Williams's delayed 2019 Formula 1 car hits the track in testing

With the build of the new FW42 having run late, the car only arrived at the track in the early hours of Wednesday morning.

Williams then worked hard on finalising preparations before rookie George Russell gave it its first run as testing resumed after lunch.

Follow F1 testing as it happens

The delay means that Williams has missed two-and-a-half days of testing so is facing a major catch-up effort if it wants to recover lost mileage.

It is coming off the back of a very disappointing 2018 campaign where it finished last in the constructors' championship.

The team has signed Formula 2 champion Russell and F1 returnee Robert Kubica for 2019.

Speaking to Sky Sports about the delay, deputy team principal Claire Williams said: "We were just not ready.

"It's been eye opening for me. You take for granted what it takes to get a car [to testing]. Even someone like me who has been around the sport for so long.

"What it takes to get these cars here in what is such a short period between the end of the previous season, when you have got significant regulation changes as well.

"There are 22 odd thousand parts on these cars just to build them and assemble them, let alone get them ready, but everyone else has managed to get here and we haven't.

"We had a lot of issues last year that we needed to handle as well and we had to make sure that we got the best car that we could out. That is why we delayed it again until today."

Williams said that "it is quite an odd atmosphere at Williams at the moment".

"I was here on Monday but there isn't much point in being here when there isn't a car here, so flew home and spent the day at the factory yesterday, literally in just the race bay," she continued.

"It has been very difficult for everybody, we cannot underestimate the disappointment that everyone feels, but there has been a kind of real sense of camaraderie and we always find that at Williams.

"In these difficult circumstances they do always dig deep, and last night there was a real crowd gathered when that car was loaded on to the truck to get it to Birmingham to fly it here today.

"And there as a palpable sense of relief that it had gone and it was in pretty good shape.

"Williams has always prided itself on its people and its spirit that those people have, we saw that last year and we saw it again today."

When discussing the team's new livery and driver line-up, Williams stated that the delays had left those developments feeling "slightly tainted".

She continued: "But that is our issue. We will deal with it and I am hoping that when the car does get out it is in good shape and come a couple of weeks' time this will be forgotten about."