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• Record Type: Instruction
• Directive Number: STD 04-00-001
• Old Directive Number: STD 4.1
• Title: Interpretations of: (a)-29 CFR 1928.51(a), Definitions "Agricultural Tractor." (b)-29 CFR 1928.51(b)(1), Rollover
• Information Date: 10/30/1978
• Standard Number: 1928.51(a)(2); 1928.51(a)(3); 1928.51(a)(4); 1928.51(b)(1)

OSHA INSTRUCTION STD 4.1 OCTOBER 30, 1978

OSHA PROGRAM DIRECTIVE #100-47

TO: REGIONAL ADMINISTRATORS - OSHA

Subject: Interpretations of: (a) -29 CFR 1928.51 (a), Definitions "Agricultural Tractor." (b)- 29 CFR 1928.51(b)(1), Roll-over Protective Structure, (ROPS)

1. Purpose

a. To provide a specific clarification on the definition of "20 engine horsepower" as used in the definition of agricultural tractor.
b. To exempt rubber-tired skid-steer equipment used in agricultural operations from the Rollover Protective Structures (ROPS) standards.

2. Directive Affected

None.

3. Background

a. Inquiries have been received from manufacturers of agricultural equipment and agricultural employers as to the meaning of "20 engine horsepower."
b. Part 1928 adopts Subpart W (ROPS) of Part 1926. Section 1926.1000(a)(2) reserves promulgation of specific standards for rollover protective structures for compactors and rubber-tired skid-steer equipment.

4. Action

a. The meaning of "20 engine horsepower" as used in definitions of "agricultural tractor" is the "net engine horsepower - continuous brake power rating per SAE J816b." Continuous brake power is the power recommended by the manufacturer for satisfactory operation under the manufacturer specified continuous duty conditions (SAE Standard J816b). This SAE standard was last revised July 1971, Editorial change March 1973.
b. The ROPS requirements contained in Part 1928 do not apply to rubber-tired skid-steer equipment, pending the promulgation of specific standards to cover such equipment.

OSHA INSTRUCTION STD 4.1 OCTOBER 30, 1978

5. Effective Date

These interpretations are effective upon receipt and will remain in effect until canceled or superseded.

Barry J. White Assistant Secretary for Regional Programs

Distribution: A-1 B-2 C-1 D-4 & 5 Training Center


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