In the first days of tunnel construction the blasting holes in the rock were drilled by hand. This was a slow and dangerous job especially for the man that 
held the drill bit. In 1866 the first pneumatic drill started to work in the tunnel. The picture to the right shows the air compressor building built along the bank of the Deerfield River. The compressors were originally powered by water supplied by a hand 
dug, half mile long sluiceway. The flow of water proved to be unreliable so the compressors were later powered by steam.
Here are the ruins of the compressor building today
The remnants of the turbine pits are visible in this photo.The blade of the turbine sat in the opening with the compressor on the floor above connected by a shaft.
Here is a slide of the old compressors.