Abstract: A tensioner for straps, especially for systems for keeping loads in position, has an anchoring means for the fixed end of the strap and a strap drum worked by a ratchet, the drum then acting as a winch for tensioning the strap. The drum has a locking pawl that may be moved clear of it. The tensioning ratchet has tooth means on the side of the strap drum so that a driving pawl fixed on the ratchet lever and loaded towards the strap drum by a spring, may be put into driving connection with the tooth means. The ratchet lever further has means limiting the torque that may be transmitted to the tooth means on operation of the ratchet lever by having the driving pawl spring-pre-loaded tangentially in relation to the strap drum.