The TMS 2 benefits from the advantages of a bale arm system, including:

• Lower cost
• Simple design
• No slip ring required
• Low maintenance

A Seaeye TMS 2 comprises a side entry garage configured to accommodate the Tiger, manufactured from galvanised steel and protective polypropylene panels. A top section contains the tether management mechanism and controls. The tether is stored on a polypropylene bobbin with a bale arm mechanism to spool the tether evenly onto and off the bobbin. The bale arm is powered by a Seaeye SM4 thruster motor, which is common to the Seaeye Tiger and hence allows commonality of spares. The control electronics are contained in a one atmosphere, hard-anodised pressure housing and all connectors are Seaeye metal shell type.

The garage is lowered to the working depth. This umbilical is mechanically terminated into a lifting device at the subsea end and electrically terminated at an oil-filled, pressure compensated junction box. The umbilical is terminated on the surface into a slip ring fitted to the ROV lift winch.

A hydrostatic release mechanism ensures that the vehicle is held securely in the garage until it reaches a depth of 10 metres, safely below surface wave action.

At the working depth the ROV can be safely flown from the TMS to the extent of its tether (140m max). The pilot operates the TMS tether in and out mechanism from the hand controller (or the surface control unit or the foot switches) as he manoeuvres the vehicle. The length of tether spooled out is displayed on the comprehensive video overlay provided as standard fit on all Saab Seaeye ROVs. This is automatically calculated by the number of turns made by the bale arm mechanism during spooling in and out.