ABSTRACT
GENERAL TEXT Principal changes from CESMM 1 The main change to the divisions in this class was that the extras to excavation and backfilling had to be classified according to whether they were in trenches, manholes and chambers, headings, thrust boring or pipe jacking (K. 1 1-5 *). Other changes to the divisions included the addition of pipe jacking as a new Second Division classification (K. 2 3 *) and the changing of 'selected granular material' to 'selected excavated granular
material' (K. 3-5 2 *). Rules were given for the calculation of the volumes for items measured as extras to
excavation and backfilling in headings, thrust boring and pipe jacking (Measurement Rule M6) and the criteria for the excavation of isolated volumes of rock was established (Measurement Rule M8).
