AN ENGINEER has swapped his tools for trainers to take on a gruelling ultramarathon that will see him run for more than 40 hours.

John Booty, of Tile Barn Lane in Lawford, will run across three countries in the Ultra-Trail of Mont-Blanc, known as the UTMB.

Starting in Chamonix in France tonight, the 103-mile run will cross into Switzerland and Italy, reach 10 summits and cross rivers and glaciers.

John, a 46-year-old engineer for the Essex Air Ambulance, said: “I watched my brother do it about three years ago and I got sucked in by the glamour of it - it looks lovely.

“I thought ‘I fancy that’ but the reality is a bit different.

“It has been hard doing the training, I haven’t done nearly as much as I should have.

“I’m going into this not as well-prepared as I would like.”

John had to qualify for the event by completing a number of 100 mile and 50 mile races.

But since last year admits he hasn’t completed any runs longer than 17 miles.

He added: “It starts at 6pm on Friday night and you run through the whole night and then all day.

“The professionals will probably pull in Saturday afternoon but the mid-packers and rear will run right through.

“The cut off to finish is 46 hours, I would like to finish in 40 hours but my only goal is to complete it.

“Last year 42per cent dropped out through the race.

“It’s semi-autonomous, you have to take your own water, food, spare clothing, head-torch and batteries, phone and blanket.

“There are aid stations to fill up water etc but it could be three or four hours between them.”

Dad of two John, who runs Manningtree Trailer Hire, is raising money through sponsorship for two-year-old Breya Ward.

The tot, daughter of a Colchester paratrooper, is battling a rare and aggressive cancerous tumour which has taken over her stomach.

Pioneering immunotherapy treatment Anti-GD2 to treat Breya’s stage four neuroblastoma is only available in America costing about £250,000.

“We sponsor the Parachute Regiment Shetland pony mascots with a trailer to attend commemorative events around the UK and Europe and heard about Breya,” John said.

“I’ve got a picture of her on my phone to look at to keep me going during the run.”

To sponsor, visit John’s fundraising mydonate.bt.com/fundraisers/johnbooty1 page.