Whittall Davits

[PCUK]

Does anyone have an old Whittall catalogue showing the carrying capacity for the various davits in the range. Now that the company has been taken over by Cooney there is no info' available. I want to get one of those new Jeanneau polythene sports tenders but don't want to overload the davits.

 

[volvopaul]

The davit should have a transfer on telling the weight, if its an ED16 its 85kg max, think an ED17 is 100kg max, but as Roger Whittall always tells me that its max load on one davit not 2 times 85kg for example

While were on the whittall subject, anyone need a passarelle whittall one with nice teak inlay, never used.

 

[PCUK]

Thanks for that but these davits are 20 years old and any transfers are long gone. I appreciate the point about the weight being on one davit and it looks as though 120 Kg plus engine (another 51Kg) is going to be a bit OTT.

 

[Forty_Two]

Just found a list with loading details from 2000. Do you have the ED number?

 

[Highland Fling]

The davit should have a transfer on telling the weight, if its an ED16 its 85kg max, think an ED17 is 100kg max, but as Roger Whittall always tells me that its max load on one davit not 2 times 85kg for example

kunfosed is me are you saying that Roger Whittall was saying that if you have for instance a RIB weighing 85kg then each Davit should be able to support 85kg or what?

 

[stelican]

kunfosed is me are you saying that Roger Whittall was saying that if you have for instance a RIB weighing 85kg then each Davit should be able to support 85kg or what?

Yes thats correct,bhave seen a few folded davit arms

 

[hlb]

Think the ones I have just had taken off, must have been ED16 as I know they were 85Kg.

Duno how that helps.

I'd worry more about whether the hull can stand the weight, rather than the davits.

There was a guy on here a few years ago, going on about wanting some thing like a 50 hp outboard on his davits. Would not be told. But next he was wailing about his gell coat being cracked.

 

[hlb]

kunfosed is me are you saying that Roger Whittall was saying that if you have for instance a RIB weighing 85kg then each Davit should be able to support 85kg or what?

What he's saying is. You cant multiply it up to 170kg. Because one davit will be lifting the outboard and the other, not very much.

 

[Highland Fling]

What he's saying is. You cant multiply it up to 170kg. Because one davit will be lifting the outboard and the other, not very much.

I am not sure if i totally agree with that even were the outboard to be on the dinghy. IF the dinghy is winched tightly onto the Whittall/Simpson style davits yes the CoG will be well to the one side But the dinghy will be acting like an I Beam A slightly flexible one if it is an inflatable but still an I Beam so both davits will be sharing the load one at a closer centre to the CoG yes but the far one will still be taking a significant share of the load. Yes during the 'lift' one will be significantly loaded vis a vis the other. But once they are snuggled in tight the situation should improve especially if using a cargo ratchet style belly strap. Could be fun working this out and measuring the loads.

 

[volvopaul]

I am not sure if i totally agree with that even were the outboard to be on the dinghy. IF the dinghy is winched tightly onto the Whittall/Simpson style davits yes the CoG will be well to the one side But the dinghy will be acting like an I Beam A slightly flexible one if it is an inflatable but still an I Beam so both davits will be sharing the load one at a closer centre to the CoG yes but the far one will still be taking a significant share of the load. Yes during the 'lift' one will be significantly loaded vis a vis the other. But once they are snuggled in tight the situation should improve especially if using a cargo ratchet style belly strap. Could be fun working this out and measuring the loads.

Surprised this thread has been re lived.

Your theory on the rib being an I beam will yes transfer weight across, but if you would care to come to my boat and wind up my avon 280 rib with a yamaha 15 on it you will clearly find that you can wind up the winch with just about 1 finger on the bow, however it takes both hands sometimes to wind up the stern end, you also in my case ALWAYS place the stern of the rib away from the transom door of the boat, at speed with the boat pitching you can clearly watch the davit flex on the heavy end, however the bow end stays where it is. This clearly provers Rogers point about weight on one davit, BHG marine will also back this theory up when selling you there kit.

On another score regarding electro hydraulic lift/walkway passarelles, if it says max 250kg thats about where the main relief valve in the pump is set to, any drop of water in the hull will make a vast difference, if your reading this "snowtiger" you will know exactly where im coming from.

While im on here I have a mint pair of ED16s and a pair of ED17 with the passarelle lift davits attatched, any takers??

 

[PCUK]

Three years later and the thread's still going. Got the details I needed at the time.
As keeps being said, majority of weight one davit is not theory, it is well documented fact!

 

[oldsaltoz]

Think the ones I have just had taken off, must have been ED16 as I know they were 85Kg.

Duno how that helps.

I'd worry more about whether the hull can stand the weight, rather than the davits.

There was a guy on here a few years ago, going on about wanting some thing like a 50 hp outboard on his davits. Would not be told. But next he was wailing about his gell coat being cracked.

I have been asked a number of times if I would be interested in installing davits on clients yachts, my first response is talk to the manufacturer or designer and advise what size you want to fit and what weight you estimate they will be required to carry.

About one in seven never go ahead and of the remaining only one will make further enquiries.

Most yachts were never designed to have any extra cantilevered over the stern. It effects performance and stability on smaller boats and even some of the narrower larger boats.

Many the do get installed are taken off a few years later because or stress cracks due to poor installation or misuse at some stage.

So, my advice remains the same, check with boats designer or builder and get the facts first, then check them.

Good luck.

 

[Forty_Two]

kunfosed is me are you saying that Roger Whittall was saying that if you have for instance a RIB weighing 85kg then each Davit should be able to support 85kg or what?

Highland Fling - can't now find the Whittall catalogue but have a Simpson one. The Simpson ones are rated as numbered . So a 175 = 175Kg per davit. The advice I was given was each davit should be able to handle the complete load as most weight is at the outboard end. personally I like plenty lifting capacity in hand.

You also have to consider the extreme situations of a snapped wire, a dingy full of rainwater if the drain is left in by accident or the dingy being pooped as once happened to me. Heavy stuff water in the wrong place!

 

[Highland Fling]

Highland Fling - can't now find the Whittall catalogue but have a Simpson one. The Simpson ones are rated as numbered . So a 175 = 175Kg per davit. The advice I was given was each davit should be able to handle the complete load as most weight is at the outboard end. personally I like plenty lifting capacity in hand.

You also have to consider the extreme situations of a snapped wire, a dingy full of rainwater if the drain is left in by accident or the dingy being pooped as once happened to me. Heavy stuff water in the wrong place!

thanks but the Simpson one is available online

 

[Highland Fling]

Yes thats correct, have seen a few folded davit arms

yes but that was fixed that by welding in a fillet in the corner

 

[Highland Fling]

Surprised this thread has been re lived.

Your theory on the rib being an I beam will yes transfer weight across, but if you would care to come to my boat and wind up my avon 280 rib with a yamaha 15 on it you will clearly find that you can wind up the winch with just about 1 finger on the bow, however it takes both hands sometimes to wind up the stern end, you also in my case ALWAYS place the stern of the rib away from the transom door of the boat, at speed with the boat pitching you can clearly watch the davit flex on the heavy end, however the bow end stays where it is. This clearly provers Rogers point about weight on one davit, BHG marine will also back this theory up when selling you there kit.
<SNIP>

If you read what i wrote i did say during the lift - one end will be much heavier than the other IF you leave the outboard on. Re flexing of the davits i cant see me having that problem yes you get this but you are doing 20+ knots I can get to 10/12 at a push well with a big puff of wind in my white things. This is mostly about dinghy security on passage. Our RIB is too big to come on deck and we have a babystay so the foredeck is not available - and dinghy security when at anchor The engine will be off on any passage longer than a long day sail say 30/40 miles at the most - so i wont have an unbalanced load. Oysters sail across the Atlantic and round the world with their RIB and engine on using Simpson Davits and i have been on an Oyster in a F9 with no worries 'about the dinghy that is'.

 

[hlb]

If you read what i wrote i did say during the lift - one end will be much heavier than the other IF you leave the outboard on. Re flexing of the davits i cant see me having that problem yes you get this but you are doing 20+ knots I can get to 10/12 at a push well with a big puff of wind in my white things. This is mostly about dinghy security on passage. Our RIB is too big to come on deck and we have a babystay so the foredeck is not available - and dinghy security when at anchor The engine will be off on any passage longer than a long day sail say 30/40 miles at the most - so i wont have an unbalanced load. Oysters sail across the Atlantic and round the world with their RIB and engine on using Simpson Davits and i have been on an Oyster in a F9 with no worries 'about the dinghy that is'.

Your theory is wrong and your I beam idea wont work. Nothing, but nothing will shift the weight, short of moveing the outboard to the middle of the dinghy.

 

[Highland Fling]

Your theory is wrong and your I beam idea wont work. Nothing, but nothing will shift the weight, short of moveing the outboard to the middle of the dinghy.

So all these people who go on long ocean passages with their dingies and outboards fastened securely onto Whittall/Simpson Davits - they are mistaken - please !!! read and learn

The photograph shows Sapphire approaching Cape Horn http://www.sapphireoflondon.org/images/photos/capehorn.jpg

Oh bugger we are rounding Cape Horn the wrong way with our dinghy in the davits MAYDAY MAYDAY MAYDAY ........................NOT!!!!!!

http://www.sapphireoflondon.org/statistics.html

one quote from their round the world trip

Whittall davits provide permanent stowage for the Avon Rover 280 tender and Suzuki 4hp, 4-stroke outboard. The davits are immensely strong and we have no concerns over leaving the tender in place, even in gale force winds. This saves an enormous amount of stowage either in the lazarette or below decks. It also allows the tender to be deployed very quickly. This was a particularly valuable asset when rowing out shore lines under adverse conditions in the Chilean channels

 

[hlb]

Whittall davits provide permanent stowage for the Avon Rover 280 tender and Suzuki 4hp, 4-stroke outboard
.....................................................................................................

Yep so do mine. But thats not the question. The dinghy and Outboard is no where near 85 kg, on the heavy end. Your arguement is that when raised, the weight will some how be spread between each davit. Not so. But no matter. the dinghy is well within safe loading.

I see you are a new poster, so I will refrain from calling you an idiot. Most folk come here to learn. But you can not diffy the laws of science.

 

[Highland Fling]

Whittall davits provide permanent stowage for the Avon Rover 280 tender and Suzuki 4hp, 4-stroke outboard
.....................................................................................................

Yep so do mine. But thats not the question. The dinghy and Outboard is no where near 85 kg, on the heavy end. Your arguement is that when raised, the weight will some how be spread between each davit. Not so. But no matter. the dinghy is well within safe loading.

I see you are a new poster, so I will refrain from calling you an idiot. Most folk come here to learn. But you can not diffy the laws of science.

Better learn to spell before you call anyone an idiot

Think on this It’s better to keep your mouth shut and be thought a fool than to open it and let everyone know you are

You have no idea what engineering/scientific qualifications i have. I could prove to you that the weight is spread between both davits when the dinghy is fully up and secured properly on Whittall/Simpson style Davits but i dont have the time or the inclination to educate you .

Finally and my mistake here Never argue with an idiot,they'll bring you down to their level and beat you with experience.


FINI