Calculating including values from consecutive row / if function (complex)

I have a question. I am working for a school project on a case for a barge operator. I have one ship, called "ERWINE" and I visit multiple ports to load and unload containers. I want to calculate the delay per trip, and need to add a value for the trip from and to different terminals. The following data is considered:

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For example: the trip from Rotterdam to Antwerp is 8 hours. Then the delay should be 14 hours and 23 minutes, since the difference is 22 hours and 23 minutes, but sailing is not considered as slack. So the values for sailing from Rotterdam to Antwerp is fixed, while the delay is based on the value from the row above. I do not know how to connect these. Can someone please help me?

I have used vistime to create a timeline, and would like to add the delay and sailing also to this picture to see where the delay occurs.