What weapons did the US use to defend Pearl Harbor?

Answer 1

Those who defended Pearl Harbor during the attack on Dec. 7th used anything and everything they could get their hands on for weapons. Rocks, pistols even though they did not have the range to be effective, Dorie Miller manned a 50 calibur Browning anti-aircraft machine gun from the deck of the USS West Virginia. Lt Welch, Lt Taylor and others also flew P-40 airplanes defending the harbor though these two men were successful doing damage that is reported.

Answer 2

US troops defended themselves at Pearl Harbor mostly with small arms. Many fired pistols and rifles at attacking planes. There's about a one in a million chance of doing the enemy plane any damage, but its satisfying. At least one sailor did shoot down a Japanese plane with a BAR - a Browning Automatic Rifle. This was the M1918, but got into service too late to be used in WWI, but was the standard squad automatic weapon in the US infantry during WWII. .30 caliber infantry machine guns were also fired, and perhaps a few .50 caliber machine guns. The standard US Army anti-aircraft artillery was a 90MM cannon, but these were new and there were not very many in Hawaii.

The Navy ships in the harbor fought back with the anti-aircraft weapons they had mounted aboard. These were .50 caliber machine guns, 3 inch and 5 inch naval cannon. Some ships had a few four-barreled "quad" .50s. None of these turned out to be very good. Excited US gunners killed about 60 Hawaiian civilians by not giving much thought to where their cannon shells were likely to land if they missed, and shooting up homes and cars in Honolulu and Pearl City by accident. None of the navy's anti-aircraft weapons saw service for too long after Pearl Harbor. The new, long-barreled 5 inch gun just coming into service was an excellent anti-aircraft gun, especially when firing shells with proximity fuses - a tiny radar set in the nose which exploded the shell if it just came close to an enemy plane - a very top-secret US invention. Every available inch of US ships was covered with newly acquired Swiss 20MM Oerlikon machine cannon and 40MM Swedish Bofors automatic cannon within a year or two after Pearl Harbor, which were much more effective than any machine gun.

The Japanese sent about 350 planes over Oahu on December 7 and had 29 shot down - most lost in the second wave, by which time the Americans were shooting back. Many more were damaged, some had to be shoved off the Japanese carriers into the sea. At least seven of the Japanese planes shot down were lost to US fighter pilots. So ground gunners manged to shoot down around 20 out of 350, or about 3%. This is pitiful in defending against a low-level attack like the Japanese mounted. The Japanese expected much higher losses.