Three Hills Lower Trail Corridor Completed

Sunday, 17-Aug 2014 @ 5:51pm

About 85mm of rain fell yesterday and overnight.  We inspected the new Casuarina and Three Hills start and were satisfied.  Most of the trail is dry and hard.  There are a handful of soft spots in low points where roots lie on a clay layer.  The mounds of mixed organic matter and excavated soil are soft and damp and good to grow.  All in all we were happy.  Any modifications will be very minor.

On the current Three Hills line, Ashley's drains and filled areas are going well when viewed in context with the overall status of the trail.  Sediment and water continue to pour onto the trail from the adjacent Centre Fire Road, so we were surprised a bit.

Our task today was to complete the new Three Hills trail corridor.  Part of the final project will be construction of a new "start" to Exit Trail.  We will have to build another 150-200m of Exit Trail. Other than clearing fallen timber, the controlled burn in Region 2 has basically cleared the corridor on that side of Centre fire road.

Let's start where we left off, looking down towards the velodrome trailhead

Climbing the trail, this is the point you will drop down towards the creek and into the lower drainage point of a 6.5m (outside trail line) radius, omega turn

Today we confirmed the centre point of the turn and measured the radius.  In the following pics you can see a shovel line at 6.5m from the centre.  The planned riding line will be at 5.5-6.5m.  The 6.5m arc will be the widest point of the rock wall in the lower half of the turn (although the base of that wall will be on a slightly wider radius again).   This radius uses the base of the dead tree we felled as the highest point of the planned rock wall.  There were suckers growing out of the base of the dead tree and we believe they and the big roots below the stump will continue to thrive and not rot away.  

We plan to use very large rocks and stone fill on the lower part of this turn, like on Brett's Trail, therefore raising the tread on the lower end of the turn.  Excavated soil from the upper half of the turn will be added to the rock below, also lowering the upper half of the turn.  The aim is a turn that can be climbed or descended confidently. It will be built with approximately a 1 vertical metre fall, not the 2 vertical metre fall the terrain currently presents.  It will also have a very durable base of massive rocks under stones and fill at the low point and therefore a reduced risk of erosion in the drain over time.  What it will retain is the thrill of a challenging turn that looks like you are falling into the creek as you descend

At the top, the omega turn allows nice flow between two large trees in both directions

Above that we use another omega turn to cross the current Three Hills Singletrack trail line.  It starts with a stony spur to climb, then crosses the trail and continues that climbing turn with an upper omega "exit" onto a new Three Hills section before finally merging with the current line

We will come back to that section soon, but first let's see how the new line will merge with Exit Trail.  After crossing the current Three Hills trail line, the new trail will enter a triangular intersection, with Exit Trail turning left after a big tree and Three Hills continuing to arc right below a little island of trees.  Here's how we go left

Closer to Centre Fire Road, the new Exit Trail will ride over an old fire road drain (that doesn't actually drain anything) and continue on its bank to the fire road crossing

Here's roughly where we go after the fire road

When it comes to the new Three Hills line, the most important thing is getting the turn through the intersection with Exit Trail to flow.  This intersection will have some interesting drainages built in when we finish, to accomodate a fast downhill turn and two climbing lines.  

It is better to illustrate this section as seen by a descending rider.  Those who know, know the bumper bar turn below the current Exit Trail intersection.  When complete, descending riders will have to take a left and then right flip-flop before passing over the bumper bar onto trail near the new intersection with Exit Trail

In the next pic you can see the line of the left turn down Three Hills and you can also imagine the Exit Trail intersection continuing to the right of the tiny sapling and medium tree already at right of the pic.  Three Hills will then continue via a left-hand, omega turn across the old trail line, off the stony spur and along the contour to the turn described earlier in the blog.  The radius of this turn will also be 6.5m on the outer trail edge!  Call it practice for the next swithchback

Here's a final look at the corridor leading up Three Hills Singletrack on the new line at the intersection with Exit trail

So we are ready to start making a sustainable trail out of the bottom of Three Hills Singletrack.  What may impact on that is that QPWS plans to execute a controlled burn in Region 1 before the end of August.  The rain this weekend has damped the ground and in a few days we suspect it will be time to light up.  For your safety, please be aware of any trail closures over the next few weeks.



ps:  New pics in from Doug's phone - measuring the turn radius on the lower switchback

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