HAMBONE

See wedge socket.

HAMMERHEAD CRANE

A tower crane with a counter weighted horizontal boom which supports a traversing crab for hoisting.

HAMMERLOCK

An attachment for joining hooks or rings to a chain.

HANDY BILLY

A fibre rope tackle where one block has two sheaves and the other block has three sheaves (double and treble blocks). It is also called ‘light gin tackle’.

HAWSER LAID

A fibre rope construction which uses three strands.

HEAD BLOCK

The top block in a purchase, tackle or block at the head of a crane boom or hoist.

HEADACHE BALL

A spherical overhauling weight.

HEAVY DUTY WORKING PLATFORM

A scaffold platform with a duty live load capacity of 675kg per bay. This is three times the capacity of a light duty platform.

HEAVY GIN TACKLE

A fibre rope tackle where the upper block has three sheaves and the lower block has three sheaves (two treble blocks).

HELIX

The spiral put into a rope construction.

HIGH STRANDING

Rope damage indicated by one strand sitting up higher than the others in a portion of the rope.

HITCH

A tie made in a fibre rope to fix it to an anchorage or to a load. Common examples include the clove hitch, rolling hitch, becket (or buntline) hitch and timber hitch.

HOIST

An appliance used to raise or lower a load with no horizontal movement.

HOISTING

Raising or lowering a load.

HOIST-LIMITING DEVICE

A device used in a crane or hoist to stop the winch or warn the operator before the hook block jams into the head block (two-blocking) while the hook is being raised. It is also called an ‘anti-two-block device’.

HOOK BLOCK

The lower block on a crane which incorporates a hook for slinging loads.

HYDRAULIC BOOM CRANE

A crane which has a boom which luffs using hydraulic power and usually also telescopes using hydraulic power.