The load

Everything else in the plan is built on what the load actually is. If that
figure is wrong, the rest of the plan is wrong too.

The weight

The weight comes from a source, not an impression. Marking on the load, a
consignment note, a drawing, a data sheet, or weighing it. “It looks like about
two tonnes” is not a source.

If the weight is an estimate, the plan should say so, and the margin should
reflect it. Remember what comes along and is not in the figure: packaging,
frames, water inside sections, snow and ice, soil on excavating equipment.

See the article Load charts aren’t suggestions.

The centre of gravity

A load whose centre of gravity is off-centre swings before it leaves the
ground, and rotates once it is free. That is not the crane behaving oddly — it is
the load.

Consider whether the centre of gravity is obvious or not. Motors, switchboards,
machinery with heavy content at one end, and anything partly filled, rarely have
it in the middle. The centre of gravity
calculator helps with the geometry, and the article Centre of
gravity with the reasoning.

Attachment points

• Are there designated lifting points, and are they intended for lifting —
  not merely for lashing
• Will the points take force from the direction they will get it? Eyebolts
  are sensitive to side loading — see the
  lifting gear reference
• Are there sharp edges where the sling bears, and is edge protection planned
• Can the load slide, tip or come apart as it lifts
• Are there loose items on top that become dropped objects

The trial lift

Lift the load a few centimetres and stop. That tells you whether it hangs
level, whether the centre of gravity is where you thought, whether anything is
slipping, and whether the crane behaves as expected — while the load is still low
enough for the answer to be survivable.