Mae fideo treigl amser o draphont Afon Seiont wedi'i ryddhau sy'n dangos sut y cafodd y gwaith ei wneud gan Gyd-fenter Balfour Beatty Jones Bros sy'n adeiladu'r ffordd osgoi £135m sy'n un o'r prosiectau seilwaith mwyaf sydd ar y gweill yng Ngogledd Cymru.
A time lapse video of the River Seiont viaduct has been released which shows how the work was carried out by the Balfour Beatty Jones Bros Joint Venture delivering the £135 million bypass which is one of the largest infrastructure projects underway in north Wales.