An effective search for German submarines in the Atlantic was possible only with the use of electronic means. For this, an SCR-517 radar antenna was installed in the nose of the B-18A bomber under a large semicircular fairing. She took the place of the former cockpit of the navigator-bombardier, who was "moved" down, to the place of the front gunner, the machine-gun point was removed from there. The radar provided surface detection of submarines day and night, in any weather. The search for submarines at shallow depths was carried out using a magnetometer installed in a long tail cone.

For long-distance navigation, a radio compass was still used, its rotary frame in the fairing was installed above the fuselage behind the cockpit.

The anti-submarine version received the designation B-18B, a total of 122 aircraft were modified. Some of them received, in addition to the internal, external suspension of bombs.

Combat use. Anti-submarine B-18B in 1941-1942 received several squadrons that patrolled the Caribbean Sea. Several cases of detection of submarines on the surface and shallow depths were recorded, but none of them ended in the sinking of the enemy by aircraft. The crew of Captain N. Meadowcroft of 90 Squadron departed on patrol from Zandri airfield in Suriname. He was tasked with checking the message about the presence of a German submarine in a given area of ​​the Caribbean Sea. From a height of about 1000 m, the pilots noticed a slowly moving shadow under the water. Deciding that this was a German boat, they dropped four depth charges on it. But it was not oil spots and debris that flared up, but a large, dead whale ...

Three "Bolos" made forced landings at sea due to various problems. The crew of the already mentioned Meadowcroft ended up on a floating aircraft after one of the engines failed. The people were captured by a Dutch patrol boat. On the fifth day after this incident, it was reported that a large plane was drifting in the ocean. A rescue tug was sent there, which found the Bolo on the water without significant damage. The bomber on the cable reached the nearest island. Then it was washed, dried and disassembled for parts.

Five days of sailing for B-18 is not a record. One car from the 80th squadron, starting from Florida, was found on the water a week after the forced landing. She was dragged into port and lifted ashore on a slip for Pan American flying boats.

The third "Bolo", who also made an emergency landing on the water, did not "live" long after the crew was rescued. The sailors considered it a danger to shipping and fired guns at the plane.

The last B-18B sorties were made from the Panama Canal Zone in August 1943.

Photo	Description
	Drawing B-18B Bolo Douglas

Bibliography

• "Encyclopedia of military engineering" /Aerospace Publising/
• "American warplanes of World War II" /under cor. David Donald/