Charles and Camilla visit County Antrim 25 June 2013 Last updated at 15:05 The Prince of Wales and the Duchess of Cornwall are in County Antrim as part of a trip to Northern Ireland. On Tuesday morning the couple visited the Wrightbus factory in Ballymena and boarded a bus as part of their tour. The company supplies ultra-low carbon double-decker buses to Transport for London (TfL). The couple were accompanied by the First Minister Peter Robinson and Enterprise Minister Arlene Foster during the visit. Wrightbus secured a £200m contract to supply 600 of the hybrid-engine vehicles. The new bus has a design similar to the old Routemaster. The buses are now used exclusively on Route 24, which passes Parliament and Trafalgar Square. TfL have said the new bus is the greenest diesel electric hybrid bus in the world and estimates the 600-strong fleet will reduce carbon dioxide emissions in the city by almost 20,000 tonnes a year. Prince Charles met crowds outside Larne town hall. He travelled there to show his support towards local famers recognising their recent trouble following adverse weather. He was accompanied by MP for the area Sammy Wilson. The Duchess of Cornwall travelled on to Broughshane Library after visiting the factory. There, she read Goldie Locks and the three bars to some local children. This was to recognise her role as patron of the Book Trust.