 |
|
 |
 |
 |
|
 |
|
 |
|
 |
 |
 |
 |
 |
 |
 |
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
DISPATCH 8 | 06.10.2007 | Fort Lauderdale Florida Today we all get to sleep in a little bit because instead of regular collection operations, we have visitors who are here to see what the ship and sub are all about and the capabilities of both. We are working off Fort Lauderdale and the goal of the first dive is to retrieve camera equipment and an acoustic monitoring system that were placed on the bottom about ten days ago. These have been monitoring this site which is a deep water coral reef with an abundance of fish. 
By leaving
the monitoring equipment on the bottom without human presence the scientists from the NOAA Ocean
Exploration expedition immediately prior to ours hope to better understand both the biological
diversity of the site as well as to see and hear what the fish and invertebrate populations are doing.
Our second dive of the day will be to collect additional specimens of the sponge Leiodermatium as part of our continued investigation into the compound leiodermatolide. Leiodermatolide is a potent antitumor compound that we hope may someday be used in the fight against cancer. We are also trying to better understand how leiodermatolide is made and answer the question does the sponge make it or is it an associated microorganism. Having fresh samples will help us answer these questions. Submersible Operations - Rex "Chip" Baumberger They make it look so effortless, yet the submersible launch and recovery is a highly precise, well-rehearsed symphony the crew of the R/V Seward Johnson has done thousands of times. It all happens in a 5 minute flurry of activity that makes one's head spin. The preparations for those 5 minutes take many hours. Prior to any dive, chief scientists select a potential dive site. The selection may have come from recent mapping by scientists on board, or from past work. Many of the sites were identified 50 to 100 years ago, and not revisited until now. This requires extensive mapping by the Seward Johnson, which is conducted when the ship arrives at a site's coordinates. John Reed, chief scientist and deep sea reef expert, conducts transects of the bottom utilizing the ship's 50 mhz fathometer. This machine displays the bottom depth in high resolution on an LCD monitor, which is anxiously watched by no fewer than 3 individuals until the bottom feature Reed is interested in is located. The exact location is marked utilizing the submersible locating system which records precise GPS coordinates, ship's heading and speed. A map of the feature is made, with coordinates at each change in depth. 
While this activity is going on, the sub crew is quietly preparing the
Johnson-Sea-Link II submersible,
JSL-II, for its next launch. The JSL-II runs on a huge bank of batteries which requires a 4 hour recharge
following each 3 1/2 hour dive. There are so many systems and things to check, it seems more like a fighter
jet than a submersible. The JSL-II is equipped with an array of sampling devices, essential for scientific
sampling and irreplaceable by any other underwater vehicle, be it ROV or AUV. On the end of the manipulator
arm there are three sampling devices, all suited to a different purpose and mounted together on a rotating
joint. The submersible pilot can select between all three for each sample collection. The jaw-like end is
best suited to collecting tall, branched gorgonians and sea fans. There is a suction hose with a beveled
acrylic tip which works well for sucking up encrusting sponges, and the occasional fish and other fauna.
Third is the "clam shell", a one gallon paint bucket-sized collector split in half which allows it to be
placed over an item, then closed around it. This is perfect for hard sponges which are one of the most
important types HBOI Biomedical Marine Research is looking at for cancer drugs. Each pilot has a preference
as to which manipulator attachment they use most, but all pilots are capable of using each function. More
technological innovation led to development of many systems of holding specimens, different missions require
a myriad of equipment for these tasks. Researchers at HBOI use opaque, insulated traps and containers for
light-sensitive animals, long cylinders which open at each end to capture long jellyfish, an acrylic "Bio-Box"
on the front of the submersible to house large sea fans or any other large collected specimens. The primary
system, however, is always used. Twelve acrylic buckets ride on a conveyer belt system connected to the suction
hose end, as well as accessible to the other manipulators. Pilots suck up specimens which are deposited into the
acrylic bucket, or the claw drops larger, solid organisms into the buckets. Once one is filled with a sample, the
carosel-like conveyer brings an empty bucket to the loading position. In this manner, scientists are able to
observe, collect and store an abundance of diverse specimens.
Scientists in the sub also manipulate the video camera system and take still photos with a digital camera mounted to the Bio Box. The video camera is on a manipulator arm with four powerful lights. The arm allows complete control of nearly 360 degree camera angle, allowing virtually everything observed by the crew to be photographed. Other inferior systems are limited to a fixed view of the bottom, typically far less than 360 degrees, and many cannot be manipulated in situ, such as those on AUVs. This advancing technology is still many years of development behind manned submersibles, and the JSL I has been in service since 1971, with JSL II following in the mid-seventies. 
So the efforts of the crew of the R/V Seward Johnson combine with the Sub Crew and the Scientific party
to pull off the safe launch and recovery of this wonderful tool twice a day, day in day out. We successfully
completed 17 dives in 9 days, quite amazing to a first-time submariner! The professionalism and expertise of
the sub and ship's crew during launch and recovery is absolutely amazing. The Chief Engineer operates the R/V
Seward Johnson's A-frame and winch system. The Second Engineer is also on deck to ensure no issues arise on
any of the deck equipment. Three deck hands tend lines, stainless submersible retaining clamps and straps,
and the submersible tow line all in such a flurry that they seem to be everywhere all at once. During
submersible launches Sub Pilots take turns as the standby subcrew on deck to maintain communications with the
JSL pilot. This crew chief ensures all the safety precautions are met, that the rear compartment seal is
achieved when the sub is place in the water and communicating between the Captain on the bridge of the ship
and the JSL. The Captain George Gunther ultimately gives permission to dive to the submersible. Another
topside sub crewman ensures loading of the sub is completed successfully, by loading oxygen scrubbers and
then securing the hatches, both front and rear. All of these jobs occur simultaneously, and in less than
five minutes, the sub goes from empty and tied down to the deck to full of passengers and on it's way to the bottom.
Retrieval of the sub includes the launch sequence in reverse and a series of additional steps to facilitate the
alignment of the submersible with the ship's A-frame. From the bridge where a sub crewman is monitoring the JSL
with Hydrophone and sonar, the submersible's depth and location are constantly observed throughout the dive. When
the bridge gives the sub the order to return to the surface, they track the JSL and the acting helmsman steers the
ship for the pick up. The R/V Seward Johnson is specially equipped for this task. On the ship's starboard (right)
side, another complete helm for the ship juts out onto the bridge wing. This provides the helmsman with an
unencumbered view of the sea on the ships starboard side. The submersible is always placed off the starboard
bow so the officer on deck can see it at all times to ensure the safest retrieval. When the JSL reaches 50 feet
depth, the pilot releases a large bubble from the ballast tanks which provides a visual reference to the ship.
Once on the surface, the sub pilot turns the sub to face the starboard side of the ship. As the JSL floats along
side the R/V Seward Johnson, crew and scientist alike line the rail, and one sub crewman is given the task of diver.
The diver jumps in with a heavy tow rope from the ship and attaches it to a hook at the front of the sub, allowing
the ship to haul the JSL close in to the stern of the ship, where the A-frame awaits.
This diver can be subject to large waves which refract along the ship between them and the submersible, more than once we watched them hang on to the sub while they were plunged underwater, only to reemerge, scrabbling for higher ground (the top of the sub). The most dangerous part is hooking up the large A-frame winch to the sub, which has a large, heavy locking mechanism that hooks into the top of the sub. The diver must handle this end and guide it into the receiver hole in the sub, without getting clobbered or squashed by the winch. Under rough sea-state conditions, this part looks exceptionally scary! 
Once the winch is connected, the sub is immediately winched up by Chief Erik Bergendahl, and then swung back
aboard the ship while dangling from the A-frame. Once aboard the Johnson-Sea Link is tethered back to the deck.
The unloading takes place as quickly as the loading, and then the science group scrambles to exchange the buckets
full of riches from the deep for fresh empties, ready for the next collection dive.
All of these procedures take place so that we scientists can explore new deep-sea realms, and a debt of gratitude is owed to the crewmen who make it possible, day-in and day-out, onboard the R/V Seward Johnson. 
|
|
| ||