Benjamin Joseph Crapo, 57, an electrical engineer with the Naval Surface Weapons Center in White Oak, died Wednesday at Leland Memorial Hospital after a heart attack.

He joined the Center, which at the time was the Naval Ordnance Laboratory, in 1946 as an electronics technician.

Mr. Crapo became an engineer after receiving a degree in physics from Catholic University in 1961. He did work in ultra high-speed photography, the application of radar to interior and exterior ballistic measurements and the applications of laser technology for penetration of re-entry blackout sheets and gas dynamic measurements.

He was considered an authority on laser technology applications and served as a consultant to all branches of the Navy.

Born in Washington, Mr. Crapo served with the Navy in World War II and was the first forces to land in North Africa.

For many years, he had been an amateur radio operator. He was a member of the Prince George's County Amateur radio Emergency Communications Network, Office of Emergency Preparedness.

He is survived by his wife, Eleanor Crapo, and a son, Michael Anthony, both of the home in Brentwood; two other sons, Charles Joseph, of Brentwood, and William Franklin, of Hyattsville a daughter, Anna Hyatt, of Mount Rainier; a sister, Evelyn Crapo, of Washington; his stepmother, Evelyn Crapo, of Laurel; a stepsiter, Gloria Schneblen, of Largo, and six grandchildren.