Allen 30mm Blocks

Allen 30mm blocks are mid sized blocks for dinghy and small keelboat systems that carry more load than a fine tune control. Typical uses include kicker and vang systems, jib and spinnaker sheet leads, halyard turning points and smaller mainsheet systems. They are available as single and double blocks, with cheek, stand up, snatch and vang key versions.

Choose a 30mm Allen block when the rope is thicker, the load is higher, or the rope turns through a large angle, because a bigger sheave reduces friction and is kinder to the rope. Choose a 20mm block for light control systems where space and weight matter most. Many dinghy systems use both, with 30mm blocks at the high load end of a cascade.

An Allen vang key block is a 30mm block fitted with a key that slots into the kicker fitting on the boom. It lets you attach and remove the kicker in seconds without a shackle, which speeds up rigging and derigging. Allen offers vang key versions for general dinghy use and a Titan block designed for the ILCA vang.

An Allen 30mm snatch block opens at the side so you can load a rope without threading the end through. It is useful where a rope is already rigged or has a spliced end, and for temporary leads such as barber haulers, twinning ropes and spinnaker sheet deflectors. Once closed, it works like a normal single block.

Allen 30mm blocks are designed for ropes up to 8mm in diameter. That makes them a good match for 5mm to 8mm sheets and control ropes on dinghies and small keelboats. Always check the maximum rope diameter and working load on the individual product page before you buy.