In bargaining with labor unions later this year, America's railroad industry may seek major changes in work rules to reduce the number of persons now required to move a single train, Norfolk & Western Railway Co. president John P. Fishwick said today.

Addressing some 700 stockholders and employees at the rail firm's annual meeting, Fishwick also said he does not think "we can build up coal use in this country as fast as President Carter would like to see it happen."

But he emphasized that N&W, which led the rail industry in return on investment last year, is capable of expanding coal-carrying capacity quickly if demand accelerates.

Carter's energy program has called for a 66 per cent increase in coal production by 1985, leading to a growth in coal shipping that the rail industry says it can handle. Other experts - notably those who advocate construction of new slurry pipelines to carry coal in a mixture with water - have argued that rail leaders are too optimistic about their ability to expand.

Fishwick's hint that rail industry leaders are considering a significant new challenge to union work rules came in response to a stockholder's question.

While it is "a little premature" to outline the industry's goals in forthcoming talks with all major unions, whose contracts expire at the end of the year, Fishwick said that in the face of competition from truckers "railroads must keep costs in line."

As a result, "The railroad industry may very well come forth with a proposal to change work rules and the number of people required on crews . . . but it's not definitely decided," he said.

Noting that most freight trains have crews of four or five persons each compared with only two persons on the non-union Florida East Coast Railway, Fishwick said there may be "opportunities to eliminate some old fashioned work rules," including the requirement that when a worker goes beyond 100 miles there must be an additional day's pay for which there is "no justification in modern practice."

He conceded that if the railroads move forward to change such rules, it would create "serious problems for the unions," who can be expected to launch a bitter fight against the proposal. "Some accomodation will have to be worked out" so that the burden of aiding workers who may lose jobs" would be shared by the railroad and unions, Fishwick added.

"We have a more favorable climate" than ten years ago to make such changes, and the railroads "will soon have to tackle" the manning problem, Fishwick told his stockholders.

The last time so-called featherbedding became a major industry issue was about a decade ago, when the position of steam engine firemen was eliminated in most states on what had become a system of locomotives powered either by diesel or electric energy.

Norfolk & Western has been moving on its own to reduce the number of workers throughout its system. In the last five years, N&W increased by 32 per cent the number of gross ton miles handled per man hour. During this period, the Roanoke-based company cut its payroll by 13 per cent. In the last year alone, the railroad's total work force was reduced by 3.2 per cent to about 24,500.

Still, total wage and fringe benefit costs in 1976 amounted to $511.5 million, or 45.6 per cent operating revenue dollar.

Speaking of the nation's energy challenges, Fishwick said "we are delighted" with possibility of hauling more coal in future years.

If electric utilities could convert generation stations quickly from other fuels to coal, "We could boost our coal volume substantially right now," he said. Coal miners served by N&W now have enough idle capacity to expand production by about 20 per cent to 80 million tons a year. In addition, 21 major new coal mines will begin production on N&M lines before 1980, adding another 24 million tons of capacity a year.

The railroad itself also has a fleet of coal hoppers and locomotives capable of handling "a good increase in coal traffic when it develops without any appreciable increase in our investment," the rail president said.

N&W's own car-manufacturing shops here can construct 16 hopper cars a day but currently are building only five a day. "In the real world, things change more slowly. It takes time for utilities to convert plants from other fuels to coal . . . We are unlikely to feel any effect from (Carter's energy) policies this year . . . But it will be at least five years, we think, before there's a really substantial boost in coal use by utilities."

N&W today also detailed the extent of damage caused by April floods in southwest Virginia and West Virginia that hurt the Roanoke firm harder that any other railroad. A total of 3,900 cars were damaged by the flood waters, and 46 locomotives were damaged when water got into electric tration motors.

Norfolk and Western reported earlier that first-quarter profits declined by 36 per cent to $17.7 million (57 cents a share) from $27.6 million (88 cents) reported in the same period last year because of record cold and snow in january and February.