... of rectangular units, fabricated from a double-twisted hexagonal mesh. Filled with stones, gabions become large, flexible and permeable ... protections, weirs, channel linings etc. GABIONSare divided into cells with diaphragms (usually spaced at 1 meter or 3’ intervals), ... installation. TOLERANCES of gabion mattress: On the hexagonal, double-twisted wire mesh opening shall not exceed ±10% on the nominal ...