Tether Specifications

VideoRay offers multiple tether options and reels for mission-specific deployments. In addition to specification documents found on our website, the following information is provided as a reference guide for all VideoRay tether types.

Tether Diameter

Units \ Type	Negative	Neutral	Performance
mm	8.51 +/- 0.38	11.18 +/- 0.50	8.18 +/- 0.50
inches	0.335 +/- 0.015	0.440 +/- 0.020	0.322 +/- 0.020

New tether was introduced in 2018. These tethers include a braided Kevlar around the conductors, are slightly different diameter and can be identified by an “FB” code printed on the tether.

Units \ Type	FB Neutral	FB Performance
mm	12.2 +/- 0.25	9.1 +/- 0.25
inches	0.440 +/- 0.010	0.358 +/- 0.010

Minimum Tether Bend Radius

Units \ Type	Negative	Neutral	Performance
mm	88.9	114	82.5
inches	3.5	4.5	3.25

Tether Connector Pin Configuration

Tether pin numbering in the connector is shown above. When looking at the mating surface of the connector, Pin 1 is the offset pin / socket. For male connectors, pins 2-8 proceed in a clockwise direction. For female connectors, sockets 2-8 proceed in a counter-clockwise direction.

Tether Pin Function and Conductor Wire Gauge

Pin	Function	Negative	Neutral	Performance
1	Interlock (GND)	24	24	28
2	Interlock (Sense)	24	24	28
3	400 VDC +	16 (x2)	20 (x2)	24 (x2)
4	M100 EOP+	24	28	28
5	Ground	16 (x2)	20 (x2)	24 (x2)
6	M100 EOP-	24	28	28
7	RS-485 A	24	28	28
8	RS-485 B	24	28	28

 All conductors are straight through, such that pin 1 in the male connector is connected to socket 1 in the female connector, and so on for all eight pins / sockets.

 Conductor pairs 1 & 2, 4 & 6 and 7 & 8 are twisted.

 Pins 3 and 5 use 2 conductors each for maximizing power transmission and tether flexibility.

Tether Buoyancy

Performance and Neutral tether includes buoyancy compensating foam that provides near neutral buoyancy in fresh water. Negative tether contains no foam and will sink. The connectors do not contain any buoyancy compensation and will sink slightly.

Tether Strength

Standard VideoRay Performance (PPT), Neutral, and Negative tethers include Kevlar that is rated at 450 kg (1,000 pounds) or more, while the connectors are rated at 80 kg (175 pounds). These values are breaking strength. The tether should not be regularly subjected to a working strength greater than one half of the breaking strength.

The ROV and tether are equipped with a strain relief cable and connectors, which are rated at 136 kilograms (300 pounds). The strain relief cable should be used to avoid separation of the tether connectors and loss of the ROV.

See the Tether Table below for maximum strength ratings (in pounds) for each VideoRay tether type.

NEUTRAL:  11.7mm, Neutral, Kevlar, 1,000lb

NEGATIVE:  7.62 mm, Negative, Kevlar, 1,000lb

PERFORMANCE: (PPT)  9-10mm,  Neutral, Kevlar, 1,400lb

EXPEDITIONARY COPPER:  4.2mm, Neutral, 375lb

HYBRID FIBER OPTIC:  12-17mm, Negative, Vectran, 1,600lb

FIBER OPTIC:  4.5mm, ~Neutral, Kevlar, 660lb

Tether Range

Tether length is limited by the ability of the tether to effectively transmit power and data signals. See the Tether Table below for maximum recommended range (in meters) for each VideoRay tether type.

See the Tether Management section of the Operations Guide for more information.

NEUTRAL:  Topside Power/Subsea Battery, 300m reel/400m loose

NEGATIVE: Topside Power/Subsea Battery, 400m reel/400m loose

PERFORMANCE (PPT): Topside Power/Subsea Battery, 400m reel/450m loose

EXPEDITIONARY COPPER: Subsea Battery, 550m reel/600m loose

HYBRID FIBER OPTIC: Topside Power/Subsea Battery, custom lengths for reel/1.2km loose

FIBER OPTIC: Subsea Battery, 1.5km reel/2km+ loose

*Tether reels reduce tether range due to capacity limits

Kevlar is a registered trademark of E. I. du Pont de Nemours and Company
Vectran is a registered trademark of Kuraray, Inc.