mooring anchors
There are different anchor systems. The capacity of anchors depend on the type of soil, type of anchor and size of the anchor. In sands and hard clays higher holding capacities are generated than in soft clays. Obviously the shape and size influence the holding capacity. Different type of anchor systems are elaborated.
Drag anchors
High holding power offshore anchors
The drag anchor is dragged along the seabed until it reaches the required depth. As it penetrates the seabed, it uses soil resistance to hold the anchor in place. The drag embedment anchor is mainly used for catenary moorings, where the mooring line arrives on the seabed horizontally. It does not perform well under vertical forces.
High holding power offshore anchors
The drag anchor is dragged along the seabed until it reaches the required depth. As it penetrates the seabed, it uses soil resistance to hold the anchor in place. The drag embedment anchor is mainly used for catenary moorings, where the mooring line arrives on the seabed horizontally. It does not perform well under vertical forces.
VLA (Vertical Lift Anchors)
Vertical load anchors are similar to drag anchors as they are installed in the same way. However, the vertical load anchor can withstand both horizontal and vertical mooring forces. It is used primarily in taut leg mooring systems, where the mooring line arrives at an angle at the seabed.
Vertical load anchors are similar to drag anchors as they are installed in the same way. However, the vertical load anchor can withstand both horizontal and vertical mooring forces. It is used primarily in taut leg mooring systems, where the mooring line arrives at an angle at the seabed.
Driven piles
To anchor an offshore unit a driven pile anchor system can be used. For this type of anchoring piles are driven into the seabed. In the movie attached you can see how this procedure takes place.
Surface systems that use driven piles for their foundations include fixed platforms (jackets), tension-leg platforms (TLP); spar platforms; semisubmersible platforms; FPSO’s facilities; and catenary anchor leg mooring (CALM) buoys. Driven piles are also required for subsea components such as riser buoys, pipeline end manifolds, arcs and templates.
To anchor an offshore unit a driven pile anchor system can be used. For this type of anchoring piles are driven into the seabed. In the movie attached you can see how this procedure takes place.
Surface systems that use driven piles for their foundations include fixed platforms (jackets), tension-leg platforms (TLP); spar platforms; semisubmersible platforms; FPSO’s facilities; and catenary anchor leg mooring (CALM) buoys. Driven piles are also required for subsea components such as riser buoys, pipeline end manifolds, arcs and templates.
Drilled piles
Depending on the soil conditions a drilled pile mooring system could be needed at a offshore location. Instead of driving a pile into the seabed a pile or ground anchor is drilled into the seabed. The movie will visualize this procedure.
Depending on the soil conditions a drilled pile mooring system could be needed at a offshore location. Instead of driving a pile into the seabed a pile or ground anchor is drilled into the seabed. The movie will visualize this procedure.
Gravity Anchors
A gravity anchor is an anchor which is buried to a depth depending on its weight, geometry and soil characteristics. The holding power is proportional to its weight. Due to the size of the vessels involved in offshore oilfield work, gravity anchors can each easily weigh several tons in order to provide the necessary holding power. Common used materials for the anchor are concrete and steel.
A gravity anchor is an anchor which is buried to a depth depending on its weight, geometry and soil characteristics. The holding power is proportional to its weight. Due to the size of the vessels involved in offshore oilfield work, gravity anchors can each easily weigh several tons in order to provide the necessary holding power. Common used materials for the anchor are concrete and steel.