The opinion of the court was delivered by: SIMMONS
This is an admiralty action arising out of a collision between a towboat and a stationary submarine gas pipeline.
The Peoples Natural Gas Company, owner of a natural gas pipeline extending across the Monongahela River, brought this suit for damages against Ashland Oil, Inc., owner and operator of a towboat that struck and ruptured Peoples' pipeline while attempting to dock an oil barge. Peoples contends that this is a case of negligent pilotage. At trial, Peoples proceeded under the theory that the towboat pilot's negligence in the navigation of his vessel was the legal cause of the damage sustained by Peoples' pipeline. The defendant, on the other hand, contends that this is a case of statutory fault. Ashland Oil asserts that Peoples' violation of navigational regulations was the cause in fact of the collision, not the pilot's negligence.
This case was tried to the Court sitting without a jury. After consideration of the applicable rules of law and the evidence adduced at trial, this Court makes the following findings of fact and conclusions of law, followed by an integrated discussion of both.
1. On January 21, 1981, Captain Eugene H. Dent was piloting the M/V Aetna Louisville, a towboat owned by Ashland Oil, Inc., to spot an oil barge at the Reserve Petroleum Dock along the western shore of the Monongahela River near mile post 40.8.
3. The former lock chamber now used as a petroleum dock is 56 feet wide, but is only accessible from the downstream or northernmost position on the river because a gate sill, 1 foot below the river's surface, impedes access to the dock from the upstream or southernmost position on the river. The sill on the northernmost or downstream position of the river is 10 feet below the river's surface.
4. In the area where the lock's gates were formerly installed, there are gate jamb recesses 3 feet deep and 30 feet long, the edges of which will fracture or puncture an oil barge if it is not properly aligned between the lock chamber walls during the docking procedure. When spotting barges at the dock, a towboad pilot's visibility is impaired by the two lock walls which protrude 20 feet above the surface of the water. Together, these physical conditions pose a hazard for barges accessing the Reserve Petroleum Dock.
5. Proceeding upstream near mile post 40.8 the Monongahela River bends in a sharp easterly direction. The mouth of the lock chamber is situated along the western shore of the river's curve. Because of the river's easterly curvature, the location of the dock on the river's western shore, and the absence of downstream access into the lock chamber, towboats must operate close to the western shore of the river downstream from the lock chamber's entrance to spot barges between the lock walls at the Reserve Petroleum Dock.
6. On September 23, 1949, pursuant to an application made by Peoples, the United States Corps of Engineers issued a Department of Army permit to install a 14 and 3/4 inch (outside diameter) metal, non-coated gas pipeline across the Monongahela River between Fallowfield Township, Washington County and the City of Monessen, Westmoreland County. A similar Permit was issued by the Pennsylvania Water and Power Resources Board.
7. Two technical drawings which outlined Peoples' proposed plan for constructing a pipeline across the Monongahela River were incorporated into the Corps' permit. The permit expressly provided that only the work shown on the drawings was authorized, "any deviations therefrom or additions made without the prior permission of the [Corps was] illegal and subject to an order requiring removal." See Department of Army Permit, Joint Trial Exhibit No. 2.
8. The permit's technical drawings specified that the pipeline would be installed at a minimum depth in the channel area of 15 feet below the pool full elevation and 4 feet below the riverbed beyond both United States harbor lines, a distance which spans the entire width of the river.
9. Prior to issuance of the permit, the Corps gave notice to navigational interests that Peoples had made application for permission to install a pipeline. Consistent with the permit's technical drawings, the public notice stated that "the proposed pipe line will be [installed] at least 15 feet below pool full elevation . . . or 4 feet below the bed of the river, whichever is the greater, for the width of the channel and 4 feet below the surface of the ground on each bank." See Corps of Engineer Public Notice, Joint Trial Exhibit No. 4. No objections were made and the permit was issued.
10. Shortly after Peoples had completed its construction of the pipeline, the Corps' Operation and Maintenance Division inspected the pipeline and determined that the installation had been done in accordance with the permit. Peoples thereafter submitted a profile of the submerged pipeline which was obtained by soundings. The profile also indicated that the location of the pipeline was in conformity with the permit.
12. Shortly following the diver's inspection, Peoples made application to the Corps to riprap a 20 feet section of the pipeline. Riprapping is a technique whereby a quantity of broken stones or other masonry materials are thrown together irregularly to build a wall, foundation or reventment of an embankment. Peoples believed that the pipeline's exposure resulted from docking activity at the petroleum dock. The technical drawing attached to Peoples application made specific engineering recommendations that the exposed area be riprapped with a material other than concrete. The permit was granted and notice of the repair was given. Contrary to the specific engineering recommendation against using concrete, Peoples riprapped the exposed pipeline using sakrete Tm, a trademarked product consisting of a pre-mixed dry concrete formula in a sack. Upon completion of the pipeline repair, Peoples notified the Corps that it had riprapped a 30 feet section of the pipeline and submitted a profile of the pipeline in the river after the repair had been made.
13. Following the repairs, Peoples' pipeline was not inspected for exposure again until September 4, 1979, almost 18 years after the repairs. During this inspection the diver, using neither a probe nor an electronic device to determine the pipeline's depth beneath the riverbed, made a visual inspection, zigzagging north and south over the pipeline. In his report the diver concluded that the pipeline was completely covered. At trial, however, the diver conceded that by using a zigzagging technique he may not have visually inspected the entire riverbed along the pipeline's path. Nor did his inspection reveal how deep the pipeline was buried.
14. Peoples' pipeline was installed approximately 350 feet downstream from the northern mouth of the Reserve Petroleum Dock. The location of the pipeline crossing is marked on navigation charts and by billboard signs posted on both banks of the river. The signs contain the following notice to mariners: