With so many unknown variables its pretty impossible for us to accurately speculate an opening time. Track should be finished soon considering the final footers are being finished, Barth crane has returned and they've a car park full of track and supports. However that's only one part of the puzzle.
There's all the theming - both sides of the sound barrier along Maus, within the area itself. How many more buildings or structures will form inside the area? How much will be done by Universal Rocks and how much could be prefabricated items? There's the Uhrwerk restaurant. Who knows what else there might be.
Other than foundations the hotel doesn't exist yet. Will the rooms and exterior theming be prefab as speculated, but then how long will it take to install those and how many will there be?
How long will testing for F.L.Y. take? Considering its a complete prototype there's obviously the risk of technical difficulties.
As things progress in the coming months and testing begins things should start to get clearer. Whether we are looking at a Autumn or Winter 2019 opening or will it be the start of the new season in April 2020. They won't open until everything is done (area, coaster + hotel) it is after all being teased as a package and with unique interplay of all these elements.
Also it seems for the first time ever Rookburgh is being teased/marketed on the park maps for 2019. It was on the maps given out to those at the Netto Corporate buy out day yesterday.
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