The Associated PressThe news that Warren Buffett's company is buying the nation's second-largest railroad boosted shares of the companies that make railcars, too. Buffett is leaving the same managers in place at Burlington Northern Santa Fe Corp., so it's not clear that the railroad will change direction ¿ or need more rail cars ¿ under his ownership. Still, the shares of railcar makers rose Tuesday. The biggest gainer was Greenbrier Co., up 60 cents, or 6.7 percent, to close at $9.54. Other gainers included Trinity Industries, up $1.05, or 6.2 percent, to close at $18.02, American Railcar Industries Inc., up 39 cents, or 4 percent, to close at $10.15, and GATX Corp., which leases operates and manages rail assets, up 95 cents, or 3.5 percent, to $27.98. Rail supplier LB Foster Co. also rose, up 84 cents, or 3 percent, to close at $28.73.