By Gene Miller
Herald Staff Writer

A homemade bomb in a cigar box, attached by a magnet to the hull of a British cargo ship, failed to explode at the Miami City Docks Tuesday - apparently because an undersea bomber didn't set it correctly.

"It should have gone off," said Capt. Tom Brodie, chief of the Sheriff's office bomb squad.

The ship the 180-foot 692-ton Oro Verde, was due to sail late in the day for a five-day trip to Cristobal, Panama. From there, after unloading, its normal route takes it through the Panama Canal to Ecuador.

"We don't have the slightest idea why anyone would want to blow up our ship, " said Robert Trost, operations manager for Chester, Blackburn & Roder Inc., Miami agents.

Horace Barron, a crane operator loading general cargo, first noticed something peculiar attached to the hull several feet below the water line.

"He'd looked at it for a couple of hours and didn't know what to think," said Bob Kretzschmar, a sheriff's deputy assigned to docks.

The ship was on the north side of Pier C, berth three.

But before it arrived there at 7 a.m., it had unloaded bananas at the parking lot dock of the Banana Supply Co. on the river. The ship reached Miami Sunday.

"The crane operator started talking to the crew and someone finally decided to call the Coast Guard," said Kretzschmar.

"The Coast Guard took one look and said 'Call the bomb squad.'" This was at 11:28 a.m.

Capt. Brodie, accustomed to frequent false reports, also needed but a single glance. He took off his shoes and shirt, jumped in, and deactivated it.

The time-bomb, put inside a wooden Cuban cigar box consisted of a cast-made explosive, pentalite, and weighed about two pounds.

Attached to it was an acid pellet triggering device floating underwater in a prophylactic. It looked like a ping-pong ball in a balloon from the surface.

When the pellet or ampule is crushed, the acid begins to eat at the wire. When the wire gives, a spring releases a hammer which strikes the primmer of the cap.

"Someone didn't set it right," said Capt. Brodie. "It should have gone off."

Pentalite, he said, is a "very high order explosive, a step above TNT or the normal plastic explosives. It would have blown quite a hole in the hull."

Investigators said they didn't know whether or not the ship would have sunk.

Capt. Brodie said that pentalite is often used by militant Cuban exiles here. There was one unverified report that the CIA once had an interest in the ship.

Trost, the agency manager, discounted thoughts of anyone trying to blow up the ship in the Panama Canal. "The detonating device was of much too short duration for that," he said. "It sure is odd."

The ship, registered as British, is managed by a crew of 17. Wendell Phillips, a U.S. citizen, is the captain.

Trost, as well as police, believed that the bomb was attached to the ship in the Miami River sometime prior to loading at Pier C.

Yet police said they couldn't tell how long it had been there.

Sheriff skindiver Ed Zender explored the underside of the hull for other bombs and Deputies J. K. Russell and James Askew searched the ship.

Neither Capt. Phillips nor John. W. Tatcher, owner of the vessel, could offer any possible motive for sabotage.

The ship, built in 1942, once was an Army cargo vessel, Phillips said.

"All we do is carry bananas from Ecuador and general cargo from Miami to the Canal Zone," said Thatcher.