craning in and strops

[tim_ber]

Watching the video that Dylan linked to here:

http://www.youtube.com/watch?v=Ey6JKVBmpYQ

At 4:27 we can see the boat going in. The strops go from toe rail to crane hook
At 5:15 in the distance we can see a crane with what I consider the better strop fitting.
This means the deck is not in compression when lifting.

So is it that important or not? Does it depend upon boat strength?

At the moment, I would go for crane at 5:15 and prefer no compression across deck, but would appreciate any better qualified opinions.
Cheers

 

[sailorman]

Watching the video that Dylan linked to here:

http://www.youtube.com/watch?v=Ey6JKVBmpYQ

At 4:27 we can see the boat going in. The strops go from toe rail to crane hook
At 5:15 in the distance we can see a crane with what I consider the better strop fitting.
This means the deck is not in compression when lifting.

So is it that important or not? Does it depend upon boat strength?

At the moment, I would go for crane at 5:15 and prefer no compression across deck, but would appreciate any better qualified opinions.
Cheers

not looked at the Vid
assume spreaders are being used to avoid crushing the hull

 

[tim_ber]

not looked at the Vid
assume spreaders are being used to avoid crushing the hull

Yes, that is what I meant to say.

I like the idea of spreaders.

In the video, the chap's boat is being craned in without spreaders. The strops do not angle in a lot, but, I would prefer totally vertical for no crushing.

 

[LadyInBed]

Yes it's important for strops to go to spreaders, without spreaders you will get spider cracks where the strops bend round the deck.

 

[prv]

Yes it's important for strops to go to spreaders, without spreaders you will get spider cracks where the strops bend round the deck.

Depends how high the hook is above the deck and hence how much inward squeeze. I've seen boats lifted by "building site" cranes that have plenty of height to spare and so can afford to use very long strops giving minimal squeeze.

When we collected KS after purchase we hired the same flatbed and HIAB (and driver) that the previous owner had always used. The angle on the strops looked a bit marginal and I queried the lack of spreaders, but he pointed out that he'd been transporting the boat around for years without any trouble, and indeed there's no evidence of squeeze on the hull or deck. Had it been the first time with that kit, I'd have been more concerned.

Pete

 

[starfire]

Best is with a lifting frame, which will produce little or no crushing force, it depends on how wide the frame or spreader bars are in relation to the hull.

Sometimes you can extend the slings using lifting chains to increase the angle to the hull, lessening the crushing or pack out the contact point of the slings with timber to spread the load, it depends how much headroom the crane has.

What is more important in the first clip, there is nothing to stop the lifting slings sliding fore or aft, we have all seen the videos of boats falling out of slings.

I spent 15 years in the crane industry & lifted a fair few boats in & out, (+ a fair few other things as well) I insisted that the slings were lashed to each other & to strong points on the boat, both fore & aft, before the lift commenced.

 

[VicS]

Depends how high the hook is above the deck and hence how much inward squeeze.
Pete

Absolutely. Below is a picture of Meon Valley Crane Hire in operation with proprietor Brian Bailey at the controls.

As you can see the hook is well above the deck so minimal crushing loads, although you'd not want to get your fingers trapped.

If anyone insists he will hire a set of spreader bars... he'll use them just for the one lift and pass the hire cost on.

Look at some of the mishaps on You tube. So many involve Hiabs or similar with short jibs and as a result needing spreader bars. The slings then don't grip the hull and mobos, in particular, with no keels to stop them slide out!

 

[LadyInBed]

Depends how high the hook is above the deck and hence how much inward squeeze.

Negligent of me not to have mentioned that

These work well:

 

[VicS]

Negligent of me not to have mentioned that

These work well:

I'd like to see it fishing them out of here

 

[oldbilbo]

You could always bodge the job.....

​

 

[prv]

I'd like to see it fishing them out of here

Never mind picking the boats out by crane, how does anyone get out through that web of mooring lines when the tide's in?

Pete

 

[yoda]

Watching the video that Dylan linked to here:

http://www.youtube.com/watch?v=Ey6JKVBmpYQ

At 4:27 we can see the boat going in. The strops go from toe rail to crane hook
At 5:15 in the distance we can see a crane with what I consider the better strop fitting.
This means the deck is not in compression when lifting.

So is it that important or not? Does it depend upon boat strength?

At the moment, I would go for crane at 5:15 and prefer no compression across deck, but would appreciate any better qualified opinions.
Cheers

A spreader bar is generally considered to be a good idea, more so with less sturdy boats however I find that it is very much easier because the strops do not need to be lead through guard wires etc but instead stay outboard of everything.

Not sure how old the video is but there is a Pioneer 9 ashore in the background as he motors off down river which looks just like my last boat with repairs done. Would be nice to know she is back in use.

Yoda

 

[Sneaky Pete]

You could always bodge the job.....

​

This pic shows the effective use of spreaders it's not squeezing the boat but it is keeping the lifting strops well apart it’s not pretty but it does work

 

[VicS]

Never mind picking the boats out by crane, how does anyone get out through that web of mooring lines when the tide's in?

Pete

They dont. They have only been brought into there ready to be lifted.