Your wrong on the employee and equipment side. Companies like this tend to have a few employees due to the months you go without work. You have contracts with people of different trades, contracts with companies owning the different type equipment you will require.
Example; our client required crane operators and a helicopter and much more. But we do not have these people sitting around in an office waiting for work, we contract out. We were paying crane operators $175.00 an hour, contract for helicopter was $5000.00 per day if it flew or not and we had it for 6 months.
So a company like this works fine with a few employees and everyone else and equipment are contracted out.