1/4 scale submersibles
Walt Conti was commissioned to develop and construct 1/4 (quarter) scale working miniatures of Flat Top and Cab 1 for the chase sequence.
Jim Cameron wanted the submersibles to be able to move at about 4 knots and sustain damage through various collisions between themselves and rock walls. The Model construction was supervised by Rick Anderson and they were built very strongly to survive the action called for in the script as well as the pressure exerted by up to 50 feet (15m) of water. The hulls were cast from 1/4 inch (6mm) thick fiberglass. The various tube frame components were made out of thin walled copper tubing which is strong but could dent realistically when hit. The models ended up weighing around 450 pounds (240kg) and had to be moved around with a crane. In order to move such heavy models at the speed required and the fact that the designs were not particularly hydrodynamic in shape, meant that very a powerful propulsion system had to be developed. It was calculated that to get the models to do the 4 knot specification they would need 14 horsepower in a very small package to match the full size submersible thrusters. In the end they had to re-engineer 2 hp electric trolling motors to produce 150 pounds (68kg) thrust each. These motors needed a lot of power and had their own set of batteries which allowed for around 10 minutes at full thrust. Originally they calculated they would need about 1000 footcandles of miniature lighting but more and more lights kept being added to the fullsize submersibles which they had to match. In the end they needed to 3000 footcandles of miniature lighting. This ate into the storage capacity of the 120 pounds (54kg) of Nicad batteries onboard and meant that they had about 6 minutes of lighting power before a battery change. This meant that the lights were only switched on for the take and battery changes needed the models to be craned out of the tank and took about 20 minutes.
|Ron Cobb's Flat bed design.
They cockpits also contained 1/4 scale puppets with radio controlled head turns.
It was decided that the radio controlled vehicles would be better operated underwater and so developed an waterproof RC controller system to go with the models. The under water set they traveled across was about 80 feet (24.3m) long and 40 feet wide. As the visibility was only about 15 feet (4.6m) and the lighting came predominantly from the models themselves they could easily move around rock set pieces to produce a new area of sea bed for each shot. The camera was run somewhere between 72 and 96 frames per second. After 6 weeks of underwater photography at Gaffney only 10 useable shots had been gathered.
|Walt Conti and the 1/4 scale Flat top submersible.
Some months later the crew re-convened at the University of Southern California's swimming stadium to continue the chase sequence. 90 gallons (340 litres) of blue food colouring was added to the water as well as the sea floor set pieces. Over four 16 hour nights of filming the remaining shots were captured. Also shot at this location was the implosion of the wrecked Flat top submersible as it plummets into the abyss. Jim Camerons brother Mike supervised a special breakaway 1/4 scale model constructed over a thin walled glass vessel. The Glass container was wrapped in tightly wound Bungee cord which when the squibs detonated shattering the glass, helped pull everything inward. Inside the glass dome was a miniature gelatin Coffey cast around a 1/4 scale plastic skeleton. The cockpit had many details made from thin lead. The pool was only 17 feet deep (5m) so the bottom was blacked out and there was a lot of particulate to drop the visibility off. The model had a cable running down to a pulley which imparted the dropping action. The first attempt failed when the squibs got wet and only partially exploded ruining the model, so a second model was rigged with waterproofed squibs and imploded successfully.
|1/4 scale Coffey figure.
Cab 3 Launch 1/4 scale
The Skotak brothers also supervised a shot of Cab 3 launching through the Benthic Explorer's well deck using a varaiation of the "hanging" miniature technique. Pat McClung converted the Conti 1/4 scale Cab 1 to Cab 3 while his brother Jerry constructed a section of the well deck on top of the tank at the San pedro Harbour Star facility. On the floor of the building was painted a full size representation of the deck. 7 actors pretended to look down through the well which was in fact above them at 1/4 fullsize. As a high camera speed was required for the model splashdown but a normal 24 frames per second for the actors the two parts were filmed consecutively with the miniature first. The floor area where the live action took place was blacked out while the miniature was shot, then the film was rewound to the start with the model area blacked out and the actors shot. The timing was figured out so that the actions of each would coincide accurately. No optical post production was needed to combine the parts, it was all done in the camera. With the aperture of the lens stopped down with adequate lighting, the depth of field was at its greatest and the foreground model much closer to the camera was as sharp as the more distant actors thus maintaining the illusion. Even though both parts were shot separately, the focus must be locked off for both parts, as the image can change in size as the focus is racked and the matte and counter matte would not fit correctly.
|First pass, the model shot high speed, floor blacked out.
|Second pass, live action at normal speed, model area blacked out.
NTI Ark Spires
Two large scale fiberglass sections of the NTI Ark's spires and an arc surface section were constructed by Design Setters. One part was just the very top of the spire to get a shot of it breaking the surface. This model was 10 feet (3m) wide and 7 feet (2.1m) high, the other was a full length spire at a smaller scale, 20 feet (6m) tall used to show the tower rising up. The Ark rising sequence was shot at the Salton Sea, a once very large saline lake in the Californian desert. Currently the lake is in danger ecologically and has diminished quite markedly from that in 1989. There is an ongoing campaign to try and save it from further degradation.
The sequence using the spires and the large scale section with the Albany and Benthic Explorer (see part 1) was supervised by Gene Warren's Fantasy II Film Effects. The spires were mounted on a lift mechanism that sat on the floor of the lake. The lake is quite shallow and very gently sloped so that they had to set up their equipment at about 500 feet (152m) from the shore to get the 12 feet (3.7m) of depth needed. The elevation system used cable and pulley system that ran back to an air air winch. Some difficulty was encountered with suction so sometimes a crane was used to assist with the lift. The spire top was shot at 128 frames per second with the rising full length tower at between 240 and 275 frames per second. Wind machines helped to blast the falling water and break it into spray.
A teardrop section of surface was constructed 20 feet by 30 feet, in 9 pieces at Fantasy II's shop for transportation to the lake. The colour scheme was meant to suggest the colours of an abalone shell.
NTI Arc complete smaller scale surface shots
In their carpark, Fantasy II built a shallow tank 35 feet (10.6) at the front increasing to 40 feet (12.2m) at the back and only 4 inches (100mm) deep except for a deeper well right in the center. Into this tank went a 17 foot (5.2m) diameter disk shaped arc complete with spires upon which sat small replicas of the Benthic Explorer, Albany, Deepcore and other assorted warship models.
The arc was constructed by Dave Goldberg and crew by first sculpting one quarter of it in clay. A mold was made and four identical pieces cast and arranged to make the whole circular shape.
|One quarter section maquette of the arc with mirrors to create a complete disk.
Colouring was added to the water and fans placed around the perimeter to produce the texture of ocean waves. There were over 200 tubes pumping out a mixture of vinegar and baking soda to produce miniature foam around the circumference of the arc. The arc disk was pushed up to the surface from its cavity by hydraulics in about a second. The camera shot at 300 frames per second which then had each frame effectively doubled on an optical printer to make it appear shot at 600 frames per second.
NTI Arc underwater shots
A second 17 foot arc pulled from the same mold ( but only half as that was all that is visible) was cast from translucent resin to allow for backlighting. The glowing coloured lights were fibre optics lit by lasers and designed by Gary Platek. This and other larger scale spires and tunnel pieces were shot motion control in a smoke filled environment at Dreamquest, supervised by Hoyt Yeatman.
Part 4 will cover some other miscellaneous models used in the film.
Part 1 is here, Part 2 is here, Part 4 is here and Part 5 is here.