General Ropewor
k & Rigging
BLOCKS
EYECROWN
SWALLOW
SHEAVE
TAIL or ARSEBECKET
CHEEK
TALLY PLATE
SNATCH BLOCKA block with a gate held by a spring toggle
Useful when a block needs to be clipped to a fixed line, e.g. RAS
Never to be used when a fixed block can be used - danger of failure
CLUMP BLOCK
•Can be made of wood or metal
•Has an exceptionally large swallow
•It will take rope one sixth of it’s size
•metal clump blocks are designed to take chain
BLOCK CONSTRUCTION - METAL
• Built up of steel plates & fittings
• Shells have binding which supplies strength
• cheeks of light plating• Some metal blocks have
their shells are cast in one piece
• Metal blocks vary considerably in quality and finish for the job they perform
BLOCK CONSTRUCTION – WOOD (Internal Bound)
BLOCK CONSTRUCTION – SRBF –Synthetic Resin Bonded Fibre
Metal Binding
Compressed resin and fibre sheaves and protective shell
Tally plates with usage details
Stamped with test dates
WHAT IS A TACKLE?
A Tackle pronounced “Taycle” is a purchase consisting of a rope rove through two or more blocks.
The effect of the ‘pull’ is increased depending on how many sheaves and the way the rope is ‘rove’ through them.
SINGLE WHIP
• A fall rove through a single standing block
• No mechanical advantage gained
• Used for hoisting light loads• Used when speed of hoisting
is required
DOUBLE WHIP
• Is used for hoisting• Consists of two single
blocks• Standing part made fast
to or near to the upper block
• It cannot be rove to advantage
LUFF
• A purchase of 24mm or greater in size
• Consists of a double and a single block
• The standing part of the fall is attached to the single block