Can this tree be saved?

http://essmextension.tamu.edu/treecarekit/index.php/after-the-storm/tree-damage-and-hazard-assessment/repairing-storm-damaged-trees/

The tree (a spruce) is a good tree to plant near a house.  It provides privacy, many bird homes, and if it falls, it has many branches which cushion the fall, and protect the roof from damage because the weight is distributed.

1.4 ft diameter (17 “) at about 5 ft.  I’m estimating 80 ft. tall.  The tables that I’m looking at show about 3000 pounds.  Of course, the actual weight that would have to be supported would have to include a wind velocity term, and a surface area term.

A doubled line, with 2-3 points of attachment.  You would probably want to double up a 3/8″ cable for each point.  The points of attachment would have to be very big stable trees (nothing staked).  There are lower possible diameter aircraft wire cable that will apparently handle the weight.  Prices range from $60 for 3/16″ to $260 for 3/8″ estimating 500 ft.  The winch itself varies a lot in prices.

One could use a tow truck once the ground is less saturated (I could barely move my car because of the saturation, and it would blow the transmission on the car to use the car).  I think one would want to put down some plywood on the lawn for the truck to avoid damaging the lawn.  One would have to rebuild part of the fence, afterward, from getting the truck into the yard.

There’s a greener way to do this, with just people – it would mean about 25 people coming together and pulling in a couple of different directions roping at intervals along the path to uprightness in a coordinated way.  It’s easy to rope this tree because of the many branches.  At $50/person, plus the cost of the cable to secure the tree, and some costs for dirt and soil improvement, it could be done in a very green way for $1400.

In retrospect, I have overestimated the labor needed.  It is the equivalent of raising the cosine of an angle that is the arctan of 15/30 x 3000 lbs x gravity from 15 ft to 30 ft.  The sine component is supported by the ground.  Somehow, converting to kg.m.newtons, I end up with 15000 Newtons as the force needed to move the tree in incremental steps, which according to Newton’s law would require x people pulling 50 kg accelerating at y m/(sec-squared).  The base of the tree is 40 ft from the base of the house, and the tree’s center of mass at 30 ft (less than 1/2 of the height of the tree), would have to move from its current position about 15 ft. high to 30 ft.  So, maybe 20 people?  Or, a pyramidal structure could be built out of pipe, and a pulley hung from the top, and weights placed on the pulley to lift the tree.  The pyramidal structure could later be transported over to the garden area and covered with plastic tarp for the winter-garden.  This would mean less labor costs, but more infrastructure.  One could probably find the pipe from fences that have fallen.

The optimum direction for the tree-restoring force is going to be in the angle created by the vector of position transition from 15 ft to 30 ft.  The higher up you go on the tree, the less force will be required, but the tree could also break if you go too high, and it would not be practical to get the best direction if one is really high on the tree.

It could be a Thanksgiving project with food and beverages.  I have somewhat covered the roots with plastic tarp.  I am not sure how much time we really have.  The roof is not the emergency, but the ground should drain a bit.  Probably, Thanksgiving is too late.  I’ve contacted an arborist for a professional consultation.
Other factors to consider include:

1) How to increase soil stability around a newly replanted uprooted tree.

There is some interesting theory about how to do this.  I would probably need to do some more measurements to get internal frictional coefficients, cohesion, density, etc.

2) The rate at which root regeneration will occur.  Are there substances that can be added to the root system to influence regrowth rate?

3) The tree will probably not be stable by itself for a few years.  Is one willing to have long cables connecting it to other trees in the yard over this period?

I think that this tree can be saved.  The above link shows precedent under conditions that were more difficult than this.  There are people who are experts at moving large trees, and have tried this before.  That said, this was probably someone’s Christmas tree many, many, many years ago.  It might make firewood for the winter (not this winter, it would have to dry), musical instruments, lumber for a project, paper, and provide an opportunity for another Christmas tree to be transplanted.  The soil should certainly be stabilized – I’m just not sure how to help it to drain better.

Update:  a visit from the arborist.

Points of agreement:

1) The tree is still alive.

2) If the tree could be uprighted, cabling the tree would ensure that all of the risk if it did fell again, would be distributed toward the property.

3) The many branches of the Norway Spruce serve to cushion the impact so that there is virtually no damage when it does fall.

4) 5/16″ cabling with a hole drilled through the tree (not 2/3 up the tree, but angled at 45 degrees) would be adequate, but it has to be certified cabling (like what they run over the powerline), and more than one cable.

5) Possibly putting some sand in the ground at a distance from the tree would help to stabilize the soil.

Points of disagreement:

1) the actual weight of the tree.  I said 3000 lbs based on a table – that value may have been a dry wood estimate.  The arborist believes it to be 10000 lbs.

The density of the wood itself is estimated to be about 33-39 lbs/cubic foot wet.  A more precise measurement of density would simply involve taking a chip from one of the few dead branches, weighing it, and then calculating the volume of water or sand it displaces in a container.

2) the arborist has no experience lifting a tree of this size without a pull-through.  In an empty field, the arborist thought it might be done.  It might require a crane, (which I don’t think is very green).  That said, access to the appropriate angle to pull the tree would require a neighbor’s permission, or possibly the church parking lot next door, but it is not clear that the angle would be correct from this parking lot.  Renting a crane for a day is $20000.

I feel confident that the solution to this problem does not involve big machines.  I wish that someone would post some You-tube videos of this being done in Africa or Costa Rica, or for that matter Israel or New Mexico where the loss of one tree represents a disaster for things that need shade.  The birds and other small animals are still running through the branches.

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