DMM Impact Blocks| Designed for DYNAMIC loads

Eric Frei · 6th July 2010, 10:54 AM

Have a look at these babies, just beautiful.

Two sizes, 40Kn and 60Kn WLL .... that's 4000kg and 6000kg Working Load Limit guys. Also PDF attached. Not sure of the cost but there's certainly a market for stronger blocks.

Also a warning to remind all readers that rigging forces at the block are far greater than the the weight of the piece being cut, as rule a minimum of double the weight of a cut piece and as high as 10X the weight of a cut piece when top stropping and not letting it run.

Drouin Tree Service · 6th July 2010, 04:47 PM

Wow there nice thats for sure

Eric Frei · 6th July 2010, 07:06 PM

The larger 60Kn block is restricted to a max rope dia of 20mm, the 40Kn block is restricted to 16mm dia rope.

Looking closely at the 60Kn block, we halve the WLL to 30Kn a side (due to doubling effect of load on block). In other words to hold up a static 30kn load we'd have 30Kn on the rope going up to the pulley and 30Kn coming down the other side to the load .... 30Kn each side = 60Kn all up on the blocks attachment point.

So looking at matching the rope, the rope's SWL or WLL should be 1/2 of the block's rating, in other words to get maximum benefit out of this block we need a 30Kn WLL rope that's 20mm diameter .... AINT GOING TO HAPPEN

Sampson 3/4" double braid is 20400lbs breaking strength = 9253kg

Yanks use 10% of breaking as SWL and we use 16.66% (1/6th)

So the rope SWL for the Yanks is only 9.25Kn (925kg)and for us it's 15.42Kn(1542kg).... way under the 3000kg or 30Kn the block can take.

You can do the sums for the smaller block but you'll find the same issue, you simply wont get a rope rated high enough to run this block out to maximum unless of coarse you get some super new hitech rope.

USA guys need to find a rope that's 66138Lbs (30,000Kg) breaking strength at 3/4" diameter

Aussies need to find a rope that's 39683Lbs (18,000Kg) breaking strength at 3/4" diameter.

Garry Brockley · 6th July 2010, 09:23 PM

DMM produce some awsome stuff the first climbs i ever carried out tree and cliff were on DMM gear, i grew up not far from the factory in Llanberis Wales.
thats a damned good looking pulley wouldnt want to scratch it at work.

TrevMcRev · 7th July 2010, 11:37 PM

They are almost....sexual! DMMs products are just geting better & better all the time.

Heres a link to some real world testing footage.

YouTube - DMM Impact Blocks

FlashD · 9th July 2010, 08:00 AM

Those are some darned sexy blocks! I was just talking to my boss about getting them earlier today. Hopefully he'll do it and we can give them a good shot.

TrevMcRev · 9th July 2010, 04:03 PM

Quote:

Originally Posted by Ekka

The larger 60Kn block is restricted to a max rope dia of 20mm, the 40Kn block is restricted to 16mm dia rope.

So looking at matching the rope, the rope's SWL or WLL should be 1/2 of the block's rating, in other words to get maximum benefit out of this block we need a 30Kn WLL rope that's 20mm diameter .... AINT GOING TO HAPPEN

Sampson 3/4" double braid is 20400lbs breaking strength = 9253kg

Yanks use 10% of breaking as SWL and we use 16.66% (1/6th)

So the rope SWL for the Yanks is only 9.25Kn (925kg)and for us it's 15.42Kn(1542kg).... way under the 3000kg or 30Kn the block can take.

You can do the sums for the smaller block but you'll find the same issue, you simply wont get a rope rated high enough to run this block out to maximum unless of coarse you get some super new hitech rope.

USA guys need to find a rope that's 66138Lbs (30,000Kg) breaking strength at 3/4" diameter

Aussies need to find a rope that's 39683Lbs (18,000Kg) breaking strength at 3/4" diameter.

Donaghys Ocean 12HS:
16mm Dia - Ave Breaking Strength = 26,100kg
20mm Dia - Ave Breaking Strength = 40,800kg

VERY strong, but very low stretch, which is not so good for dynamic shock loading....

Check this out though... 44mm Dia - ABS = 193,300kg

This stuff aint cheap either!

pomme · 15th July 2010, 08:31 AM

I was at the Rigging research seminar where we were shown this block. Stressed to disform but not explode, with some massive loads.DMM had to get special machinery to put the test loads through it. Awesome block i am sure its going to be expensive but if you do loads of rigging it will be worth the expense

jim1nz · 2nd August 2010, 07:14 AM

Beautiful piece of kit thats for sure, great video too, no going lightly on the test!

Therrin · 2nd August 2010, 12:12 PM

Quote:

USA guys need to find a rope that's 66138Lbs (30,000Kg) breaking strength at 3/4" diameter

Amsteel Blue 16mm
5/8-inch dia. = 52,800lb tensile strength.

Not sure that they make a 3/4", but if they ever do, it'd be right up around that figure.

charlie davis · 21st February 2011, 11:37 AM

Therrin, do you know if these blocks are available here in the U.S?

Eric Frei · 21st February 2011, 06:12 PM

Charlie, does it matter?

Just buy anywhere coz this is the internet and global market.

Waiting for USA to catch up to the rest of the world will mean missing out.

pomme · 21st February 2011, 06:54 PM

Look up HONEY BROTHERS in Guildford UK they have them in stock and they are not as expensive as I thought they d be.

newguy18 · 22nd February 2011, 01:33 AM

Loos like i have an excuse to replace my block for tailing out big wood.Safe working load on it is 6 ton.I attach with a chunk of chain when i use it.

TrevMcRev · 22nd February 2011, 11:04 PM

Quote:

Originally Posted by charlie davis

Therrin, do you know if these blocks are available here in the U.S?

Treestuff have them in the US.
Treegear has them here in Australia.
Tree Rigging Arborist Gear and Equipment Australia | DMM Impact Rigging Block | TREEGEAR Arborist Supplies

Same price.

charlie davis · 23rd February 2011, 02:42 AM

Quote:

Originally Posted by TrevMcRev

Treestuff have them in the US.
Treegear has them here in Australia.
Tree Rigging Arborist Gear and Equipment Australia | DMM Impact Rigging Block | TREEGEAR Arborist Supplies

Same price.

Thanks for the tip.

6th July 2010, 04:47 PM	#2
Drouin Tree Service Veteran Heritage Status Join Date: Jan 2007 Location: Australia Posts: 1,697	Re: DDM Impact Blocks\| Designed for DYNAMIC loads Wow there nice thats for sure __________________ Drouin Tree Services \| Excavator Hire - Drouin and SE Gippsland \| Landclearing Melbourne

6th July 2010, 07:06 PM	#3
Eric Frei Admin - Razor sharp and independent 2 X Diploma Level 5 qualified arborist Join Date: Jan 2007 Location: Brisbane Posts: 12,820	Re: DDM Impact Blocks\| Designed for DYNAMIC loads The larger 60Kn block is restricted to a max rope dia of 20mm, the 40Kn block is restricted to 16mm dia rope. Looking closely at the 60Kn block, we halve the WLL to 30Kn a side (due to doubling effect of load on block). In other words to hold up a static 30kn load we'd have 30Kn on the rope going up to the pulley and 30Kn coming down the other side to the load .... 30Kn each side = 60Kn all up on the blocks attachment point. So looking at matching the rope, the rope's SWL or WLL should be 1/2 of the block's rating, in other words to get maximum benefit out of this block we need a 30Kn WLL rope that's 20mm diameter .... AINT GOING TO HAPPEN Sampson 3/4" double braid is 20400lbs breaking strength = 9253kg Yanks use 10% of breaking as SWL and we use 16.66% (1/6th) So the rope SWL for the Yanks is only 9.25Kn (925kg)and for us it's 15.42Kn(1542kg).... way under the 3000kg or 30Kn the block can take. You can do the sums for the smaller block but you'll find the same issue, you simply wont get a rope rated high enough to run this block out to maximum unless of coarse you get some super new hitech rope. USA guys need to find a rope that's 66138Lbs (30,000Kg) breaking strength at 3/4" diameter Aussies need to find a rope that's 39683Lbs (18,000Kg) breaking strength at 3/4" diameter. __________________ Protect your rights to work - Join Australian Tree Association My businesses:- Qualified Brisbane Tree Lopping \| Stump Grinding Brisbane \| Brisbane - Gold Coast Consulting Arborist

6th July 2010, 09:23 PM	#4
Garry Brockley Bayside Tree Care Brisbane Join Date: Jun 2008 Location: Brisbane Aus Posts: 1,649	Re: DDM Impact Blocks\| Designed for DYNAMIC loads DMM produce some awsome stuff the first climbs i ever carried out tree and cliff were on DMM gear, i grew up not far from the factory in Llanberis Wales. thats a damned good looking pulley wouldnt want to scratch it at work. __________________ My business:- Brisbane Bayside Tree Care

9th July 2010, 08:00 AM	#6
FlashD Semi-mature vigorous tree Join Date: Feb 2008 Location: Kansas Posts: 213	Re: DDM Impact Blocks\| Designed for DYNAMIC loads Those are some darned sexy blocks! I was just talking to my boss about getting them earlier today. Hopefully he'll do it and we can give them a good shot.

15th July 2010, 08:31 AM	#8
pomme Mature tree Join Date: Mar 2007 Location: england Posts: 251	Re: DDM Impact Blocks\| Designed for DYNAMIC loads I was at the Rigging research seminar where we were shown this block. Stressed to disform but not explode, with some massive loads.DMM had to get special machinery to put the test loads through it. Awesome block i am sure its going to be expensive but if you do loads of rigging it will be worth the expense

2nd August 2010, 07:14 AM	#9
jim1nz Mature tree Join Date: Jan 2007 Location: International, Germany Posts: 476	Re: DMM Impact Blocks\| Designed for DYNAMIC loads Beautiful piece of kit thats for sure, great video too, no going lightly on the test! __________________ SPEED ALWAYS FOLLOWS TECHNIQUE

21st February 2011, 11:37 AM	#11
charlie davis Sappling Join Date: Jan 2011 Location: eugene oregon Posts: 5	Re: DMM Impact Blocks\| Designed for DYNAMIC loads Therrin, do you know if these blocks are available here in the U.S?

21st February 2011, 06:12 PM	#12
Eric Frei Admin - Razor sharp and independent 2 X Diploma Level 5 qualified arborist Join Date: Jan 2007 Location: Brisbane Posts: 12,820	Re: DMM Impact Blocks\| Designed for DYNAMIC loads Charlie, does it matter? Just buy anywhere coz this is the internet and global market. Waiting for USA to catch up to the rest of the world will mean missing out. __________________ Protect your rights to work - Join Australian Tree Association My businesses:- Qualified Brisbane Tree Lopping \| Stump Grinding Brisbane \| Brisbane - Gold Coast Consulting Arborist

21st February 2011, 06:54 PM	#13
pomme Mature tree Join Date: Mar 2007 Location: england Posts: 251	Re: DMM Impact Blocks\| Designed for DYNAMIC loads Look up HONEY BROTHERS in Guildford UK they have them in stock and they are not as expensive as I thought they d be.

22nd February 2011, 01:33 AM	#14
newguy18 Part of the Furniture Join Date: Jun 2007 Location: orlando,fl Posts: 4,977	Re: DMM Impact Blocks\| Designed for DYNAMIC loads Loos like i have an excuse to replace my block for tailing out big wood.Safe working load on it is 6 ton.I attach with a chunk of chain when i use it. __________________ Have your say join us today. old schooler

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