OK now, prepare yourself, this is a brainstorm type idea

The idea I propose is: To “Harvest about 1/5 of the eucalyptus trees in El Granda for several years in a row. Sequester the carbon in the eucalyptus trees by converting the trees into a 16 foot wide two lane wood bicycle path. The bicycle path would go from Montara to Half Moon Bay.  Sell the carbon credits to partly offset the project costs.”

This is an idea that addresses the following urban issues:

How do we reduce the eucalyptus tree forest that blankets a large portion of El Granada? How do we do it in a safe and relatively cheap manner that gets the most carbon credits and does not set off another round of deforestation problems. 

How do we create a safe, low carbon emission, environmentally friendly pathway for bicycles and battery assisted bicycles along the Coastside. How do we boost low carbon emission tourism?

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This proposal has a pretty simple series of inspirations.

First, some nearby eucalyptus trees that are not on my property have grown from about 90 feet to 140 feet in 7 years.

There are thousands of eucalyptus trees in El Granda that have sprouted from seed and outgrown their urban setting.

So the problem as I see it is how could we as a community address the eucalyptus problem?

I asked on Town Hall about a year ago if anybody knows a recommended “natural” replacement tree. No alternate tree mentioned. This leads me to a thinning approach: Cut a fraction of the eucalyptus community on an annual basis.

The next part of the problem is how do we cut eucalyptus trees on an economical basis. 

A high productivity approach would be to bring in big logging machinery to cut a lot of trees cheap with the local tree contractors doing the safer cleanup and chipping. Suppose we bring in a logging tractor, a crane and a flatbed logging truck to cut, limb and haul 10 to 20 big trees a day for $700 each. Leave the stump grinding, leaves and branches under 6” diameter for the property owner to deal with.

Now what do we do with the eucalyptus wood? Burning it releases carbon. Chipping it, or burying it in a landfill or using it in a durable structure are ways to sequester the carbon in the eucalyptus for a period of time.

The gentleman who runs the firewood business on Highway 92 tells me that one of the few things you can make out of eucalyptus is truck beds. You have to mill the eucalyptus wood and immediately bolt the planks to the steel frame because eucalyptus warps as it dries.

So this gave me an idea. Lets look at the extraordinary characteristics of eucalyptus wood as the material for making a prefab bikeway plank. Use a 2 layer core of milled trees,  the layers crossed at about 90 degrees. Make planks 16’ wide x 48’ long x 16” thick. Use melted polyethylene milk cartons and eucalyptus wood fibers to make a water proof top layer. Place these big planks on piers.

40,000 trees at 16” diameter x 26’ long = 6 mile ~> 50,000,000 lb carbon

A news item recently said that the price of oil was $20 a barrel on the day before the invasion of Iraq. Five years later, in April 2008, as I write, oil is regularly trading for $100 a barrel.

The price of oil is a major factor in the price to construct asphalt bike paths, High oil prices point to high costs to build bike paths.

So in this setting, I have continued to think about how to build an elegant, beautiful bike path using those extraordinary 140 foot tall weeds called “Eucalyptus”.

Eucalyptus failed to provide the railroad ties it was originally imported and planted for. Wouldn’t it be neat if we could design and build a bike path that succeeds as a structure because it utilizes the good qualities of eucalyptus?

Bike path made out of hex milled eucalyptus blocks, eucalyptus branches and matted wood fibers. Cap with a melted milk jug polyethylene top layer with heat embedded sand for traction.

Wood and plastic components:

Make the body of the bike path out of eucalyptus tree trunks cut into 18* high cylinders with 6 flats milled to produce a hexagonal prism with rounded edges. Drill three 4* diameter holes at 6”, 10” and 14”.

Make pins out of 3” to 4” eucalyptus branches.

Crush and roll eucalyptus stems to make sheets of wood fiber or wood splinters. Cross sheets and roll the assembly to make a “stick felt’. Try steam for dense felting.

Crush and roll polythylene gallon milk jugs with heating to make plastic top layer. Embed sand into the top of the sheet to make a traction surface.

Construction:

Grade the path: Make drainage and critter tunnels across the bike path as required. A tunnel could be shaped by laying some branches and pulling the branches out after the path is made. Test if layer of eucalyptus leaves or litter reduces wood rot.

Lay the 18” eucalyptus hex prism pieces standing on end in a tiling pattern. Hex shape objects fit together The eucalyptus stumps are different sizes of hex. so we lay courses of stumps where adjoining stumps are within 3/4” face to face dimension. Stumps from the same log would be placed up, down, up, down for similar end dimensions.

Pin the stumps together using 3 to 4” branches pounded into the 4” holes previously drilled.

Railing stanchions or curb for the edge of the bike path would be made of longer eucalyptus pieces.

Use a heavy duty floor sander to level the surface formed by the stumps.

Lay the mat of rolled eucalyptus fiber over the stumps. The fiber is intended to bridge the gaps between stumps so the force applied by the rolling bicycle tire causes a consistent and pleasant deflection that does not dissipate too much energy from the rolling bicycle.

Lay the sheet of sand embedded polyethylene milk cartons over the eucalyptus fiber mat. Slide sheet into horizontal slot sawed in curb. Bend sheet for 1 to 2” edge. Push edge into a vertical groove sawed through mat and stump