The second and third platforms measured were production platforms of 

 ARCO. They are located off Kenai, Alaska. Platform King Salmon is a 

 quadripod type located in about 60 feet of water. The four legs are each 16 

 feet in diameter. The measuring equipment was set up in Leg Room 2 with the 

 hydrophone in the water suspended from the east side of the platform. The 

 wind was 30 knots with a sea state of 2. The cable was streaming with the 

 strong incoming tide and wind, causing FM recorder channel blockage due to the 

 large signal level from the vertical hydrophone movement. Measurements were 

 taken at slack high tide. The highest airborne noise level measured was 

 outside the boiler room. This was thought to have been caused by the air 

 intakes from the Worthington compressors on the deck above. 



Platform Spark is about five miles to the north of King Salmon. It is a 

 tripod platform with 16-foot diameter legs. This platform is mostly electric 

 or turbine powered with only 1 reciprocating engine on board. Water depth at 

 time of recording was approximately 75 feet. Equipment was set up on the 

 north side on a catwalk on the lower deck between legs two and three. The 

 equipment set-up is shown in figure 5. The hydrophone was estimated to be 24 

 feet from leg 2 and 21 feet from leg 3. The hydrophone was streaming with the 

 tide which was estimated to be flowing at three knots. The degree of cable 

 streaming is illustrated in figure 6. Recording was started when the 

 hydrophone cable was vertical at slack tide. Wind was about 10 knots and sea 

 state was estimated to be 1. Recordings were made at hydrophone depths of 20, 

 30 and 50 feet. The major airborne noise area on board was the turbine room. 



D-5 



