Jump to content

Log in or register to remove this advert

openspaceman

Veteran Member
  • Posts

    9,299
  • Joined

  • Last visited

  • Days Won

    5

Everything posted by openspaceman

  1. I would expect the bigger danger to be from any elastic energy built up in what the choker is attached to. The choker will have a proof load which is about half the expected breaking strain. The choker proof load should exceed the winch bare drum pull. Good 7mm choker chain has a breaking strain of ~6tonnes. Yes we frequently winched trees of all sizes over before 360 excavators became common.
  2. Still have that number in my 'phone. I didn't realise he was hauling again.
  3. I araldited a 135 4 cylinder that had frost damaged at one of the pedestals that the clamp for the injector bore on, 1972 and it was still ok when it got exported to Pakistan some years later. Subsequently I used a local metal stitcher on a Holder gearbox, in those days (1986ish) he charged £10/inch of crack. I see there are several firms offering the service via google. The technique is to clean the crack and pull it together, or indeed insert a new piece. Then a series of pairs of holes are drilled either side of the crack, with a slot machined between them. Into this a tapered dumbbell link of nickel is hammered, these progressively bridge the crak. To make it leak proof overlapping screws are threaded into the line of the crack and sealed in with loctite.
  4. I sent a PM! We found the trouble with the Ryetec was it got so heavy on the back wheels the frequent long trips off the heath made significant ruts. Not to mention the heaps of cuttings dumped under trees.
  5. I doubt you are alone from the trucks I see. In fact I am astounded people I deal with don't attract more attention.
  6. Pine trees off sandy heaths seem to collect sand in their bark, you'll notice the spark as you cut through in dull light, converslly cut smooth barked species like hornbeam or beech coppice on wealden soils and even cutting a bit of clay inclusion doesn't dul, them much.
  7. Watch the line wrap: Planning Portal - Approved Document J First make sure that your local BCO ( or private one such as: Assent Building Control Ltd) will assess the installation for that price, it normally needs to be bundled in with other work to be economic. Schemes like corgi and hetas, whilst being apparently laudable have ended up like the old restrictive practices of guilds. Nominet seems to work the same way, they make it too expensive to register other than through a member and members get a huge discount. They give a commercial advantage in that the fitter can self certify his work. It becomes a form of pyramid where the installer has to have periodic inspections by a verifier and they all have to have a minimum number of installations and attend annual seminars at large expense to maintain their credentials.
  8. Many civils firms insist on compliance certificates and LOLER testing and you won't get past induction without them and CPCS for the machine driver.
  9. Yes that's my understanding but in my post I left off the words "are excepted" I meant Ten years ago the rules were that cranes needed independent inspection (as per LOLER) but 3pt linkage, front loaders, digger and grapple loaders where no one other than a driver protected by a fops/pops/rops cab was within the working envelope are excepted. And I definitely was not meaning to cast aspersions about anybody on this forum's equipment.
  10. I pay about 4p/kWhr(t) for gas and the boiler works close to 90% efficient. 5 tonne of wood at 40% mc wwb dumping flue gas at 160C will have a net calorific value of about 14MWhr(t). Boiler efficiency will be largely dependent on excess air which with wettish wood is likely to be high. I'd not expect much better than 70%. On that basis useable heat into the building with wood at £20/tonne is ~1p/kWhr(t) and doing the same with gas would cost £435 if my maths is correct, that's more than my annual gas bill but I do burn a couple of tonne of wood too. The firm I do some work for sell woodchip delivered in at ~30quid/tonne but chipping costs over £10/tonne so I'm sure they would let it go at this. The difficulty I see is a boiler that will take chogs from arb work, firstly they won't dry (hence my 40mc figure) secondly the gasifying boilers I dealt with wanted straight cord or cut firewood. There are issues with the gas evolution from slowly cooked large lumps of wood. Wood chip stoker costs seem largely fixed in that they will work with 25-150kW boilers but the cost benefit is best at 150kW. The only stoker I have seen built into a boiler that will also handle large logs doesn't seem to be the cleanest burning, I own one and wish I had the energy and money to modify it. The Kobs I worked on would not adapt at all and of course they would no longer be compliant in their type approval. My old boss does still have a Veto head that could have a firebox and boiler built around it to accommodate large logs, it would be an interesting project.
  11. I'll consider the prices right when people no longer chip to waste on roadside work. As far as I can see prices are lower now than a year ago when the delivered in price of chip was the same as the delivered in price of hardwood pulp ten years earlier.
  12. Ten years ago the rules were that cranes needed independent inspection (as per LOLER) but 3pt linkage, front loaders, digger and grapple loaders where no one other than a driver protected by a fops/pops/rops cab was within the working envelope. There is still a duty under PUWER to maintain the equipment in good working order.
  13. As others have said you must check the plate but pre 2004 transit 350s seem to have a max trailer mass of 2250, difficult to tow a >6" tracked chipper behind. Some time after that one could buy a 350 with a towing mass of 2800 but the axle ratio was higher to accommodate.
  14. "Waste" being an operative word in this context. At best you may claim the wood to be clean untreated biomass ( no paint or chipboard glue?). The leglislation will have bearing on the size of plant. 15 years ago I would have looked to the Hurst boiler company in america, I'm way out of touch now. Then it was reckoned the smallest viable plant with a steam turbine was 3MW and cost millions. This is about 30 times more than your need. Most CHP plant need to run 8000 hours a year to be cost effective. There are numerous small scale attempts of doing this by gasification, have a look at GEK from California for a cheap learning unit. Any other gasifiers I'm aware of outside the third world haven't stayed in commission long. Variious reasons often to do with pollution and low engine life. If I had to do it I'd probably use high temperature charcoal if the feedstock were free. The most recent costly project that wasn't quite working was the one at the University of East Anglia. Other possible routes to electricity from wood are direct combustion gas turbines, that worked quite well but relatively low conversion efficiency. Indirect heated GT, Talbott built some but major problems with heat exchangers. Solid oxide fuel cells, been just 2 years from launch by Siemens and Rolls Royce for 10 years now and simple semiconductor thermopiles as used in space craft and russian army, high cost and low conversion, Caterpillar got one working at 5kW on a large truck exhaust.
  15. I thought it was 24ton (24.39 tonnes). By the time you consider other legislation about axles and power to weight ratio you'll see it's pretty difficult to pull an agricultural rig with a payload of 12 tonnes even though many large grain trailers are rated at 15tonnes. Can you get a modern 150hp tractor weighing <6 tonnes?
  16. I have no knowledge of semisynth oils but generally veg oils are better lubricants than mineral, especially at elevated temperatures. Castrol R (castor oil) was the stuff teddy boys added to their fuel to make a bike smell like a race track. Indeed a vsit to a motorcycle scramble in the 60s was full with the aroma. It also adheres to metals better becase it has polarity that attracts it to the metal. I got the impression that it didn't pump qute as easily so , in my case, it may not have oiled as much as ideally.
  17. I was never able to get cherry pips in sufficient quantity but they and olive pips work well as is in a pellet stove.
  18. single stage ground source heat pumps seem to have a COP of about 3 when delta T is no more than 10C, great for spring and autumn. I do think they complement a woodfired system but would still use the boiler for DHW as the heat pump is far less efficient at heating water to 50C.
  19. You've hit a couple of nails on the head there, Sweep auger systems under the hopper are a pain it the backside although they are cheap and suitable for grain or pellets.. They always fail when the hopper is full. Points of failure are interesting, the original models I dealt with used the auger to provide power to the gearbox for the sweep auger in the middle. After the auger jams a few times it gets out of true and over then next few weeks gradually fatigue fractures. Welding it up just makes it more rigid and it fails even quicker. The reasons I have seen for the auger failing are also interesting and, to me, counter intuitive. The obvious one is slivers bridging the flights and then being carried forward on top of the auger to be impacted into a mass at the auger exit. G30 specifies no slivers over 100mm and presence of these loses you any warranty claim. The one that confused me most was some dry woodchip from a joinery firm which was dusty. With high mc chip dust is not a problem as it sticks to the bigger chips but in this instance as the silo emptied and was regularly topped up the dust gradually worked its way to the bottom and settled on the bottom of the auger trough where it compacted. As this layer built up the auger ran on it but was bowed upward until it jammed on the top side of the trough and brought the system to a halt with initially a motor thermal trip and later as they fooled about with the current overload sensor, snapping the drive chain.
  20. The difference is largely down to capital cost. The woodchip is fed into the boiler concurrent with the air supply so easier to get the combustion rigt. Very hard to get chips to a G30 W30 spec, even if the supplier tells you it is. Much easier to stack and dry cordwood.
  21. I used straight OSR from the grocers from about 1990 till I packed up proper work a few years back. No problems except maybe a perceptible increase in bar wear. A chap who went to university after cutting for some years did his thesis on veg oils and basically told me to go for the cost saving of ordinary cooking oil. Big problem if you park a saw up with it as it oxidises on the chain and the saw grows green fur. When I started it was common practice to use sump oil and we hated it as much as the arbrex. It is also definitely implicated in scrotal cancer, the first known industrial cancer which was identified in young chimney sweeps, a resurgence occurred in the US and was traced to young mechanics putting oily hands and rags into their pockets. Benzo(a)pyrene is a product of incomplete combustion found in soot, tobacco smoke and sump oil.
  22. I think you have that right, I hadn't realised Laddomat was a make of back end protection. Yes they work just like the thermostat and water pump on a car engine, if you take one apart, as I did with one of a different make, you will probably find the waxstat looks just the same as the one from a car. All the time the water in the boiler circuit is <60C it circulates it back to the boiler return, as it gets toward 60C the waxstat opens and a small amount of hot water is directed to the heat load, with a similar small amount of cold water blended into the boiler return. When all the boiler circuit and the return circuit is above 60C the waxtat is open fully and it then blocks the recirculation to the short circuit to the boiler retuirn. In larger installations the valve and thermostat are all electric. It's not an uncommon problem and I have experience of a complete talbot C150 install where this vital back end protection was left out. The client became so disillusioned that they had scrapped the boiler after 3 seasons because the firetubes were fouling with tar, poor woodchip aggravated this, before I could advise them.
  23. I have the G9 and don't trust Canon because it has died because of a generic fault with loose screws shorting the DC board. Geotagging is not a big issue if you have a smartphone or gps device, make sure the gps is on and has lock, either synchronise the camera and gps or photgraph the time on the device and then use software like gpicsync to tag the files.
  24. It was a regular thing before chippers became ubiquitous, turf up a bit of rough grass, burn arisings, go back and rake ashes next day and if cool replace turfs. not on Tuesdays as that was washing day. He can get an exemption for burning up to 10 tonnes of plant material a day on an open fire as long as the plant material is produced on the site e.g. one cannot bring arb arisings to a yard and burn them. In practice nothing is likely to be said as long as dark smoke is not emitted or
  25. It is about stratification, keeping a hot body of water sitting on top of the unheated water underneath. Water is a poor conductor and as hot water is lighter than cold ( until 4C) there is little heat transfer from top down. If you introduce hot water at the middle of the tank it rises through any cool water above it and mixes as it does so, producing a layer of warm water at the top. If you introduce the hot water at or near the top there is less opportunity for mixing and the top remains available to draw off as hot water from the top.

About

Arbtalk.co.uk is a hub for the arboriculture industry in the UK.  
If you're just starting out and you need business, equipment, tech or training support you're in the right place.  If you've done it, made it, got a van load of oily t-shirts and have decided to give something back by sharing your knowledge or wisdom,  then you're welcome too.
If you would like to contribute to making this industry more effective and safe then welcome.
Just like a living tree, it'll always be a work in progress.
Please have a look around, sign up, share and contribute the best you have.

See you inside.

The Arbtalk Team

Follow us

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.