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Expedition 384 began with a ~5 day transit from Kristiansand, Norway to the first site U1554 (REYK-6A). Due to the shallow water depth in the North Sea the bathy was not run until the ship passed through the Fair Isle channel into the Atlantic. The transit also took the ship almost entirely within EEZ boundaries of various countries which caused us not to be able to tow the magnetometer. Upon approaching the first site when the bathy was ramped up to obtain an accurate PDR it was apparent that it was not functioning correctly. Much troubleshooting was conducted throughout the expedition and can be found in more detail below. As of now now the bathy is able to be used to obtain depths when needed, but is not in full working order. The next site U1555 (REYK-13A) was a very short distance away, just far enough to lift up the thrusters for the transit. Upon the end of drilling operations the magnetometer was able to be towed for a short period before entering EEZ waters for the remainder of the transit back to Kristiandsand. Navigational data was collected during the entirety of the expedition and a summary of the ships movements is shown below.
Instrumentation
Navigation
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- No issues recording data or communicating with WinFrog.
- Run with no issues at power levels below -6 dB. When output power levels are increased to -6 or 0 dB the signal becomes extremely faint and erratic or lost altogether.
- Much testing and troubleshooting was conducted on the bathy hardware, and the cables going from UW to the Fwd Thyrig room junction box and onto sonar dome.
- SyQwest was most unhelpful during all attempts to communicate with them and obtain any guidance for troubleshooting. Their response was for us to either send all of the hardware, cabling, and transducers in to their facility for testing or to buy a whole new system.
- It was a real team effort working on the instrument with lots of help from everyone on board and many on shore as well.
Syqwest Hardware / Sonar Dome Troubleshooting
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Syqwest Hardware / Sonar Dome Troubleshooting
- Chirp coming from the amplifier unit in UW sounds as loud as usual and scales with the power setting properly.
- Cables from the unit in UW to junction box in Fwd Thyrig room tested for continuity and passed. Megger test was also completed and passed on each cable.
- When testing the cables from the junction box down to the transducers the tests failed indicating that there was an issue and possible short. The values for these tests as conducted by the SIEM ETs can be found below. As shown the 12KHz cable tested better than the 3.5KHz cable.
- These cables were tested again after opening up the floor and top hatch. Tests were conducted from the dry side of the O'brien connections up to the junction box with the same poor results.
- LPA-10kV A Power Module was removed, cleaned, and re-seated with no improvement. The spare module was also cleaned and tested with seemingly no difference. The original module we have been using was replaced back into the unit.
- In the upper unit, the 'brains', of the Bathy boards A00107 and A00108 were taken out, cleaned and inspected for any damage. Spares boards were installed and tested with no noticeable improvement.
Magnetometer
- Cable was taken from underway and spooled back onto the winch.
- The depth is still not being recorded properly but it was decided that we did not have the expertise on board to fix the internal electronics even if we opened it up and identified the problem.
- One short deployment was conducted during the transit back to Kristiansand. No issues running the instrument and collecting data besides the depth displaying as 0.
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