The once-controversial F1 halo likely saved 2 racers' lives this week

• The F1 and F2 races at the British Grand Prix were marred by scary wrecks.
• The wrecks might have been life-threatening if not for the halos above the heads of the drivers.

Two drivers at the British Grand Prix escaped serious injury and may have even had their lives saved by a device that was once considered a controversial addition to the cars.

During the opening lap of the Formula One race at the Silverstone Circuit, Alfa Romeo's Zhou Guanyu got tangled up with another car and flipped upside-down. His car then slid across the track quite a ways before eventually flipping over the tire barrier and ending up lodged between that and the fence.

Zhou was taken away on a stretcher but was later dismissed from the track's medical center without any major injuries.

In an Instagram post following the race, Zhou said the car's halo saved his life.

"I'm ok, all clear," Zhou wrote. "Halo saved me today. Thanks everyone for your kind messages."

Zhou's car was destroyed in the wreck. However, it's clear that the halo — the hoop that frames the top of the driver's cockpit and is supported by a post in front — was still intact except for some missing paint.

In other words, the halo, which is made of titanium and can withstand the weight of a London double-decker bus, did its job perfectly.

In these photos, you can see Zhou's head protected by the halo as the car slid upside-down.

Incredible as it may sound, that may not have been the scariest crash of the day.

In the earlier F2 race, Dennis Hauger was pushed off the track and lost control of his car. He eventually hit a curb and was launched into the air and directly on top of the cockpit of Roy Nissany's car.

In the replay at the end of this video, you can see the right-front wheel hit the halo of Nissany's car.

Both drivers were able to climb out of their cars and walk away.

Sky Sports commentator and former driver Tom Gaymor praised the job of the halo during the broadcast.

"That is one of the most frightening accidents I have seen for a long, long time," Gaymor said. "That is why the halo is there. And full credit to all the engineers and those behind the safety measures that we continue to see advancing in motorsport saving the lives of drivers who are out on circuit because the halo there has done its job."

Many were against the halo because it was ugly

Most agree now that the halo has saved drivers in life-threatening crashes many times in recent years — including Charles Leclerc in 2018. However, when the halo was first proposed, not everybody thought it was a good addition. The main complaint was aesthetic, as people considered it ugly, but there were also concerns about the added weight and hampered visibility for the drivers.

In 2016, after driver Kimi Raikkonen tested a car with a halo, seven-time champion Lewis Hamilton slammed the car's look.

"Please no!" Hamilton wrote on Instagram. "This is the worst looking mod in Formula 1 history. I appreciate the quest for safety but this is Formula 1, and the way it is now is perfectly fine."

Likewise, Mercedes team principal Toto Wolff complained about the halo after it became mandatory in 2018, saying he would cut it off if he had a chance.

"If you give me a chainsaw, I would take it off," Wolff said. "We need to look after the drivers' safety, but what we have implemented is aesthetically not appealing. We need to tackle that and come up with a solution that looks better. It's a massive weight on top of the car, you screw up the center of gravity massively with that thing."

Like others, Wolff eventually came around and recognized the importance of the device.

During the 2021 Italian Grand Prix at Monza, Hamilton and Max Verstappen got tangled, and the Red Bull driver's car landed on Hamilton's cockpit.

After the race, Wolff admitted the halo saved Hamilton's life.

"Halo definitely saved Lewis's life today," Wolff said. "It would have been a horrible accident that I don't even want to think about if we wouldn't have had the halo."

Later, during an episode of the popular Netflix series "Drive to Survive," Wolff admitted he was glad he lost the fight over the halo, noting that there were tire marks on Hamilton's helmet.

"That was me, you know, four years ago, I was fighting the halo," Wolff said. "Thank God I didn't win that fight."