Ronstan BB Orbit Blocks™ feature a unique Lashing head. Building on the latest trends in grand prix dinghy and ocean racing, it replaces the steel head post and shackle arrangement of traditional blocks.
IMPORTANT: In order to meet breaking loads this block must be lashed with the lashing, strop or link passing through the hub.
The lashing must be passed down through the head, out through the cheek, through the hub, back in through opposite cheek and back up and out through the head. Repeat for lines, sizes that require more than one strand to meet load rating.
The Maximum Working Load and Breaking Load of the assembly (Block + Lashing) is generally limited by the strength of the rope and the joining method. Knots, splices, stitching, etc. will generally have a lower Breaking Load than the rope itself. It is possible to use up to 4mm (5/32”) lashing line for lashing the RF25109 running the lashing around as a single strand, but a neater result with more secure knotting can be achieved by using the smaller line size provided (e.g. 1.7 - 2mm) passed through multiple times. The RF25109 Series 20 Orbit Block™ is supplied with 750mm (30”) of 1.7mm (1/16”) diam. covered Dyneema® lashing line.
For best results, the lashing must be attached to a mounting point with a smooth, well rounded profile.
Avoid attaching directly to fittings with sharp edges or rough surfaces that may damage the lashing through abrasion or point loading. For this situation use a shackle with a smooth surface between the lashing and the fitting. Regularly inspect the lashing for damage, if found replace immediately.
Where attachment to a large diameter object, wider than the head of the block, is required (eg. a boom) the lashings must cross each other between the head of the block and the object. Four strands of lashing are required to prevent the block twisting and creating a poor lead. The strands from one side of the block should be to the outside and the strands from the other side passing between them. See diagram 1.4.3.
A through-hub can be used as a becket for up to 3mm (1/8”) lines. A take-off becket can be created with the lashing line for use with 4-6mm (5/32” - 1/4”) sheets.
BB = Ball Bearing
MWL = Maximum Working Load
BL = Breaking Load
Dyneema® is a trademark of Royal DSM NV.
DSM is the inventor and manufacturer of Dyneema®, the world’s strongest fibre™. “Dyneema®”, and “Dyneema®, the world’s strongest fibre™” are trademark(s) (applications) owned by Royal DSM NV.