TDOT has offered its assistance to the National Park Service to handle a huge boulder that tumbled down the side of Lookout Mountain on New Year's Eve and landed on the Hardy Trail just above Scenic Highway.
Jennifer Flynn of TDOT said, depending upon approval of the NPS, the work should start Tuesday of inserting an expandable grout into the big rock that will cause it to crumble over a few weeks time.
She said, "In this process, holes are drilled into the rock and an expandable grout is inserted into them. As the grout expands, the rock cracks from the inside, breaking up the rock into manageable pieces that can be hauled away. This process is advantageous because it's a non-explosive method to deal with this rock, which also makes it safer than blasting, plus it is much more controllable and predictable than blasting is. Although blasting is quick, there is always a danger that it might dislodge other unstable material. The expandable grout takes some time to work, but in this case it is the best way to go.
"After the rock is broken up, we will remove it with a small track-type bobcat loader so as to not damage the terrain or the pathway.We would use a larger piece of equipment but we are afraid of the damage that we would cause to the pathway and park property.
"As for how long this will take, it depends upon the air temperature. The grout works better when the temperatures are above 50 degrees."
She said, "It is hoped to have it completed within the month, however it could take longer. That is, of course, if this is the method that the Park Service wants to use."
Ms. Flynn added, "Although technically this is not a TDOT problem, we have offered our help to a fellow government agency because we are accustomed to dealing with issues like this and have access to the equipment needed to get the job done. We want to help them be able to reopen this important trail as soon as possible so the community can take advantage of this special asset."