Gari la kumlinda Obama 'labuma' getini, atokea mlango mwingine

It's designed to protect the President from terror attacks but Barack Obama was left red-faced after one of his armour-plated Cadillacs was brought to a halt as it left the U.S. Embassy in Dublin.

The gigantic bomb-proof General Motors vehicle, with eight-inch thick steel on its door, didn't even make it as far as the road outside the consulate.

The car had to be abandoned after the collision in front of waving crowds while Mr Obama and his wife were en route to his ancestral home in County Offaly.Scroll down to watch video...

Luckily, the vehicle that broke down was the spare limo used by the President's Secret Service protection team.

Mechanics rushed in to rescue the vehicle which was lodged helplessly on the ramp, while onlookers stood and watched - some of whom took video footage and photos.

The car, worth over $1million, is 18ft in length, weighs 8 tons and has 8in thick armour plating on its doors.When the President is riding in one, the vehicle is officially known as Cadillac One. However, it's more apt nickname is 'The Beast'.

Specially built for Mr Obama, the General Motors GM.N vehicle boasts its own oxygen supply in case of chemical attack and puncture resistant, run-flat tyres reinforced with Kevlar.

However none of this, it appears, could overcome the might of a lowly speed hump.

Secret Service spokesman Robert Novy said: 'A Secret Service spare limousine, carrying staff and support personnel only, bottomed out at the top of the driveway rendering the vehicle inoperable.

'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 incident will bring Obama's security into question. His aides have gone to great lengths to ensure the President's safety while he's visiting the UK.

Such is the emphasis on security that Mr Obama’s team has even asked to fit bomb-proof double glazing to the windows of his guest suite at Buckingham Palace.

Stuck: The 'terror-proof' Cadillac fails to even make it on to the road outside the U.S. Embassy in DublinThe moves to increase the First Couple’s safety come in the wake of the killing of Osama Bin Laden three weeks ago.

Also joining the President on the trip will be one military officer carrying a suitcase containing America’s nuclear missile launch codes, plus representatives of six departments of state.

Mr Obama himself will fly on Air Force One, which doubles as a flying luxury hotel and command post complete with an operating theatre and gym.

The customised Boeing 747-200B, which is accompanied by a decoy aircraft, is said to cost around £110,000 an hour to run.