• Thank you for visiting HeavyEquipmentForums.com! Our objective is to provide industry professionals a place to gather to exchange questions, answers and ideas. We welcome you to register using the "Register" icon at the top of the page. We'd appreciate any help you can offer in spreading the word of our new site. The more members that join, the bigger resource for all to enjoy. Thank you!

2 Sheave Hook Block

FirstEliminator

Well-Known Member
Joined
Apr 2, 2012
Messages
53
Location
North Adams, Massachusetts
Hey guys,

I am not a professional in the crane industry so I don't know of many resources on where I'd find a 15 ton, 2 sheave crane block for 1/2 cable. Any good places to look? Or anyone have something collecting dust?
There is a decent looking single sheave block on e-bay. But, my Grove has a 7000 lb single line pull and I would only get 3 parts of line with this single sheave. This would max out at 21,000 lbs. Not sure if I will ever lift something even that heavy. But, I think it would be a good idea that if I am going to buy something, it'd be best to get a block that would perform on par with the capacity of a 15 ton crane.

thanks in advance,
Mark
 

John H

Well-Known Member
Joined
Jan 22, 2007
Messages
170
Location
Mass
Occupation
Arborist, Equipment operator
Try CRW they always have stuff kicking around.
 

crane operator

Senior Member
Joined
Mar 27, 2009
Messages
8,274
Location
sw missouri
Hey mark, I'm not sure what you are doing most of the time with your 15 ton crane.

I use a rough rule of thumb for cranes. A 15 ton crane has a "real world" capacity of 15,000lbs. A 35 ton- 35,000lbs. 60 ton -60,000lbs. It doesn't apply in the 200 ton and up class, but you get the idea.

Seldom will you get close enough to rig and pick up a 15 ton load with your 15 ton crane. I think a single sheave block with a possibility for a three part, would pick most of what you want. I'm not sure you will get close enough very often to something big enough to weigh any more than 21,000lbs and pick it up. A example would be unloading something off a truck to the ground. The truck bed is 8' wide, so its 4' to the center of the load. Your outrigger span is probably 18-20', so you will lose 10' of radius there. So for even a typical close, heavy lift, you have a radius of 15' minimum ( with the trailer touching your outriggers), and sometimes closer to 20'. What is your load chart capacity at 15'? That is what capacity you need a block for.

So unless this crane sets in a yard where you are moving 6'x6' transformers from between your outriggers on one side of the crane, up and over the outriggers to between the outriggers on the other side of your crane, I'm not sure you need more parts of line, or a 15 ton block.

The other thing to remember is if you run a 4 part line, and you have 50' of boom out, you have to run in and out 250' of cable just to take the block from the tip to the ground. That takes fooorrreevvveeerrr. I really think for a crane that size if you ran a two part on a single sheeve block, it would be a great compromise between line speed and capacity, and if you wanted to just creep with a load you could put in the three part. The other bad part about a two sheeve block, is that you really can't run a two part in it because the block hangs crooked, so you have to put in at least a 3-part.

If your set on a 2 sheeve block, the best places I've found are ritchie bros, ebay, purple wave, and even craigslist.
 

FirstEliminator

Well-Known Member
Joined
Apr 2, 2012
Messages
53
Location
North Adams, Massachusetts
Hey Crane Operator,

Thanks for the informative and realistic reply. I will probably never pick up anything that weighs 20,000+. The one drawback with the single sheave block I am looking at is it has a sheave for 5/8" cable and my crane runs 1/2" cable. I know over time it will wear a groove in the sheave. But in the real world, with seldom use would it be o-k? I run an automotive transmission shop and use the crane more as a hobby. Like I try to find things around the shop to use the crane for. Like setting a 275 gallon heating oil tank on the side of the building. Something two guys could lug along, but I much prefered to find joy of using the crane. 99.9% of the time the crane just sits waiting to be run.

thanks,
Mark
 
Last edited:

crane operator

Senior Member
Joined
Mar 27, 2009
Messages
8,274
Location
sw missouri
I don't think you would need to worry about the 5/8" block mark. A lot of the older Grove 25-85 ton cranes come equiped with two winches, the big main winch running 3/4" cable, and a smaller "whip line" winch running 9/16-5/8" cable. All the boom head sheaves are for 3/4" cable, which tells you that they were'nt to worried about smaller cable in their sheaves.. With steel sheaves you're not going to see a lot of wear on the sheaves with the smaller cable. The bigger problem is that the larger diameter sheaves don't support the cable as well around the curve of the cable, which can lead to premature cable deformation and break down, especially with rotation-resistant cable.

If you're just using it to move some engines or trannys around, or even cars or trucks (even those are less than 8-9000lbs), you won't probably ever notice that type of wear. If you were using it every day running in and out for 8 hours with maximum line pull- you would get extra wear/ deformation on the cable.

You may also check your specs on your chart, most 7,000 line-pull, older grove winches, are able to run 1/2 to 5/8" cable. Buy the 5/8" block now and in 5 years when you replace the cable, buy 5/8" cable to replace it- it wouldn't cost a lot more and might give you peace of mind if you were worried. But make sure that your chart shows 5/8 cable as a option for your winch and check your pulleys for 5/8" diameter before you buy cable.
 

FirstEliminator

Well-Known Member
Joined
Apr 2, 2012
Messages
53
Location
North Adams, Massachusetts
I bought the McKissick single sheave block. It looks like a substantial piece. Most of the other hooks i saw were snatch blocks and much smaller. They didn't look appropriate for a crane. Another thing I ordered is a set of sheave gauges to find out what size the sheaves really are.
Upgrading the cable to 5/8" has been on my mind. Especially after seeing a roll of 385 feet of new 5/8" 6x25 wire rope for $200 on e-bay. Seller says he bought it for Morain Motocrane a long time ago. It is right hand regular lay which is what I already have on the Grove. But not sure if the 6x25 is exactly what I would need. The 1/2" cable is sufficient for now. The guy before me only used the crane to set house trusses. He never needed more than a single line pull with 1/2 cable. He also didn't need the skylight for the crane cab and a bunch of other immenities to the crane as odds and ends are either missing or nonfunctional.
Thanks a bunch for the info and insights,
Mark
 

gostr8r

Senior Member
Joined
Jun 21, 2011
Messages
259
Location
Orlando, Fl.
Occupation
Full time crane operator for Crane Rental Corp sin
I wouldn’t spend any money on a block with an even number of sheaves for the reason already noted, that a 2 part won’t hang plum. Go 3 sheaves and eliminate that issue all together. The extra block weight will help overhaul the rope off the drum, with more control and reduce the rope fouling back there too. And you can use a 3 part, when a two is needed as well, if you have enough rope, because it’s much easier to correct a twisting load line when the becket is on the block than it is to boom back down and correct it. BTW, FYI, a crane is required to only have enough rope on the drum to lift it’s rated loads for each of the various boom lengths. So if 3 parts is good for 21000, then the rope needs to only be long enough for the longest boom that can pick 21000 lbs, not for all 6 parts to reach the ground at that same longer boom length.
 

dbl612

Well-Known Member
Joined
Jul 6, 2012
Messages
111
Location
torrington, ct.
Occupation
crane operator
I wouldn’t spend any money on a block with an even number of sheaves for the reason already noted, that a 2 part won’t hang plum. Go 3 sheaves and eliminate that issue all together. The extra block weight will help overhaul the rope off the drum, with more control and reduce the rope fouling back there too. And you can use a 3 part, when a two is needed as well, if you have enough rope, because it’s much easier to correct a twisting load line when the becket is on the block than it is to boom back down and correct it. BTW, FYI, a crane is required to only have enough rope on the drum to lift it’s rated loads for each of the various boom lengths. So if 3 parts is good for 21000, then the rope needs to only be long enough for the longest boom that can pick 21000 lbs, not for all 6 parts to reach the ground at that same longer boom length.

your experience is showing again!
 

gostr8r

Senior Member
Joined
Jun 21, 2011
Messages
259
Location
Orlando, Fl.
Occupation
Full time crane operator for Crane Rental Corp sin
Thanks fellow brother of the hook! I get the thing from some newbies a lot that they seem to think that max reeving needs to hit the ground when the boom is run out all the way. DUHH! No, just the reeving ‘required' for the boom length and the rating at a specific distance. That’s all I try to impress when they want more rope. They would find it would over spool the drum anyhow, when they scoped in with enough parts to reach the ground on a long boom. The chart specifies one OEM rope length, that will hit the ground for all ratings and all boom lengths as needed. More is not an option sometimes nor is it a good thing either.
 

td25c

Senior Member
Joined
Feb 14, 2009
Messages
5,250
Location
indiana
I agree whith gost8r about using the 3 sheave block . I assume the TM 155 has a 3 sheave boom head like the TM 150 used,if so that would make the 3 sheave block a handy item on the crane.You could run two part,four part ,and 6 part lines depending on the job.I'd just about bet thats the block that crane would have came with from the factory. The picture on Groves website looks like a 3 sheave block on the TM 150 crane .I also noticed the TM 150 used 1/2 inch cable as well. www.manitowoccranes.com/~/media/Files/Products/Grove/truck Mounted/TM150/TM150-specandcap.pdf
 

gostr8r

Senior Member
Joined
Jun 21, 2011
Messages
259
Location
Orlando, Fl.
Occupation
Full time crane operator for Crane Rental Corp sin
Any thing that is more than that 3 part can get would likely need a bigger crane anyway. Make sure the block’s hook capacity will get that full 21000 line pull tho.
 
Top