Base History

 Initial formation meeting:

June 1, 2008 at American Legion Post #200 in Lake Elsinore, California.

Trieste Base Plankowners are:

Mike Bircumshaw, WD6 Commander
Dave Brown
Bob Cox
Dave Eisner
Jim Hayes
Bill Jonker
Keith Newell
Kent Weekly
Mike Williamson

See June 1, 2008 minutes for more information.

No photographs exist of this meeting.


Base Charter meeting:

Trieste Base received its Certificate of Charter dated July 20th, 2008 from Western District Six Commander Mike Bircumshaw.  The base is located in Murrieta, California.  This meeting was held at Carrows Restaurant in Murrieta.


Kent Weekly was our first Base Commander

No photographs exist of this meeting.



Bathyscaphe Trieste I

Trieste was a Swiss-designed deep-diving research bathyscaphe (“deep boat”) with a crew of two people, which reached a record-breaking depth of about 10,900 meters (35,761 ft), in the deepest part of any ocean on earth, the Challenger Deep in the Mariana Trench, in 1960.  The dive has never been repeated, and presently no crewed or uncrewed craft exists capable of reaching such depth.

Bathyscaphe Trieste IDesigned by the Swiss scientist Auguste Piccard and built in Italy.  The pressure sphere, composed of two sections, was built by Acciaierie Terni, and the upper part was manufactured by Cantieri Riuniti dell’ Adriatico, Trieste; thus the name of the vessel. The installation of the sphere was done in Cantiere navale di Castellammare di Stabia, near Naples. The Trieste was finally launched in 26 August 1953 in the Mediterranean near the Isle of Capri.  The design was based on previous experience with the FNRS-2, also designed by Piccard and built in Belgium and operated by the French Navy. After several years of operation in the Mediterranean the Trieste was purchased by the U.S. Navy in 1958 for $250,000.


The Trieste consisted of a float chamber filled with gasoline for buoyancy, and a separate pressure sphere.  This configuration (dubbed a “bathyscaphe” by Piccard), allowed for a free dive, rather than the previous bathysphere designs in which a sphere was lowered to depth and raised from a ship by cable.

At the time of Project Nekton, Trieste was over 15m (50 feet) long, the majority of this was a series of floats filled with 85m (22,500 US gallons) of gasoline, and water ballast tanks at either end of the vessel as well as releasable iron ballast in two containers along the bottom, fore and aft of the crew compartment sphere.  The crew occupied the 2.16 m (6.5 ft) pressure sphere, attached to the underside of the floats and accessed from the deck of the vessel by a vertical shaft which penetrated the float and ran down to the sphere hatch.

In the Trieste the pressure sphere provided just enough room for two persons.  It provided completely independent life support, with a closed-circuit rebreather system similar to that used in modern spacecraft and spacesuits: oxygen was provided from pressure cylinders, and carbon dioxide was scrubbed from breathing air by being passed through canisters of soda-lime.  Power was provided by batteries.

Trieste was fitted with a new pressure sphere, manufactured by the Krupp Steel Works of Essen, Germany, in three finely-machined sections (an equatorial ring and two caps).  To withstand the high pressure of 1.25 metric tons per cm� (110 MPa) at the bottom of Challenger Deep, the sphere’s walls were 12.7 centimeters (5.0 in) thick (it was overdesigned to withstand considerably more than the rated pressure).  The sphere weighed 13 metric tons in air and 8 metric tons in water (giving it an average specific gravity of 13/(13-8) = 2.6 times that of sea water). The float was necessary because the sphere was dense: it was not possible to design a sphere large enough to hold a person which would withstand the necessary pressures, yet also have metal walls thin enough for the sphere to be neutrally-buoyant.  Gasoline was chosen as the float fluid because it was lighter than water, yet relatively incompressible even at extreme pressure, thus retaining its buoyant properties.


Observation of the sea outside the craft was conducted directly by eye, via a single highly-tapered cone-shaped block of Lucite (Plexiglas) plastic, the only transparent substance identified which would withstand the needed pressure, at the design hull thickness. Outside illumination for the craft was provided by quartz arc-light bulbs, which proved able to withstand the over-1000 atmosphere pressure without any modification.

Nine tons of iron pellet shot were taken on the craft as ballast, both to speed the descent and allow ascent, since the extreme pressures would not have permitted air-ballast tanks to be refilled with gas at depth. This additional weight was held actively in place at the throats of two hopper-like ballast silos by electromagnets, so that in case of an electric failure the craft would immediately rise to the surface.

Transported to the Naval Electronics Laboratory’s facility in San Diego, the craft was extensively modified and then used in a series of deep-submergence tests in the Pacific Ocean during the next few years, including a dive to the Mariana Trench, the deepest known part of the ocean, in January 1960.

Trieste departed San Diego on October 5, 1959 on the way to Guam by the freighter Santa Maria to participate in Project Nekton a series of very deep dives in the Mariana Trench.

Trieste IOn January 23, 1960, Trieste reached the ocean floor in the Challenger Deep (the deepest southern part of the Mariana Trench), carrying Jacques Piccard (son of Auguste) and Lieutenant Don Walsh, USN.  This was the first time a vessel, manned or unmanned, had reached the deepest point in the Earth’s oceans.  The onboard systems indicated a depth of 11,521 meters (37,799 ft), although this was later revised to 10,916 meters (35,814 ft), and more accurate measurements made in 1995 have found the Challenger Deep to be slightly shallower, at 10,911 meters (35,797 ft).


Jacques Piccard (son of Auguste) and Lieutenant Don Walsh, USN

The descent took 4 hours and 48 minutes before reaching the ocean floor.  After passing 9,000 meters one of the outer Plexiglas window panes cracked, shaking the entire vessel.  The two men spent barely twenty minutes at the ocean floor, eating chocolate bars to keep their strength.  The temperature in the cabin was a mere 7-C (45-F) at the time.  While on the bottom at maximum depth, Piccard and Walsh (unexpectedly) regained the ability to communicate with the surface ship, USS Wandank II (ATA-204), using a sonar/hydrophone voice communications system.  At a speed of almost a mile per second (about five times the speed of sound in air), it took about 7 seconds for a voice message to travel from the craft to the surface ship, and another 7 seconds for answers to return.

While on the bottom, Piccard and Walsh observed small soles and flounders swimming away, proving that certain vertebrate life can withstand all existing extremes of pressure in earth’s oceans. They noted that the floor of the Challenger Deep consisted of “diatomaceous ooze”.

After leaving the bottom, they undertook their ascent, which required 3 hours, 15 minutes.  Since then, no manned craft has ever returned to the Challenger Deep.  A Japanese robotic craft Kaiko reached the bottom of the Challenger Deep in 1995. This craft was lost at sea in 2003, leaving no craft in existence capable of reaching these most extreme ocean depths.

In April 1963, Trieste was modified and used in the Atlantic Ocean to search for the missing submarine USS Thresher (SSN-593). In August 1963, Trieste found the wreck off New England, 8,400 feet (2.56 km) below the surface.  The bathyscaphe was then retired and dismantled.  The Krupp pressure sphere is now on display at the Naval Historical Center, Washington D.C.

Her original Terni pressure sphere was incorporated into the Trieste II, which also conducted some dives to the Thresher site in 1964.

In 1966, the pressure sphere of the Trieste II was replaced by a new sphere designed for work at 20,000 ft depth.


Bathyscaphe Trieste II

Trieste II (DSV-1) was the successor to Trieste – the United States Navy’s first bathyscape purchased from its Swiss designers. The original Trieste design was heavily modified by the Naval Electronics Laboratory in San Diego, California and built at the Mare Island Naval Shipyard.  Trieste II incorporated the original Terni sphere, built in Italy but cast by the German, Krupp Steelworks, used in Trieste, but suspended it from an entirely new float, more seaworthy and streamlined than the original but operating on identical principles.  Completed in early 1964, Trieste II was placed on board USNS Francis X. McGraw (T-AK241) and shipped, via the Panama Canal, to Boston.

Bathyscaphe Trieste IICommanded by Lt Comdr. John B. Mooney, Jr, with co-pilot Lt. John H. Howland and Capt. Frank Andrews, Trieste II conducted dives in the vicinity of the loss site of Thresher – operations commenced by the first Trieste the year before. She recovered bits of wreckage, positively fixing the remains as that of the lost Thresher, in September 1964.


Between September 1965 and May 1966, Trieste II again underwent extensive modification and conversion at Mare Island Naval Shipyard, but there is no clear record that she was ever operated in that new configuration, i.e., the addition of skegs or outriggers on both sides of the sphere.

During that same time period work was under way on a third configuration of the bathyscape.  This work resulted in yet a new appearance for the Trieste II, and included the installation of a new pressure sphere, designed for operation to 20,000 feet.

As the bathyscaphe continued her operations as test vehicle for the deep submergence program, she qualified four officers as “hydronauts” – the beginning of a burgeoning oceanographic operation.  Trieste II’s valuable experience in deep submergence operations has helped in the design and construction of other deep-diving submersibles which could be used in rescuing crews and recovering objects from submarines in distress below levels reachable by conventional methods.

This unique craft was listed only as “equipment” in the Navy inventory until the autumn of 1969.  On 1 September 1969, Trieste II was placed in service, with the hull number X-1.  Reclassified as a deep submergence vehicle (DSV) on 1 June 1971, Trieste II (DSV-1) continued her active service in the Pacific Fleet into 1980.

The Trieste class DSV were replaced by the Alvin class DSV, as exemplified by the famous Alvin (DSV-2).  The Alvin’s were more capable, more maneuverable, less fragile, but also could not dive as deep, reaching only a maximum of 20,000 feet (for the Sea Cliff (DSV-4)).

Trieste II is now preserved as a museum ship at the Naval Undersea Museum, Keyport, Washington.


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Chartered 20 July 2008