confused about wind dragging

Today I went to Stuttgart Airport to see some landings and taking off, like i do regularity, but today was the first time I saw 4 planes (3 germanwings Boeing A319 and one Ryanair Boeing 737 400 last flight) taking off less than 30 seconds between them, in fact Ryanair has dont made any stop on runway before running to take off Germanwings has made a short stop lower to 30 seconds I always heard and thought that this was not possible or permitted because of the aircraft dragging winds…

and the weather was good with little wind which makes it more difficult to disappear dragging winds… so i´m really confused about

someone more experienced in that can me clarify??

Thanks in advanced

Aircraft are categorized by weigh for wake turbulence. If the aircraft are within the same category, there is no real issue with short interval take offs. The big issues arise when you have a medium or light aircraft taking off behind a heave aircraft.

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