Todd Shipyards (“Todd”) petitioned for review of an order of the Occupational Safety and Health Review Commission (“the Commission”) dated January 31, 1975 imposing fines for several “repeat” violations of the Occupational Safety and Health Act of 1970 (“OSHA”), 29 U.S.C. § 651 et seq. Three issues are presented: (1) whether the citation was issued with “reasonable promptness,” (2) whether these violations were properly classed as “repeated,” and (3) whether a manhole with a six inch coaming was properly regarded as “flush” so as to fall within the scope of 29 C.F.R. § 1915.-43(a). Under the circumstances of this case, we find no error in the Commission’s ruling. We therefore affirm.
I. The Facts
Todd is a California-based corporation engaged in shipbuilding and ship repair. From January until September 15, 1972, it performed extensive repair and maintenance work on the S/S OREGON MAIL at its shipyards in San Pedro, California. As a result of a routine inspection of the OREGON MAIL on June 5, 1972, the Secretary of Labor (“Secretary”) cited Todd for five nonserious and two repeated violations of mandatory OSHA safety standards, including a failure to provide adequate scaffolding under 29 C.F.R. 1915.47(b),1 a repeated failure to guard open manholes under 29 C.F.R. 1915.43(a),2 and a repeated failure to *1329keep passageways used by employees clear of hazardous tripping obstructions under 29 C.F.R. 1915.51(a).3 The violations were pertinently described, with data indicating their locations, as a failure to prevent an employee from using a ladder as a working surface during extensive welding; a failure to guard three open manholes around which employees were working; and two instances in which a working tank surface and passageway were obstructed with air hoses, welding leads, lumber and other materials. All violations were ordered abated within one day by this citation, which was not contested by Todd and became final and conclusive by operation of law pursuant to 29 U.S.C. § 659(a) and § 660(b).
During a routine reinspection of the ship on August 17, 1972, working conditions were observed which led the OSHA compliance officer to conclude that potential violations of these same regulations had occurred due to improper scaffold use, failure to guard manholes, and failure to keep passageways unobstructed.4 He informed Todd of these problems and they were either abated or ordered abated before he left the ship. The OREGON MAIL left port on September 15, 1972. Formal citations proposing penalties of $2125, $400 and $350 were received by Todd on September 20, 1972, 34 days after the inspection of August 17, 1972.
Todd timely contested the citations and penalty proposals. Hearings before the administrative law judge were held in April and May of 1973. On July 30, 1973, he found that repeat violations of 29 C.F.R. §§ 1915.47(b), 1915.43(a), and 1915.51(a) had occurred, but reduced the penalties imposed to $700, $350, and $350, respectively. On appeal, the Commission affirmed, noting that Todd had failed to show that it had been prejudiced by the delay in the issuance of the citation, but limiting the administrative law judge’s ruling by indicating that there was no need to address the general legal question of what would form the basis for a repeated violation in a case where facially identical violations had occurred on the same ship within three months of each other.
II. Reasonable Promptness
Todd first contends that the delay of 34 days between the date of inspection and the receipt of the citation mandates that the citation be vacated. The relevant statutory authority provides that
If, upon inspection or investigation, the Secretary or his authorized representative believes that an employer has violated a requirement of section 654 of this title, of any standard, rule or order promulgated pursuant to section 655 of this title, or of any regulations prescribed pursuant to this chapter, he shall with reasonable promptness issue a citation to the employer. 29 U.S.C. § 658(a) (1970).
The meaning and function of this “reasonable promptness” language is perhaps more clouded than clarified by the legislative history found in the report of the congressional conference committee.
The Senate bill provided that if, upon inspection or investigation, the Secretary or his authorized representative “deter*1330mines" that an employer has violated mandatory requirements under the Act, he shall “forthwith” issue a citation. The House amendment provided that if on the basis of an inspection or investigation the Secretary “believes” that an employer has violated such requirements, he shall issue a citation to the employer. The conference report provides that if the Secretary “believes” that an employer has violated such requirements he shall issue the citation with reasonable promptness. In the absence of exceptional circumstances any delay is not expected to exceed 72 hours from the time the violation is detected by the inspector.
The House amendment permitted a citation to be issued no later than 90 days following the occurrence of a violation. .There -was ,no comparable Senate provision. The House receded.
The House amendment prohibited issuance of a citation more than three months after the occurrence of any violation. The Senate bill had no such statute of limitations. The Senate receded with an amendment changing the three months to six months. 1970 U.S.Code Cong. & Admin.News, p. 5234.
The Commission originally tried to accommodate this legislative history by taking the position that a citation had to be issued within 72 hours from the time the Secretary “believed” it appropriate. The Seventh Circuit in Brennan v. Chicago Bridge & Iron Co., 514 F.2d 1082 (1975) rejected this reading for reasons well stated in that opinion. The court left the Commission free to adopt a new rule, which it has now done. A citation will be vacated if delay in issuance has resulted in demonstrable prejudice to the employer. E. C. Ernst, Inc., 1974-1975 OSHD ¶ 19179 (Rev.Comm’n 1975). Even if we were not bound to yield to the Secretary and the Commission a rela tively broad discretion in interpreting the Act, The Budd Co. v. OSHRC, 513 F.2d 201, 204-205 (3d Cir. 1975), we would still be compelled to recognize the merit of this approach. It is very much in keeping with the remedial purpose of the Act, for the six month statute of limitations found in section 658(c) protects the employer, while the “reasonable promptness” language of section 658(a) is designed to protect the employee. To vacate a citation because of delay that is less than prejudicial would clearly run counter to the concern for safe working conditions that led to the enactment of OSHA.
Todd urges that even if prejudice to the employer is the appropriate test, the citation should be vacated because the departure of the OREGON MAIL from port three days before the citation was received severely hampered the preparation of . its defense. Neither the administrative law judge nor the Commission found that such prejudice existed. The inspector reported the violations to the employer before leaving the ship; moreover, since the unsafe practices were abated immediately, photographic evidence of conditions at the time of inspection was particularly important. On the record before us, the Commission’s determination must be upheld.
III. Repeat Violations
29 U.S.C. § 666(a) provides that
Any employer who willfully or repeatedly violates the requirements of section 654 of this title, any standard, rule, or order promulgated pursuant to section 655 of this title, or regulations prescribed pursuant to this chapter, may be assessed a civil penalty of not more than $10,000 for each violation.
The $10,000 maximum fine under'this section contrasts with the $1000 maximum for both serious and nonserious violations set forth in section 666(b) and (c).
Todd cites Bethlehem Steel Corp. v. OSHRC, 540 F.2d 157 (3d Cir. 1976) in support of its argument that a common, wilful or conscious design to flout a specific safety standard, not merely a second5 fortuitous *1331violation is necessary before the more severe sanction associated with a repeat citation may be invoked. We decline to adopt that view, which essentially equates “wilful” with “repeated” while failing to give appropriate weight to the disjunctive “or.” Like the Commission, however, we do not regard this case as an appropriate one in which to address the general question of what is a repeat violation. Here, as a factual matter, the administrative law judge found that the violations were identical in character, occurred on the same ship, and took place within three months of each other. We believe that on such facts, the violations were indeed repeated.6
Todd also raises a due process challenge, arguing that the repeat citation failed to describe with particularly the nature of the earlier violation which was allegedly repeated. Because Todd failed to raise this issue in its appeal to the Commission, however, we are precluded from considering it here under the terms of our jurisdictional statute, 29 U.S.C. § 660: “No objection that has not been urged before the Commission shall be considered by the court, unless the failure or neglect to urge such objection shall be excused because of extraordinary circumstances.” Felton Construction Co. v. OSHRC, 518 F.2d 49 (9th Cir. 1975).
IV. Raised Manhole
Todd finally challenges its citation for violation of 29 C.F.R. § 1915.43(a) which requires that “flush manholes or other small openings of comparable size” be covered or guarded to a height of not less than 30 inches. Because the manhole in question had a six inch high “coaming,” it was not literally “flush” with the deck. However, the administrative law judge found that the six inch rim failed to satisfy the 30 inch guard requirement also applicable to small openings. We can think of no case where deference to administrative expertise would be more appropriate. See Udall v. Tallman, 380 U.S. 1, 16-17, 85 S.Ct. 792, 13 L.Ed.2d 616 (1965); California Stevedore & Ballast Co. v. OSHRC, 517 F.2d 986 (9th Cir. 1975).
The Commission’s decision is AFFIRMED.
. 1915.47 Working surfaces.
(b) When employees are working aloft, or elsewhere at elevations more than 5 feet above a solid surface, either scaffolds or a sloping ladder, meeting the requirements of this subpart, shall be used to afford safe footing, or the employees shall be protected by safety belts and lifelines ....
. 1915.43 Guarding of deck openings and edges.
*1329(a) When employees are working in the vicinity of flush manholes and other small openings of comparable size in the deck and other working surfaces, such openings shall be suitably covered or guarded to a height of not less than 30 inches, except where the use of such guards is made impracticable by the work actually in progress.
. 1915.51 Housekeeping.
(a) Good housekeeping conditions shall be maintained at all times. Adequate aisles and passageways shall be maintained in all work areas. All staging platforms, ramps, stairways, walkways, aisles, and passageways on vessels or dry docks shall be kept clear of all tools, materials, and equipment except that which is in use, and all debris such as welding rod tips, bolts, nuts, and similar material. Hose and electric conductors shall be elevated over or placed under the walkway or working surfaces or covered by adequate crossover planks.
. A fourth repeat violation, failure to comply with the requirements for platforms of staging set forth in 29 C.F.R. § 1915.41(h)(2), was also alleged. The administrative law judge found that no chargeable violation had occurred and ordered this section of the citation and the $375 proposed penalty vacated.
. The administrative law judge found, relying on an exhibit introduced by the Secretary, that Todd had violated 29 C.F.R. § 1915.43(a) and § 1915.51(a) more than twice. We cannot say, *1331on the record before us, whether these violations, like those of June 5, 1972, were facially identical to the violations at issue here. In any event, we do not find the Third Circuit’s analysis in Bethlehem Steel defining “repeatedly” as “more than twice” persuasive. A distinction in meaning between the adverbial and adjectival forms of the word “repeat” was surely not intended by Congress and cannot be supported by reference to common usage or common sense. On the facts of this case, second occurrences of the self-same violations satisfy the multiplicity requirement implicit in the term “repeatedly.”
. Although we need not dispose of Todd’s arguments in general terms in light of the facts of this case, we must note that when taken together their ramifications would be quite far-reaching. Todd demands notification within 72 hours of inspection; it would also require the Secretary to give specific notice of the details of the earlier violation on which the repeat violation is based. Finally, it would expect repeat citations to issue only after more than two prior violations which were of a similar specific character. It would be virtually impossible for the Secretary to issue repeat citations if all of these requirements were read as Todd would wish.