[Code of Federal Regulations] [Title 46, Volume 7] [Revised as of October 1, 2003] From the U.S. Government Printing Office via GPO Access [CITE: 46CFR174.330] [Page 181] TITLE 46--SHIPPING CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PART 174--SPECIAL RULES PERTAINING TO SPECIFIC VESSEL TYPES--Table of Contents Subpart I--Hopper Dredges With Working Freeboard Assignments Sec. 174.330 Jettisoning of spoil. (a) When doing the calculations required by Sec. 174.310 for a hopper dredge with bottom doors, it may be assumed that the spoil is jettisoned immediately after damage and that the bottom doors remain open if: (1) The bottom doors are designed so that they may be fully opened from: (i) The closed position within two minutes even if the main power source is lost or the bottom door actuating mechanism is damaged; and (ii) The navigating bridge; (2) The discharge area through the bottom doors is equal to or greater than 30 percent of the maximum cross sectional area of the hopper measured in a plane parallel to the waterline; and (3) Asymmetrical jettisoning of the spoil is impossible. (b) When doing the calculations required by Sec. 174.310 for a hopper dredge with a split hull, it may be assumed that the spoil is jettisoned immediately after damage if-- (1) The hull is designed so that-- (i) The complete separation is effected within two minutes even if the main power source is lost or the actuating means is damaged; and (ii) The actuating means can be operated from the navigating bridge; (2) It is shown to the Commanding Officer, Marine Safety Center, either by calculations or by operational tests, that the hulls can separate sufficiently to allow the dredged material to dump without bridging; and (3) Asymmetrical jettisoning of the spoil is impossible. Design