The voyage has been over for almost two months, and there has been no time to write the summary of this voyage. The main reason is that the tasks I have undertaken have to be checked and accepted. It took a lot of effort to process the data into what the acceptance unit needs. Fortunately, there should be no problem now. Now, it meets the special requirements. During the voyage, I still slept for 5-6 hours a day because of the geotechnical examinations. I ate the textbooks on gravity and magnetism and concentrated on breaking through the bottleneck of gravity and magnetism. I found that as long as I forced myself, I still had some potential. of. Closer to home, I did not participate in the field business of this voyage very much, but I encountered some minor problems. It is necessary to make a summary.
1. Multi-beam parameter settings and efficiency issues
In the previous article, I have done some experiments and given the recommended parameters. In the process of checking the parameters, I don't know who changed it, because if the recommended parameters are used, the effect is obvious.
The above picture uses the recommended parameters, and the effect is immediately improved, and the two stalks in the center will be cured immediately.
In the course of the multi-beam used in this voyage, due to the bad sea conditions in the sea area, the efficiency of the multi-beam is very worried about the coverage problem. When the chief mate wanted to drain the ballast water in the front compartment to increase the speed, our master Ren found that the multi-beam effect was getting worse. After reporting to the chief and the team leader, we started the reverse operation, loading the ballast water, and multi-beam coverage. Even better, although a little bit of speed is sacrificed, the efficiency is greatly improved. This discovery can be said to have saved us a lot of time and saved millions for the unit. The devil is hidden in the details.
2. Recovery of floating ball in distress
In the process of retrieving the float, we used to retrieve it at the bow of the ship before. The float was on the side of the ship, but it was not hooked. It approached and hooked again. However, on the last voyage, they used ship-side recycling again, and the effect was good. It was hooked on the bow and then pulled to the mid-ship side for recycling. The advantage was that the work surface was large and there was no need to move the float. The first recovery went smoothly, but during the second recovery, the rope entered the bottom of the ship and was caught by sea oysters, so the rope could not fall off regardless of whether it was reversing or loading.
The final method is to pull the floats on both sides separately, and then cut off the rope once, then pull it to the middle of the boat, pull up the equipment, and then pull up the other side, which takes a lot of time.
3. MVP test
My colleagues on the previous voyage tried MVP (aeronautical multi-parameter profile measurement system). For geophysical voyages, it is mainly the measurement of the sound velocity profile. Its lowering and recovery speed is much faster than the CTD winch, and it can also be used for navigation measurement. . However, the navigation measurement depth is not deep enough, which may affect the towed equipment.
(1) Connect tow fish:
At the beginning, it is 2, 3, that is, after the tow fish is connected, it is 2, 2 after entering the water, and you can go indoors and give instructions;
When mvp is connected to the towfish, the power must be turned off and cannot be hot plugged
The rope seemed to lie on the surface of the water when it was placed, and it didn't go down so fast. The speed was 8.5 knots, and when it was 1600m, it was close to 700m in depth.
So, if you want to put a depth of 1000m, then the speed is 8.5 knots, the length of the cable? With surplus cable protection, set the depth, and observe the depth of 1000m, what is the cable length?
Directly add tasks without canceling the current tasks
Withdrawal, there is a topping alarm, 3,3,
count reset, cable car information,
2,2, which means you can send instructions. If you want to operate outside the field when a dialog box pops up, you can operate outside the field or add a new task
During the recovery, the winch suddenly braked and did not recover. Later, I communicated with the equipment manufacturer and opened the protective cover, and found that the travel switch had been rusted out.
Since no suitable travel switch was found, it was directly short-circuited. Without going through the travel switch, the pick-up was manually controlled. Fortunately, the pick-up speed was fast, and the pick-up was completed in 20 minutes.