News

An Accidental Drop Test for a PMEL CO₂ System

PMEL's Moored Autonomous Partial Pressure Carbon Dioxide (MAPCO₂) system is routinely put to the test in harsh ocean conditions, but for one buoy off the coast of Georgia an accidental drop test led to some surprising results regarding the resistance of the system. To date over 30 systems have been deployed and have survived typhoons, intense tropical heat, fishing encounters, and vandalism. However, in May of 2009, one system experienced a very unique 'recovery' when a NOAA National Data Buoy Center (NDBC) coastal weather buoy with a MAPCO₂ system installed broke free of its mooring off the coast of Georgia. The buoy drifted at sea for some time and eventually washed ashore on a sandy beach in northern Florida. The buoy was inaccessible by truck or boat so a decision was made to lift the buoy with a Coast Guard helicopter and set it in the ocean to be recovered by a ship. As the buoy was lifted, the helicopter became unstable and the buoy was released from a height of 150 feet. Fortunately, the buoy landed in the water and nobody was hurt, but the impact with the water was enough to crush the tower and bridle and damage the aluminum buoy hull. NDBC was able to recover the buoy that remained floating, but it was expected that all systems would be a total loss due to the tremendous shock from the drop into the ocean. The buoy's tower was damaged beyond repair and had to be cut away during recovery.

The MAPCO₂ system was sent back to PMEL for inspection with the hope that a few components could be salvaged. The complete circuit board assembly and all supporting electronics were operational and the data collected before the buoy broke free were safely recovered. Only minor damaged occurred when the valves, airlines, and filters on the outside were disassembled on shore. Surprisingly, everything else looked as if it had just left the Lab. What a ride for this MAPCO₂ system, but it lived to be deployed another day!

Buoy on the beach

Damage to buoy after drop

pCO2 system in buoy

System electronics after drop	No damage to electronics	Licor undamaged by drop