I transport firewood home in an Astro van and plan to stay under 1,000 pounds of firewood per load versus a payload rating of 1300 pounds because of rust. I measure the length, width, and height of each load and calculate the percentage of a green cord. Green cord weight tables are based on so many cubic feet of solid wood in a cord times the green wood density so the cubic feet of solid wood in a cord is important. Calculating the volume of solid wood in a cord of rounds turns out to be very easy and surprising. Fill a cord box with 2 rows of 2' diameter, 2' long rounds, and stacked two high or a total of 16 rounds. The volume of a round (cylinder) is half the diameter (or radius) squared times pi, 3.14, times the length. The volume of a box is length times height times width. A round with a diameter of 2' has a radius of 1' and 1' squared (1 x 1) is 1. Multiply times pi, 3.14, and the length, 2' and the volume of each 2' round is 6.28 cubic feet. 16 rounds times 6.28 cubic feet per round is a total of 100 cubic feet of wood in this cord box of rounds. A cord is 8' x 4' x 4' of volume or 128 cubic feet. A cord of rounds is 78% wood, 100/128. Switching to 6" rounds has the same result: 0.5'/2 squared times 2' length times 3.14 times 16 pieces in a row times 2 rows across times 8 rows high yields the same wood volume, 100 cubic feet. This shows the diameter of the rounds does not change the wood volume of rounds in a cord, 100 cubic feet, stacked as rounds or 78% of the cord volume. My last two Astro loads were bitternut hickory rounds which has a green weight density of 62 pounds per cubic foot and so a cord of green bitternut hickory rounds weighs 6200 pounds (100 cubic feet of wood in a cord times a density of 62 pounds per cubic feet). The stack measurements for two Astro loads of bitternut hickory rounds was 7 feet long by 3 1/2 feet tall by 20" lengths or 41 cubic feet (20/12 x 7 x 3.5) or 32% of a cord (41/128) or 2000 pounds (32% of 6200 pounds) for two loads green bitternut or 1000 pounds per load. These calculations suggest stacking as rounds or purchasing wood as a stack of rounds contains the most heat. The easy short calculation for weight of a wood stack of rounds would be length of pile times height times width times 78% wood times wood density. My pile: 7' x 3.5' x 20"/12 x 0.78 x 62 lb/cubic feet or 2000 pounds. This has probably been discussed before but it is new to me and keeps me occupied in these perilous times.
, I am not a number kinda guy, reading this post confirms what I already knew... Still not good with math.
I like crunching numbers too, but I'd load the mule, take it to the weigh station, and find out what that is vs the tare weight of the empty vehicle. Then adjust. Best bet would be to get a trailer and haul loads if at all possible. Trailers are easier to load and unload, and you can haul more. An Astro van at least has a frame, so towing a pretty heavy load is safer than what you could inside the van. I used my dad's Astro cargo van, roof rack and only 2 front seats to drive back to Maine with a buddy to retrieve my possessions, and my mustang that I stored for the winter, that following Spring. We then drove back in the 2 vehicles to Wisconsin. We packed that van, and had my canoe on the roof of the van.
For pickup truck folks: My Ford 1/2 ton truck manual says my 8' bed has 80 cubic feet of space below the bed rail tops. A 6 1/2' bed has 65 cubic feet of space. A 5 1/2' bed has 55 cubic feet of space. A carefully loaded full bed of bitternut hickory rounds filled flush with the top of the bed rails would weigh 3800 pounds for the 8' bed (80 x 0.78 x 62 lb per cubic feet), 3100 pounds for the 6 1/2' bed, and 2600 pounds for the 5 1/2' bed. Better switch to a one ton truck when carrying a full load of bitternut hickory rounds or only fill the bed half full when carrying carefully loaded bitternut hickory rounds.
As for me, I'd always take a load of split wood over a load of rounds and would not feel that I got cheated on weight or btu's either.
I agree. Most folks will not deliver a stacked cord of rounds or splits. But, I will look more favorably on my stacks/loads of rounds prior to splitting knowing they contain a lot of wood. I split most of the big bitternut hickory rounds today and bitternut is the easiest wood I have split. I used an ax head instead of a splitting wedge. I scaled one 8 1/2" inch round by 20" long at 41 pounds which calculates out to 62-64 pounds per cubic foot, right on the published density. The drying cracks are showing already so bitternut is right up there with sugar maple and ironwood for my favorite firewood, quick drying and a lot of heat (oak takes a long time to dry).
I hear you iowahiker but as for those "drying cracks" really don't mean much at all. All it says is that it has started to dry, but only on the very ends. I have always looked on them as meaningless. I've cut wood and seen the ends crack within a couple of weeks. Doesn't mean a thing to me.
If you know the total lenghts of the rounds, the diameter of the large end and small end, and the species, you can use this site to help calculate the weight of the wood. Log Weight Calculator at WOODWEB
After researching, this is my favorite source for data and information for green wood weight: Calculating the Green Weight of Wood Species Combining this data with a cord of rounds is 78% wood (the calculation above)/22% air is my preferred method for weight limited transportation.
It varies greatly species to species but most hardwoods are much more than that especially when green which he’s talking rounds so I’m assuming they are
Sorry for any confusion but I did use the word "green" in my first paragraph. I did not emphasize "green" because a stack of seasoned/dry rounds would also calculate as 78% wood and 22% air, i.e. rounds are rounds. Calculating the weight of a stack of seasoned/dry rounds would require using the dry wood density which is 42 pounds per cubic feet for bitternut hickory or 4200 pounds for a dry cord of bitternut rounds (100 cubic feet of wood in a cord of rounds).
The math on rounds to cords is a lot easier pi*r^2 * .78. If you take a piece of wood that is 1' in diamater you come out with 3.14*.5^2 =.785, which is very close to the 78% air factor that you have adopted. So instead of doing the pi math just treat your round as if it is a square. To figure the volume/cordage, square the diameter and multiply by its length then divide by 128, the air factor is magically figured right in. With logs I usually measure both ends and take the average, close enough for estimating.
