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INSTRUCTIONS

Step-by-step lashing and becket options for the Ronstan RF25109HL Series 20 BB Orbit Block™ lashing head, plus lashing inspection and bearing care.

DocumentRonstan Series 20 BB Orbit Block Lashing Head User Instructions
FormatPDF · 4 pages · 1.2 MB
LanguageEnglish
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Key PointsLashing OptionsBecket OptionsCareProducts
Ronstan Series 20 BB Orbit Block Lashing Head — User Instructions

Before You Lash

  • To meet the breaking loads the block must be lashed with the lashing, strop or link passing through the hub.
  • Lashing path: down through the head, out through the cheek, through the hub, back in through the opposite cheek and up out of the head. Repeat for line sizes that need more than one strand to meet the load rating.
  • The MWL and BL of the assembly (block + lashing) are generally limited by the rope and the joining method; knots, splices and stitching are generally weaker than the rope itself.
  • Up to 4mm (5/32") line can be used as a single strand, but a neater, more secure result comes from smaller line (e.g. 1.7 - 2mm) passed several times. The block is supplied with 750mm (30") of 2mm (3/32") single braid Dyneema® lashing line.
  • Attach to a smooth, well rounded mounting point. On sharp-edged or rough fittings put a smooth shackle between lashing and fitting. Inspect the lashing regularly and replace it immediately if damaged.

Attachment at 0° (In-line)

  1. Pass the line down through the head and out through the cheek.
  2. Pass it in through the opposite cheek and back up through the head.
  3. Pass it around the fixing point; repeat if more than one strand is needed for the breaking load.
  4. Finish with an appropriate knot, splice or whipping.

Attachment at 90°

  1. Down through the head, out through the cheek and through the hub.
  2. In through the opposite cheek and back up through the head.
  3. Loop over the fixing point, back down through the head and out the same cheek it last passed through.
  4. Through the hub, in through the opposite cheek and up through the head; repeat if more than one strand is required.
  5. Finish with an appropriate knot, splice or whipping.

End Attachment

  1. Down through the head and out through the cheek.
  2. Through the hub.
  3. In through the opposite cheek and back up through the head.
  4. Tie a bowline above the block – the knot must be non-slipping (non-tightening) – or, for the cleanest finish, use an eye splice.

Large Diameter Object (e.g. a boom)

  • Where the object is wider than the head of the block, the lashings must cross each other between the head and the object.
  • Four strands are required to stop the block twisting and giving a poor lead.
  • Strands from one side go to the outside; strands from the other side pass between them.

Becket Options

Option Sheet size How
Through-hub becket Up to 3mm (1/8") Attach the block as in the lashing options; the hub is the becket.
Lashing used as becket 4mm (5/32") to 6mm (1/4") Down through the head, out the cheek and through the hub; loop under the bottom of the block and again through the hub (repeat for more loops if needed for the breaking load); in through the far cheek and up through the head. Finish, then attach the sheet to the becket loops with a bowline or splice.
Single line as becket & sheet Up to 3mm (1/8") In through a cheek, up through the head, around the fixing point, back down through the head and out the opposite cheek; pass both ends through the hub in opposite directions and finish.

For the single-line option the knot must not be a slip knot and must pull equally on each line leading to the hub – a bowline is ideal. The breaking load of the installed block depends on the breaking load of the line, up to a maximum B.L. of 900kg (1980lb).

Care and Maintenance

  • Install lashings correctly, inspect them regularly and replace them when required. Lashings degrade from fatigue, wear and UV: inspect them with the rest of your rigging and replace them if they show significant wear or fibre damage.
  • Grit and sand damage the bearings: flush the blocks, especially the bearing areas, with fresh water regularly and clean them periodically with mild detergent and water.
  • Dry lubricants such as Ronstan Sailfast™ silicon spray may be used on the bearings. Never use oil/petrochemical based lubricants.

BB = Ball Bearing. MWL = Maximum Working Load. BL = Breaking Load.

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