Key point: These ships helped hunt down surfaced Nazi subs. This is how they did it.
When the United States entered World War I in April 1917, the nation’s Navy was shockingly short of combat ships—particularly the submarine chasers that would be vital to combating the German U-boat menace. A prodigious ship-building program was hastily implemented, but because of heavy demands on the country’s steel industry for destroyers, cruisers, and battleships, the only material left available for submarine chasers was wood. Small, privately owned shipyards soon received contracts to build wooden submarine chasers. The design approved by the Navy Department called for a sturdy vessel with an overall length of 110 feet, a displacement of 85 tons, and a maximum speed of 18 knots.
The new subchasers, nicknamed 110s in honor of their length, were originally armed with two 3-inch cannons and a couple of machine guns. The objective was to provide heavy firepower against enemy submarines running on the surface. In practice, however, the original design proved faulty. Whenever a U-boat was sighted, it would immediately submerge, leaving the chasers vulnerable to an underwater attack. Subsequently, a Y-shaped depth charge thrower was substituted for one of the ship’s 3-inch guns. Prior to the development of the Y-gun, depth charges were simply dropped off the stern of a subchaser. The ship then would race away at top speed, putting as much distance as possible between it and the underwater blast. Occasionally, the depth charge would explode prematurely, shaking up the subchaser much more than the submarine. The Y-gun was a marked improvement over the drop-and-run method of fighting U-boats. It permitted two depth charges to be shot from a ship at the same time. Both canisters would plunge into the sea at a safe distance from the attacking vessel, thereby lessening the danger to surface ships.
The Wooden Warships Soon Prove Their Worth
As the Navy’s new submarine chasers began to come onto line, they were formed into units of three ships each. The small wooden vessels were looked upon with disdain by sailors on steel warships, who dubbed the new chaser force the “splinter fleet.” It would not take long, however, for the sub chasers to prove their worth—to enemies as well as friends.
In late May 1918, four units of Submarine Chaser Detachment Two, equipped with hydrophones, radios, and Y-guns, sailed for Europe. Crossing the ocean in the small ships was a battle in itself. Atlantic gales and high seas often caused the vessels’ wooden seams to open and flooded their engine rooms. Clothing and bed sheets were used to plug the leaks, and disabled chasers had to be towed. Upon arrival in Queenstown, Ireland, the submarine chasers were immediately put to work escorting convoys and dashing after sighted U-boats. In his memoirs, Cary Johnston, a radio operator aboard SC-129, recalled a few of the problems encountered while serving with the splinter fleet. “After a few weeks of the same rations—bully beef and hardtack—the very thought of the next meal turned one’s stomach,” he recalled. “Then there was the continuous heaving and rolling of the ship. Even a light breeze tossed us about. But, as if that was not enough, the windblown ocean salt spray—combined with the engine exhaust gasses—kept the crew in a constant state of nausea.”
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Conditions "Ideal for Hunting U-Boats"
In the mid June of 1918, Submarine Chaser Detachment Two, under the command of Captain Charles P. Nelson, sailed from the British Isles toward the Adriatic Sea. Throughout the war, the Adriatic had been a hornet’s nest of activity for German and Austrian submarine forces. U-boat sorties were routinely dispatched from Cattaro, Pola, and Durrazo through the Otranto Strait to prey on Allied shipping in the Mediterranean Sea. In early 1916, an attempt was made to stop such attacks. A so-called barrage, or net barrier, was stretched across the 40-mile strait. The barrage was maintained by 120 net trawlers and 30 motor launches, each armed with depth charges to be dropped on any U-boat that became trapped in the nets. Stopping the submarines as they attempted to run through the barrage, however, was like trying to stamp out an ant colony one ant at a time, and in the spring of 1917 an Austrian sortie managed to sink 14 of the trawlers and drive off the rest. Subsequently, the barrage was left untended at night, leaving the strait unguarded. Allied shipping losses soon increased alarmingly.
As Nelson’s fleet approached Gibraltar, a British aircraft reported sighting two German submarines lying in wait for the Allied convoy. The warplane managed to chase off one of the U-boats, and SC-129 pursued the other for several miles before losing contact. Despite the scare, the submarine chasers safely entered the Adriatic Sea and anchored in the harbor at Corfu Island. Charles Scott, a civilian engineer for the General Electric Company who made the journey aboard SC-129, described the situation when the chasers arrived on the scene. “Conditions in the Adriatic were ideal for hunting U-boats,” he said. “The sea was very deep, with depths ranging from 2,500 to 3,600 feet. Commercial traffic was light, and the sound man had only a small amount of extra noise to contend with.”
Occasional Breaks in the Monotony
German U-boats usually waited for bad weather to attempt to sneak through the mine barrier into the Mediterranean. But even under the worst atmospheric conditions, the submarines were often detected. Cary Johnston remembered: “While on barrage duty, we were continually in sound contact with U-boats—especially when they attempted to traverse the Otranto Strait at night. Upon leaving their base, the enemy subs would run on the surface at top speed, and could be heard for more than an hour before they reached the nets. The difference between the sound of a U-boat’s engine and its batteries, was so distinctive that it was comparatively easy to tell when a submarine submerged and switched to its battery motors. But the Germans knew approximately where our ships were located, and invariably dived before they reached the barrage.”
Searching the Adriatic for enemy U-boats was a monotonous job, but there were occasional breaks in the dreary routine. One morning at the Mediterranean entrance to the Adriatic, an enemy submarine was reported caught in the nets. A nearby trawler dropped depth charges, then backed away to check the results. Suddenly the ship’s hydrophone operator heard a heavy object brush against the sound detector. Moments later, a dripping-wet German sailor climbed over the side of the trawler. The man had evidently been blown clear of the U-boat by the force of the exploding depth charge, and had saved himself by grapping the hydrophone cable and pulling himself to the surface.
On another morning, SC-129 was patrolling the barrage when she picked up the sound of a submerged U-boat at a distance of 200 yards. The American vessel laid out a pattern of depth charges to cover all possible escape routes by the sub, then cut her own engine and listened. After a 20-minute wait, the Americans picked up a squeaking sound—the sub’s propellers had been bent. More depth charges were dropped, and subsequent sounds indicated that the Germans were attempting to repair their craft. Then there was dead silence, followed by a series of 25 pistol shots. The U-boat crew, realizing that they could not escape, had decided to take their own lives.
Preparing for the Land Attack Against Bulgaria
In the late summer of 1918, the Allies planned a land attack against Bulgaria. It was considered essential to the campaign that the port of Durazzo be destroyed. On September 28, Captain Kelly prepared his subchasers to screen and protect an Allied task force during its bombardment of Durazzo. The mission’s objective was to destroy enemy shipping, warehouses, and dock facilities. Beside’s Nelson’s flotilla, the Allied fleet consisted of the Italian armored cruisers San Giorgio, Pisa, and San Marco, British cruisers Lowestoft, Dartmouth, and Weymouth, and several destroyers and torpedo boats. According to intelligence reports, two enemy destroyers, a torpedo boat, and a few submarines were sheltered in Durazzo Harbor.
Just before dawn on October 1, Submarine Chaser Detachment Two hurriedly sailed from Corfu Island to Brindisi. The rest of the day was spent stacking ammunition, cleaning guns, and writing letters home. The next day before dawn, 11 of the detachment’s subchasers steamed out of Brindisi, passed through the barrage, and entered the Adriatic. The bombardment fleet followed some distance behind.
At 10 am, as the enemy coastline and harbor came into few, Nelson ordered all ships to general quarters. Mattresses were quickly rigged as splinter mats around the bridge and charthouse to protect against flying wooden fragments, and sand was scattered across the decks to prevent the gun crews from slipping on blood. Johnston recalled the Allied approach: “We headed into the bay—then made a high-speed circle in an effort to lure enemy warships out from the harbor. Meanwhile, Austrian coastal batteries were busy shooting at us. It seemed as if we were being used for target practice. Although their shells were high and off the mark, the missiles flew overhead with a wicked shriek and a menacing ricochet when they hit the water. I was so frightened that I had difficulty remembering the radio code.”