DEAD END

The tail of a rope which does not take load.

DEAD LOAD

The self weight of a crane, hoist or scaffold before it is.

DEBRIS NET

A fine mesh net usually laid over an industrial safety net in order to catch small light items of falling debris

DEE SHACKLE

A shackle with parallel sides, resembling the letter D on its side.

DERRICK CRANE

A slewing strut-boom crane with the boom pivoted at the base of a mast which is either guyed (guy-derrick) or held by backstays (stiff-leg derrick). Can luff under load.

DIAMETER

The distance across a circle measured through its centre.

DIVERTING SHEAVE

A sheave set up to change the direction of the lead rope between the winch and the head sheave.

DOG KNOTTING

A method of finishing a splice in a fibre rope by halving each strand and knotting each half to the adjacent half strand. It prevents the splice from loosening during use.

DOGGING

The application of slinging techniques, including the selection or inspection of lifting gear, or the directing of a crane or hoist operator in the movement of a load when the load is out of the operator’s view.

DOUBLE BASE CLAMP

A wire rope grip with two or more bolts along a split barrel to minimise damage to the FSWR.

DOUBLE ROPE SUSPENDED SCAFFOLD

A scaffold where the cradle is suspended using two hoists and two suspension ropes at each support point.

DOUBLE THROAT WIRE ROPE GRIP

A wire rope grip which uses a saddle on each side to minimise damage to the FSWR.

DOUBLE WRAP

A method of slinging where the sling legs are passed twice around the load with the eye choked back to the sling. Often called a round turn.

DRAGLINE

A crane fitted with a bucket or scoop which is thrown outwards and retrieved by a drag cable arrangement.

DRIFT

1. A steel handtool consisting of a tapered shaft which is used to align bolt holes in structural steel connections. It is sometimes driven in with a flogging hammer to ‘drift’ the bolt holes into alignment.
OR
2. The distance between the upper and lower blocks of a tackle or purchase.  The drift determines the maximum height a load can be lifted.

DROlT

A brand name for excavators and loaders.

DRUM

The cylinder of a winch around which the rope is wound and stored. It may be plain or grooved.

DUAL COVERAGE

Work which can be performed by someone who holds either the appropriate class of rigging certificate or the appropriate class of scaffolding certificate, because the work is within the scope of both types of certificate.

DUAL LIFT

See multiple crane lift.

DUCK

A light canvas material similar to calico.

DUNNAGE

Packing under loads to allow the removal or placing of slings.