Uttarkashi, Nov 22: Drilling with the American auger machine resumed at the Silkyara tunnel overnight to prepare an escape passage for the 41 workers trapped inside for more than 10 days, officials said on Wednesday.According to officials, 800 diameter steel pipes have been inserted up to 32 metres through the rubble so far.Drilling was suspended at the tunnel since Friday when the auger machine hit a hard object.The resumption of drilling with the auger machine is likely to speed up the rescue efforts. (Agencies)