daltontrees

Maybe I have been a little harsh. In controlled situationsmaybe they are OK, but on a dirty site and pushing the saws as you do on a commercial job the Windsors snap like knicker-elastic.I should perhaps be retensioning new chains every 20 minutes, but frankly who has the time to do that?

Yesss! Finally killed the thread! That Newton knew his stuff, you english punters should rejoice in his F=ma type stuff. It is as important to understanding as is 'to be or not to be'. No, considerably more so.

Windsor chains are shockingly bad. The chisels are ok but I have never had the chance to see how they are after a few sharpenings because by then the tie straps have stretched and broken. I use them in one sitution only; when I know there is a 50:50 chance of hitting metal inside a butt. When new they will get through a nail or piece of fence wire. Then you can bin them and put on a real chain.

Just happy to have beaten Rob Arb to it for once. I want one of these, the geometry of the underside of the leaves is sublime. I shall investigate hardiness in Scotland.

Your recent poll and thread about this was very much in my mind as I posed this question. In your thread all the contributirs seemed to thrash out a realy useful perspective on compensation claims but I realise now I was left with a slightly unsatisfactory lurch about whether the dodgy-tree owner should put it in his diary to bang in a TPO application once a year to make sure he doesn't lose his statutory rght to claim compensation. Up here where we have a new form of government that doesn't question the recommendations put to it by the Cilly Servants, we have this riduculous 6 month period for claims; i challenge anyone to find a circumstance in which a claim for compensation could be succesful.

Lyonothamnus floribundus?

A useful clarification... I would add that for compensation to be payable the TPO would have to be confirmed, amn application be put in to do work on it, the application would have to have been refused and the damage would have to have been foreseeable and highlighted in teh reasons supporting the application. even then, the compensation claim would have to go in within a year of refusal. Does anyone other than me have abit of a problem with the last bit? In Scotland the period is 6 months. So if you have a steadily worsening tree that you are not allowed to remove but not bad enough to be dangerous, do you have to put in an application for tree works every year to make sure you always have the right to claim compensation?

Aargh! Yes I suppose so. It is a bit hard to get your head round but when moving at constant speed up or down no additional force is put on the anchor point or rope. So once you have started descending on a static line and have reached a steady, unjerky rate of descent, the load on the rope is the same as when stationary. To calculate what happens when you stop, you either need to know the time it takes you to stop or the distance over which you stop. Time is the easier one. Let's say you are descendign at 1 m/s. And you stop in 2 seconds. The deceleration is 1 m/s divided by 2 seconds = 0.5 m/s/s. The additional force on the rope is therefore F = m a = 100kg x 0.5 = 50 Newtons. The total force on the static line is therefore the dead load of 100kg x 10 m/s/s plus the deceleration load 100kg x 0.5. Total 1050 newtons. This assumes the treee is rigid and the rope does not stretch at all. In reality it's more complex than that, the tree and rope flex and store energy temporarily, reducing the overall rate of deceleration and reducing the load on the anchor point. And I forgot the first bit. As you start to descend you reduce the load. Say you get from o m/s to 1 m/s in 2 seconds. The overall load is reducxed by 50N, the reverse of the stopping calculation So the load in this example goes from standstill 1000N, drops to 950N as you move off, stabilises at 1000N for the descent and then increases to 1050N as you come to the ground. Then when you stand on the ground it becomes 0N. How quickly that happens depends on the gracefulness of the landing. I am assuming stopping at waist height then standing up. The load in your feet then becomes 1000N. 500N each foot.

LAZZzzzzz......

The descending climber would be accelerating, which is taking soem of the force that otherwise gravitational acceleeration would take. So if you descend and accel;erate downwards at 2m/s/s the effective gravitational acceleration is reduced from 10 to 8 m/s/s, reducing the effective load. The potential energy released is absorbed in the crotch and the hitch, manifesting itself as heat and/or mechanical damage. Reductio ad absurdum: if you cut the hitch like Adam did to dolly, the acceleration of dolly equals gravitational acceleration, and the load on the curtain rail is (10 - 10) x dolly's weight. This will equal zero, there is no longer any load on the curtain rail or the rope.

And that, my Arbfriends, is how to kill a thread!

The problem is, the guy's application was refused originally on the grounds of 'unsustainable location', so working round the tree is not the whole answer to his problem.

Uh oh, looks like saome basic physics is needed here. Don't run away, it's fairly easy. You need only one equation. F=ma. Force equals mass times acceleration. When you are hanging on a single line the force on the branch equals your mass (and the mass of teh rope and the harness etc.) times the acceleration which if you are static is the gravitational acceleration. it is about 9.8 m/s/s. Call it 10. 100kg x 10 m/s/s = 1000 Newtons (the unit of force). Or 1kN. If you think about it, this is why gear rated to say 30kN can hold 3 tonnes or 3000kg. F = m a. So in the example, the rope is resisting all of this force, so the load on it is 1000N. every action has an equal and opposite reaction. One of Newton's laws of dynamics. But if you pull up on the single line to go up the ways, and you accelerate at 2 m/s/s, you are adding that much to the acceleration of gravity, so the load becomes 100kg x 12 m/s/s = 1200 Newtons. The load on the rope therefore depends on how fast you go up, and is only greater than the static load while you accelerate upwards. It might not be surprising to know then that if you start to descend, the load on the rope decreases. Using a doubled rope is a little more complicated. When static, the load on teh branch is still 1000N, but the load on each half of the rope is 500N. As you ascend, the load on each side is increased by half the additional total load. If you were accelerating upward at 2 m/s/s, the additional load on each side of the rope is equivalent to 1 m/s/s which means each side is loaded 10 + 1 m/s/s = 11 m/s/s times half the deadwweight. Using f=ma again, the load is therefore 11 x 500kg = 600N. With ropes of standard rating 3kN or 3000N, neither SRT nor DdRT will come anywher near breaking strain. To do that you would need to (using our F=ma in reverse now) accelerate at a = F/m = 3000/100 = 30 m/s/s. That is, your upward speed would need to increase by 30 metres per second per second. After the first second you would have to be travelling at 30 metres per second. Now I don't care how fast SRT is, that aint going to happen unless you're being hoisted by a medieval battle trebuchet. The modest DdRT man would by comparison have to be pulling through 60 metres of rope a second and be body thrusting like Beyonce on speed.

No no no. You pull 2 foot through. The rope shortens by 1 foot on one side of the crotch and 1 foot on the other side of the crotch. To go up a foot you have to shorten both sides of the pulley/crotch by a foot. To do that you needs to shorten the whole rope by 2 feet.

DdRT is definitely a 2:1 system. Again it's one of teh advantages of it because when bodythrusting you shove yourself up a foot and pull 2 foot of rope through. You gain a foot for 2 foot of rope pulled through.

You need have looked no further than Arbtalk's fungi directory Ganoderma pfeifferi - Bees wax bracket - David Humphries’s Fungi Directory - Arbtalk.co.uk | Discussion Forum for Arborists I'm not saying it's G. pfeifferi. It may well be lucidum. That's on the directory too.

You can see annual growth rings on these brackets, they seem to be perennial.

The branch/fork/cambium saver in DdRT is the pulley! The friction in it is quite useful in bodythrusting, buying you tiem to advance your friction hitch. But the same friction is the thing that makes it hard work.

That's a little harsh. Tony's post contained a clickable link to Wikipedia's definition of countercoultire. Something like 'A counterculture (also written counter-culture) is a subculture whose values and norms of behavior differ substantially from those of mainstream society, often in opposition to mainstream cultural mores.' It goes on to say 'A countercultural movement expresses the ethos and aspirations of a specific population during a well-defined era. When oppositional forces reach critical mass, countercultures can trigger dramatic cultural changes.' Makes a SRT counterculture sound rather noble ands progressive. Now that's wortt a Teeshirt. Anyone got a suggestion of a suitable motto? I don't know Tony but I know of him here on Arbtalk as someone whose choice of words is first class. Please don't let your passion for SRT prevent you seeing that his comments were pretty objective and apposite.

Did he say you were outcasts? I missed that bit. Fair enough about muscle groups. A hard day's body thrusting knocks the heck out of me. It's fairly simple for me. I use STR sometimes to get into a tree, quite often to get out of a tree and rarely within a tree. It's just part of a repertoire of tricks and techniques. I don't intend to get a bumper sticker and tee shirt to say which camp I'm in. I kind of expected someone to suggest that if SRT is quicker a business will be more profitable or more competitive, meaning food on the SRTers table while the prussikers starve. Now that's a selection pressure!

I don't think you understood what he said. What would the selection pressure on climbers to use SRTWP be?

I'd largely go along with that. Please don't get your hopes up though, the Council must have due regard to objections but if it then cracks on and confirms the TPO, there is no statutory right of appeal. You could complain to teh ombudsman if you think you have been unfairly treated or you could in theory and with very deep pockets raise a judicial review. Focus on the question of whether the tree provides amenity to the wider public. That's the real test. I think the Council has probably satisfied the expediency test already.

You could even if you were using a base anchor.

It's not a course, it's a chapter. In a book called the Traffic Signs Manual. It's the 8th chapter. The chapter is devoted to the design and operation of signage and work sytems where the road is to be obstructed temporarily. It is there to protect workforce and to manage traffic safely and efficiently around the obstruction. It is for the employer to ensure that the health and safety of his employees is taken care of and that road users are not put at risk or unduly inconvenienced. Now in theory an employer can delegate responsibility of the design and operation of the signage to employees. But he cannot do so without ensuring that the employee is competent to do the design and to make sure the signage is set up on site properly. He can't just pass the buck. So if you work full time for someone there should be a clear understanding in place about who is responsible and that the responsible person has the right training. The way this operates within the organisation should be set out in the health & safety policy and should work its way through to the site-specific risk assessment and method statement if the contract requires one. If your employer is requiring you to design or set up signage (i.e. the typical cones and signs around the chipper, truck and worksite) and didn't specify in your employment contract that you had to hav ethe relevant training, it is your employers responsibility either to design and set it up himself or to provide you with the training to do so. It's the law, there is no contracting out of it. Insurers will run for cover if you have not complied with it. If it's not done right people can get hurt or killed. So the question, should you 'have' chaper 8, I suppose means should you have been trained in the correct design and operation of signage for temporary traffic managment around a work site in accordance with the Traffic Signs Manual? Someone in the organisation, the person responsible for the design and operation, must. Thereafter it is a case of what your employment contract says. If it says nothing about it, in my view if you are being asked to set up cones and signage regularly you should have been trained through your employer. I hope that's clear and helpful. Welcome to Arbtalk, by the way. Be smart and be safe and you may have a long and enjoyable career in arb ahead of you. An understanding of Chapter 8 is one of many many things you will pick up along the way. Arb is mored with health & safety, and there are good reasons for that.

It is for the Council alone to decide whether it is 'expedient' to make a TPO. One of the usual justifications is tha there is a real or perceived threat to the tree. Looks like the Council was right. And/or you have been out-manoeuvred. It doesn't really matter whether the Council TPOd because of a neighbour suggestion or not. What is jumping out at me is this. If the Council is satisfied with its reasons for refusing your previous planning application, there should be no reason to make the TPO. But if the Council perceives that you perceive (think about it) that removal of the tree would improve your chances of getting permission next time, it can make the TPO. It doesn't really matter whether that perception is justified or not. There is only one thing that matters. The TPO must be on the basis that the protection of the tree is in the interests of the amenity of the area. Is it a good specimen? Is it visible from public areas? Has the TPO just been served and are you therefore within the timescale for objecting?