Coastal Surface Electro-Mechanical (EM) Moorings
Electro-mechanical (EM) moorings will be used on the Endurance Array Oregon Line offshore and at the shelf and on the Endurance Array Washington Line's inshore site. They will provide meteorological observations, power to surface and subsurface instruments, and real time data transmission.
These moorings will be similar in design to those used in the Pioneer Array. Since they do not have to support extensive water column and benthic sensors that are connected through the cabled infrastructure, they do not carry optical fiber or power transmission below the near surface sensor attachment point at 5 m.
Like the Pioneer Array buoys, power will be generated using a combination of wind turbines and photovoltaic panels. Due to the lower power requirements of the Endurance coastal moorings, they will not include methanol fuel cells. Wind and solar power will be used to charge storage batteries in the buoy, and ultimately will be delivered to meteorological and near surface instrumentation.
Inshore mooringThe inshore (25 m) surface mooring will be used at the Endurance Array's Oregon and Washington Lines. It will support sensors at the air-sea interface and on the instrument frame at the EM termination.
Control and data signals to and from sensors below the buoy flow along copper conductors built into the mooring strength member elements. These include steel armored electro-mechanical (EM) cable approximately 15 mm in diameter, EM urethane molded chains approximately 75 mm in diameter and 5 m in length, and, depending on water depth, one or two EM mooring stretch hoses that are approximately 100 mm in diameter and can stretch from an original length of 15 m to upwards of 32 m, and serve to reduce shock loading in the mooring for increased longevity.
Frames for sensors are provided for the mounting of instruments at the junctions between the various mooring elements. Electrical breakouts provide the instruments with connections for power and telemetry. The EM cable allows for high-speed communication and power transmission between the surface buoy controller and the multi-function node (MFN) instrumentation.