|
|
AUV Gulf Recon 2011
-
2011
-
Sentry
|
|
|
|
Project Title: |
AUV Reconnaissance Survey II of Hard-Ground Megafaunal Communities in the Vicinity of the Deepwater Horizon Spill Site |
Project Status: |
Submitted |
|
Principal Investigator: |
Timothy M. Shank, WHOI |
Project Institution: |
WHOI |
|
Project ID: |
102923 |
Version #: |
2 |
|
Date Submitted: |
3/31/2011 12:00:00 PM |
Created By: |
Timothy M. Shank |
|
Date Last Modified: |
6/9/2011 2:51:00 PM |
URI Serial #: |
None |
|
Funding Agencies: |
INST - NONE - Funded
NOAA - NONE - Funded |
|
Summary of Field Work: |
This natural resource damage assessment (NRDA) sampling plan describes cruise-based investigation of potential hard substrate benthic sites in the vicinity of MC 252 that, based on currently available data and NOAA models, are projected to have been potentially exposed to oil, dispersants, or indirect adverse ecological effects attributable to the the MC 252 oil spill. Target sites have the potential to harbor megafauna communities (principally deep-sea coral or chemosynthetic seep communities). Members of the Deepwater Benthic Communities Technical Working Group (TWG) reviewed and selected initial sites, and will review and select additional sites to be surveyed. An approximately 28-day cruise with 24 days of on-station work will take place, over two legs, utilizing the autonomous underwater vehicle (AUV) Sentry as the primary tool, supplemented with the deep-sea digital camera system TowCam, to survey predicted hard-ground areas and obtain visual determination of the presence of megafaunal communities. Surveys will consist of initial high definition bathymetric mapping surveys, with subsequent photo surveys of areas with potential megafauna communities to be conducted in closer proximity to the sea floor. Identifying the existence and location of these communities will guide subsequent follow-up assessment of these communities with remotely operated vehicle (ROV) for purposes of injury determination, as necessary. |
|
Summary of Facility Requirements: |
AUV Sentry (and TowCam imaging system) on capable ship |
|
Summary of other requirements and comments: |
The AUV Sentry is specifically designed to operate from a ship of opportunity and to be as flexible as possible in the ships it operates from. Despite the emphasis on portability and flexibility, significant care is still required in ship selection to ensure safe and effective operations.
The basic requirements involve space, crane, and access to the water. Space is required for a 20ft shipping container, the sentry cradle, and several pieces of deck cargo. Lab space of at least 30 linear feet of bench is required. A crane capable of dealing with 3500lb static loads and 4500 – 5000lb dynamic loads at a distance of 20+ ft from the side of the ship is required. Our launch and recovery methodology has been devised for a safe and effective means of putting sentry in the water and recovering it later but different ship layouts and capabilities require that adaptation to a specific vessel is often required. This generally dictates a low freeboard in at least one place on the side of the vessel as far from the props as possible. Roll stabilization is helpful as it increases the operable weather window.
Beyond the physical requirements that the ship be able to accommodate the equipment, it is also necessary that the crew be experienced in launch and recovery of delicate equipment such as AUV’s moorings, buoys, or gliders. The ability to lay a ship alongside a floating object and stand off from that object at a desired distance during deck operations despite currents, waves, or winds is critical. A skilled crane operator used to dealing with minimally arrested loads on long booms while at sea is critical to safe operation of the vehicle. Both hand and powered tag lines are used as much as possible, but are not fool proof.
We require information from the vessel’s data system to support the real time navigation of the vehicle. Data items needed include vessel position from the shipboard GPS receiver and the vessel heading from the ship’s gyro. Note that the vessel direction of travel provided by GPS is not a substitute for the vessel gyro heading.
GPS
The GPS data should be furnished as an RS232 NMEA serial string on a conventional serial line. We use the GPGGA string, and the minutes field should have at least 4 decimal places. NMEA convention is for 4800 baud, we can accommodate any baud rate.
Gyro
We use the HEHDT or GPHDT strings for the ships gyro. These provide the vessel’s true heading independent of the direction of travel. Note that strings like GPVTG, which provide the vessel track made good, are not suitable for this purpose. The data must come from a heading reference such as an INS or gyro not the GPS alone. As for the GPS, we can accommodate any baud rate. The data can come in on a separate serial line or it can come on the same line as the GPS data.
We can accommodate either DB25 or DB9 connectors of either gender. If you use other connectors (RJ-45, etc) please provide us with adapters for DB9 or DB25.
We can deal with other formats if they are properly documented and we get some prior notice. We suggest that these lines be tested with a simple ascii terminal program (hyperterm for example) before we arrive.
USBL/LBL (Navigation)
Sentry Utilizes an Ultra Short Base Line (USBL) or a Long Base Line system for subsea navigation. From a ships perspective, the primary requirements for USBL are a GPS feed, and the ability to place a transducer in the water in a repeatable location that is un-shadowed by the hull in all directions. Over the years we have used a number of options for mounting this transducer, but the most common is a swinging pole (see drawing) that is lowered by a ships crane during operations and can be pulled up during transits. The LBL system requires what are essentially standard mooring operations and do not require installing permanent infrastructure on the ship.
If the ship has a transducer well with a carriage or mechanism that the USBL & LBL transducers can be mounted on then the installation and the operation of the navigation system is much easier and less of a burden for the ship.
TowCam:
MISO TowCam Shipboard Requirements
1) A-FRAME AND OVER-BOARDING MID-SHIP LOCATION
TowCam requires an over-boarding capability on the vessel the permits launch/recovery of the TowCam frame and towing operations. Usually this is provided via an A-frame with sufficient lift capability and side-load capability to meet normal launch/recovery and towing operations at speeds < 1 kt. What is normally available on all UNOLS vessels is sufficient.
A-frame must provide at least 10 ft of reach over the side of the ship.
A-frame sheave must be at least 25 ft above the deck level to permit sufficient lift capability to clear side rails of the ship.
TowCam weighs ~1300 pounds in air and ~800 pounds in seawater
Sheave dimensions must be matched to the UNOLS standard 0.322" 3-conductor seacable that is normally used for CTD operations.
2) CTD CABLE AND DEEP-SEA WINCH AND CONTROLS
A UNOLS-standard deep-sea winch in good operating condition with properly adjusted level-wind is essential for safe/efficient TowCam operations. For reference, the following is a standard description of a UNOLS CTD winch and a photo is provided. The winch cable fair-leading must be matched to the over-boarding location and sheave placement.
Model: Markey DESH-5
Power: Electric, AC-SCR/DC, 75 HP
Rated Line Pull: 7,000 lbs. mid-scope
Average Working Speed: 80 m/min
Wire capacity: 10,000 m of .322" E-M cable
Controls: CTD winch controls both on deck and remote in the lab are required as TowCam operators need to fly the system from a controlled/indoor space in order to monitor depth and altitude above bottom on a second/by/second basis. On deck controls are needed for safe/efficient launch/recovery of the system.
3) DECK SPACE
The TowCam has a footprint of approximately 12 ft x 5 ft x 4 ft tall. The A-frame must have at least 2-3 times this area beneath it to permit sufficient space for safe launch/recovery operations.
4) LABORATORY SPACE
One bench 15 ft long, desk height, in a laboratory space on the main deck level is sufficient to service and maintain TowCam during a cruise.
The CTD deck cable must be delivered from the CTD winch slip rings into a lab space that also has a display of bottom depth and ship's navigation on computer monitors that are readily visible to the operator.
The interior, lab-based CTD winch controls must be co-located at the same location as the CTD deck cable as that is where TowCam will be 'flown'.
Winch tension and wire-out readouts must also be provided at the location of the interior winch controls.
5) ELECTRICAL SUPPLY
TowCam requires 110VAC current at 20 amps of clean, regulated power to power the battery chargers and computers needed for operations.
6) NAVIGATION
USBL navigation is preferred- a USBL beacon is required. If LBL navigation is used a relay transponder is required.
7) DYNAMIC POSITIONING FOR SHIP
The ship must have DP for controlled low speed traverses at 1/4 to 1/2 kt in wind up to 20-25 kts and seas to ~8 ft.
8) LAUNCH/RECOVERY AND SECURING TO DECK WHEN NOT IN USE
The A-frame and winch are used to launch/recover TowCam. Deck cleats are required to assist with launch/recovery tag lines as well as to secure the system to the deck when not deployed. |
|
|
Type of Request: |
Primary Ship Use |
Request Status: |
Submitted |
|
Request ID: |
1004538 |
Created By: |
Timothy M. Shank |
|
Date Last Modified: |
6/9/2011 2:51:00 PM |
Date Submitted: |
3/31/2011 12:00:00 PM |
|
|
Year: |
2011
|
Ship/Facility: |
Sentry
|
|
Optimum Start Date:
|
4/20/2011 |
Dates to Avoid: |
The AUV Sentry is available between April 20- May 22, 2011. The vehicle MUST have completed any operations and be mobilized by May 22nd for shipment back to WHOI. Therefore, any date after May 22nd must be avoided. |
|
|
|
|
|
|
Earliest Start Date: |
4/20/2011 |
Multi-Ship Op: |
No |
|
Latest Start Date: |
4/24/2011 |
Other Ship(s): |
|
|
|
Operating Days Needed: |
Science Days |
Mob Days |
De-Mob Days |
Estimated Transit Days |
Total Days |
|
24 |
4 |
2 |
4 |
34 |
Repeating Cruise?
(within same year) |
No |
Interval: |
|
# of Cruises: |
|
|
|
Description of Repeating cruise requirements: |
|
Justification/Explanation for ship choice, dates,
conflicts, number of days & multi-ship operations: |
|
|
Short Description of Op Area
for use in schedules: |
East Gulf ofMex |
| Description of Op Area: |
Area to be surveyed is an area between a 5 and 15 mile radius around the DeepWater Horizon Site (lease block MC252) |
| Op Area Size/Dia.: |
|
|
|
| |
Lat/Long |
Marsden Grid |
Navy Op Area |
|
Beginning
|
|
|
|
|
Ending
|
|
|
|
|
|
|
Foreign Clearance Required? |
No |
Coastal States:
|
 Important Info on Foreign Research Clearances
|
|
Are you or any member in your science party bringing in any science equipment items which are regulated for export by the International Traffic in Arms Regulations (ITAR) and/or the Export Administration Regulations (EAR)?
|
No |
If yes, have you applied for the necessary permits through your export control office?
|
No |
| Questions about ITAR/EAR regulations?
|
Comments about foreign clearance requirements or
description of any other special permitting requirements
(e.g., MMPA, ESA, IHA, Marine Sanctuaries, etc.) |
|
|
|
Requested Start Port |
Intermediate Port(s) |
Requested End Port |
|
None |
None |
None |
Explanation/justification for requested
ports and dates of intermediate stops
or to list additional port stops |
Port Fourchon, Louisiana |
Important Info on Working in Foreign Ports
|
|
|
|
Chief Scientist: |
Timothy M. Shank, WHOI |
|
# in Science Party |
20 |
# of different science teams |
3 |
# Marine Technicians to be
provided by ship operator:
(include in science party total)
|
1 |
|
Explanation of Science Party Requirements and Technician Requirements |
|
|
 Dynamic Positioning |  ADCP | Multibeam | Seismic |
| Dredging/Coring/Large Dia. Trawl Wire | Stern A-frame | Fiber Optic (.681) | 0.680 Coax Wire |
| SCUBA Diving | Radioisotope use - briefly describe | NO Radioisotope use/Natural level work | Other Operator Provided Inst. - Describe |
| 0 PI-Provided Vans - briefly describe | MOCNESS | | |
|
Explain Instrumentation or Capability
requirements that could affect choice
of ship in scheduling. |
|
|
|
|
Explain Major Ancillary Facilities
Requirements and list description
and provider for "other" systems. |
WHOI MISO TowCam towed imaging system (see above) |
|
