Uttarkashi, Nov 24 : Former adviser to the Prime Minister's Office, Bhaskar Khulbe, has said the rescue operation at the Silkyara tunnel here will conclude by Friday evening and hopefully 41 trapped workers will be evacuated. "The drilling work resumed at 11.30 a.m. The situation now is better. On Thursday, we had to work on two things -- repairing a cracked platform for American Augur drilling machine and ground penetration radar work by Parsons company. With this work, we got to know there is no metal obstacle till five metres. When we were removing the debris, two pipes were found." Drilling work was halted on Thursday night due to a steel pipe, and resumed after cutting and removing it. Uttarakhand Chief Minister Pushkar Singh Dhami is present on the rescue site since Wednesday evening. Dhami has been interacting with the trapped workers from time to time and assuring them of their safe evacuation. Union Minister General V. K. Singh is in Uttarkashi since Thursday. Relief and rescue work, which entered the 13th day, is being carried out by scientists, international experts, NDRF, SDRF, BRO on a war footing. On November 12, an under-construction tunnel collapsed in Uttarakhand's Uttarkashi leaving 41 workers trapped. /IANS