Description of AHAB design - Oregon State Universitycioss.coas.oregonstate.edu/CIOSS/workshops/MOBY... · Temperature (inside of 1, 1a) Humidity (inside of 1) Powered by CS5000 (1a)

NOAA Research and Operations Marine Optical Buoy Design Review July 18-19, 2006

Description of AHAB design Physical Structure

Mooring Buoy and Tether System

Mark Yarbrough Moss Landing Marine Laboratories


MOBY Calibration Site- Lanai, HI

• 1200 meter Mooring • Data Recovery via

Analog Cellular • Meteorological Sensors

on mooring float • MOBY totally

autonomous • Has batteries and solar

panels


MOBY is aging

• Damage from environmental causes are decreasing.

• Data loss due to random component failures are increasing.

• Changes to FCC regulations render existing data telemetry obsolete.

• Limited sample rate


R&O Redesign Summary Objectives

• Demonstration of Mooring Based Power System concept

• Use power system to test new MOBY components: MOBYNet

• Test new swivel/tether system mechanical operation and endurance

• Develop deployment and servicing techniques


Communications System Design: AHABNet


AHAB

• Reduced size & weight • Ionomer foam float • Fiberglass frame • Low self shadowing • Double collectors • Depth adjustable • Reduced diver servicing • Drop weight for easier

recovery


Mooring Meteorological Buoy

• Increased payload – 450 watts Solar Panels – 1200 ah Batteries – More ballast – Increase stability – Easier Maintenance

• Control System – Campbell Data logger – Cellular Phone WAN – Wireless Router LAN – Meteorological Sensors

QuickTime™ and aYUV420 codec decompressor

are needed to see this picture.


Mooring Flounder Plate and Swivels

• Attachment point of tether at Mooring

• Swivel • Must be redesigned to

allow electrical conductors from Mooring to AHAB




MOBY in action

• Buoy Dynamics • Vertical Orientation

due to Float/ballast • Requires Drogue

array to dampen the “bounce”




Buoy Motion Damper (Flopper Stopper)

• Nylon Line • Dacron “cones” • Line Length

determined by water depth, anchoring requirements

• Cones trap large mass on upstroke




R&O Buoy System: Accomplishments

• Accepted delivery of mooring components in Hawaii 13 March 2006

• Completed initial testing of the integrated tether electrical system 20 March 2006

• Successful system deployment 2 March 2006 • Performed post deployment line load testing 2 March 2006 • Conducted in-situ electrical testing 2 March 3006 • MOBYNet and MOBYCam testing using tether power source

3-4 March 2006 • Performed diver tether servicing under marginal sea conditions

2-4 March 2006


R&O Buoy System: Outline

• System Overview • Communications system • Mooring Buoy • Radiometric Buoy • Tether – Tether Test - status • Data System


Sunset over Kauai




System Overview


Mooring Buoy


Mooring Buoy Electrical System


Mooring Buoy Electrical System

1. Controller Box Campbell Scientific Data Logger CS5000: Controls operation of the Mooring data

system Programmable operation schedule Controls power to Campbell cell modem

(1b,c) Controls power to MOBYNet Cell

modem (1h,j), Wireless Router (1g)

Data logging: battery voltages, drain currents, charge Currents Monitors and logs tether conductor

voltages and current Provides remote monitoring and control

via cellular system Monitoring and control via local

connection


Mooring Buoy Electrical System 2. Cell modem

Cellular system to RS232 connection to CS5000 (1a) Airlink Redwing

3. Amplifier Dual band bidirectional cellular amplifier Boosts signal in fringe areas

4. Monitor/Control Electronics Interface electronics between CS5000 (1a) and Power Relays (1e) Scaling and filtering for analog inputs: Battery volts (5), Charge currents (3,4), Temperature (inside of 1, 1a) Humidity (inside of 1) Powered by CS5000 (1a) 12 volt SW (Battery 5)

5. Power Relays Switch Battery (5) power to other systems (1b,c,g,h,j) Provides switched power to systems requiring more amperage than can be provided by CS5000 (1a) 12 volt Switched Power (12v SW). Switching power to subsystems reduces overall power consumption since only the required subsystems are powered at any given time.

6. Charge Controller


Mooring Buoy Electrical System (continued)

7. Controls Solar charge current to Battery (5) 12 Ah, 12 volt

8. Network Wireless router Interface and IP handling between Cell modem (1h) WAN and Wireless LAN. Provides multiple IP addresses for local use from the one IP of the Cell modem.

9. Cellular modem Airlink E-Raven. Ethernet cellular CDMA modem operating of Verizon Wireless. Facilitates internet access to the mooring site. Modem is operated with a static IP. Upgradeable as cellular providers change their communication protocols.

10. Amplifier Dual band bidirectional cellular amplifier Boosts cellular system signal in fringe areas


Electromechanical (EM) Swivel

• Provides rotating attachment point for MOBY tether.

• Prevents tether from wrapping on mooring as shifting ocean currents rotate MOBY about the central mooring and watch buoy.

• These R2O modifications add electrical slip rings to the mooring, providing a rotating electrical joint to the mechanical swivel.


Electromechanical Swivel Specifications

• Mechanical – 10 ton SWL swivel – Constructed of Stainless steel

core elements, Silicon Bronze shell and Titanium fasteners

• Electrical – 4 –Slip ring conductors – 4 ampere capacity – 600 volt isolation – Underwater mate-able

bulkhead connectors – Diver serviceable tether

connections and junction boxes


Conducting Tether • Provides connection between MOBY and main

bottom mooring. – This line must float during slack wind and current

conditions to prevent tangling with MOBY.

• Tether is oversized to maintain integrity if abraded or cut.

• The R2O modification adds wire conductors to the tether line. – These electrical conductors provide power to MOBY from

the main mooring buoy.


Conducting Tether Specifications • Mechanical

– 100-meter line length – Samson 1.5” Round Plait 12 Ultra

Blue – Samson Nylite Spool and Shield eye

termination at swivel end – PMI Everflex Bending Strain Relief

(BSR) at MOBY end – Final assembly slightly buoyant in

seawater • Electrical

– Wire construction • Alpha Wire XTRA-Guard High Flex • 4 x 1, 18 (19/30) AWG • 1.5 ohms per conductor at 300’

– SeaCon underwater mate-able connectors

– Wire free floating in kink resistant HDPE tube placed down the center of the tether braid


Predeployment Testing Initial continuity testing

• Following delivery in Hawaii, the tether was tested for continuity and isolation. – The conductor resistance measured with a Fluke 87 DVM was 1.5

ohms per conductor, well within the manufacturer’s specification for the cable.

– A Meg Ohm Meter was not available for this test but the Fluke DVM measured an inter-cable resistance in excess of 20 Meg ohms, indicating a lack of gross shorts within the cable.

– The cable was tested again with similar results after adding the SeaCon connector terminations.

• The four EM swivel conductors and contacts were tested in similar fashion. – The slip ring conductors showed no measurable resistance or shorts. – the EM swivel conductors showed no resistance changes or dead spots

when rotating the swivel.


Predeployment Testing: Static Tension Test (1)

• We performed an initial load test of the tether line and the inner wire conductors at the dock.

• One end of the Tether assembly was secured to a substantial dock bollard, the other end to the forklift and a Dillon dynamometer.

• Continuity of the four conductors were monitored as the forklift slowly increased tension on the tether. – We estimated the working maximum MOBY drag in the water at 3000 lbs at 3

knots current. It is unlikely the tether will ever experience this load during a deployment even considering acceleration due to waves.

– Our forklift tensioner allowed us to achieve a sustainable tension of 2500 lbs with peak loads of about 2800 lbs.

• We repeated the test four times to cycle the load on the tether. • Tether elongation during the test was approximately 10 feet.

– About half this length was recovered within 30 minutes of removing tension from the line.


Predeployment Testing: Static Tension Test (2)

• The design of the tether assembly allows the wire to float within the HDPE tubing in the tether.

• The wire length is sized to allow large excursions of tether line length without stressing the relatively non-stretchy wire. – Wire movement within the tether should be less than 24”

under the expected deployment loads. • Experience with previous tethers indicates there will

be little if any additional permanent elongation of the tether line, which if excessive, could ultimately damage tether conductors.


Predeployment Testing: Divers

• The divers gained familiarity and practiced with the new system while on shore. They received instruction on the details of connector handling, cable fairleads and fasteners.


Deployment (1) • The tether was prepared and deployed using our “standard” MOBY

procedures. • The BSR/stainless steel clevis end of the tether is attached to MOBY at the

dock before loading the buoy aboard the ship. • The electrical conduit is fed through a hole in the MOBY floatation up to

the buoy deck. • Protective conduit guides the wire to the well containing the reservoir of

excess wire loops. • The wire connects to the Power Junction Box via SeaCon WetMate

connector. • This connection was replaced by a temporary shorting connector to allow

testing the wires after deployment. • The tether is hinged to the up position and secured with line to the buoy

tower for transit to the site. • The remainder of the tether is flaked on deck with the Samson eye

termination attached to the stern of the ship.


Deployment (2)

• In preparation for deployment, the tower lashings are cut and the tether is dropped to the down position.

• MOBY is deployed and the tether paid out. • MOBY, secured to the stern of the ship, is

taken under tow until it is positioned in close proximity of the mooring, where the tether is handed off to the dive boat for attachment to the mooring.


Deployment (3) • Divers make the attachment of the MOBY tether to the

subsurface mooring swivel. • For this deployment we are performing a long term mechanical

test of the EM swivel so the tether is attach to the standard mooring Flounder Plate, not the new swivel – The new EM swivel is bypassed with a safety chain to prevent loss of

the mooring if this swivel should fail. – Since the EM swivel is blocked from rotating, we cannot leave the

tether electrical cable permanently attached for this test. – The tether will be attached directly to the EM swivel in future

deployments after we gain confidence in the new components. • The divers then completed the temporary electrical connection

of the tether to the EM Swivel.


At-Sea Testing: Mechanical • A dynamometer was used to measure the tension on

the tether while monitoring the integrity of the tether conductors under increasing line loads.

• MOBY was pulled by the ship at speeds up to 3 knots exerting a Maximum pull of 2500 lbs. – The tether tension at 1.5 knots through the water was

between 800 and 1000 lbs. – These are the maximum loads we expect the tether to

experience during a normal deployment. – The wire showed no signs of breakage or shorting (between

wires or seawater) during this test.


At-Sea Testing: Electrical • We continued electrical testing of the tether and the

attached equipment after the divers completed the underwater connections. – The system was manually powered up and tested for proper

tether voltages and currents. – The power system on the mooring buoy provides 200 watts

of power at 48 volts to MOBY instrumentation through the EM swivel and 300’ of tether.

– We left the power system on through the night and again tested the tether in the morning before disconnecting the tether wire from the swivel and securing the loose connector loop.


FACILITATED OPERATIONS: MOBYNet and MOBYCam

• The additional power provide by the tether system and the ability to add instrumentation to MOBY allowed us to test new and updated systems currently under development for MOBY. – Though not activated for this test, we have added a new

controller and data telemetry system to the mooring float. – For testing, we added an AXIS real time networked camera

system to MOBY. The camera system provided a suitable electronic load for the tether tests as well as a useful video data stream to test the wireless LAN.

– The Campbell data logger was configured to monitor the electrical performance of the tether and power supplies.


Tether & Swivel Test Report • Tether recovered during the June 06 MOBY

swap • Tether conductors damaged by fishing snag • Damaged because the EMS connection could

not be left connected • Tether repaired for redeployment • Swivel electrically intact • Swivel shows no significant mechanical

degradation

Documents

Description of AHAB design - Oregon State Universitycioss.coas.oregonstate.edu/CIOSS/workshops/MOBY... · Temperature (inside of 1, 1a) Humidity (inside of 1) Powered by CS5000 (1a)