Abstract: A tensioning and securing device for a lashing system comprises a U-shaped member (10), for engagement with first lashing elements (24) and a cross-member (16) having holes through which the legs of member (10) extend and which can slide up and down the legs of member (10), the member (16) having hooks at its ends for attachment of second lashing elements (25). The ends of the legs of the member (10) carry a formation or formations (20, 34) for supporting the neck of a removable jack (26) by which the cross member (16) may be jacked towards the loop end of the U-shaped member (10) to tension the lashing. Securing elements (18) on the cross member (16) or on the legs of member (10) allow the cross member (16) to be locked in place, then the jack may be collapsed and removed.