---
kind: "section"
citation: "46 C.F.R. § 174.330"
title: "46"
number: "174.330"
heading: "Jettisoning of spoil."
url: "https://uscodex.org/cfr/46/174.330"
---

# §174.330. Jettisoning of spoil.

- (a) When doing the calculations required by [§ 174.310](/cfr/46/174.310.md) 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 [§ 174.310](/cfr/46/174.310.md) 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.**

## Notes

### Source

Source: CGD 76-080, 54 FR 36977, Sept. 6, 1989, unless otherwise noted.

### Authority

Authority: 42 U.S.C. 9118, 9119, 9153; 43 U.S.C. 1333; 46 U.S.C. 3306, 3703; E.O. 12234, 45 FR 58801, 3 CFR, 1980 Comp., p. 277; Department of Homeland Security Delegation No. 0170.1. Section 174.180 also issued under sec. 617, Pub. L. 111-281, 124 Stat. 2905.

### Source

Source: CGD 79-023, 48 FR 51048, Nov. 4, 1983, unless otherwise noted.