Donald W. Elberg, a welder employed by Nicor National (Nicor) at its shipyard, was injured when he fell into an open hatch on the M/V Mobil Leader, then in the shipyard for repair. He sued Mobil Oil Corporation (Mobil), the owner of the vessel, for negligence under the Longshore and Harbor Worker's Compensation Act (LHWCA), 33 U.S.C. § 905(b). After a bench trial, the district court entered judgment for Mobil, and Mr. Elberg now appeals. We affirm.

* BACKGROUND

We state the facts as found by the district court. Nicor, a shipbuilding and repair company, operates a shipyard on the Mississippi River near Hartford, Illinois. From July 13, 1987, through August 25, 1987, the M/V Mobil Leader underwent extensive repairs at Nicor's shipyard. Mr. Elberg worked in a crew with three other welders repairing the fuel tanks and replacing rusty elbows on fuel tank vent pipes. The district court found that, when this kind of work, done with arc welders and acetylene torches and known as "hot work," is performed on a fuel tank or on vent pipes from a fuel tank, the tank must be opened and the cover removed to prevent explosions and to permit immediate access in case of fire. Before any shift begins at Nicor, a "competent person" opens every tank on which hot work will be done and checks to see if there are explosive fumes in the tank. However, even though the tanks are checked, it is still necessary to keep the covers off while hot work is being done on the vent pipes. Although there was testimony that at times the covers would be laid sideways over the openings, the district court credited testimony that during work on fuel tanks, the covers were laid aside.1 The district court also found that it was not always feasible to barricade or cover an open tank because of the nature of the work being conducted, or the short period of time the cover would be removed.2

On the day before his fall, Mr. Elberg worked on the fuel tanks on the port side of the M/V Mobil Leader from 7:30 in the morning until 4:00 in the afternoon. He testified that he was "in and out" of several of the fuel tanks that day. The evening shift worked on the same fuel tanks. On the day of his fall, Mr. Elberg worked along with three other welders on the vent pipes leading from the port side fuel tanks. The work included cutting off the rusty elbows with an acetylene torch and welding on new elbows and flame screens with an arc welder. Between 8:15 and 8:30 in the morning, during the progress of this work, Mr. Elberg stepped back without looking, fell into the open hatch of the number two port fuel tank, and was injured. Mr. Elberg testified that he did not know the hatch was open, asserting that the evening before he had closed it and "finger tighten[ed]" it shut. The district court found that on the morning of his fall Mr. Elberg knew or should have known that the tank was open. The district court noted the testimony of Donald Delp, the foreman of Mr. Elberg's crew, that it was necessary to have the tank open during the work being done that day, that he did not know who had opened the tank, but that he had probably done it himself, and that safety chains were not up because it was necessary to get into the hatch.3

Finally, the district court found that Mobil neither supervised nor assisted in the work on the fuel tanks, and that none of Mobil's employees were in the immediate vicinity of the accident site. Mobil employees on the vessel were involved in tasks unrelated to tank repairs, such as painting and cleaning. Moreover, there was no contract provision, positive law or custom requiring Mobil to supervise or to warn Nicor's welders of open and obvious conditions on the vessel.

The district court concluded that, absent any contract provision, positive law or custom, Mobil's duties to Nicor employees under section 905 of the LHWCA were those identified in Scindia Steam Navigation Co. v. De Los Santos, 451 U.S. 156, 101 S. Ct. 1614, 68 L. Ed. 2d 1 (1981): (1) turnover duty of safe condition; (2) turnover duty to warn; (3) the active control duty; and (4) the duty to intervene. The court held that Mobil had breached none of these duties: there was no evidence that Mobil had failed to exercise ordinary care in turning over the vessel for repairs to Nicor; it had not breached its turnover duty to warn, because Mr. Elberg knew or should have known of the open tank; Mobil was not in active control of the area where Mr. Elberg's crew was working; and finally there was no evidence showing that circumstances existed giving rise to a duty to intervene in the repair operations because Mobil could reasonably rely on Nicor to remedy any unsafe situation. Also, in regard to the duty to intervene, the district court noted that, although an OSHA regulation required open hatches to be barricaded, the regulation did not apply when the use of guards is made impracticable by the work in progress.4 In accordance with its finding that the use of guards was impracticable, the district court determined that the regulation did not alter his conclusion that Mobil had no duty to intervene. Accordingly, the district court found in favor of Mobil and against Mr. Elberg.

On appeal, Mr. Elberg contends that Mobil had actual knowledge of a dangerous condition (the open hatch) and knew that Nicor would not correct it. Therefore, argues Mr. Elberg, Mobil had a duty to intervene and correct the danger. Mr. Elberg also takes issue with the district court's findings that it was customary and necessary to keep the hatches open during work on the vent pipes and that it was impracticable to erect barricades around the open hatch. Mobil contends that it had no actual knowledge that the hatch was open, and that, in any case, it was reasonable to rely on Nicor to barricade open hatches when practicable.

We review cases brought pursuant to section 905(b) of the LHWCA under the standards generally applicable to negligence cases. See Ludwig v. Pan Ocean Shipping Co., 941 F.2d 849, 850 (9th Cir.1991). A determination that particular facts constitute negligence involves a mixed question of law and fact that is reviewed under the clearly erroneous standard. See Ludwig, 941 F.2d at 850; Mucha v. King, 792 F.2d 602, 605 (7th Cir.1986). A finding is clearly erroneous when the reviewing court on the entire evidence is "left with the definite and firm conviction that a mistake has been committed." Bennett v. Local Union No. 66, Glass, Molders, Pottery, Plastics & Allied Workers Int'l Union, 958 F.2d 1429 (7th Cir.1992) (quoting Inwood Laboratories, Inc. v. Ives Laboratories, Inc., 456 U.S. 844, 853, 102 S. Ct. 2182, 2188, 72 L. Ed. 2d 606 (1982)). The question of whether the district court applied the proper standard of care, however, is one of law and is subject to de novo review. Ludwig, 941 F.2d at 850.

Section 905(b) of the LHWCA provides longshoremen and harbor workers with a cause of action against vessel owners for injuries caused by the "negligence of a vessel."5 In Scindia Steam Navigation Co. v. De Los Santos, 451 U.S. 156, 101 S. Ct. 1614, 68 L. Ed. 2d 1 (1981), the Supreme Court considered the scope of a ship owner's liability under section 905(b) in the context of a cargo loading operation. Under Scindia, shipowner liability can arise in several circumstances. First, when a shipowner turns a ship over to the stevedore, the shipowner must exercise ordinary care to have the ship and its equipment in a reasonably safe condition and must "warn[ ] the stevedore of any hazards on the ship or with respect to its equipment that are known to the vessel or should be known to it, that would likely be encountered by the stevedore in the course of his cargo operations and that are not known by the stevedore and would not be obvious to or anticipated by him if reasonably competent in the performance of his work." Scindia, 451 U.S. at 167, 101 S.Ct. at 1622. Second, a shipowner may be liable if it actively involves itself in the operations of the stevedore or if it fails to exercise due care to avoid exposing longshoremen to harm from hazards they may encounter in areas, or from equipment, under the active control of the vessel during the stevedoring operation. Lastly, even if the shipowner is not actively involved in operations and does not have active control of the vessel, if the shipowner has actual knowledge of a dangerous condition which has arisen after the turning over of the ship to the stevedore, the shipowner has a duty to intervene, under certain circumstances which we discuss in the following paragraphs, to correct the dangerous condition.

In the present case, the appellant challenges the district court's determination that there was no evidence to show that Mobil had a duty to intervene; he does not challenge the district court's determinations with regard to the shipowner's other duties. Therefore, we set out in more detail the principles governing the duty to intervene. The LHWCA places a statutory duty on the employer (here, Nicor, the repair company) to provide and maintain reasonably safe working conditions. See 33 U.S.C. § 941. Thus, "as a general matter, the shipowner may rely on the stevedore to avoid exposing the longshoremen to unreasonable hazards." Scindia, 451 U.S. at 170, 101 S.Ct. at 1623.6 The shipowner "has no general duty by way of supervision or inspection to exercise reasonable care to discover dangerous conditions that develop" after the ship is turned over. The shipowner has "justifiable expectations that those duties will be performed" by the stevedore or repair company without the shipowner's supervision. Scindia, 451 U.S. at 176, 101 S.Ct. at 1626. Therefore, a shipowner's actual knowledge of a dangerous condition is not enough in itself to create a duty. However, if the shipowner has actual knowledge that an unsafe condition exists and that the stevedore is allowing that condition to continue, and if the stevedore's judgment in not remedying the condition is "obviously improvident," the shipowner has a duty to intervene. Id.7

Law, custom, or contract may affect the shipowner's duty to intervene. In Scindia, OSHA regulations required that defective winches "be reported immediately to the officer in charge of the vessel," id. at 177, 101 S.Ct. at 1627 (quoting 29 C.F.R. 1918.53(a)(5)), thus permitting an inference "that when a defective winch is discovered, it should not be repaired by the stevedore but should be reported to and repaired by the shipowner." Id.

In the present case, the district court made no explicit finding as to whether Mobil had actual knowledge of the open hatch. However, such a finding was not necessary in view of its determination, with which we agree, that Mobil could reasonably rely on Nicor to remedy any dangerous situation. The district court found that the hatches Mr. Elberg and his crew were working near were necessarily open and that it was not always feasible to barricade them because of the nature of the work being conducted or the short period of time the cover would be removed. Mr. Elberg disputes these findings, but, based on the record before us, we cannot say they are clearly erroneous.8 The district court heard conflicting testimony regarding the necessity for keeping the hatches open during hot work on the vent pipes and regarding the practicability of erecting barricades.9 See Connors v. United States, 917 F.2d 307 (7th Cir.1990) ("A factfinder's choice between two permissible views of the evidence cannot be clearly erroneous.").

The OSHA regulations considered by the district court impose a duty on the employer (Nicor) to barricade open hatches and other deck openings.10 Nevertheless, the imposition of that duty on the employer does not relieve the shipowner of any duty which it would otherwise have under existing law, custom or contract. 29 C.F.R. § 1915.3(b). Moreover, OSHA regulations may be relevant evidence as to whether a particular condition creates an unreasonable risk of harm. See Ollestad v. Greenville S.S. Corp., 738 F.2d 1049, 1053 (9th Cir.1984), cert. dismissed, 469 U.S. 1197, 105 S. Ct. 982, 83 L. Ed. 2d 984 (1985). However, in the present case, the relevant OSHA regulations recognize that work in progress may make it impracticable to cover or guard hatches; thus, at times, open hatches may present "a risk 'inherent in the carrying out of the contract' for repairs." Stass v. American Commercial Lines, Inc., 720 F.2d 879, 884 (5th Cir.1983) (quoting West v. United States, 361 U.S. 118, 123, 80 S. Ct. 189, 193, 4 L. Ed. 2d 161 (1959)). Indeed, in the present case, the district court found that it was not always feasible to barricade the open hatches. In the days before the accident, Nicor employees had been working not only on the vent pipes, but also down in the tanks. Mr. Elberg himself had been in and out of the tanks on the day before his accident.

In these circumstances, Nicor's judgment in leaving the hatch open and unbarricaded at the time of the accident was not "obviously improvident," whether or not barricades would on that morning have hindered the work then in progress or have affected Nicor's ability to respond quickly to a fire or other emergency. Although Mr. Elberg characterizes the duty he alleges Mobil had as a duty to intervene, the duty he seeks to impose on Mobil would amount to a requirement that Mobil supervise and inspect the work, that Mobil keep tabs on the work in progress and determine when the nature of the work allowed closing the hatches or made positioning barricades around the open hatches practicable. Mobil had no such duty. See Scindia, 451 U.S. at 172, 101 S.Ct. at 1624; Hines v. British Steel Corp., 907 F.2d 726, 729 (7th Cir.1990).

For the reasons stated above, the decision of the district court is affirmed.

AFFIRMED.