Knotted Net Twine Length, Mass & Mesh Count for a Panel

The formula

This is the expression the tool evaluates. Every term is named underneath, with the unit it must be supplied in.

How the result is derived

Step by step, from the values you type to the figure on screen.

1. The 6 inputs are read from the form on every keystroke: Panel Length, Panel Height (Depth), Mesh Bar Length, Knot to Knot, Panels, Twine Runnage and Knot & Selvedge Allowance.
2. Each value is checked against the accepted range in the input table below. A value outside its range stops the calculation rather than producing a misleading figure — the results blank out and a message appears.
3. The validated values are substituted into the expression above, which resolves Twine Mass per Panel together with every supporting figure in one pass — no value is carried over from a previous entry.
4. The supporting outputs — Panel Area, Meshes in the Panel, Meshes along the Length, Meshes Deep, Twine in the Grid, Twine incl. Knots & Selvedge, Net Mass per m², Stretched Mesh and Twine for All Panels — come from the same pass, so they always describe the same case as the headline figure.
5. Results are rounded for display only. The full-precision value is used throughout the chain, so reading a rounded intermediate figure back into the tool by hand can shift the last digit.

What each input means

Where to read each value on the floor, the unit it must be in, and the range the tool accepts.

What the tool returns

The headline figure and every supporting value it is built from.

Worked example

Substituting

Halve the bar to 25 mm and the mesh count quadruples but the twine only doubles, to 5,376 m and 3.58 kg: twine goes with the inverse of the bar, not its square.

How to use it

1. Work through the input groups in order — Panel and Twine. The defaults are a realistic case, so you can change one value at a time and watch what moves.
2. There is no calculate button. Every figure recalculates as you type or drag, which is what makes this usable for a what-if sweep rather than a single answer.
3. Read Twine Mass per Panel in the dark results panel — that is the headline figure, expressed in kg.
4. Check the supporting rows underneath (Panel Area, Meshes in the Panel, Meshes along the Length, Meshes Deep, Twine in the Grid, Twine incl. Knots & Selvedge, Net Mass per m², Stretched Mesh and Twine for All Panels) before acting on the headline — they are where an implausible input usually shows itself first.
5. Reset to defaults returns every field to the reference case, which is the quickest way to check whether a surprising result came from the tool or from an input you had changed earlier.

Where this is used

• Process planning — establishing Twine Mass per Panel before a trial is booked, so machine time and material in Cordage, Ropes & Heavy Netting are committed against a calculated figure rather than an estimate.
• Costing and quotation — Twine Mass per Panel is an input to the cost sheet, and quoting from a worked number rather than a remembered one is what keeps a margin intact.
• Troubleshooting — when the floor result drifts from plan, entering the measured values (starting with Panel Length) shows how much of the gap in Twine Mass per Panel each variable explains.
• Teaching and study — the accepted ranges bracket normal Cordage, Ropes & Heavy Netting practice, so moving one variable at a time shows the shape of the relationship rather than a single answer.

Reading the result

Typical bands and what each one is telling you.

Assumptions and limits

• The count assumes the meshes hang square, so each mesh opening is a square of the bar length and a grid of n x m meshes holds about 2 x n x m bars of twine. A net hung tighter or slacker (a different hanging ratio) covers a different area with the same meshes and the same twine; count the meshes the net is made with, then hang it. Runnage is the twine maker's figure for the finished twine, knots included in the allowance rather than in the runnage. Mesh count is rounded to whole meshes along and deep, which is how a net maker orders it. Knotless (raschel) netting has no knot take-up but its own selvedge loss; set the allowance from a weighed sample. **This counts twine; it does not rate the net for impact, UV life or ball stop.**
• Every input is bounded to the range normal practice occupies (Panel Length 0.5 to 500 m, Panel Height (Depth) 0.5 to 100 m and Mesh Bar Length, Knot to Knot 5 to 500 mm, and so on for the rest). Those bounds are guard rails against typing errors, not a claim that the formula fails one unit outside them.
• The calculation is deterministic: the same inputs always give the same result. It carries no allowance for machine condition, operator skill, ambient conditions or lot-to-lot material variation unless an input above explicitly represents one.
• Nothing is sent anywhere. The maths runs in your browser, so the numbers you type never leave the page.

Standards and further reading

• ISO 1107, Fishing nets, netting, basic terms and definitions: bar, stretched mesh, hanging ratio and the other words this tool uses.
• ISO 1530, Fishing nets, description and designation of knotted netting: how a netting specification states twine, mesh and depth.
• EN 1263-1, Safety nets: the standard a construction safety net is tested to; this tool counts its twine, it does not rate it.

Questions people ask