Top handled chain saw use

This is an excellent training brochure from HSE in the UK.

http://www.hse.gov.uk/research/crr_htm/2001/crr01402.htm


Tom

A very good link. I've never seen anyone cut themself nor have I but I've seen a lot more close calls with a rear handled saw and usually due to poor positioning. Thanks.

Mike

I know a number of people with close calls with top handle saws. Most from 1 handing.

I guess I'm thinking of the 009 in particular where some feel they can 1 hand it but with better positioning they wouldn't have to. Where some rear handled saws they would never even try 1 handing.

Mike

The 009 can cut things? Man it must be better than all the ones I have ever seen

The little "report" had some good tips for beginer climbers, but as far as any useful information about top handled chainsaws, I found it to be useless.
They seem to take the stand that top handled saws are small and light, and rear handled saws are big and heavy. If you know about saws, you know this is false.
They also recommned holding the saw in unsafe manners, notice in almost every picture the arborist has his hands on the saw in a way that if kickback where to occour, the chain brake would not be activated. Even a moderatly skilled climber can position himself in a way to hold the saw properly with two hands.
Another interesting assumtion they make is that top handled saws were made for one handed use, show me that in the users manual! No saw maker in his right mind would ever recommend one handed use.
They also state that top handled saws have less kickback potential than a rear handled saw if used with one hand. This is wrong also.
The conclustions are all based on assumtions and incorrect information.
If for no other reason not to waste your time down loading and paging through this mess, this PDF is 70 pages long, with about one and a half pages worth reading.

Now, now, Mike, Why are you challenging the assertion that tophandles have less kickback potential? We understand that assuming equal power, weight and chain speeds the actual force will be equal. HOWEVER, the location of the hand is in effect the position of the fulcrum. Assuming equal bar lengths the rear handle saw is a longer lever providing increased leverage against the user's wrist-(In ONE HANDED use.) if we break the rules then the tophandle is safer and more comfortable to cheat with. If we follow the two hand rule then rearhandled saws balance better.

Brian,
It is true that top handled saws are small and light, but not all rear handled saws are big and heavy. Although it is true that some are big and heavy.
I'll try to explain it another way, top handle and rear handle discribe where the rear handle is placed on the saw, not how big or heavy it is.

I may be an idiot, drunk, or both, but I don't use drugs.

Stumpy,
Sorry, I missed your question.
Let me answer it with more questions. Why are top handled saws under fire? Why are top handled saws use restricted to specially trained proffessionals? Why are there a disproportionally high number of injuries with top handled saws?

You wrote:
" Assuming equal bar lengths the rear handle saw is a longer lever providing increased leverage against the user's wrist-(In ONE HANDED use.)"

I might have written:
" Assuming equal bar lengths the rear handle saw is a longer lever providing increased leverage against <B><I>KICKBACK</I></B>-(In ONE HANDED use.)

Mike,

You've made your point before about using small, light, rear handle saws in the tree. My guess is that you are in the very small minority of climbers, world wide, that prefer to climb with a rear handle. Given that statistical distribution, there is good reason to train climbers to use top handled saws properly.

Rather than banning one handed use outright with a weiner-type allowance in the Z133, it makes outlaws of most climbers. In the UK, they've taken a more pragmatic than dogmatic approach. They understand that there are times when it is safer to use a saw one handed. There are also times when, with proper procedures, a climber can use a saw one handed. Those times are very limited. Learning to identify those times is part of the training.

Both the US and UK agree that the climber MUST have two means of attachment when using a chainsaw. ALL of the time! I have to wonder how many climbers follow that rule. I just hired a woman who worked the last two years for one of the larger tree companies here in the Twin Cities. I'm puttin gher through chainsaw trainging. When I told her about one handed use she knew that was bad. I talked about two tie ins and she said that most of the climbers for the other company NEVER used a second tie in. At the end of the day, I think that the second tie in is more important for the climber's safety. BUT!!! not by very much more than two hands on the saw.

The site has many pages with lots of pictures. Using a dial up it might be a long down load. There is still value in the page. By editing the URL you can find some other information that HSE has made available. Arbos are better supported on the web in the UK than in the US by the government. Can anyone direct me to any US government training sites for climbing arbos?

Tom

i think that it is only logical that everything else being equal, that top trigger (where you have to hold the saw to rev it to get kickback) that divides the length of leverage against your hand, and places some of it as counter balance behind would give less kickback.

That trigger behind all of saw grip, places full length of saw as levearge against your hand, and provides no counter balance, or top position control to the kick. in 1 hand position. In 2 hand position, the points of support are more spread out with C.o.B. in between. As always in single pivot i think balanced first class lever position is best. Maintaining that imbalance, requires more effort. Also, that as single fighting point against this upward push, would be logically on top, rather than out from point of contact and not as firmly set against lifting force.

i think that Top trigger saws come more under fire, for they allow/invite more single hand use; and provide less leverage against kick in 2 hand position.

Or something like that.

Great Linx again Tom, here and Rope Curl, Thanx!

:alien:

Mike and Brian,

If you two are going to beat on each other, why don't you do it in private, outside. Strating flame wars inside threads or on the page is a really good way to turn people off.

How about each of you considering using your EDIT feature and get your pi**ing match off the thread.

Thanks,

Tom

Ok, I was critical of the artical because the heading made me think it was going to support top handled saw use and/or one handed saw use. In fact, the contents of the article would apply to rear handled saws as well. The bulk of the report was about body positioning and tying in twice, not so much about top handled saws. Then, I didn't think some of the information use to conclude the report was accurate or even correct. Don't try to tell me something I know not to be true, unless you can back it up. Even then I might argue.

I think every single cut made in a tree can be made with two hands on the saw, if you are a skilled climber. Those cuts they refer to at the tips should be made with a handsaw.
Similarly, every cut shoud be made with two tie ins, a skilled climber can also do this. If you tell me the majority of climbers cut with one tie in so we need to train climbers to catch themselves on limbs on the way down, I might say it might be better to tie in twice.
Simirarly, if there are many accidents with one type of saw, certainly traning is in order for the short run, but perhaps improving the saw with different braking systems, handle configurationsor whatever, should also be undertaken.

Mike wrote:
"perhaps improving the saw with different braking systems, handle configurationsor whatever, should also be undertaken"

In January I attended a course arranged by the national wood
care institute. I got to use a Husqvarna 346 xp with the TAC-system.
The TAC-system is a chain-brake that is activated by the right
hand. See attached image. I felled spruces and pines in
the woods for 2 days with this saw, no climbing.
I was certain that the brake would get in the way, but I didn't even think about it after a few minutes. If you try to hold the saw
in bad and unessecary possitions the TAC-brake will engage and if
you get a kickback and the left-hand brake doesn't engage, the
TAC-brake will.
This system is available on most Husqvarna models for an
additional $20 over here. Maybe in the future they will incorporate
a similar system on the top-handled saws.

Stihl has a handle chain brake that comes standard on their saws. It is called the Quickstop® chain Brake.

How much force or 'kick back' does it take to enable an inertia brake (lead in brake engagement handle)?

Is that realizable in small saws?

Is that patented to Stihl only?

i think top handles w/single hand are for informed, ready for kickback proffessionals, that know enough not to get kickback in the first place; and when they could fight it least, so set themselves up approporately; and limit the amount of times they do it. Surveying all strategies; using it as one of the last choices.

The position of the hand right over the upward push, and balanced positioning should give help along with awareness to the compromised position.

i think with 2 hands the stress of the chainsaw is not only on the 2 arms, but also somehow carried through the chest, making ergonomic arguments for 2 hand use, as well as switching single hand use viable. Also think it is less fatiguing to cut down with 1 hand, rather than up; as you can rest it on the work; locking the saw in with the bumper spikes, and pivoting on them. This i think is also safer, as the machine pulls itself into this lock when cutting down.

Mike, I won't argue with you about the ergonomics of two handed saw operation-The rear handled saws are superior for 2 hand use. The top handle configuration exists for 2 reasons (maybe more but these are what occur to me) 1. compactness. 2. improved control in one handed operation. You have made the argument before about the rear handle configuration providing superior leverage to resist kickback when operated one handed. Unfortunately, you are still wrong. Leverage is a function of lever length and fulcrum positioning. The greater the distance from input force to the pivot point the greater the potential output force UNLESS the output lever is lengthened proportionally. In one handed chainsaw use the hand placement becomes the fulcrum. A tophandle benefits you by: A. shortening the lever from input(bar nose) and pivot point. B. positioning some of the saw body behind the pivot point to serve as a counterweight.
Thanks for giving me something to argue about-I was starting to agree with far too many of your posts!

I would like to think the modern climbing methods being spread thorough the industry would include improving safety. The days of cowboy tree work should come to an end. Insurance companies don't want to pay the claims, tree workers don't want to pay the high insurance rates, saw maker don't want the liability.
Don't cry to me about the extra seconds it takes, or how uncomfotable the longer saw is, I've used both and know the difference. Same goes for any theories about top handles having more control over kickback.
Single tie ins, unsafe saws, and one handed saw operation should go the way of hemp rope, pruning paint, and tree topping.

i was trying to make same points as Stumper on 1 handed use leverage; but i guess he said it better (more understandaable?); so in addition to those 2 points of leverage and counterbalance (only 1stclass levers can have counterbalance, any other lever has pivot on end); i add again this... that having your hand on top of the saw; in most resistant direction to control kickback (and as good controlling weight over) is another plus of this 1 handed center positioning, over 1 handed rear end positioning; in addition to more control over the C.o.B. for such a kickback incident in center positioning of the hand. All of this is lessened by trying to cut over shoulder high i would think. i think these more compact, higher revving, light saws offer more oopurtunity perhaaps for

i think that there are a number of occassions where tight quarters, pushing something 'off' of you, drawing back quickly etc. that don't involve just simple positioning strategies to route around 1 handed use.

i use 1 hand when i need to, and try to limit that, and try to keep body parts, lines out of the axis of the cut. Either worried about cutting thru and hitting my knee, or kicking back into shoulder/neck/face; in 1 handed use make an extra effort to plot hazards of things on the line of the cut, up or down.

Mike are the casuaulty numbers you refer to broken down into diffrent aspects of injury causes, like new user to center trigger saw, new to high revving saw, new climber, kickback injury etc.?