Safety equipment for structures comprising at least one lower level and one upper level supported by a series of pillars extending between said lower level and upper level; equipment comprising: - a series of uprights with lower end section adapted to be fixed on top of a pillar and with upper end section; - at least one horizontal rope supported by one of said uprights on its upper end section; - a sling worn by the operator; - a safety cable with lower end fixed to said sling, and upper end slidingly fixed to said at least one horizontal rope; equipment comprising at least one tightening device arranged on top of at least one of said uprights to tighten a portion of the horizontal rope supported by the upright whereon the tightening device is arranged; it being provided that said tightening device is a tightening and tensioning device of the horizontal rope supported by it; said tightening and tensioning device consisting in a sleeve inserted into the upright; equipment wherein: - said tightening and tensioning device consists in a sleeve with circular section, provided with lower end; - said upright has an upper end section provided with upper circular mouth adapted to house the lower end section of the tightening and tensioning device; - said sleeve comprises a pair of longitudinal notches adapted to house one of the horizontal ropes; - locking means (7c, 9) are provided both on the lower end section of the sleeve and on the upper end section of the upright; said means (7c, 9) mutually cooperating as soon as the sleeve is completely inserted into the upright; - equipment characterized in that it comprises a bush adapted to be inserted, from up downwards, on said sleeve and provided with: - a top wall with side (T1 a) facing towards the sleeve when the bush is inserted onto the sleeve; - a hole with square section obtained in central position with respect to said top wall; said hole being adapted to house a square pin of a dynamometric wrench; - at least one tooth protruding in lower position from said side (T1 a) and inserted into a notch of the pair of notches when the bush is inserted onto the sleeve. - a series of uprights with lower end section adapted to be fixed on top of a pillar and with upper end section; - at least one horizontal rope supported by one of said uprights on its upper end section; - a sling worn by the operator; - a safety cable with lower end fixed to said sling, and upper end slidingly fixed to said at least one horizontal rope; equipment comprising at least one tightening device arranged on top of at least one of said uprights to tighten a portion of the horizontal rope supported by the upright whereon the tightening device is arranged; it being provided that said tightening device is a tightening and tensioning device of the horizontal rope supported by it; said tightening and tensioning device consisting in a sleeve inserted into the upright; equipment wherein: - said tightening and tensioning device consists in a sleeve with circular section, provided with lower end; - said upright has an upper end section provided with upper circular mouth adapted to house the lower end section of the tightening and tensioning device; - said sleeve comprises a pair of longitudinal notches adapted to house one of the horizontal ropes; - locking means (7c, 9) are provided both on the lower end section of the sleeve and on the upper end section of the upright; said means (7c, 9) mutually cooperating as soon as the sleeve is completely inserted into the upright; - said tightening and tensioning device consists in a sleeve with circular section, provided with lower end; - said upright has an upper end section provided with upper circular mouth adapted to house the lower end section of the tightening and tensioning device; - said sleeve comprises a pair of longitudinal notches adapted to house one of the horizontal ropes; - locking means (7c, 9) are provided both on the lower end section of the sleeve and on the upper end section of the upright; said means (7c, 9) mutually cooperating as soon as the sleeve is completely inserted into the upright; - equipment characterized in that it comprises a bush adapted to be inserted, from up downwards, on said sleeve and provided with: - a top wall with side (T1 a) facing towards the sleeve when the bush is inserted onto the sleeve; - a hole with square section obtained in central position with respect to said top wall; said hole being adapted to house a square pin of a dynamometric wrench; - at least one tooth protruding in lower position from said side (T1 a) and inserted into a notch of the pair of notches when the bush is inserted onto the sleeve. - a top wall with side (T1 a) facing towards the sleeve when the bush is inserted onto the sleeve; - a hole with square section obtained in central position with respect to said top wall; said hole being adapted to house a square pin of a dynamometric wrench; - at least one tooth protruding in lower position from said side (T1 a) and inserted into a notch of the pair of notches when the bush is inserted onto the sleeve.