Instrumented Metering Sheave

• Fully-Instrumented (shown above)
• Cable Speed and Cable Out Only

This system can be used for the overboarding (while on station) and the towing of instrumentation and hardware. Comprised of a rugged, lightweight sheave block, personal computer (PC) based laboratory unit (Lab Unit) and remote displays, the system is equipped with the following sensors: cable tension, scope, speed, inclinometers. An acceleration sensor is an available option.

The Lab Unit and Remote Displays are equipped with inter-system communications features for sending commands and messages to the winch operator.

Sheave Block Features

The Sheave Block consists of a Nylatron sheave, an anodized aluminum framework and instrumentation. The sheave has eight perimeter permanent magnets at 45 degree spacing. The framework supports the sheave, two waterproof electronic housings, two hinged cable follower arms and an electronic load sensing clevis pin.

The small electronic housing mounted on the central support arm, contains the main electronics package, inclinometer and the reed switch (position) sensors. The reed switches detect sheave rotation and direction. A temperature compensated load cell is used as the load bearing point, providing cable tension data to the electronics package.

The large electronics housing, mounted on the outboard cable follower, houses two inclinometers. The inclinometers are used to determine the cable wrap angle, for calculating tension, and cable angles for station-keeping or towing.

Lab Unit
The Lab Unit, mounted in a standard 19 inch rack, comprises a PC and a Junction Box. The Junction Box houses the following: 12 VDC power supply; 110 VAC power connection; and connections to the PC and Remote Displays.

The Lab Unit displays incoming and outgoing data; provides the communications link to the Remote Displays; and supplies the 12 V power to the Sheave Block and Remote Displays. The Lab Unit can also be supplied as a Notebook PC with a small junction box.

Remote Display Features
The Remote Display, mounted in a NEMA-4 enclosure, displays tension, scope, cable speed, cable angles and messages from the Lab Unit. The Remote Display can be used with a block sheave as a standalone system, or in conjunction with a Lab Unit. Displays can be "daisy chained" to supply block data to more than one ship location.



3rd Party Integration:
ODIM Brooke Ocean's new software allows the sheave to run inside the Sea-Bird "SeaSave" package when used for CTD rosette applications! Click here for details!

ODIM Brooke Ocean has collaborated with L-3 Communications / Klein Associates (www.l-3klein.com) to interface the Instrumented Metering Sheave output with the sidescan sonar data output from their sonar products. Please contact ODIM Brooke Ocean for more details.

Specifications:

Safe Working Load: 16,700 N (3750 lb) on the block @100 degree wrap: 11,800 N (2650 lb) on the cable @180 degree wrap: 8,300 N (1875 lb) on the cable (Higher safe working loads and larger diameters supplied on request.)
Ultimate Strength: 80,000 N (18000 lb)	Sheave Block Tread Diameter: 44 cm (17.3 in)
Outputs: Serial: RS 232 (ASCII) to LCD display Resolution: Speed: 0-190 m/min, +0.5 m/min Cable Out: +0.2 m Tension: +32 lb Cable Angles: +0.5 degrees	Displays: Speed: 0-255 m/min. Cable Out: 0-9999 m Tension: 0-9999 lb Cable Angles: +72 degrees Port/Starboard and Forward/Aft

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ODIM Brooke Ocean's sister company, ODIM Spectrum Ltd., supplies their own fairlead solutions. Information on their unique fairlead mechanism, the space-saving cable guidance device fast becoming the standard on multi-streamer seismic vessels, can be seen here.