A Seaeye bale arm TMS comprises a side entry garage configured to accommodate the size of vehicle installed. A detachable 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 connected to the bale arm reduction gearbox by a hard rubber universal coupling. 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 using contra-helically wound double armoured umbilical. 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 30 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. The pilot operates the TMS tether in and out mechanism from the hand controller as he manoeuvres the vehicle. The length of tether spooled out is displayed on the comprehensive video overlay provided as standard fit on all Seaeye ROVs. This is automatically calculated by the number of turns made by the bale arm mechanism during spooling in and out.
Three types of bale arm TMS are manufactured by Seaeye:
The Type 2 is used for the smaller vehicles, 600DT and Tiger,