GPS controlled graders deliver a smooth surface

1486 Birse has used two machine control systems on the A14 project in the UK, one GPS-controlled to provide excavators with a +/-30mm accuracy and a second system which used a 2122 Trimble UTS as control on a grader to achieve +/- 5mm - well within the Highway Agency's sub-base tolerance of +10/-30mm. This meant that when it came to the asphalt surface, Birse agreed a thickness and 3180 Lafarge, the blacktop contractor, let the paving machine run instead of the operators constantly making manual adjustments. At the end of the job, one of Birse's engineers looked at a 1km section of type 1 sub-base in detail. The average surface deviation on this tested carriageway was zero and local users of the A14 have even been phoning and emailing their approval of the smooth finish.