A double block contains two sheaves. It is very widely employed because it can be used to create four- or five-line tackle, considerably increasing mechanical advantage.
Combined with a becket block, these devices can be used to make efficient five-line tackle.
The axis of effort will be determined, in part, by the block's attachment method. Careful mounting will avoid overly large angles. Usually equipped with a ring, the block must be attached with a shackle. This should be chosen carefully to ensure that the tackle is oriented to reduce friction to a minimum.
The diameter of the lines and the working loads will be the main elements to consider.
- Multiples purchase by four or five
- Requires a becket for maximum efficiency
 |
 |
Sailboat double block with swivel / becket (max. rope ø : 10 mm) 94206 Wichard
Commentary Complete range of blocks Excellent high-speed low load and high-function load characteristics Interchangeable head fastening systems for multiple attachment...
 |
 |
Sailboat double lashing block (max. rope ø : 6 mm) 250 KG | KBO1 DOUBLE Karver Systems
KBO lashing blocks have the best size to weight ratio on the market. KBO rope lashing makes fitting easier and quicker than standard shackle LIGHT...
 |
 |
Sailboat double block with swivel (max. rope ø : 12 mm) 01476-25 Eval
STAINLESS STEEL BLOCKS WITH DOUBLE WHEELS AND SWIVEL Code 1476-25 , Dimensions mm L...
 |
 |
Sailboat double block with swivel (max. rope ø : 16 mm) PBB 80 - SWL = 2000 KG Seldén
Glass fibre reinforced sheave with Teflon® bushing Bronze top swivel bushings Optimised 8/10 shackle...
 |
  |
Sailboat double block with swivel (max. rope ø : 16 mm) 3248 Harken
Sheave Ø (mm)100 mm Sheave Ø (in)3 15/16...
 |
 |
Sailboat double block with fixed head / becket (max. rope ø : 12 mm) HT 92225 - BL 1300 kg Holt
Classic ball bearing blocks. Functional, strong and reliable. Conventional ball...
 |
 |
Flat double cheek block for sailboats RF60251 - M.W.L - 600 kg Ronstan
Low friction, 2-stage ball bearing...
 |
 |
Sailing dinghy thru-deck double block (max. line ø : 8 mm) A...7 Allen Brothers
Sheave Boxes Allen sheave boxes are available with either plain or ball bearings, a choice of sheave material, Acetal resin, pressure...
 |
 |
Flat double cheek block for sailboats (max. rope ø : 12 mm) BL = 2000 KG Rutgerson
40mm double foot block with a composite sheave....
 |
 |
Sailboat double block with swivel (max. rope ø : 30 mm) Hi-MOD Petersen Stainless
The Hi-MOD Marine Blocks are a simple and durable cruising block which work well under heavy loads and are less prone to jamming . Made...
 |
 |
Sailboat double block with fixed head Equiplite Europe
Equiplite™ Dual Sheave Block use DSK 75 ULTRA loops to take the loads directly through the centre of the sheave. This allows the blocks to be extremely...
 |
 |
Sailboat double block with shackle / becket 19.84 Sea Sure
19mm carbon fibre cheeked ball race blocks Light weight, high load carrying capacity blocks Reliable race proven designs High wear resistant cheek material extends life if miss-lead occurs Freewheeling...
 |
 |
Advantages: •easily running ball bearing stainless steel •bearing shell and balls of stainless steel •wobble riveting:...
 |
 |
Sailboat double friction block with lashing (max. rope ø : 7 mm) CSS242 Colligo Marine
Enhanced Double Lashing Block, 7 mm, Black Price: US$69.00 Ask a question about this product Our Patent Pending, Enhanced Double...
 |
 |
Double block for classic sailboats Dryade
Dryade blocks are made in a wide variety of sizes accepting sheaves of diameters from 30 to 160 mm in the standard series. The technical and marine shells,...
 |
 |
Double block for classic sailboats 2FA90D - SWL 350 La Nantaise de Poulies
Double Hand Strap Force II 12mm Fonctionnalities Double Hand Strap Optional Becket Optional Rope Specifications Force II blocks are made in order to join together the design features...
 |
 |
Sailboat double block with shackle / becket S315 SINOX INTERNATIONAL
Field of application Mame blocks are specifically...
 |
 |
Our High Performance blocks are developed with emphasis on design and strength. The blocks have aluminium ball...
 |
 |
Double block for classic sailboats Esprit Yachting
Wooden blocks by Esprit Yachting is a complet range of...
 |
 |
Double block for classic sailboats Maritime Enterprises I.O.W.
Our 'Maritime' range of blocks are made to the highest possible...
 |
 |
Double block for classic sailboats THROAT HALYARD Blockmakers Ording
Wood: elm or teak Bindings:...
 |
 |
Genoa lead car control with double sheave / cam cleat for sailboats 40X8 Antal
High resistance silver anodized light alloy extrusion. Rounded upper edges, larger...
