Oil spill containment boom can be anchored using three different techniques: (1) Free Anchoring (2) Shoreline Anchoring, and (3) Dock Anchoring. This edition will focus on Acme’s free anchoring technique. Acme extensively uses a standard, double 40 lb Anchor system when anchoring oil spill containment boom sections in an open body of water. A standard 40 lb Anchor system consists of the following components:
- 2 - 40 lb. Danforth Style Anchors
- 2 - 9” Red Inflatable Marker Buoys
- 1 - 12” Hard Shell Mooring Buoys
- 6 ft of 3/8” galvanized chain
- 2 - 3/8” screw pin anchor shackles for anchor attachment to chain
- 1 - 500 ft roll of ½” poly rope
- 1 - 100 ft of ¼” poly rope
Please reference the picture below for the general anchor system layout.
Oil spill containment booms can be anchored from the end section as shown in the diagram or connected to anchor points along the length of an oil spill containment boom. For example, sections of oil spill containment boom that are deployed to protect shoreline may require several anchor points along the length of the containment boom. Prevailing wind and current conditions coupled with the water body classification will directly affect the amount of anchoring systems required throughout the length of deployed oil spill containment boom. If there are alternating currents available, two anchor systems may be required on each side of the anchor point to keep the boom in place.
Acme extensively uses the 40 lb Danforth style anchors due to their buying characteristics and its high resistance once set. The weight of the anchor coupled with its design allows for easy retrieval and storage. Referencing the anchoring diagram, the two, red marker buoys are connected to the top screw pin shackle of the 40 lb anchor with ½” or ¼” rope. These marker buoys are simply placed onto the anchors to allow for response personnel to locate the anchors upon retrieval. The primary anchor is located approximately 20 ft behind the secondary anchor and both anchors are connected by a minimum of 20’ of 5/16” galvanized cable or 5/8” rope. The secondary anchor is attached to the mooring buoy via 5/16” galvanized cable or 5/8” rope. For long term anchoring, it is advised that a 5/16” cable is used for the connection of the anchors and for the connection of the secondary anchor to the mooring buoy. The mooring buoy is connected to the designated anchor point by 1/2” rope or 5/16” cable. The anchor point may be located on the coupler or a connection directly to the ballast along the length of the oil spill containment boom. Anchor points are typically located on the ballast at 25’ increments which allows for multiple anchoring locations if needed. The mooring buoy allows for the response personnel to remain dry and safely inside the boat during deployment and retrieval. Mooring buoys also keep the main tensions of the anchor from pulling the boom into the water.
The length of the connection between the mooring buoy and the secondary anchor shall be a minimum of 3 times the water depth. This is a good rule of thumb for calm water conditions. For choppy water conditions, the length should be adjusted to 5 times the water depth and for rough water conditions the length should be adjusted to 7 times the water depth. Want more information on anchor systems? Contact us today for more information!