Lifting a Rib

timw · 29 July 2003, 09:12

Can anyone give any advice regarding lifting a RIB from the water.

I will be keeping my new RIB (7.5m) at a Marina where they lift the boats in and out of the water for use and store them on their trailers on the dock side. There is no slipway.

The method for lifting is a mobile crane with two large webbing straps slung beneath the hull of the boat.

The Marina says this is fine for sportsboats and yachts, but they are relectant to use this method for RIBS as they are concerned about the tubes getting damaged from sideways pressure of the straps, and they want the RIBS to be fitted with lifting eyes on the deck as an alternative point for attaching the straps.

I'm not so keen on getting these lifting eyes fitted, and wondered if anyone has any views as to if RIBS really would suffer from this lifting method, or if it is OK.

Many thanks for any views.

Charles · 29 July 2003, 09:25

Too right Tim - I arrived a minute too late when they craned me in and I was lucky to get away without any damage to the tubes. Just look at the strain on them. Can you not manufacture something that can be removed and placed back when required?

Julian · 29 July 2003, 10:15

Tim

Go for lifting eyes in on the transom and the bow. Seen a few Ribs crained in like charles picture above and it puts a huge amount of pressure on the tubes. Make sure the lifting eyes are fitted proffesionaly and check the desk is strong enough to take them.

Julian

Dirk Diggler · 29 July 2003, 10:39

Quote:

Originally posted by Julian
check the desk is strong enough to take them.

Julian

Hey Julian, are you another one of Narked's virtual boaters?

mstacey · 29 July 2003, 10:46

Get the liffting eyes fitted. They are not intrusive and can always be used for strapping things down on the deck (mine are)

timw · 29 July 2003, 10:48

Now I can see what they mean about tubes getting damaged.

I wonder if the use of spreaders on the crane straps could keep the straps away from the tubes.

Regarding the fittment of lifting eyes, would it be 2 at the back and one at the bow, or 4 evenly spaced?

Does anyone know how they should be fitted, i.e. I guess you would need a large reinforcing plate beneath the deck for each eye, and how is it possible to do this without magor surgeory on the deck?

John Kennett · 29 July 2003, 11:33

I've fitted lifting eyes to a smaller RIB, but it may need a bit more planning on a larger, heavier boat.

For the front pair of lifting points I used a fairly hefty U-bolt right through the hull on each side of the boat, a metre or so back from the bow. They were backed with stainless steel plates about 15cm x 8cm and lots of Sikaflex. At the transom I had a pair of U-bolts like towing eyes but fitted to the inside.

Alan Priddy fitted similar lifting eyes to "Still Never Enough" a 7.4m Ribtec -- see dodgy picture below. As far as I remember a similar system of through bolted plates is used on Still Deep One, Jim and Yvonne's 10m Delta.

Before you start drilling make sure you've worked out the position of the lifting points to get the balance right. You may also want to consult the manufacturer or someone who understands the ins and outs of boat construction.

As a side note, it's also worth having your own set of lifting strops with hooks so that the crane crew only have to hook up to a single point, keeping that dirty great hook away from your console, GPS, plotter etc!

John

Charles · 29 July 2003, 13:16

Quote:

Originally posted by timw
I wonder if the use of spreaders on the crane straps could keep the straps away from the tubes.

Spreaders is the preffered option if you do not want to go drilling into the deck, hull etc. You need to discuss this option with the crane operator.

timw · 29 July 2003, 13:17

Thanks for the very useful info.

There's no way I'm going anywhere near my new boat with a drill...I shall ask the dealer to do it.

Tim

Keith Hart · 29 July 2003, 15:06

Hi timw

Take a look here you will see Cyanide being lifted out of the water. As far as I am aware there are lifting points fitted. Over to you Brian...

Keith (just two weeks to go...) Hart

Andre · 29 July 2003, 15:08

Best to fit in the bow area the folding lifting eyes made by WICHER . In the UK these are supplied by PROBOAT
Of course it is much easlier when this is done during the manufacturing of the rib as the fitting goes through the hull as shown on the photo posted by JK. This is what I hv on my rib and must say as they fold down you don't trip over them

Andre

cloudy · 29 July 2003, 16:24

Could you not just let the sponsons down so all the pressure is on the hull?

timw · 29 July 2003, 17:05

The yard did suggest letting the sponsors down, but as the boat will be in and out each weekend during the season this would probably be too much hassle.

After all the excellent feedback I've had, especially the picture of the scorpion being squeezed, I've decided to have lifting eyes put in by the dealer who reckons it's quite straightforward.

Tim

Richard B · 29 July 2003, 17:59

Strange as it may seem, deflating the tubes for a crane lift is definitely not the correct procedure. Keep 'em hard.

If you deflate the tubes, it allows the tube to deform too much and places too much load on the joint of the hull to the underside of the tube, cracking the layers which are glued together. I was told that Mark Pascoe used to have some problems from doing this, hence the recommendation from his crane driver to keep 'em pumped up.

I've had four crane lifts with Blue Ice now (using a spreader frame), and the process looks much worse than it is! I've examined the tubes very closely afterwards, and I'm pleased to say that there's not a single mark. (It would be interesting to hear from the tube guys about this - have they seen any nasty damage from lifting?). In fact the worst marks on the tube are from using an over-the-top webbing strap on the trailer.

Having said that, I'll be giving some consideration to getting lifting points fitted during the winter. Two on the inside of the transom (as that's where most of the weight is and these are the easy ones to fit - I could do that bit myself) and then either two up front (but don't relish the thought of going through the hull) or a single point in the anchor locker (possibly on the back of the towing eye?) I'm not keen on using a reinforced deck point as the deck was originally designed for a downwards load! A consultation with Mr Jelley in order her.

The photo of Charles' RIB is unusual as being a cabin RIB, there's a significant load on the forward lifting strops which isn't the case with a conventional open RIB. When Blue Ice is lifted, her tubes at the front are hardly touched.

Tim - which yard are you using? do you want to answer by PM? Doesn't sound like they are used to handling RIBs!?! (although I suspect you may have received some confused information here).

Jklingel · 30 July 2003, 00:27

Having had experience lifting my alum riverboat, sure; get a spreader. The force inward is ENORMOUS when you lift anything with with a strap hooked at two places. For that same reason, you do not yank a truck out of the muck wi th a chain tied to each towing hook, as you can pull your frame rails together a tad. I built my spreader out of 2" pipe with a "U" welded on the ends to catch the strap. Pipe is great in compression; you may need larger pipe. PS: Two hooking points in the stern deck are the same phenomenon; make sure your deck can take the compression and keep the lifting strap long. Best to you. John

timw · 30 July 2003, 10:34

The yard is Sparkes Marina at Hayling Island. They are an excellent yard with great service.

As the service I have is on the basis she is lifted in and out most weekends, they have costed this on a quick lift basis. To use spreaders each time makes things much longer for them. However, until I get the eyes fitted they are happy to do this to protect the tubes.

On consultation with the manufacturer, I am going to get 2 eyes bolted to the transom, and one in the anchor locker which means not having to mess about with the deck.

I'm very pleased to have got a better understanding of the lifting issues and the method of fitting eyes from this thread and thank everyone for their input.

Tim

paul tilley · 30 July 2003, 13:20

as a tube builder best way to lift is with lifting eyes the simplest being two on transom and one in the bows preferably through hull not deck ie in bow locker . second best is with hard tubes and spreader bars and thirdly with hard tubes definitely NOT with deflated tubes as this will cause most damage

Nigel · 30 July 2003, 19:40

Tim and Ian Anderson (who are running the Ken Brown Boat Park in the Camber Dock now) have built a spreader frame which seems to spread most of the load and is the best way of craning I have seen yet. I certainly woudln't want to crane a RIB without one, or lifting eyes.

Jklingel · 30 July 2003, 21:15

Wow! That is a kick-buttinski setup for lifting a boat. Looks as if those guys know what they are doing. Great job, gents. I guess the operative word is "brill" ?????

Alex Brown · 30 July 2003, 21:33

Alternatively, you could always goto a marina/boatyard with a Wise boat hoist, which avoids the need for spreaders

When I lifted my old rib off its trailer last year, to avoid strain on the tubes, cos it didn't look too good, I opened the hoist as wide as it would go before lifting. It ended up putting most of the pressure on the hull, and the tubes 'just' touched the strops enough to prevent the boat from rocking.

It did look well odd, and I'd suggest that if you do that on a slipway hoist, it might also be worth attaching ropes from the strops to something inside the boat, perhaps to the a-frame just to stop it slipping back.

-Alex