Three of seven boy racers who swarmed up Arnold’s Hill on the A40 at up to 100mph have been jailed this morning.

The other four received suspended sentences and all were banned from driving.

Judge Paul Thomas told them at Swansea crown court their racing had been childish, immature, astonishingly bad and dangerous.

The seven had been in a convoy of up to 40 cars that had met at a Murco garage in Haverfordwest on August 11, 2013, to drive to Swansea.

Stephen Murray, 23, of Lawrenny Street, Neyland and Ieuan Power, 18, of Harbour Close, Milford, began showing off almost immediately by racing round and round a roundabout, said Robin Rouch prosecuting.

As the convoy reached Arnold’s Hill, where the east bound carriageway opened to two lanes, several cars began racing and using the third, oncoming lane, as an additional overtaking lane, effectively turning that stretch of the A40 into a one way street.

Power became blocked in and undertook a car before swerving back into the regular overtaking lane. As the vehicles slowed at the top of the hill Scott Beavis, 21, of Skomer Drive, Milford Haven could not control his braking and swerved into the oncoming lane at 80mph, hitting head on a Seat Ibiza being driven by Andrea Gainfort.

She suffered a punctured lung and was in hospital for 13 days. Her daughter Zoe and her mother Maureen Howells were also injured.

Beavis himself had to be airlifted to Morriston hospital, Swansea.

Today, Beavis was jailed for six months and banned from driving for two years.

Ian Lloyd, 22, of College Park, Neyland, received the same sentence. Judge Thomas said he had set the pace going up Arnold’s Hill and others had followed his example.

Jack Murdoch, 18, of Main Road, Waterson, was jailed for 16 weeks and banned from driving for 12 months. Her had told a jury “bare faced lies,” said Judge Thomas.

Edward Adams, 19, of Thornton Road, Steynton, was jailed for 16 weeks, suspended for 12 months, and ordered to carry out 180 hours of unpaid work for the community James Adams, 23, also of Thornton Road , Stephen Murray, 23, of Lawrenny Street, Neyland and Ieuan Power, 18, of Harbour Close, Milford, were jailed for 12 weeks, suspended for 12 months, and ordered to do 150 hours of work.

All seven will have to take extended driving tests before getting their licences back and to pay government surcharges.

Judge Thomas said they had driven “like idiots” on what would have been a busy summer Sunday afternoon in Pembrokeshire.

Beavis had caused the accident but it could have been anyone one them as they had all “driven like lunatics, competing to see who could drive the fastest.”

“Cars are not toys for little boys. It is a culture amongst young men of your age in Pembrokeshire to show off, to pose at ridiculous speeds, buzzing and swarming like bees,” added Judge Thomas.

The judge said he noted that even before August 11 Beavis had received five written warnings from police about his driving. James and Edward Adams had each received two notices and Edwards Adams had once been banned for driving at 107mph in a 60mph area. Lloyd, Power and Murdoch had each received one warning.

Lloyd and Murdoch had denied dangerous driving but had been convicted by a jury after a trial. The other five defendants had entered pleas of guilty.

Judge Thomas again raised concern about the evidence given by two witnesses on behalf of Lloyd and Murdoch.

Mr Rouch said, “It will not be overlooked. It is not going to go away as far as they are concerned.”