Section 147.819 - Allegheny Tension Leg Platform safety zone(a)Description. The Allegheny Tension Leg Platform (Allegheny TLP), Green Canyon Block 254A (GC 254A), is located at position 27°41'29.65" N, 90°16'31.93" W. The area within 500 meters (1640.4 feet) from each point on the structure's outer edge is a safety zone.(b)Regulation. No vessel may enter or remain in this safety zone except the following: (2) A vessel under 100 feet in length overall not engaged in towing; or(3) A vessel authorized by the Commander, Eighth Coast Guard District.CGD08-01-025, 68 FR 4102 , Jan. 28, 2003