Rep-Robert E. Bauman (R-Md.) and Sen. Paul Sarbanes (D-Md.) today urged the Carter administration to provide new federal aid for rail service on the Delmarva Peninsula.

At Interstate Commerce commission hearings on the future of rail-roading in Delaware, Maryland's Eastern Shore and the Peninsula's Virginia tip. Bauman said inadequate rail service here is causing growing economic hardship.

"Success in industries such as chemical production, poultry processing, grain shipping and others on the Delmarva Peninsula is being prevented because of inadequate rail transportation on which the shipment of these bulk commodities depend," he testified.

Expressing the consensus of Delmarva businessmen and government leaders who testified today, Bauman forecast that rail service will continue to deteriorate unless the lines are purchased soon by a viable and interested private company willing to serve the region.

Since last April 1, the most heavily traveled rail freight lines in Delmarva have been part of Consolidated Rail Corp., the new Northeast rail firm set up and partialy financed by the federal government to replace the Penn Central and other bankrupt line. The Delmarva network formerly was part of the ill-fated Pennsy.

Branch lines not taken over by Con-Rail have been maintained since last April by a federal subsidy which is scheduled to be reduced in about two months. Under federal legislation, the subsidy declines to 90 per cent in the second year, 80 per cent in the third year, 70 per cent in the fourth and fifth years, and then is discontinued.

"This projected subsidy arrangement . . . makes no provision for track rehabilitation and upgrading which is very important if operating costs are to be reduced and service improved," Sarbanes said in testimony submitted today.

Furthermore, the declining subsidy jeopardizes continuation of a railroad car ferry across the lower Chesapeake Bay with a rail connection at Norfolk, he said "Without the car float, the vital link to Virginia and to the rail lines further south would be lost, with deterimental consequences for users . . . and hence for the economic health of the area," the Maryland Democrat added.

Most witnesses said today that the only solution would be a takeover of the Delmarva lines from ConRail by a private company, such as Washington-based Southern Railway, which Bauman noted "does not have to be coaxed into expanding and improving the level of rail operation to make it successful."

A number of witnesses today charged that ConRail has expressed no interest in Delmarva business development and is shipping freight cars on circuitous routes, causing delays.

Under original railroad reorganization legislation, Southern Railway was scheduled to take over in Delmarva but union representatives and the railroad failed to reach agreement on a labor contract. Hence, the deal fell through and ConRail took over Delmarva service by default.

Officials of Southern Railway have maintained that they would reconsider a Delmarva takeover only if the same conditions were established. The only other firm to express interest in the peninsula's rail lines is Eastern Shore Rail Road Co., formed in 1974 for that purpose with $55 million of financing promised by a Philadelphia life insurance company and banks in Maryland and Delaware.

Bauman, who told a reporter that he will seek a meeting with Transportation Secretary Brock Adams in the next two weeks, said he is considering introduction of legislation to extend 100 per cent federal subsidies at least through the current fiscal year ending Oct. 1.

Sarbanes also revealed that he has written to Adams requesting that the administration begin to explore new aid, including continuation of the 100 per cent subsidy and upgrading of present tracks and equipment.