the protective-enclosure loading shall be on the side with least space between the centerline of the seat and the protective enclosure.

(vi) Low-temperature characteristics of the protective enclosure or its material shall be demonstrated as specified in paragraph (e)(1)(ii) of this section.

(vii) Rear input energy tests (static, dynamic, or field-upset) need not be performed on enclosures mounted to tractors having four driven wheels and more than one-half their unballasted weight on the front wheels.

(viii) Accuracy table:

(ix) When movable or normally removable portions of the enclosure add to structural strength, they shall be placed in configurations that contribute least to structural strength during the test.

(2) Static test procedure. (i) The following test conditions shall be met:

(A) The laboratory mounting base shall be the tractor chassis for which the protective enclosure is designed, or its equivalent; and

(B) The protective enclosure shall be instrumented with the necessary equipment to obtain the required load-deflection data at the locations and directions specified in Figures C-13 and C-14.

(ii) The following definitions shall apply:

W = Tractor weight (see 29 CFR 1928.51(a)) in lb (W″ in kg); Eis = Energy input to be absorbed during side loading in ft-lb (E″is in J [joules]); Eis = 723 + 0.4 W (E″is = 100 + 0.12 W″); Eir = Energy input to be absorbed during rear loading in ft-lb (E″ir in J); Eir = 0.47 W (E″ir = 0.14 W″); L = Static load, lbf [pounds force], (N) [newtons]; D = Deflection under L, in. (mm); L-D = Static load-deflection diagram; Lmax = Maximum observed static load; Load Limit = Point on a continuous L-D curve where the observed static load is 0.8 Lmax on the down slope of the curve (see Figure C-5); Eu = Strain energy absorbed by the protective enclosure in ft-lbs (J); area under the L-D curve; FER = Factor of energy ratio; FERis = Eu/Eis; and FERir = Eu/Eir.

(iii) The test procedures shall be as follows:

(A) When the protective-frame structures are not an integral part of the enclosure, the direction and point of load application for both side and rear shall be the same as specified in 29 CFR 1928.52(d)(2);

(B) When the protective-frame structures are an integral part of the enclosure, apply the rear load according to Figure C-14, and record L and D simultaneously. Rear-load application shall be distributed uniformly on the frame structure over an area perpendicular to the load application, no greater than 160 sq. in. (1,032 sq. cm) in size, with the largest dimension no greater than 27 in. (686 mm). The load shall be applied to the upper extremity of the structure at the point that is midway between the centerline of the protective enclosure and the inside of the protective structure. When no structural cross member exists at the rear of the enclosure, a substitute test beam that does not add strength to the structure may be used to complete this test procedure. The test shall be stopped when:

(1) The strain energy absorbed by the structure is equal to or greater than the required input energy Eir; or

(2) Deflection of the structure exceeds the allowable deflection (see paragraph (e)(1)(i) of this section); or

(3) The structure load limit occurs before the allowable deflection is reached in rear load (see Figure C-5);

(C) Using data obtained in paragraph (d)(2)(iii)(B) of this section, construct the L-D diagram for rear loads as shown in Figure C-5;

(D) Calculate Eir;

(E) Calculate FERir;

(F) When the protective-frame structures are an integral part of the enclosure, apply the side load according to Figure C-13, and record L and D simultaneously. Static side-load application shall be distributed uniformly on the frame over an area perpendicular to the direction of load application, and no greater than 160 sq. in. (1,032 sq. cm) in size, with the largest dimension no greater than 27 in. (686 mm). Side-load application shall be at a 90° angle to the centerline of the vehicle. The center of the side-load application shall be located between point k, 24 in. (610 mm) forward of the seat-reference point, and point l, 12 in. (305 mm) rearward of the seat-reference point, to best use the structural strength (see Figure C-13). This side load shall be applied to the longitudinal side farthest from the point of rear-load application. The test shall be stopped when:

(1) The strain energy absorbed by the structure is equal to or greater than the required input energy Eis; or

(2) Deflection of the structure exceeds the allowable deflection (see paragraph (e)(1)(i) of this section); or

(3) The structure load limit occurs before the allowable deflection is reached in side load (see Figure C-5);

(G) Using data obtained in paragraph (d)(2)(iii)(F) of this section, construct the L-D diagram for the side load as shown in Figure C-5;

(H) Calculate FERis; and

(I) Calculate FERir.

(3) Dynamic test procedure. (i) The following test conditions shall be met:

(A) The protective enclosure and tractor shall be tested at the weight defined by 29 CFR 1928.51(a);

(B) The dynamic loading shall be accomplished by using a 4,410-lb (2,000-kg) weight acting as a pendulum. The impact face of the weight shall be 27 ±1 in. by 27 ±1 in. (686 ±25 mm by 686 ±25 mm), and shall be constructed so that its center of gravity is within 1.0 in. (25.4 mm) of its geometric center. The weight shall be suspended from a pivot point 18 to 22 ft (5.5 to 6.7 m) above the point of impact on the enclosure, and shall be conveniently and safely adjustable for height (see Figure C-6);

(C) For each phase of testing, the tractor shall be restrained from moving when the dynamic load is applied. The restraining members shall have strength no less than, and elasticity no greater than, that of 0.50-in. (12.7-mm) steel cable. Points of attachment for the restraining members shall be located an appropriate distance behind the rear axle and in front of the front axle to provide a 15° to 30° angle between the restraining cable and the horizontal. For impact from the rear, the restraining cables shall be located in the plane in which the center of gravity of the pendulum will swing, or alternatively, two sets of symmetrically located cables may be used at lateral locations on the tractor. For the impact from the side, restraining cables shall be used as shown in Figures C-15 and C-16;

(D) The front and rear wheel-tread settings, when adjustable, shall be at the position nearest to halfway between the minimum and maximum settings obtainable on the vehicle. When only two settings are obtainable, the minimum setting shall be used. The tires shall have no liquid ballast, and shall be inflated to the maximum operating pressure recommended by the manufacturer. With specified tire inflation, the restraining cable shall be tightened to provide tire deflection of 6 to 8 percent of nominal tire section width. After the vehicle is retrained properly, a wooden beam no smaller than 6-in. × 6-in. (150-mm × 150-mm) cross-section shall be driven tightly against the appropriate wheels and clamped. For the test to the side, an additional wooden beam shall be placed as a prop against the wheel nearest the operator's station, and shall be secured to the base so that it is held tightly against the wheel rim during impact. The length of this beam shall be chosen so that it is at an angle of 25° to 40° to the horizontal when it is positioned against the wheel rim. It shall have a length 20 to 25 times its depth, and a width two to three times its depth (see Figures C-15 and C-16);

(E) Means shall be provided for indicating the maximum instantaneous deflection along the line of impact. A simple friction device is illustrated in Figure C-4;

(F) No repair or adjustments shall be made during the test; and

(G) When any cables, props, or blocking shift or break during the test, the test shall be repeated.

(ii) H = Vertical height of the center of gravity of a 4,410-lb (2,000-kg) weight in in. (H′ in mm). The weight shall be pulled back so that the height of its center of gravity above the point of impact is: H = 4.92 + 0.00190 W (H′ = 125 + 0.107 W′) (see Figure C-7).

(iii) The test procedures shall be as follows:

(A) The enclosure structure shall be evaluated by imposing dynamic loading from the rear, followed by a load to the side on the same enclosure structure. The pendulum swinging from the height determined by paragraph (d)(3)(ii) of this section shall be used to impose the dynamic load. The position of the pendulum shall be so selected that the initial point of impact on the protective structure is in line with the arc of travel of the center of gravity of the pendulum. When a quick-release mechanism is used, it shall not influence the attitude of the block;

(B) Impact at rear. The tractor shall be restrained properly according to paragraphs (d)(3)(i)(C) and (d)(3)(i)(D) of this section. The tractor shall be positioned with respect to the pivot point of the pendulum so that the pendulum is 20° from the vertical prior to impact as shown in Figure C-15. The impact shall be applied to the upper extremity of the enclosure structure at the point that is midway between the centerline of the enclosure structure and the inside of the protective structure. When no structural cross member exists at the rear of the enclosure structure, a substitute test beam that does not add to the strength of the structure may be used to complete the test procedure; and

(C) Impact at side. The blocking and restraining shall conform to paragraphs (d)(3)(i)(C) and (d)(3)(i)(D) of this section. The center point of impact shall be at the upper extremity of the enclosure at a 90° angle to the centerline of the vehicle, and located between a point k, 24 in. (610 mm) forward of the seat-reference point, and a point l, 12 in. (305 mm) rearward of the seat-reference point, to best use the structural strength (see Figure C-13). The side impact shall be applied to the longitudinal side farthest from the point of rear impact.

(4) Field-upset test procedure. (i) The following test conditions shall be met:

(A) The tractor shall be tested at the weight defined in 29 CFR 1928.51(a);

(B) The following provisions address soil bank test conditions.

(1) The test shall be conducted on a dry, firm soil bank. The soil in the impact area shall have an average cone index in the 0-in. to 6-in. (0-mm to 152-mm) layer of not less than 150. Cone index shall be determined according to American Society of Agricultural Engineers (“ASAE”) recommendation ASAE R313.1-1971 (“Soil cone penetrometer”), as reconfirmed in 1975, which is incorporated by reference. The incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. The path of vehicle travel shall be 12° ±2° to the top edge of the bank.

(2) ASAE recommendation R313.1-1971, as reconfirmed in 1975, appears in the 1977 Agricultural Engineers Yearbook, or it may be examined at: Any OSHA Regional Office; the OSHA Docket Office, U.S. Department of Labor, 200 Constitution Avenue, NW., Room N-2625, Washington, DC 20210 (telephone: (202) 693-2350 (TTY number: (877) 889-5627)); or the National Archives and Records Administration (“NARA”). (For information on the availability of this material at NARA, telephone (202) 741-6030 or access the NARA Web site at http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.) Copies may be purchased from the American Society of Agricultural Engineers 2950 Niles Road, St. Joseph, MI 49085.

(C) An 18-in. (457 mm) high ramp (see Figure C-10) shall be used to assist in upsetting the vehicle to the side; and

(D) The front and rear wheel-tread settings, when adjustable, shall be at the position nearest to halfway between the minimum and maximum settings obtainable on the vehicle. When only two settings are obtainable, the minimum setting shall be used.

(ii) Field upsets shall be induced to the rear and side.

(A) Rear upset shall be induced by engine power, with the tractor operating in gear to obtain 3 to 5 mph (4.8 to 8.0 kph) at maximum governed engine rpm by driving forward directly up a minimum slope of 60° ±5° as shown in Figure C-11, or by an alternate equivalent means. The engine clutch may be used to aid in inducing the upset; and

(B) To induce side upset, the tractor shall be driven under its own power along the specified path of travel at a minimum speed of 10 mph (16 kph), or at maximum vehicle speed when under 10 mph (16 kph), and over the ramp as described in paragraph (d)(4)(i)(C) of this section.

(e) Performance requirements—(1) General requirements. (i) The protective enclosure structural members or other parts in the operator area may be deformed in these tests, but shall not shatter or leave sharp edges exposed to the operator. They shall not encroach on a transverse plane passing through points d and f within the projected area defined by dimensions d, e, and g, or on the dimensions shown in Figures C-13 and C-14, as follows:

d = 2 in. (51 mm) inside of the protective structure to the vertical centerline of the seat; e = 30 in. (762 mm) at the longitudinal centerline; f = Not greater than 4 in. (102 mm) measured forward of the seat-reference point (“SRP”) at the longitudinal centerline as shown in Figure C-14; g = 24 in. (610 mm) minimum; h = 17.5 in. (445 mm) minimum; and j = 2.0 in. (51 mm) measured from the outer periphery of the steering wheel.

(ii) The protective structure and connecting fasteners must pass the static or dynamic tests described in paragraphs (d)(2), (d)(3), or (d)(4) of this section at a metal temperature of 0 °F (−8 °C) or below, or exhibit Charpy V-notch impact strengths as follows:

10-mm × 10-mm (0.394-in. × 0.394-in.) specimen: 8.0 ft-lb (10.8 J) at −20 °F (−30 °C); 10-mm × 7.5-mm (0.394-in. × 0.296-in.) specimen: 7.0 ft-lb (9.5 J) at −20 °F (−30 °C); 10-mm × 5-mm (0.394-in. × 0.197-in.) specimen: 5.5 ft-lb (7.5 J) at −20 °F (−30 °C); or 10-mm × 2.5-mm (0.394-in. × 0.098-in.) specimen: 4.0 ft-lb (5.5 J) at −20 °F (−30 °C).

Specimens shall be longitudinal and taken from flat stock, tubular, or structural sections before forming or welding for use in the protective enclosure. Specimens from tubular or structural sections shall be taken from the middle of the side of greatest dimension, not to include welds.

(iii) The following provisions address glazing requirements.

(A) Glazing shall conform to the requirements contained in Society of Automotive Engineers (“SAE”) standard J674-1963 (“Safety glazing materials”), which is incorporated by reference. The incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.

(B) SAE standard J674-1963 appears in the 1965 SAE Handbook, or it may be examined at: any OSHA Regional Office; the OSHA Docket Office, U.S. Department of Labor, 200 Constitution Avenue, NW., Room N-2625, Washington, DC 20210 (telephone: (202) 693-2350 (TTY number: (877) 889-5627)); or the National Archives and Records Administration (“NARA”). (For information on the availability of this material at NARA, telephone (202) 741-6030 or access the NARA Web site at http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.) Copies may be purchased from the Society of Automotive Engineers, 400 Commonwealth Drive, Warrendale, Pennsylvania 15096-0001.

(iv) Two or more operator exits shall be provided and positioned to avoid the possibility of both being blocked by the same accident.

(2) Static test-performance requirements. In addition to meeting the requirements of paragraph (e)(1) of this section for both side and rear loads, FERis and FER ir shall be greater than 1.0.

(3) Dynamic test-performance requirements. The structural requirements shall be met when the dimensions in paragraph (e)(1) of this section are used in both side and rear loads.

(4) Field-upset test performance requirements. The requirements of paragraph (e)(1) of this section shall be met for both side and rear upsets.

[70 FR 77004, Dec. 29, 2005, as amended at 71 FR 41145, July 20, 2006]

1. Securely fasten your seat belt if the tractor has a ROPS. 2. Where possible, avoid operating the tractor near ditches, embankments, and holes. 3. Reduce speed when turning, crossing slopes, and on rough, slick, or muddy surfaces. 4. Stay off slopes too steep for safe operation. 5. Watch where you are going, especially at row ends, on roads, and around trees. 6. Do not permit others to ride. 7. Operate the tractor smoothly—no jerky turns, starts, or stops. 8. Hitch only to the drawbar and hitch points recommended by tractor manufacturers. 9. When tractor is stopped, set brakes securely and use park lock if available.

[71 FR 41146, July 20, 2006]