The political maneuvering on both sides of the coal-slurry-pipeline debate in Maryland and Virginia entered a new phase this week, producing some unlikely alliances as well as winners.

There were setbacks as well, but so far no clear losers.

One thing is certain, however. Buried somewhere in the protracted debate over proposals to construct coal slurry pipelines in Maryland and Virginia is the truth about what is in the public interest.

Principal proponents of the pipelines -- Dominion Resources Inc. of Richmond and Baltimore Gas & Electric Co. -- maintain that construction of the systems would lower their costs of shipping coal from the coal fields of Virginia and West Virginia, enabling them to pass on the savings to customers.

The railroads, which currently transport most of the coal used by electric utilities, oppose attempts to win legislative approval for the pipelines. Environmentalists contend that the pipelines would pose a threat to land and water, and some property owners oppose it on grounds that pipeline owners would have the right to acquire land through eminent domain. Under the power of eminent domain, land can be acquired, over the objection of a property owner, at market value.

The proposed pipelines would move a mixture of pulverized coal and water from the coal fields to a terminus, where the coal would be extracted for use in generating electric power.

A special Maryland House and Senate committee dealt a setback to pipeline proponents Tuesday when it voted to recommend that the full legislature withhold approval for the system. State Sen. Arthur Dorman (D-Prince George's) who voted with the majority in the 5-3 decision, bases his opposition on what he believes is in the public's interest. "When you're dealing in the area of eminent domain, necessity has to be proved," and proponents of the pipeline have failed that test, Dorman maintains. "That's a dilemma when you ask the legislature to approve the taking of someone's property," he said.

Although the result of his action favors the railroads, Dorman emphatically denies he supports that industry's position. "I felt some of the stuff they presented was . . . inadequate," the senator observed.

Dorman agrees that reducing energy costs is important, but construction of a pipeline is no "guarantee" that consumers will pay less, he argues.

There is no gurantee either that the railroads will lower their shipping costs. The Edison Electric Institute reports that electric utilities paid the railroads about $5.5 billion last year to transport coal. Rail rates for "captive coal shipments" to the electric utility industry could double in five years, the institute projected last month.

Still, proponents of a pipeline in Maryland haven't proved the necessity, Dorman and his colleagues maintain.

Score one for the railroad monopoly and perhaps the public interest, with an assist from a political decision.

In Richmond, meanwhile, a practical business decision with political overtones puts the pipeline issue in a new context as it moves its way back toward the legislative calendar.

Dominion Resources Inc. (formerly Virginia Electric and Power Co.) announced Tuesday that it had reached an agreement in principle with Norfolk Southern Corp. calling for the railroad to haul coal by a more direct route to Dominion's Chesapeake Energy Center coal terminus. From there, Dominion will ship the cargo over water to its coal-powered generating stations, all but two of which are accessible by barge.

Unencumbered by excessive switching, indirect routes and traffic density, the direct rail route on which the two companies have reached agreement will reduce Dominion's fuel costs by an estimated $750,000 next year. It also is expected to save the utility's customers "several million dollars" annually in coal transporation costs, a spokesman explained.

"The agreement with Norfolk Southern is another important step in Vepco's efforts to keep costs to our customers as low as possible," said William W. Berry, Dominion's president and chief executive officer.

Having established a more economic means of shipping coal across the state, Dominion announced that, although it will continue to give financial support to efforts to build the pipeline, it no longer will lobby for it.

The strategy, which puts Dominion in the background in the campaign to win approval for the pipeline, was plotted last summer by the utility and other partners in the venture. The effectiveness of such a strategy is debatable, considering that Vepco's deal with Norfolk Southern would tend to obviate the need to pursue a cheaper alternative for transporting coal.

The president of the company that would build the pipeline contends that the outlook is more promising now that Dominion has taken a back seat. "This not a Vepco bill, and perhaps now it can be decided on its merits," said Charles M. Guthridge, a vice president of Transco Coal Co. and president of the newly formed Trans-Virginia Public Service.

Score one for Dominion and Norfolk Southern. Whether their agreement is a "political plus" for the pipeline, as Guthridge described it, remains to be seen.