Most of our shifts as the science crew have become very routine as of recently. While the airguns are shooting the ship is cruising at a laid back 4 kt and if everything is going smoothly all we need to do is take periodic logs, note line changes, and occasionally do an XBT scan. The point is that things are usually very calm especially on the 12-4 shift when most are trying to catch some shut eye. Last night however, had an injection of excitement when an airgun failure was recorded just past midnight as our shift began.
Once the error flashed on the screen, a communication failure with the third out of 4 airgun strings, members of the science party began to gather around the monitors to get an idea of what was happening. After another failed shot and some attempts to fix the problem from the main lab systems it was clear that the string would need to be brought on board in order to figure out what went wrong. Hard hats and life vests were quickly donned and the gunners headed to the main deck to start reeling in the string. As the main buoy neared the tail of the ship it began to twist at a strange angle. The main lab called the bridge to kick the speed back up to 4 kt to try and force the string to straighten out. All the while the scheduled shots continued on the 3 working strings.
Once the gunners had winched up the string and brought a majority of it on board they were able to quickly diagnose the problem. One of the jumper cables coming from the front most gun connecting the rest of the array had become dislodged breaking communication between the string. Further, it appeared that the cable tie used to connect the sting to the ship and control its position relative to the other strings had slipped by a few meters. To top it off, there was a decent amount of discarded XBT line, thin copper wire sent down with the XBT probe, that had managed to wrap itself around the front of the string. Once the cable was reconnected and the cable tie secured the team began testing single guns at the rear of the string and when satisfied they redeployed the string. The final test was to ensure that the entire array was firing and after a few successful shots and several nods of approval things were back on track.
All in all, this ended up being a simple fix. The gunners had the string out of the water, repaired, and back in in about 40 min and only 40 shots were disrupted by the failure. This of coarse is all good news since early in the cruise delays and ship repairs cut into the timing of the science operations. Knock on wood, everything seems like its back to normal and our watch continues, conveniently just in time for 2 am ice cream break, as is the tradition.
– Miles Bodmer
