Log Weight Calculator

[SW_IOWA_SAWYER]

Has anyone used the log calculator and checked it for accuracy. I have some logs that I want to pickup. It is butternut and the weight the calculator states is quite a bit lower then what the logger is telling me he thinks the weight will be. It is a long trip and I am limited on what the trailer will haul. Just trying to get a feeling for what the weight will be.

[beenthere]

Butternut is a pretty light-weight wood. What is the weight difference between the calculator and your logger? 

Do you have the size of the logs (possibly the big as well as the small end diameters and the lengths). Do you know what 'calculator' the logger is using, or what he calculates for individual weights for each size log?  Or maybe he is going by 'sperience' ?   

[Jeff]

We have this on the bottom of the lumber/log weight calc:

  This calculator is useful in providing approximate weights for species, but the user should be careful in how the product is used. Wood varies considerably in weight per constant volume (density) on a regional level and at the local level. That is, the weight of a piece of wood from one area or tree will differ from the same species in the another area. The growth rate is the most significant factor in determining density, with slower growing trees having a higher density (therefore greater weight), than faster growing trees. This is due to the late wood cells (the dark ring seen when a tree is cut) having thicker walls and being closer together than the early wood (lighter wood between the rings).
     Where the board is cut from the tree is another factor, the heartwood portion of the tree (the center portion, often characterized by a change in colour) is composed of dead cells and will be lighter than the sap wood, where the cells are still living. Wood that is cut from the portion of the stem that still has live branches on it will be lighter due to hormones produced by the foliage.

     In different areas, genetics will play a factor in wood density, along with the growing site (moisture and nutrient characteristics of the soil). Where the tree grows on the hillside, eg south facing versus north facing slope, high elevation versus low elevation, areas of heavy snowpack versus light snowpack, constant winds versus sheltered locations all have an influence on the density of wood.

[SW_IOWA_SAWYER]

He is telling me that he thinks butternut is in the range of 8 or 9 ponds per board foot in log form. I have tried two different calc and get between 5 or 6 pounds per bdft.

Jeff, I read the disclaimer information, I am just trying to get a feel for what others have experienced. I have flipped 12" dia 8' logs end for end so I know they must be fairly light.  I am just trying to figure out how much I can carry without going over my load limit.

They logs range in size from 16" dia. and down, and would be 8' long.

[Jeff]

I have been sawing red pine the last couple weeks. Some logs coming from one location, some from another, and I gotta think there is at LEAST 25 to 30%  difference in the weight of the wood. The one site has red pine that had between 10 and 12 growth rings per inch. The other, 3 or 4 per inch. You can easily guess which one is way heavier.  The Calcs are good for general estimations, but the results could actually be far from what you actually have.

[Ron Wenrich]

Butternut has a green weight of about 46 pounds/cu ft.  If you use a lumber recovery factor of 6 bf/cu ft, then you would roughly get 8 lb/bf.  That might not be that bad of a number.

[brucehuggins]

A cubic inch of water weighs .0361 lbs. 
144 cubic inches of water (BF) weighs 5.2 LBS.
A cubic foot of water weighs 62 lbs.

Therefore any substance weighing more than 62 lbs per cubic foot would sink in water. 

Observation and experience tell me that a butternut log will float so the question is how much less than 62 lbs per cubic foot does butternut weigh?

I accept the weight of 46 lbs per cubic foot as reasonable. 

So use the woodweb calculator, calculator here ( http://www.timberbuyer.net/toolbox.htm  ), or make a spreadsheet and compute the volume of your logs in cubic feet X 46.

You can verify the density (46lbs/cubic foot) by measuring the volume of a piece of butternut and the colume of water it displaces when you float it. Set up a ratio and you should get back a figure close to 46 lbs/cubic foot.

[extrapolate85]

This is a little late, but according to Smith 1985, "Factors and Equations to Estimate Forest Biomass in the North Central Region" Butternut will average about 52 lbs/ft3 in the log form (green weight with bark, but volume of wood only).

[JP]

After sawing some 12" pine I carefully waighed some and found the following: wgt per green  white pine per bf =3.46 lb=41.5 lb per cu ft I would think the 51 lb for Butternut would be a good figure---JP