Map of Hawaii
Figure 4: Map of the Hawaiian Islands. The DUMAND detector matrix is located about 30 km west of Keahole Point, the most western tip of the "Big Island" (Hawaii), at a depth of 4800 m.
Figure 5: Artist's conception of the DUMAND II installations on land and on the ocean floor. The airport near the shore station is served several times daily from Honolulu on Oahu.
The subsequent figures show important subsystems and components of the detector matrix (figs. 6 to 10).
Figure 6:
Optical detector module. The highly sensitive "electronic eye", a 15
inch photomultiplier with its complex electronics on the
printed circuit board, clearly visible in the upper half of the picture,
is enclosed by two exactly matching one half inch thick pressure
resistant glass hemispheres. They can withstand pressures in excess of
700 atmospheres, corresponding to a water depth of 7 km.
The photomultiplier is optically coupled to the lower glass sphere by a
silicone compound to prevent light from being reflected before reaching
the photocathode, the multiplier's "retina". The coarse wire mesh serves
as shield against the Earth's magnetic field.
Two pressure resistant penetrators through the upper hemisphere
provide the essential links to the outside world.
The electrical penetrator carries the 48 volts dc to power the unit and
provides the two-way communication link necessary to operate the module
interactively. The other, an optical fiber penetrator, carries the
scientific data recorded by the module.
Figure 7: Manufacturing of the optical detector modules at Tohoku University in Sendai, Japan.
Figure 8: The string controller, the "brain" of each string, removed from its pressure housing. From left to right: Power converters, two-way communication with the modules, computer systems, 1 GHz digitizer system, 1 GHz two-way communication with the shore station, wavelength multiplexer / demultiplexer and optronic receivers for module data. The "porcupine" (figure 9) will be attached on the right.
Figure 9: The "porcupine", a titanium housing with a 1 inch wall thickness with its roughly 60 high pressure penetrators and connectors for the optical fibers (red) and electrical connections (black) between shore station, string controller and modules.
Figure 10: Assembling of a string at the University of Hawaii at Manoa. The overall length including all support and auxiliary units measures 415 meters. The modules will be inserted into the titanium frames, clearly visible, that are attached on two sides along the riser cables. These consist of kevlar strength members and hold the optical fibers and electrical wires.
The next set of figures shows the preparations for the execution of Phase I of the DUMAND II Octagon installation (figures 11 to 14), portions of the actual deployment of the first string, the junction box and of the cable laying operation to the shore station (figures 15 to 23).
Figure 11: The oceanographic research vessel T.G. Thompson in Snug Harbor, Honolulu, during its preparation for the deployment and cable laying operation.
Figure 12: Cable container on deck of the T.G. Thompson. It holds the 36 km long and 55 ton heavy electro-optical cable that links the junction box to the shore station. The cable has 12 single mode optical fibers at its center, surrounded by the power carrying copper mantle, an electrical insulation and a torque compensating double helix (left and right handed) steel armor. To avoid torque accumulation while passing through the winch the cable is stored in multiple figure-8 loops.
Figure 13: The research vessel T.G. Thompson shown approximately 30 km west of Keahole Point, Hawaii, where the DUMAND shore station is located, at the position where the junction box will be put in place at a depth of almost 5 km.
Figure 14: Preparations on deck of the T.G. Thompson for the deployment operation. On the left the 35 ton cable winch with its ten foot drums, on the right a white container for storing a string, and in between the titanium framework of the junction box. It has on either side 6 combined electro-optical connectors for the strings, and a separate interactive control and data transmission system for the sonar and television systems of the array.
Figure 15: Start of the deployment of string one. The circular bodies, barely identifiable, are floatation units and hold among other devices a radio transmitter and xenon flashers that remain deactivated under water pressure, but are activated automatically upon returning to the surface. They serve to help find a string surfacing after having been released from the array on command from the shore station, or by a sonar code from a ship, for recovery and servicing. A string requires about 60 minutes to reach the surface after release.
Figure 16: Deployment of a sensor module from the stern of the vessel. On the left the junction box in vertical position.
Figure 17: Detailed view of the deployment of an optical module.
Figure 18: Deployment of a laser calibration module. A downward directed pulsed ultraviolet laser beam hits the soap bubble like scintillation ball, barely visible, about 1 meter below the module, in the center just above the spacer bar between the two riser cables. A well defined blue light flash is produced.
Figure 19: Preparing the string controller, which is located in the center of each string, for deployment. Clearly visible in front of the controller housing is the next module that follows about 4 meters above the controller on the string.
Figure 20: Deployment of the junction box (2500 kg). It holds its own controller and data communications system for the precision sonar and two video cameras. The latter are located 10 meters above the junction box and equipped with floodlights. They have remote tilt and pan control.
Figure 21: Deployment of the junction box. On the left the attached electro-optical cable with the first cable splice that can easily be recognized. The entire cable consists of four 9 km long sections. It supports the full weight that reaches about 16 tons just before touching ground.
Figure 22: Cable layout to shore. The cable is temporarily kept afloat by small buoy to facilitate its transport through the underwater pipe that protects it from the surf and takes it into the building.
Figure 23: The DUMAND shore station (center) on the beach at Keahole Point, the most western tip of the Big Island (Hawaii). It is located on the site of the Natural Energy Laboratory of Hawaii (NELH). In the future the array can be remotely operated via computer network from the University of Hawaii in Honolulu on Oahu and, in principle, by any of the collaborating universities.
In addition we show a picture of the manned deep dive submarine "Sea Cliff" at its base in San Diego, CA (figure 24), and a view of the junction box at the DUMAND site on the ocean floor at a depth of 4800 m, taken with the video camera that is mounted above it (figure 25).
Figure 24: The U.S. Navy's Sea Cliff, a manned autonomous deep dive submarine with two manipulator arms. It requires a crew of two and can take one observer. We have used Sea Cliff successfully in 1992 in a dummy deployment operation at the DUMAND site at a depth of almost 5000 m. We plan to use this system or the remotely operated robot ATV (Advanced Tethered Vehicle) to connect the strings to the junction box.
Figure 25: Junction box after deployment at the DUMAND site, approximately 30 km west of Keahole Point (Hawaii) at a depth of 4800 m. Its measures are: length 104 in (2.65 m), width 68 in (1.75 m), height 49 in (1.25 m). The picture was taken with one of the two video cameras that are located 10 meters above the junction box on the center string. Floodlights coupled with the camera illuminate the scene.
DUMAND Installation
Optical Detector Module
Module Production
String Controller 
Porcupine
String Assembly
T.G. Thompson (TGT)
Cable Container
TGT During Deployment
Winch+Junction Box
String Flotation Units
Optical Module (OM)
OM Deployment
Calibration Module
String Controller
Junction Box (JB)
J-Box Deployment
Cable to Shore
Shore Station
Submarine 
J-Box on Seafloor