Can anyone offer any suggestions on the following. I need to cut trenches in the back of oak sleeperes which are 230mm x 125mm. The trenches will be 20mm deep and 130mm wide. I need to make lots of these cuts and currently I am using a circular saw making a series of paths, digging the kerfs out with an SDS hammer drill with a wide chisel on the end then final finish from a route set up on a jog to leave a smooth finish. This does work, but as you can see it involves three separate processes and I need to be able to do the job quicker than this but with the same accuracy and finish. Any suggestions?