413 - 05/05 - Houston Ship Channel - Texas, USA
It is anticipated that the project of deepening and widening the Houston Ship Channel will be completed this month. Information received suggests there is concern about the affects on vessels moored along the channel of the larger vessels that will now be able to transit further up the channel. The charted dimensions of this project are from the entrance area in the Gulf of Mexico to the Shell and Oil Tanking facilities on the Houston Ship Channel in the vicinity of light 142.
The project will enable vessels with a maximum draft of up to 45 feet to transit from the entrance channel up to facilities just below the Beltway 8 Bridge. Vessels of this size may possess a cargo load capacity 40% greater than the current largest vessels transiting the area. Due to the dynamic forces of these larger vessels, larger volumes of water being displaced will have a significant effect upon vessels moored along the edge of the channel.
Particular attention should be given to proper moorings while berthed along docks or breasted up to other vessels. The Houston Pilots will employ a phased approach to bringing in deep drafted vessels; however, due to the movement of these vessels, there will be a substantial increase in surge, suction and water displacement even at low speeds.
Vessels must ensure that all moorings are properly tended to, equally distributing the loads on all lines. Further, the lines should be tensioned as to not allow any movement of the vessel at the dock. Should the vessel be allowed to move as much as a few feet along the dock due to slack lines, the lines will be subjected to a substantial amount of energy that will surge loads and subsequently part overloaded mooring lines.
Source of information:
5625 - Bulletin 413 35 KB