Vandenberg: BEHIND THE SCENES!
Later this week, the long-awaited sinking of the Vandenberg will take place in the Florida Keys. Ever wonder HOW it will take place? What explosives are being prepared? How will it be safe for divers? Mike Ainge, one of the dive supervisors shares specific details in this feature also available at SeaDuction.com
Sinking a wreck in modern America is a very complex task. All pollutants, hydrocarbons, even electrical wiring must be removed to protect the environment and there are a number of sites that will tell you all about the hundreds of hours and dozens of volunteers that have made the sinking of the Vandenberg possible.
The Vandenberg is going to be sunk inside the boundaries of the Florida Keys National Marine Sanctuary. As a result, the sinking will not include the showy pyrotechnics normally used for artificial reef projects, although the ship will sink as a result of explosive charges. Placed in two rows on the lowest deck levels, highly specialized and directed cutting charges will leave 21 holes on each side of the vessel. Most of these charges will be detonated below the water line and because of the controlled nature of the explosions they will be barely visible from the surface.
Once the charges are blown, the wreck should sink keel-first and settle upright on the bottom. To accomplish this goal, the explosive experts have developed a plan in conjunction with naval architects and computer model simulations. Not only do you have to let water into the ship, you also have to let air out and the planning includes the very complicated process of calculating the best vent locations, the best flooding locations, and of course, the appropriate explosives to do the job without excessive force. The result is a well choreographed dance, and if it comes off as planned, the Vandenberg will sit upright in 140 feet of water – in less than 2 minutes.
Once the Vandenberg is on the bottom, safety divers must clear the wreck before it can be opened to divers. This process will be completed by volunteer divers from public safety teams in South Florida and a technical dive team drawn from much of the eastern half of the U.S. The first divers on the ship will be Bob Smith and Bob Jason, both with the Monroe County Sheriff’s Office, and Seaduction.com’s senior editor, Mike Ange, who is also a former law enforcement diver and the team leader for the technical divers who will clear the interior of the wreck. As soon as the Vandenberg settles on the bottom, these three divers will enter the water to survey the wreck and check for obvious structural hazards before returning to two salvage boats located on the surface. The boats, provided courtesy of the Mel Fisher Organization in Key West, will provide the operating platforms for the public safety dive teams on the RV McGruder and the technical dive team on the RV Dare. As soon as the survey team is picked up and returned to their respective boats, the captains will position their vessels at the bow and the stern of the Vandenberg. Bob Smith will at that time become the diving control officer and Bob Jason will take charge of the public safety dive team while Mike Ange takes charge of the technical dive team. The McGruder will drop two sorties into the water. The first team of six divers will enter amidship, drop to a predestined point and move toward her stern if the prevailing currents are consistent. The McGruder will then move forward and the second team of six divers will be dropped on the bow. The second team will move from the bow to the mid-ship area. The teams will attempt to limit their bottom time to 15 minutes in order to stay within no-decompression limits, and their task is simple: They will count the number of blast holes in the ship to verify that all charges went off as planned.
In the event that the ship rolls to either side or settles too deeply into the bottom, the specialized skills of the technical clearance team will come into plan. These divers are all qualified for deep decompression diving and extensive wreck penetration. If the blast holes cannot be viewed from outside the ship, this team will have to penetrate to the lowest levels of the interior. Due to the complexity of the dives, these divers will be spending between 40 and 60 minutes at depths that may be in excess of 140 feet. Dives of this duration and at this depth will require staged decompression of 30 minutes or more before the divers can safely surface. The 20-member dive team will work in buddy pairs (with back up safety divers) checking pre-determined grids of the ship to ensure that all the explosives have detonated.
The public safety and technical teams have a number of hazards to be aware of. By the nature of the sinking, the ship’s structural integrity can be compromised. The ship’s exterior super structure, including the 80-ton radar dishes, and the ship’s numerous internal structures, can become dislodged, unstable and could possibly fall on a diver.
Additionally, any unexploded ordinance that detonated while the divers were in the water could cause serious injury to anyone even at a significant distance from the blast. So, the divers will have to tread cautiously, remaining acutely aware of their surroundings while completing their missions. In the event that all the blast holes have cleared and there are no explosive charges remaining, the technical team will remove the pre-laid guidelines from the wreck so that they do not create a hazard. They will also inspect the external superstructure, especially the dish antenna, at their weld points to ensure that segments of the wreck will not fall on the divers who will be cleared to dive her.
In the event that one or more of the charges fails to detonate, the real challenges begin. By their very nature, explosive charges which do not detonate as planned are unstable, so removing them will be by far the most hazardous part of the dive operation.
Team leaders Bob Jason and Mike Ange will then revert to lead divers backed up by four members of the technical dive team: Jim Driscoll, Bill Stone (on-line editor for Seaduction.com), Tracy Grubbs, and Red Sullivan. Jason and Ange will enter the water, go inside the ship to the location identified as having the unexploded ordinance, remove the mounting for the charges, remove the explosive material, and with the assistance of the back-up divers, bring it outside the wreck. The material will then be brought to the surface where it will be passed to a law enforcement vessel and removed from the site.
After the teams have finished their dives, and once the technical team has completed their decompression, the divers will exit the water and report to Bob Smith that the wreck is clear. This word will then be passed to the civilian authorities who will make the decision on when to open the wreck to recreational divers.