Chainsaw Trousers & Electric Chainsaws

[CDMR]

I wonder whether the issue is around what happens if a saw on full throttle hits PPE. Presumably when a petrol engine saw jams up the clutch drops out and drive is disconnected,  whereas with a mains saw if you keep on holding the trigger (through panic, fault or whatever) you could have a very torquey, stall proof motor still trying to turn the chain. Am I right in thinking that mains saws are primarily direct drive without a clutch as the brake is generally electro-mechanical?

[openspaceman]

23 minutes ago, CDMR said:

I wonder whether the issue is around what happens if a saw on full throttle hits PPE. Presumably when a petrol engine saw jams up the clutch drops out and drive is disconnected,  whereas with a mains saw if you keep on holding the trigger (through panic, fault or whatever) you could have a very torquey, stall proof motor still trying to turn the chain. Am I right in thinking that mains saws are primarily direct drive without a clutch as the brake is generally electro-mechanical?

In ADW's post you will see that even if the drive is released at 60m/sec the electric chainsaw has the energy in the moving chain plus the rotating  heavy armature to dissipate, in the case of the petrol powered saw when the clutch disengages there is only the moving chain and the relatively light  clutch drum moving. So effectively  there is more force times distance for the electric chainsaw to stop.

 

It is ambiguous as there are other electric saws than chainsaws but I imagine much the same applies as circular saws probably get through layers easier.

 

Incidentally if you have ever had chainsaw trousers cut off you in an emergency, I have but not chainsaw related, you will be surprised how easily scissors cope with the layers.

 

It's not something I would have considered but if you look at the wiki article  the user that inserted the comment was from Sweden. Also at the same time in 2016 there is a person making a (entirely separate) comment  with the same forename and surname on Husqvarna's website.

[Khriss]

Bloody Internet nonsense,  is just yr chain speed and class of trouser. K

[outonalimb]

38 minutes ago, Khriss said:

Bloody Internet nonsense,  is just yr chain speed and class of trouser. K

If you believe everything you read on Wikipedia you would eat everything you see.

Wikipedia is full of unsubstantiated crap.

[Eglwyseg]

13 hours ago, NFG said:

Hi

Your post refers to a Wikipedia article, the text: "Protection is only given for gas (petrol) chain saws, not for electrical saws" to me, is slightly ambiguous in that it refers to an electric saw, not specifically an electric chain saw. Although the article title is chain saw safety clothing.

 

I looked at Husqvarnas website for their 536Li battery powered saw, as I dont have an electric saw and the chain speed quoted is 20 m/s. To me, 20m/s is 20m/s wether its electrical or petrol, I take the point that an armature contains mass & thus kinetic energy when its spinning, but so will a petrol driven flywheel. Edit: I agree with Mick D - the chain stops faster with an electric chainsaw of the ones Ive witnessed in use than a petrol one.

 

I would obtain the relevant clothing for the chain speed of your saw and if it really bothers you, go up a class.  In addition, practise safe working procedures to minimise the risk of an accident in the first place.

 

 

Thank you for this information.

 

I have checked the spec' of my Titan mains electric chainsaw and chain speed  13.5m/sec is quoted, while the stopping time once power released, 0.1 sec.  

 

The trousers I have ordered are class one, "Chainsaw Fabric Classification" up to 20m/sec.  I have spoken with the retailer over the phone who confirms this class as correct.  

 

As a retired furniture maker/designer/restorer, I have been used to working most machines the trade involves and on retiring, very happy to have all my limbs, digits and any other bits intact.

 

Chainsaw cutting is a late tool for me to handle and will be used only for cutting firewood for my own stove only but as with the other tools used all my life, I need to know with good discipline and the correct PPE, I will  be safe.  As an aside I also have a 4 ton log splitter.

 

Joseph

 

 

[TGB]

Doesn't matter what powers the chain's movement. The fact is, that the chain is moving at great speed. If the chain is at all capable of cutting wood, then it's capable of cutting flesh. PPE gets you so far but it's a properly functioning brain which is the best protection.

[Stubby]

5 hours ago, TGB said:

Doesn't matter what powers the chain's movement. The fact is, that the chain is moving at great speed. If the chain is at all capable of cutting wood, then it's capable of cutting flesh. PPE gets you so far but it's a properly functioning brain which is the best protection.

seems I have been lucky all this time then

[Rough Hewn]

When chainsaw trousers are tested, the power is cut then the saw swings at the material.
So whatever the saws's power source is, the throttle is released.
Just the kinetic energy of the chain to stop.
What worries me though, is what would happen if the throttle was still on full and you hit your trousers/boots...
I've been told they just cut straight through.
Anyone got any videos of this?

[Stubby]

1 hour ago, Rough Hewn said:

When chainsaw trousers are tested, the power is cut then the saw swings at the material.
So whatever the saws's power source is, the throttle is released.
Just the kinetic energy of the chain to stop.
What worries me though, is what would happen if the throttle was still on full and you hit your trousers/boots...
I've been told they just cut straight through.
Anyone got any videos of this? I saw a video of a pair of strides  tied to a saw horse and the saw was put onto them at full chat . It stopped but cut a good way into the material . Would have gone into your leg but not cut it off .
 

They do stop as the ballistic material wraps around the drive sprocket as it is intended . You do however get more penetration than you would with a coasting chain . 

Edited December 19, 2017 by Stubby

[Rough Hewn]

They do stop as the ballistic material wraps around the drive sprocket as it is intended . You do however get more penetration than you would with a coasting chain . 

Even with a big 90cc+ saw?
I've seen the video comparing composite vs steel toe cap.
Scary.