Archive for the ‘ Silver Comet Trail ’ Category

measuring the grade

Thanks to the Hilti company for loaning me one of their super accurate laser levels for the weekend. I spent a portion of Friday and Sunday afternoon-evening taking measurements on the the tunnel gradient. Good news, the tunnel is definitely going downhill to the west and we will have no drainage toward the east entrance. Total elevation drop east-to-west is 30″.

I must say that it is really nice to have access to some first class equipment to do these measurements. The Hilti level is accurate to 1/16″ in 300ft, self-leveling with a detector that tells you how far you are off zero with audio cueing. There’s no guessing with this data, I took readings every twenty feet over the measured 723ft of the tunnel. Very kind of the local Marietta office of Hilti to help us out. Still need to plug the data into a spread sheet to calculate the height of the curbs we will need to divert the water out the west end; however, reviewing the raw numbers, it looks like the 2″ height for the curb I was thinking of will be adequate for most of the tunnel. There is one “bump” ~60ft in length on the norhside of the tunnel that will require some lowering to make the curbing work efficiently.

Hilti laser detector

(Click image to enlarge) In the enlarged image you can see the red light from the rotating laser beam. The self-level feature made this soooo easy. Just attach the laser to their tripod and press the “on” button. It was ready to go in about a minute! Hilti provided everything except the sliding transit stick which I had to buy from Home Depot… the $50 dollars was well spent as it made the measuring process easy. Just slide it until the detector read “zero” (like the photo) and read the height on the stick.


Butterfly

Butterfly


Also managed to sneak in a photo of a butterfly that was visiting our work site. Sorry that the macro quality on my camera isn’t the best, but a colorful subject.

Brushy Mtn Tunnel, update July ‘10

We’ve achieved some amazing results with our clean-up efforts at the Brushy Mtn Tunnel on the Silver Comet Trail. Dry weather during early July rewarded us with a nearly dry and mud free tunnel to ride through. (Click images to enlarge)

Brushy Mtn west

Brushy Mtn Tunnel west entrance, early July

Inside tunnel, near the east entrance:

Inside tunnel, early July '10

However, with the return of warm humid weather, the cool interior temperatures of the tunnel cause a rapid transition. The high humidity causes the formation of tunnel fog. In early morning you often can’t see the other end of the tunnel. Wisps of fog emanating from the tunnel form “tunnel ghosts”.

Tunnel Fog

Tunnel fog, approaching west entrance to tunnel.

Tunnel fog at west entrance, the east entrance is not visible due to the dense fog.

Tunnel fog, early morning.

Tunnel fog, early morning.

As the exterior temps and humidity rise, the tunnel walls begin to condense water. The condensing water trickles down the walls and pools on the tunnel floor.

Condensate on tunnel wall.


If you click and expand the image to the left, you can see condensing moisture running down the tunnel wall and pools of water forming at the base of the wall.

When high humidity and warm temperatures persist for several days, the interior surfaces of the tunnel will become saturated with moisture. During the late evening, the interior lights of the tunnel and evening sunlight from the west entrance can form a shimmering effect on the moist tunnel walls and floor.

Evening at the tunnel.

Evening at the tunnel.

I don’t like the tunnel being so wet, but it is a pleasant visual treat and dramatically demonstrates how the water accumulates in the tunnel.

SCT Hwy92 and Old Harris

Worked on the Hwy92 bridge section of the Silver Comet Trail today. Build-up from erosion has been forcing mud onto the trail at this point and creating a hazard. I had removed the mud from the trail previously but didn’t have time or a plan to address the real source of the problem. Sorry, no before pictures for today’s work. The plan that I came up with was to create two berms to channel the silt laden runoff away from the trail. I then created a runoff channel adjacent to the trail. I was able to merge the three channels into the existing natural runoff.

In this image you can see the trail runoff channel on the left and the upper silt berm to the right. (click images to enlarge)

Upper Silt Berm and Runoff Trench

In this image you can see the drainage channel and the lower silt berm. A lot of material had to be moved to create the berms and drainage channel, as accumulated soil was well above the level of the trail. If I had more time and energy I would have extended the runoff channel as sections are still encroaching onto the trail. These mods will get the job done for now.

Lower Silt Berm and Drainage Channel

On the opposite side of the bridge, the silt accumulation had formed a bog with several inches of standing water. I was able to open the drainage and the bog is now draining.

Bog at Hwy92 bridge.


    Erosion Control at the new Old Harris bridge


A professional erosion control team came in and did an outstanding job of cleaning up the potential disaster area at the new Old Harris bridge. This action prevented imminent disaster as the hillside was on the verge of failing. I don’t know who was responsible for getting this work completed, but it was timely and well executed. The huge amounts of accumulated silt were moved, the drainage re-contoured and straw-matting was secured to the slopes.

Before:
In this image the silt was a foot high and the force of the silt had broken the fence stake.

Massive silt accumulation at Old Harris bridge.

Muck had accumulated into an sludge pool.

Massive silt accumulation at Old Harris bridge.

After:
What an amazing difference. I hope we can get this team to repair other areas of the trail.

Old Harris bridge erosion control.

Old Harris bridge erosion control.

Overall the work was excellent. I wish they had removed a section of slumping (see image below), but the drainage provided should be adequate. I hope they re-seeded as part of the process.

Slumping on South side.

WG@frankie’s.tunnel

WG at the Tunnel

Frankie had a cute idea. With all the work we’ve been doing at the tunnel, what better than a photo of me at the tunnel.

(click image to enlarge.)

Coots Lake Mirror

Coots Lake Mirror

We rode from Coot’s Lake this morning. While getting ready to ride, I happened to notice the mirror like calmness on the lake. Pulled out the camera and shot this photo.

(Click image to enlarge).

Brushy Mtn Tunnel, Amazing Results!

The tunnel as we started Sunday morning.  These guys wasted no time, they had already shoveled the mud  into buckets that I had piled up on Friday and hauled it off down the trail.

(click the images to view enlarged).

Brushy Mtn Tunnel when we arrived.

Tuesday evening we rode out to the tunnel to inspect the results of our efforts.

Can you believe the difference???

The tunnel east entrance, Tuesday evening.

The Brushy Mtn Broom Brigade ROCKS!

 
What a wonderful bunch of folks, they worked hard and made a difference.

Brushy Mtn Tunnel workday #2

Thanks to Tibike and Hollywood for helping. We were able to clean-up an area that has been a problem for years, with some very dramatic results.

SCT Brushy Mtn Tunnel East entrance Friday 5/28

This is what we started with on workday #2. 1/2″ thick muck you couldn’t even walk on. To trim the silt fence I had to get Hollywood to shovel me a path.   While HW and I worked on the entrance, Tibike worked the mud problem in the tunnel, moving it over to the wall, we ended up with about 2″ of mud accumulated along the wall.

Brush Mtn Tunnel east entrance 5/28/2010

It didn’t take too long and we had cyclists using this space.

Tire tracks in the cleaned section.

After trimming the silt fence back for trenching. Tibike suggested we put the trimmed section at the tunnel entrance. Great idea! We trenched about 8″ next to the wall and trail to bury the silt fence. With a 2lb sledge we were able to get the silt fence sunk deep enough to secure the bottom with rock. We then covered the rock and fence with dirt.

the next day….

SCT Brushy Mtn Tunnel East entrance Monday 5/31

What an amazing difference. After ~1″ of rain the previous night there is absolutely no muddy runoff. In fact the rain has washed most of the residual mud off the concrete.

Tunnel entrance, mud and silt fence

(Click the image to see details.) In this image you can see the great job Tibike did accumulating the mud against the wall of the the tunnel, the placement of the silt fence and especially, note, there is NO new mud flowing into the tunnel even with 1″ of rain during the night!

Detail: tunnel entrance, silt fence

Detail at the tunnel entrance.  Look Ma, no fresh mud!  A small rivulet of clear water was actually flowing along the wall in this photo, but no mud.

Equipment trailer loaded with gear.

This is the trailer I got from Nashbar to haul gear to the work site.  It’s attached to my Surly CrossCheck rain bike.

the Brushy Mtn Waterfall or Mudfall?

The Brushy Mountain tunnel on the Silver Comet Trail has been a mucky mess, of varying degrees, for several  years.   We’ve had riders go down in the slick muck and the recent rains, of record intensity,  have washed a lot of mud into the tunnel.   Many of us now just refuse to ride through the tunnel as the passage will leave  bike and rider filthy.   I don’t have the time to clean the bike after these trips nor do I appreciate having my back side splattered with muck.  For the Polk County community there is a negative impact,  many cyclist will no longer make the trip to Rockmart.  Calls to the county have had no results, perhaps because the tunnel is in Paulding County, not Polk?

I miss those trips to Rockmart and some of the road loops that we’d use the tunnel to get there.  Our primary distance route, the Land of Sunsets Century also went through the Brushy Mtn Tunnel. This photo, taken in May 2004,  shows the mud flowing onto the trail.  The problem has gotten much worse over the last six years.    This is really a shame, as it is a beautiful section of trail to ride on, with  jagged rock walls covered with native plants, mosses and ferns lining this section of the trail. 
Summer Solstice 200K
With the third annual Summer Solstice 200K approaching it was time to make a decision.  Either change the route or fix the problem with the tunnel.
Based on recent success with fixing another mucky section of trail around mile-marker 16 on the SCT, I decided to give this “larger” problem a look-see.   On Wednesday evening a few of us rode to the tunnel entrance and I saved off a waypoint marker on my Garmin 305.  I knew Brushy Mrn Road (gravel) passed over the tunnel but I had no idea where this would be as the trail can’t be seen from the road.   My plan started by driving the road and see how close I could get to the waypoint I had saved on my Garmin.     This is where today’s “adventure” began.
Today…
My goal was to try and find a way to divert the water higher up the mountain and prevent it from entering the railroad cut and the Silver Comet Trail at the base of the those rock walls.
My plan for finding the tunnel entrance from the road worked well.   I could see the route track from the Wednesday ride and the two waypoints I had set to mark the tunnel entrance and the point I’d have to hike to access the trail.
Hiking to the tunnel entrance was easy.  No barbwire vines or poison ivy.
Above the tunnel entrance I found an existing network of silt fences.   The top of the tunnel entrance and trail below are in the center of the photo.  Not easy to see, the black horizontal bar is the top of the tunnel and gray is trail concrete.
What I also found was  unfortunate. Two large ravines drain into this area. There is already an extensive amount of silt fencing above the tunnel entrance and along a dirt road on the south side, which is likely an access road for phone cables.  There is a bog up the ravine that the current water problem is coming from and the water has channeled under what what looks like a primitive road that had formed a small dam.
This is a photo of the bog that is feeding the waterfall.  The water flows out the channel (lower left of the photo) and under the natural bridge I was standing on.   As you can see from the photo.  This ravine drains a rather large area.  No way this was going to be diverted.  Fortunately, the ravine above the tunnel entrance drains a much smaller area and not a continual problem.
the Plan…
Well, I guess I could have just given up, went home and popped an MG64, but that would be too easy for a webgeek.  I went home and thought about it.
I’m going to get a length of silt fence and see if that will help.  Next stop Home Depot.   Silt fences come in 100ft lengths, they’re not light either.  Humm, I’m an old guy.  Carrying a silt fence + gear around hiking down to the work site ain’t gonna be fun.
So there I am, back on Brushy Mtn Rd, loading up my Camelback with a 2 lb sledge, scissors, snacks, water, gps, etc.  So off I go.  Silt fence and shovel on the shoulder, ouch.  So I decided an a two forked approach.  Slow the flow of water and re-direct the flow along the trail.   I started with rolling up one section of fence (two stakes) and putting it at the mouth of the channel under the natural bridge and a second section across the channel.  That should slow most of the torrents during bigger rains, at least for awhile.   Sorry, no photos.
Next, hiking down to the trail.
It was a much longer hike.  As soon as I had a clear shot, I slid the remainder of the silt fence and shovel down the rock wall.  Phew, that was a relief to get rid of.   Heading east to the next ravine I was able to easily climb down to the trail.  My plan for the trail section was similar to what I did with the natural spring near mile marker 16, which to divert the flow along the side of the trail, not across it.   I probably had about 70ft of silt fence left to do this with.  At this point I could have really used a hoe to create a channel with.  The shovel would have to do.
Here’s what it looks like.  When I left it was actually working and channeling the water down the side of the trail.  It’s not finished and temporary at best. A meager effort, but it might help for the Summer.  We had a good rain tonight so that will be a good test.
Maybe I’ll see ya in Rockmart?
Yes, that’s TomA in the photo.  He showed up after all the work is done.  Serotta:Rick stopped by too, but I missed getting a photo with him.