Dam the torpedoes, full speed ahead!
That was the cry 60 years ago when Caltech teamed up with the Navy to hurriedly turn a mountain dam into a weapons test site whose remnants remain visible above Azusa -- and whose effects are still felt beneath the sea.
Scientists and sailors built a secret torpedo research station at Morris Dam. Work done there helped produce torpedoes that could be launched from fighter planes for the first time.
These days, motorists traveling up San Gabriel Canyon Road toward Angeles National Forest recreation areas are not likely to be aware that work done at the Morris Dam Naval Ordnance Test Station helped the United States win World War II, and that a half-century later it played a role in helping end the Cold War, too.
Still visible clinging to the shoreline behind the dam is an unusual 250-foot concrete ski jump-like ramp that was a launch point for thousands of unarmed torpedoes between 1943 and 1993.
One torpedo test resulted in the accidental launch of the world’s first underwater rocket -- a mishap that eventually led to development of underwater missile systems that are used by today’s sophisticated Navy submarines.
It was the menace of enemy subs operated by Germany and Japan in World War II that led to American torpedo tests at the dam’s skinny, 1 1/2-mile-long lake, located about four miles north of Azusa.
The U.S. was looking for a way for fighter planes to drop torpedoes powerful enough to blow a hole in the thick-skinned Nazi and Japanese subs. Conventional torpedoes that naval fliers tried to use were being damaged by the impact of hitting the ocean from hundreds of feet in the air.
Allied forces were losing about 20 ships a week to Nazi U-boats in the Atlantic and the Caribbean during the summer of 1942 when Caltech scientists working on military rocket designs were asked by Washington officials to help with the submarine problem.
“A lieutenant from the Navy Department came out to Caltech and wanted to know if the rockets we were working on would work underwater,” remembers Conway Snyder, who then was a Caltech graduate student involved with the rocket project. “We went up to Morris Dam to find out.”
Now an 85-year-old retired Jet Propulsion Laboratory scientist who spent 30 years working on lunar and interplanetary exploration projects, Snyder inadvertently helped invent what is now known as the intercontinental ballistic missile while in a rowboat at Morris Dam.
“If the rocket would fire underwater, the Navy was particularly interested in knowing whether it would produce bubbles that could be tracked from above,” Snyder said.
Snyder and his co-workers took a half-dozen 4 1/2-inch-diameter barrage rockets up to Morris Dam to find out. They tied an improvised pipe “firing tube” to two pieces of rope, stuck one of the artillery rockets inside and connected igniter wire to it.
“We went out to the middle of the lake in a rowboat and lowered the ‘launcher’ about four feet into the water,” said Snyder, of Redlands. When he touched the igniter wire to a battery in the rowboat, the rocket fired.
Five of the little rockets were shot off as planned at depths to 15 feet, producing the bubble trails the Navy was curious about. The sixth rocket surprised everybody in the boat, however, by shooting out of the water and through the air.
“The last one emerged from the water about 50 feet from us and shot out of the lake. It landed on the shore, luckily not starting a fire in the dry brush,” he said. “We were happy there was no fire -- we left it there and went home.”
Snyder’s accidental underwater rocket launch eventually helped trigger development of what would become the Navy’s submarine-launched Polaris ICBM -- a strategic weapon in maintaining the balance of power in the Cold War that came later. Caltech’s presence at Morris Dam increased as more sophisticated torpedo test facilities were built there. The goal of each was to determine how various styles of torpedoes reacted when they hit the water at various speeds and angles.
According to naval records, the Morris Dam tests resulted in modifications to torpedoes that “paid off for the fleet with the tremendous victories won by Navy aviators at the Battle of Leyte Gulf in October, 1944" who sunk 60 enemy ships.
Isolated but relatively close to Caltech’s Pasadena campus, the 160-foot-deep reservoir was perfect for the research. Morris Dam had been built in 1934 by Pasadena officials to eventually hold water that was planned to be piped from the Colorado River by the Los Angeles area’s Metropolitan Water District.
The 245-foot concrete dam was named after Samuel B. Morris, who headed Pasadena’s Water Department. Former President Herbert Hoover attended its dedication, offering the prescient observation that it “represents the fine flowering of the American system of liberty.”
For the testing, a 150-foot tower was constructed atop the dam. It was part of what engineers called the “slingshot,” a device that sent torpedoes flying 200 feet along a cable into the lake.
The heart of the test site was the ski jump-like structure about a quarter mile north of the dam, however. The $3-million “variable angle launcher” boasted a 300-foot-long welded-steel frame that could be moved to change the direction that torpedoes were fired into the water.
The 500-ton framework was equipped with blowgun tubes 22 1/2 and 32 1/2 inches wide that used compressed air to shoot torpedoes into the lake at speeds of up to 680 mph. A counterweight on the opposite side of the spit of land that the launcher was built on could roll the frame up and down the ramp so the torpedo angle could be adjusted from 5 to 38 degrees.
A network of cameras mounted on the shoreline -- on cables above the water and in housings beneath the water -- recorded the tests on film. An array of underwater hydrophones also plotted the torpedoes’ trajectory by sound.
None of the torpedoes carried explosives. But there were mishaps -- such as the time a torpedo bounced along the lake surface instead of going underwater. It shot over the top of Morris Dam at about 600 mph and disappeared down the canyon. It was recovered. But dozens of the underwater missiles disappeared after sinking into mud at the bottom of the lake.
“We found a whole bunch of torpedoes when we cleaned out the reservoir in the mid-'90s. We called the Navy to come take it away. We’ll probably find more the next time we clean it out,” said Leopoldo Herrera, a water resources engineer for the Los Angeles County Department of Public Works. The county took over the dam from the Metropolitan Water District in 1995.
The $10-million worth of towers, steel framework and other equipment, along with a few barrels of lead-contaminated soil, were removed in the early 1990s after the Navy ended its Morris Dam operations. These days the lake stores water that is carefully released into downstream percolating basins to replenish San Gabriel Valley groundwater supplies.
Because of the steepness of the canyon, the lake is not used for recreation. But the dam and reservoir that for so many years was a military secret is visible to those who want to pay for a $5 Forest Service Adventure Pass that allows visitors to park their car for a look.
There are some who would like to torpedo the controversial forest-access fee requirement. But that’s something not likely to be tested at Morris Dam.