Most baskets also contain a support framework made of wood, aluminum, steel, cable, rope, or a combination of these materials. Baskets are designed so that the weight inside the basket, i.e. fuel tanks and passengers, is transferred directly to the load tapes or ropes of the envelope. Rip-stop nylon is the most common material. Polyester and other fabrics are sometimes used. The lower portions around the opening are usually made from a fire resistant material like Nomex, similar to what race car drivers and firemen wear.
Propane is used for fuel.
It is carried in aluminum or stainless steel tanks that range from 10 to 20 gallons in size. Average fuel consumption is about 15 gallons an hour. The crown line on top of the balloon is used to stabilize the balloon during inflation. However, due to something called a temperature inversion, it can sometimes be warmer at that same 3000' than on the ground. Temperature inversions mostly occur during the winter on clear, cold, calm nights.