openspaceman

Yup a worthwhile bit of targeted marketing

It doesn't blow off, when it reaches pressure it cuts the power to the 2kW motor, as pressure drops the switch cuts the motor in and stalls the genset. I still think of it as new :-(

Yes my mistake there, its =Pi()*5.6^2, paste that in excel to get m2 and then divide by 10000 to get to ha. That's a fair crop, better than what was planted on Kilvey Hill in 69.

My 4kVA genset actually won't start my 2kW compressor unless I start from an empty air tank.

I'll disagree with you there, the only reason the bore cut is above the fell cut is because the saw clutch cover has to clear the bottom of the hinge in order to take out the the middle of the tree that the bar cannot reach from the back. Not only does the retained bit stop the tree from falling it also pulls a long sliver from the butt when it goes. When I started ash up to 15QG was more valuable than oak of the same size, for sports goods and before hurley sticks were heard of in Sussex and Surrey. Ash was the species famous for what is now called barbers chair where the force necessary to bend and break the hinge exceeded the tearing of the fibres. A bore cut lessens the bending force of the hinge without weakening it because the hinge works on the principle that wood is most strong in tension if the hinge is correctly sized. If the tree sits back the tension on the front of the hinge prevents the tree going over backwards before the hinge fibres have a chance to bend, if it tries to go sideways its mostly the tension on the opposite side that holds it up with a significant contribution from the compression of wood on the side it is trying to go. That leaves it to bend the fibres in the hinge and topple until the gob shuts and the momentum snaps the hinge in tension. So taking out a bit from the gob face in the middle of the hinge doesn't weaken the hinge much but for a given width of hinge it lessens the force necessary to bend it significantly, in the same way Matteck advises a hollow tree has not lost significant strength till 30% of the wall thickness remains. So with high value hardwoods, especially ash, using a bore cut aided felling. We also used a shallower angled gob which otherwise would have closed too early and potentially split the stem coupled with thinner than the recommended 10% hinge to maximise saw timber. Incidentally if you consider the fell cut coming higher above the bottom of the sink you will see that as the fibres at the back of the hinge have little resistance to separating that the hinge has more height within which to bend the fibres often giving a bit more control. The trouble is if there is any spiral or sloping grain you need to keep the fell cut as close above the bottom of the hinge to make sure all the fibres in the hinge are working for you. Get the fell cut below the gob and the sloven pulls fibres from the tree rather than the stump, again ruining timber. As to using the bore cut to fell bigger than twice the operating bar length have a look at the attached graphic of an idealised cylindrical tree and consider how far a bar that is 40% of the trunk diameter has to be pushed into the gob, the limiting factor tends to be the front handle of the saw, so it makes sense to pencil in the buttesses and make use of flutes to make sure of severing all the central fibres.

Yes this is 0.1ha as near as makes no difference I worked this above, I make it 0.862 see my last post there are 10,000 cm2 to a m2

8607cm2 is 8607/(100*100)=0.8607m2/0.1ha=8.607m2/ha 8.60*8.34=71.7m3/ha

Past my bedtime but I suppose this depends on what the variation in top height is Per hectare? That gives a form height for NS of 8.34 and CP 9.11 8.34 times 86.07 equals 723.08m^3 norway spruce 9.11 times 86.07 equals 784.10m^3 corsican pine

OK as long as crane has closed cenre hydraulics and load sensing Very poor view point Self powered Heizohack with remote control fed by separate grapple loader makes sense to me.

You are right, that is what the form height does, so at 18 metres the volume per ha of true cylinders would be basal area times true height but because trees have different form factors either side of a cone the actual volume for norway spruce would be basal area times 8.35 not 18. There are a couple of ways to do this, easiest is to get a tariff number for each tree by running its height off against its dbh on one of the charts. The arithmetic method requires you to convert the basal area at breast height from your plots into a basal area per hectare. Then using your top height read what the form height is. As volume is area times height you then multiply these two numbers to give a volume per hectare. Please don't ask me about relascopes as I've had a 40 year mental block understanding them.

Yes, what heights do you want to compare, at 10m its 3.9 and 4.31, 18m its 8.35 and 7.64 I can probably scan the lot tomorrow.

I'm sure a modern 14-18V one would be fine, back in 85 my 12V one just managed to cut a 3/8 hose before being flat but still better than a hacksaw.

Yes the original James Jones butt plates had this, I had one of the Morse Starret impact cutters but towards the end I carried a cheap 2t genset and an angle grinder, fusing the wire ends with oxy-acetylene where necessary. I also enebeld me to quickly cut damages hydraulic hose.

Soft spliced eyes are good for quick release systems but wedge eye sockets are more practical for a permananet solution, after the knot is used to get out of trouble I used 2 soft eye splices and a quoit to join an extra lenght of wire rope for the occasional longer pull and being able to pass through the fairlead

I'll be a bit careful here as it's not clear to me which "same" instance. If your 4x4 qualifies as a dual purpose (the unladen weight of less than 2040kg with a modern diesel double cab may be the gotcha here) then you may tow a trailer (own goods or hire and reward) and not need an operator's licence. You will need a tacho if the gross train weight exceeds 3.5 tonnes unless you come under one of the exemptions for radius when carrying working tools but this exemption would not apply to deliveries of any sort.

Stallion lifting at Ditchling or ATS at Lower Beeding, get a quote first

These were THE logging bench in the 70s, availble 3 point linkage too, and the engine is economical. We used one for splitting rails and stake pointing as well as logs. I know of one person that lost some fingers on one and I wouldn't think it would be considered properly guarded nowadays.

I used to get brothers where one leg had stretched and failed, 7 and 10 mm, the 7mm take standard Kuplex choker hooks and the 10mm ones just about stood the stress from the 8 tonne Farmi. Never use 7mm chain with more than 4 tonne pull as the safe working load when lifting is only 1500kg. More recently I have seen the tester insisting the chains are destroyed after failing loler assessment when in the past they just cut the ID tags off.

If it's not then I expect it'll be 5/8 BSF and that is very close to the metric M16 LH thread the chap in Sevenoaks with the nice secretary will sell you. You will have to run a 5/8 LH tap down the cone, I have a mate with one if you're ever local to NW Surrey.

In that case 7-13 tonne 360 with rake, windrow at one end of the site as mulcher runs through it.

Yes if you take it off site you must deliver it to a licensed premises as it is a controlled waste. There is no legal obligation on you to remove it from site. It may be burned or buried on site but EA would like to know if you do and there are various specifications to adhere to.

The fungus may well be in the stem, attacking the wood, but the spores only develop in the leaves and petioles ( possibly buds and seeds) and this is what spreads the infection. I'm still not inclined to transport leaves and buds off site but then I'm no longer doing this work.

I'll be interested to see what quotes and exceptions you get. Standard premiums seem to be limited to 30 metres from buildings, airports and railways, stuff all use for most survey work.

I'm dubious at how these efficiency figures translate to actual use, they seem to work on the difference between the heat in a piece of dry wood and the flue losses in the enthalpy of the flue gases and again assume near stoichiometry. In practice as you increase moisture content then excess air increases so the flue temperature is distributed over a much higher mass flow. Also it looks like they can use a spot measurement which doesn't allow for the time constant on a massive stove. They assume smokeless combustion, as smoke is unburnt particles and represents a loss of fuel. I think the adiabatic flame temperature of dry wood is 1600C and 1kg of wood would need 4.5kg of air for stoichiometric combustion, so a total mass flow of 5.5kg. As a first approximation, because I haven't time to work out the specific heats of CO2 H2O vapour , Nitrogen and Oxygen at typical discharge temperature of 150C, I'll use a specific heat of air at about 1kJ/deg K. I also assume an ambient temperature of 0C. If we call the 5.5kg at 1600C losslessly discharged at the flue as 0% efficiency then burning the same piece of wood at 25% moisture content,150% air and a flue exit temperature of 150C then we have a mass flow of 1*1.25+4.5*1.5=8kg Energy from first example lost up chimney = 5.5*1600*1kJ and from second =8*200*1kJ which gives an efficiency of 81%, anyone care to refine on that? The last big (500kW) installation I monitored was running at 10% Oxygen in flue gas with 44% mc woodchip and a flue gas temperature of 180C and I would think this was a typical real world figure and 78% efficient. I too would be happy with 72% actual heat ending up in the room from a small stove. With electricity at around 12p/kWhr and 100% delivered into the room that piece of wood is saving 43p which values it at ~£430/tonne Mind you'd be better using the electricity in a heat pump cutting the cost to 1/3 at today's temperature here.

There was certainly not much sound wood left in that stump. Not a lot of indication from the crown just the flared base showing any reaction to the lost of strength. What how was your decision to fell based?