- Effective silt and sediment control
- Robust construction
- Easy installation
- Highly visible
The silt curtain is designed to be used in conjunction with a conventional containment boom where the problem is the presence of silt and sediments drifting in water, caused by dredging or other work being carried out in a port or harbour. These materials are often drifting at a greater depth than usually covered by the skirt of a containment boom.
The silt curtain has a 2000 or 4000 mm high skirt and comes in stretches of 25 m. It is made of a polypropylene fabric reinforced with a highly resistant PET fibre, which due to its drainage capacity allows water to pass through while efficiently retaining the sediments.
The silt curtain is easily fixed to MARKLEEN A and P Series containment booms. For permanent installations the silt curtain used in conjunction with a MARKLEEN P Series boom is recommended.
The silt curtain is connected to the chain hanging from the boom using shackles (see Fig. 1). The stretches of silt curtain are connected to each other also using shackles (see Fig. 2), while the boom itself is connected up using its normal connectors (ASTM, Norwegian, UNICON, etc.)
As defined by ASTM standard F 625 for classifying water bodies spill control systems, the recommended use for silt curtains is generally in protected water, characterised by small waves of up to 1 metre high and currents below one knot.
The effectiveness of any silt curtain, as defined by its ability to reduce suspended particles on the other side of the curtain, will be detrimentally affected if it is used offshore, where currents exceed 1 knot, in areas frequently exposed to high winds or waves, in wave-breaking areas or in any other environments where the curtain is frequently tossed about, thereby preventing it from performing its function.
In spite of this, the mechanical properties of the materials used by Markleen mean that the silt curtain will withstand the rough conditions associated with an offshore environment (waves up to 2 metres high) for brief periods, although obviously the curtain's ability to filter suspended particles will be greatly reduced while it is being tossed about.