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Surface Transportation

Ship and Pressurization Chamber
The first major consideration in designing the boat was stability. Since the research facility relies on the ship to bring supplies and transport scientists to and from the facility, efficient operations are necessary even under poor conditions. The possibility of emergency further underscores this need. As a result, the logical choice was to use a catamaran-style hull. The wider base possessed by catamarans provide more stability than a typical mono-hull. Moreover, the boat chosen is fifty-seven feet long, since a large craft is better able to survive and operate in a storm better than a smaller boat.

The next major factor is speed. Since the scientists and crew are working long hours under pressure, they need to be depressurized quickly and brought to shore for rest at the end of each mission. In addition, emergency situations may require swift transportation. As a result both of the engines selected are rated at 1,200 horsepower, giving the ship the ability to make the journey from the shore to the reef rapidly and reliably.

The speed in deploying the sub is just as important as the speed of the ship. Since supplies must be routinely transported to the facility, docking was a critical factor in the decision to use a catamaran hull. The pressurization chamber is mounted on the horizontal section that spans the distance between the two sub hulls. Below the pressurization chamber is an airlock capable of docking with the conning tower of the submersible. Thus, on the journey to the reef the submersible lies in a sheltered position between the two sub-hulls. Moreover, once pressurized, the crew can quickly move through the airlock to the vehicle. In case of an emergency the submersible can dock with the airlock and return the injured, but still pressurized, crewmembers to the hyperbaric chamber, where a large space is reserved wholly for emergency medical procedures.

Constructed of stainless steel, the hyperbaric chamber is designed to pressurize passengers and cargo to 4.5 atmospheres. The inner volume of 6 cubic meters easily accommodates 6 to 9 people, in addition to tie-up bunk beds and seats along the walls. The pressurization chamber will also contain oxygen breathing units with overboard dumping. Dynamic communication with the crew of the ship will be available. For the safety of the passengers, hyperbaric fire extinguishers and oxygen analysis stations for internal atmosphere precision control are located in the chamber. The hyperbaric chamber has two outlets, both fitted with double safety automatic valves, one at the side for entry from the ship deck and the second on the floor for docking with the submersible.

Docking
An androgynous docking system is implemented between the pressurization chamber and the submersible. The system on each side consists of a structural ring and a movable ring integrated with alignment guides, latches, hooks, dampers, and fixers. After the active ring on the conning tower comes in contact with the structural ring on the hyperbaric chamber, the system dampens out any relative motion between the support ship and the submersible. The capture ring on the ship aligns the two vehicles, after which structural hooks join the two rings and lock together the silicon pressure seals encircling the conning tower and the chamber entry. Pressure gauges are located both inside and outside the conning tower, and if the two readings are close enough, crewmembers will open a valve in the hatch and allow the pressures to equalize before entering or exiting the craft. View ports around the conning tower will aid in positioning the craft. As the system is androgynous, crewmembers will be able to initiate docking from both inside the vehicle and inside the chamber.

Since the habitat is at ambient pressure 50 meters below sea level and the submersible has already been pressurized to 4.5 atmospheres, such docking procedures between the submersible and the habitat do not take place. Instead, the pilot has to maneuver the submersible such that the conning tower rises above water level in the moon pool of the habitat. Once the pressures are equilibrated, movement between the submersible and the habitat is safe.

 

This page was last updated on 12/5/01. For questions regarding this site, email Atlantis One WebMasters.
For questions regarding the Atlantis Projects (a.k.a. Mission2005), email our professor, Kip Hodgesor visit the Mission 2005 Web Page.
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