Curtain Line From the sediment control plan

Run Length along the Water m

Measured along the line the curtain will follow, shore to shore or round the work.

Slack for Current, Wind & Tide %

Extra length so the curtain can bow without pulling its anchors; the plan or supplier sets it.

Deepest Water along the Line m

At the highest water level the curtain must work in.

Clearance Kept above the Bed m

The gap the plan leaves so the skirt does not drag or stir the bed at low water.

Anchor Spacing m

Sections From the supplier

Section Length m

Curtains come in standard sections joined end to end.

Skirt Depth of the Sections m

The depth of fabric hanging below the float, as made.

Sections to Order

— sections

Curtain length with slack, divided by the section length, rounded up

Take-Off

Curtain Length with Slack: — m
Length Ordered in Whole Sections: — m
Section Connections: — joins
Skirt Depth Needed at the Deepest Point: — m
Skirt Left over (Negative = Too Short): — m
Skirt Fabric Bought: — m²
Anchors: — anchors

Every dimension is the plan's or the supplier's: slack, bed clearance and anchor spacing depend on current, tide, wind and the bed, and the tool has no figure of its own for any of them. Sections are whole sections of the length you enter, joined end to end. Skirt needed is the deepest water less the clearance; a negative spare means the sections are too shallow there, while sections deeper than the water elsewhere simply hang closer to the bed. Fabric bought is the ordered length times the skirt depth of the sections. Anchors count both ends of one run at the spacing given; shore ties and corner anchors on a curving line are extra. **This is a quantity take-off, not a design: it does not choose the curtain type for the current or check the anchor loads.**

Turbidity Curtain (Silt Curtain) Take-Off: Sections, Skirt Depth, Fabric & Anchors — free, with the formula and a worked example, at Textile School.