29 TRANSPOR T A TION In recent years advances have also been made in highway trucking operations for movement of mining products Aluminum truck bod ies are being used allowing higher payloads through reduced empty weights of the trucks and more powerful truck engines expedite truck shipments New er t echnologies in transporting ore from the mine to the process ing location by truck include trollyassist systems for steep grade transport GPS monitoring systems for movement control and remote control truck oper ation Other Shipping Methods Conveyors and pipelines are two additional transportation methods employed in mining Versatile conveyor systems and aerial tramways are normally used to move coal or miner al or e from production sites to storage and transportation facilities pr oc es sing plants or nearby power plants Tramways usually cover relatively short distances while conveyors can be several miles long What ar e the light es t and the hea vies t metal miner als Lithium is the lightest metal and third lightest of all elements Platiniridium a natural alloy of two members of the plati num group is the heaviest T he spac e shuttle s super light w eight e xt ernal fuel t ank w as made fr om an allo y of lithium and aluminum It pr o vided the liquid h y dr ogen fuel r equir ed f or lif t of T he use of the lithium allo y pr o vided a 7 000 lb w eight r eduction o v er pr e vious t ank s and each pound in w eight r eduction incr eased the shuttle s c ar go c apacit y b y nearly a pound Phot o NASA The average car contains 2 000 lbs ir on st eel 300 lbs aluminum 50 lbs carbon 40 lbs c opper 7 5 lbs f or a h ybrid 40 lbs silic on 2 4 lbs lead 2 2 lbs zinc 17 lbs mang anese 15 lbs chr omium 9 lbs nick el 45 lbs magnesium 2 lbs sulfur 1 lb molybdenum and smaller amounts of v anadium platinum antimon y barium beryllium c obalt g allium g old neodymium indium palladium rhodium silv er str ontium tin titanium tungst en and zir c onium US GS NMA SME f ast act T he Institut e f or Def ense Analy sis estimat es that r oughly 7 50 000 t ons of miner als ar e r equir ed annually t o maintain our national def ense