meanwhile, provincial engineer edward dobson submitted his own plan for the completion of the tunnel from the workings left behind by smith & knight. the biggest problem faced by the previous contractors had been encountering water which leaked into the working faces. this made drilling difficult, slowing progress. dobson proposed the boring of additional shafts from both ends which would eventually drain the excess water. the work commenced with 340 men at an estimated cost of £42,800. only 96 yards had been driven in the shafts before the next contractors took over the work six months later.