Formula 1 has waived the paddock's mandatory curfew at Interlagos to allow teams to catch up on their preparations and build processes in the wake of a lengthy delay in freight delivery.
Inclement weather that hit Mexico City on Tuesday delayed and hampered the air transfer to Brazil of a significant number of the teams' cargo containers.
The back log of stranded containers built up over the day which led to half the teams waiting for part of their equipment on Wednesday evening.
F1 freight continued to trickle in on Thursday as planes landed in Sao Paulo and the cargo was processed by customs.
However, midday at Interlagos, the Alfa Romeo team's garage remained worryingly empty with no cars or engines in sight. Ferrari and Haas were also waiting on their engines while McLaren's cars were still on their way.
A mandatory nine-hour curfew - which normally kicks off 12 hours before the start of FP1 the following day according to F1's sporting regulations - is imposed on teams during a race weekend.
But given the exceptional circumstances, F1 has now waived that constraint, which will allow teams to catch up on their preparations, albeit by burning a lot of midnight oil.
“I think the guys just have to work through the night, that’s the only thing you can do," commented Haas boss Guenther Steiner.
"I don’t know if they need to work [all the way] through the night, but it will be a late night and the regulations have been changed as of this morning with the curfew and scrutineering times all adjusted.
"So we can still do the event as planned and not change the timetable of the event.
"Everything is here now in Brazil so it’s just a question of being a few hours away from the racetrack."
This weekend's Sao Paulo Grand Prix is the second race in a demanding two-continent triple-header that will see teams cross the Atlantic early next week and move on to Qatar for the next round of racing in the 2021 F1 World Championship.
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