What does a cube of dry logs weigh? Test

[Woodworks]

I think you will find a stacked cube is heavier than that Luke.

 

http://arbtalk.co.uk/forum/firewood-forum/64099-stacked-v-loose-logs-conversion-rate.html

 

but you had better check my maths again

Edited March 21, 2014 by Woodworks

[luke_mclachlan]

I think you will find a stacked cube is heavier than that Luke.

 

http://arbtalk.co.uk/forum/firewood-forum/64099-stacked-v-loose-logs-conversion-rate.html

 

the interesting thing is that this is the same conversion rate as used in Austria (1.4). However in the literature I've been reading, such as The Biomass TradeCentre II project | home, the norm seems to be ~ 1.58. The only thing I'd say against your analysis, and please don't take this the wrong way , is that you were comparing a "settled" loose load against a freshly stacked load. I can imagine maybe a 5% reduction in settled volume compared to fresh? Would be good with a new test based on fresh loads

Oh what a pain this new forum member is

[luke_mclachlan]

but you had better check my maths again

 

LOL oh yes you better be sure of that

[Woodworks]

the interesting thing is that this is the same conversion rate as used in Austria (1.4). However in the literature I've been reading, such as The Biomass TradeCentre II project | home, the norm seems to be ~ 1.58. The only thing I'd say against your analysis, and please don't take this the wrong way , is that you were comparing a "settled" loose load against a freshly stacked load. I can imagine maybe a 5% reduction in settled volume compared to fresh? Would be good with a new test based on fresh loads

Oh what a pain this new forum member is

 

I am so sad I did check to see if they had settled by throwing them back into another crate. Could not see any measurable difference.

[luke_mclachlan]

I am so sad I did check to see if they had settled by throwing them back into another crate. Could not see any measurable difference.

 

very interesting ! this weight-to-volume and loose-to-stacked stuff is very difficult all of a sudden, seems as though you guys are getting very different results to the men in white coats.

[Lucan]

Solid Hardwood 1m3 green = average 1000kg (ref blue book)

 

Solid Hardwood 1m3 at 20% MC = 750kg (ref blue book)

 

Conversion of Solid to stacked = 0.7 (ref blue book again)

 

=> Stacked Hardwood 20% = 525kg

 

Conversion from stacked to loose = 2/3 (ref previous threads)

 

=> 1m3 of loose hardwood 20% = 350kg

 

Do I get extra marks for showing my working?

[Mark Bolam]

Big ticks all round from me.

 

Helping a mate fell some oaks and I know some builder boys who have bought a processor who might be interested.

They are. 10 minutes from site on a timber trailer, mate wants £300/load.

8-9 t per load easy.

They then demand every load takes a 5 mile detour onto a weigh bridge.

I'm embarrassed I introduced them.

Builders, what can I say.

 

 

Sent from my iPhone using Arbtalk

[bobh]

Umm? Don't different hardwoods have different densities? If so then the weight of a cubic metre would vary depending on the percentage of different types of wood used.

 

Sent from my Nexus 7 using Arbtalk mobile app

[Lucan]

Bobh, yes but my understanding is once the most common hardwood species (the ones used for firewood anyway) have been dried to similar moisture contents, any difference in weight is relatively insignificant (<5%).

 

This document contains figures for kg/m3 for different species.

 

http://www.videncenter.dk/Groenne%20trae%20haefte/Groen_Engelsk/Kap_04.pdf

[bobh]

I know its American species but this shows a massive difference in the densities

 

 

This shows that the percentage of species can hugely change the weight of a given volume of logs.

 

Sent from my Nexus 7 using Arbtalk mobile app