The busy Port of Houston usually ranks second among United States ports in total waterborne commerce. It averages almost 60 million tons a year. Outgoing domestic cargoes of crude petroleum and petroleum priducts, carried mainly in tankers moving through the Gulf Intercoastal Waterway, make up about half the total tonnage.
Many tons of seashells, source of lime for the cityâs chemical plants, are shipped for short distances through the port....
