Memorial service tributes have been paid to a true pioneer of the sugar beet industry who transformed a family blacksmith's business into an engineering company exporting around the globe.

David Mountain, who represented the third generation of a family business that grew into CTM Harpley Engineering, died suddenly aged 71, three days after having a pacemaker fitted.

More than 400 people packed St Nicholas Church in Dersingham for a memorial service that paid tribute to a man with a passion for life that kept him working long after his official retirement at the age of 60.

Mr Mountain's sons Andrew and James, who now run the multi-million pound turnover business in Cross Street, Harpley, with their cousins Adrian and Nigel, highlighted the immense impact their father's innovations had on the sugar beet industry.

'Put simply, before him they used to load sugar beet with a fork; now our machines are capable of cleaning and loading six tonnes per minute,' said 41-year-old Andrew.

During a lifetime of invention, Mr Mountain, who took the business forward with his brother Michael, also designed all manner of other farm machinery from beet top lifters and vegetable ploughs to lily harvesters and scrub cutters.

Andrew said: 'It's quite a list and it's also worth mentioning that my dad was responsible for exports of CTM machinery from the 1980s to Holland, Denmark, Germany, New Zealand and the USA.'

Mr Mountain was born in Harpley, near King's Lynn, in February 1943 and attended the village school and later Gaywood Park before studying agricultural engineering and technical drawing at King's Lynn Technical College.

He had a holiday job on a local farm before joining the family blacksmith's business where his father Charles had begun to increase development of machinery for the sugar beet industry.

He quickly took over development of the machinery section, designing cleaner loaders and land preparation equipment.

He travelled to such continental countries as Holland and Denmark to promote sales of the machinery and gradually built up the business to one that employs more than 20 people today.

Andrew said: 'For 50 years he exhibited the machines at agricultural shows throughout the country and enjoyed meeting customers, many becoming friends.'

He had always been fond of telling the story why his father chose the distinctive red colour of their cleaner loaders - 'That was the only colour he had in stock.'

While CTM has grown to export as far afield as Russia and China in recent years, the original blacksmith's forge remains untouched in a small corner of the original building as testimony to the heritage of the building.

Mr Mountain, who lived in Dersingham, leaves a widow, Ruth, who he married in 1967, two sons and four grandchildren.

He had varied interests outside work and was a keen photographer who travelled the world taking pictures of places, animals, flowers and anything unusual.

He had a passion for speedway and his interest developed when his son Andrew and, later, grandson Connor started to ride.

After his retirement, he became a keen gardener, joining the local horticultural society and winning prizes for vegetables he grew.

'He was meticulous in all he did, he never could stand bodged jobs,' said Andrew.