I think everyone in construction should be able to roughly find the volume of things, have a sense of their density and be able to make a decent calculation of what they weigh. For example, a tree being removed next to a house. Say the tree is about 3′ diameter with 15′ of main trunk and branches that go another 25′.
Just to keep it simple, assume a 3′ x 3′ x 40′ volume x 40 pounds per cubic foot = 14,400 pounds. Everyone involved in this industry that faces us with all sorts of odd challenges should be able to do a similar calculation. We should all know that wood = 40 lbs/cf, soil = 100 lbs/cf, concrete 150 lbs/cf and steel = 500 lbs/cf.
Yesterday in Santa Rosa CA, a crew worked to remove a tree and ended up using the crane boom like a knife to slice the house in half. As in normal in these situations, the workers claimed it was a freak accident. Fortunately no one was hurt. The crane boom missed the worker in the tree by about 4′ and the homeowners were dealing with a car accident they had earlier in the day. A day they won’t forget.
As you work through your day, think about what things weigh. Get adept at volumes, densities and weights and avoid injuries to yourself and others.