Metro officials are examining new ways of clearing ice and snow from rail lines that would enable them to keep trains running during periods such as last week's storm.

The methods, outlined at a Metro budget committee meeting yesterday, will center on the possible purchase of special equipment to remove ice and snow from the 750-volt "third rail" that provides power to the trains. A buildup of ice on the third rail that blocked the flow of electricity and halted trains was a major problem after last week's snowstorm.

But the expense of buying new equipment, which might not be needed again for years, is expected to be a key concern for the financially strapped system.

Theodore G. Weigle, Metro's assistant general manager for transit operations, said four options are being weighed--heating devices to prevent ice from forming on the third rail, antifreeze spraying equipment, snow-blowing machines and special rough-surfaced rail "shoes" to help rub snow off.

The shoes maintain electrical contact between rail cars and the third rail and normally have smooth surfaces. During snowstorms, shoes with abrasive surfaces might be used to help keep the third rail ice-free, Weigle said.

Each of the proposals is expensive. Snow blowers or antifreeze sprayers would cost several hundred-thousand dollars each, according to Weigle. Installation of equipment to heat key sections of the third rail could cost up to $5 million, he said.

After a major 1979 snowstorm, Metro spent about $1 million for equipment designed to handle up to 12 inches of snow in a 24-hour period. Last week's storm, however, dumped as much as 2 feet of snow in some areas. Weigle said officials would seek to determine how much more equipment would be needed to deal with an 18-inch snowfall.