‘STEALTH SUB’ PROPELLED BY SEAEYE

Seaeye was picked for their expertise and pioneering work in using brushless DC motors for thruster systems in ROVs. Their task was to provide propulsion that would offer extremely delicate manoeuvrability in difficult conditions, including strong currents, and over an extended period of time: the Talisman can be deployed 50 miles offshore and remain in operation for 24 hours.

With BAE Systems wanting commercially available equipment, Seaeye proposed their world-proven SM5 thrusters, the same that propel their Panther Plus ROVs, and similar to that used in the Cougar ROV. The command protocol for the thrusters was made available to BAE for incorporation into the Talisman control system.

Precise handling in all directions comes from six thrusters, two at the front, and four at the back in two pairs. A Seaeye rotary actuator is used to vector each pair of thrusters and to operate the hydroplanes. This actuator was originally developed for pan and tilt applications and is widely used in a range of ROVs. It incorporates a brushless DC motor with an harmonic drive output stage that provides high torque with zero backlash, making it ideal for this particular application.

With reliability a vital element in the project, BAE opted for Seaeye’s own metal shell connectors. These were developed by Seaeye when rubber moulded connectors had become a major reliability problem in their early ROVs and where a suitable off-the-shelf metal alternative could not be found.

Seaeye leads the market for electrically operated ROVs and already sells systems to the defence industry, and the oil and gas business where it has long experience of working in demanding conditions. “The Company is very pleased to be associated with such a prestigious AUV project,” said Chris Tarmey of Seaeye Marine.