US President Barack Obama’s limousine is one tough Cadillac. The doors weigh as much as the cabin doors of a Boeing 757. Parts of the body are covered with military grade armour up to eight inches wide. The windows are so thick that a fluorescent light is needed to illuminate the cabin. The fuel tank is resistant to explosions. There is a Remington Arms shotgun stored under the driver’s seat. It’s little wonder the First Limousine is nicknamed ‘The Beast’. Yet overnight in Ireland it got stranded on a driveway ramp, and was about as vulnerable and useless as a turtle on a pointy rock.

It turns out the President wasn’t actually in The Beast at the time. When he is out of town, Obama travels with a motorcade of up to 45 vehicles – many of those decoys – and Secret Service spokesman, Robert Novy, said on this occasion the President was riding in a different vehicle.

“A Secret Service spare limousine, carrying staff and support personnel only, bottomed out at the top of the driveway rendering the vehicle inoperable,” Mr Novy said.

“Occupants were relocated into other vehicles and the motorcade departed out another exit without further incident. There were no injuries.

“The size of our vehicles is always an issue and taken into consideration during the advance process. However, it only takes a slight miscalculation for a problem like this to occur.”

The Secret Service has not detailed how it freed the stranded limo.

The current presidential state car is a 2009 Cadillac, and it is the first not to carry an official model name. Many of the car’s details remain a secret, although it is said to borrow parts from the Cadillac DTS, STS, Escalade and GMC Topkick.

Its weight is estimated at around eight tonnes and, in case you were wondering, its combined cycle fuel consumption is reportedly 30 litres/100km.

Perhaps the President should take a Knight XV for a test drive. It would have no trouble getting out of driveways, and apparently it's pretty handy in case of a zombie apocalypse too.