Hard versus Soft Nose!?

[Charles]

Following on from Magellan Alpha's little disaster and from my own incident last year, I was wondering what the general feeling was towards having a hard nose or soft bow nose. The incredible forces that the tubes are subjected to when you 'stuff it' would be of serious concern to me. Scorpion, Osprey and a few other manufacturers give a choice between the two when a rib is 'specced up.' Why does everyone not just go for a hard bow nose? People like Nick Gilbertson and other manufacturers and tube-makers who post here could have some important information for us all - particularly those who have actually not given it much thought previously. Any comments?

[Richard B]

All I can say is that with the benefit of your experience, and now Mike & Di's, if I could afford a hard nose, it would definitely be on the shopping list!

(I bet Mark was glad he's got the hard nose on his boat)

[Alan]

I dont think a hard nose is needed on say a 7.5m or less RIB. However when you get to bigger boats with much more weight and momentum behind them it is clearly the way to go IMHO. Your experience, Mikes, Chris Strickland etc. Either that or slow down a bit Redbay put hard noses on their big RIBs for the same reason.

[Brian]

That seems sensible to me too.
Is there anything against having a hard nose then?

[Alan]

Well the only things that spring to mind would be perhaps a harder ride as their is no cushioning effect of a soft bow burying itself into a wave. Also less bouyancy at slower speeds - although I know that Cyanide goes through a channel chop at 12kts not over it even with a soft nose. Finally more chance of damaging boat or other boats when manouevering in a marina!

[mstacey]

Originally posted by Brian
That seems sensible to me too.
Is there anything against having a hard nose then?

Was it not Tony of Flatacraft experience that once debated the pros and cons of a hard nose ?

Seem to remember something along the lines of the forces being strong enough to rip off the sponson were also likely to be strong enough to do some serious damage to the hard nose as at least the sponson does have that cushioning effect.

I belive the same source also stated the way in wich he felt the bow of the sponson should be fixed. HD Webbing at the collar, and also by clever design and use of webbing (or other straps from bow eye over the tube to the deck at the bow and same at right angles over the tubes at the bow the force that rips the sponsons off can be made to actually pull the straps tight and roll the spons on.

Very poor explanation on my part.

IIRC it was in a recent (ish) copy of RI magazine.

[Charles]

Originally posted by Alan
Finally more chance of damaging boat or other boats when manouevering in a marina!

I do realise that many people have ribs simply because they are crap at berthing etc and use the tubes as a great big fender. This surely is not a reason to have a soft nose. I raised this thread as a matter of safety. Your previous post Alan, re size matters also would not hold true. I witnessed a 5.8 Humber on the east coast of Jersey rip the front off as well. It was a newish boat, well looked after. As Brian says, is there is anything against it?
I would consider it seriously now particularly what I know now and did not then!
Any other thoughts?

[Alan Priddy]

And for those "Old hands" Does anyone remember Mikes Deacons first hard nose rib in Scotland? That came off as well!
Alan P

[Alan]

Originally posted by Charles
I do realise that many people have ribs simply because they are crap at berthing etc and use the tubes as a great big fender.

Errm not sure thats true, although mebbe in some cases! There are folks who use their RIBS in support of yachts etc where a hard bow would be a disadvantage. I was merely trying to think of other reasons. Most RIBS of small/medium size are soft bows. (Osprey being the notable exception). Why is this? Cost? Performance? Dunno, back to you Charles!

[Manos]

Although I would prefer a 'hard nosed' RIB (and without been an 'expert' on the subject-unlike many) I would say that in respect of safety it makes no difference what you have on the boat, provided all is constructed as is suppose to be constructed.

I know of 7, 8,10 and 15 mtr Loa RIBs that they have soft noses and NEVER had a problem due to the very high quality of construction and materials used. But I also know of RIBs that having an inferior construction ripped up all the pontoons on the first hard dive they got.

I also know of RIBs 7, 8, 10 and 15 mtrs Loa with hard nose and some of them are very good and some are rubbish.

So I think is how good, reliable and honest manufacturers are when they advertise that they can build a seaworthy RIB

This reply doesn't help, does it??

[Alan]

Originally posted by Manos
This reply doesn't help, does it??

Errm, NO!

[Manos]

Right then
Have to get the books out

[Charles]

Originally posted by Alan
Errm, NO!

Agreed.
I am really quite keen to have 'expert witnesses' as this decision (hard or soft schnoz) surely is important enough to assist in considering what to go for if you are in the market for a new rib - probably on the larger side -ok, Alan W?

[mstacey]

Further to my earlier post.

It was Tony Lee-Elliott writing in Rib International Mag June 2003 issue.

When writing about the Nose of RIBS

A part of the article is about how the forces encountered in a stuff can in a good design be used to keep the tubes on the hull.

quote

' when the nose of a RIB is rammed deep into the back of a wave in what is called a folowing sea, the force of the action tries to lift the nose of the collar and sepearte from the still plunging hull. This is called a STUFF and the force of the whole action can be reversed and put to good use and so pulling the bows down onto the hull by simply applying two strops of strong two inch webbing. The first runs from mooring line bow eye up and backwards over the nose, down to floor inside the bows to be tensioned to a U bolt set in the floor. The second strop runs at right angles through the bow eyelet, up and around each side, over the top of the collar to join each end with the first strop on the same floor mounted U bolt'

[Dirk Diggler]

Originally posted by mstacey

'and so pulling the bows down onto the hull by simply applying two strops of strong twwo inch webbibg. The first runs from mooring bline bow eye up and backwards over the nose, down to floor inside the bows to be tensioned to a U bolt set in the floor. The secondstrop runs at right angles through the bow eyelet, up and around each side, over the top of the collar to join each end with the first strop on the same floor mounted U bolt'

As Mike Ring does with his ribs!

[Alex Brown]

Originally posted by Charles
I do realise that many people have ribs simply because they are crap at berthing etc and use the tubes as a great big fender. This surely is not a reason to have a soft nose.

Not so much on the safety side, but when my *new* (damnit) engine was having random stalling sessions (mostly when berthing), I had a couple of head ons with walls whilst dropping or picking people up. Only at very very low speed, but a hard nose would have probably cracked, whilst the tubed bow just bounced off and all was well - ie, no damage to anything on the front of the boat.

I have only managed to nearly stuff my boat twice into the water - the first time was an accident on a misjudged wave (not taking power off quick enough), and the 2nd time cos there were 4 adults at the bow of the boat, and I guess it was inevitable - we slowed down pretty quick when doing this . In both cases, we didn't get water in the boat, but it was about a few centimetres from coming over and in.... it looked pretty spectacular as the water went in both directions to the side of the boat mind Also, in both cases, the tube was inflated to the right pressure, and didn't even show a hint of folding back. From some other comments, it must also come down to the construction of the boat..... the Humber seems quite strong up front, and there is what seems to be a fair bit of extra fabric around the bow to re-enforce this.

-Alex

[Andre]

Originally posted by Alan Priddy
And for those "Old hands" Does anyone remember Mikes Deacons first hard nose rib in Scotland? That came off as well!
Alan P

Alan
Was that during "Round Scotland 1998" cos I was there and do recall a rib stuffing a wave and the tube coming off. The next wave shatted the console and most of the instruments popped out

Not something I would want to experience

Andre

[crazyhorse]

Well for what its worth,my opinion on the subject is its all down to how the boat is designed and its used?,and how the tubes are fixed on to the tube carrier and there expected loads / impact.

As some are aware we decided for tubes as apposed to a hard nose.
I questioned should we fit a 2ft wide bow metal bridle that could be bolted top and bottom,so as to give full enclosure of the bow tube,just in case?.

But I was quite rightly told,they had no problems with fixings and if needed they use them with a detachable rubber bridal for tug work,pushing logs down the rivers ect.

I had heard some tales of stress cracks appering on some hard nose boats,being driven at speed in bad conditions.I also heard of tubes comming off in moderate seas on some boats.

After a quick look into this I felt that the common denominater was a tube glued on to a flimsy fixing point ,or not fixed properly to the hull or abused.As if fixed with glue onto a descent carrier it should be ok as most still work fine and some commercial avons 20yrs on.

Avon,and Zodiac and Delta havent had these problems as far as I am aware, as if they had then maybe as they want to keep there commercial markets they would of changed it,or it would start to cost them real money ?so it must be IMHO design of fixing .

As a builder can change his design if needed to a hard nose and some havnt?,some have.

So my take on the subject is,Its down to what sort of tube carrier you have and its fixing points to the hull and if designd correctly to take the loads then tubes are no problem .Ours can come off and the sea is faced with a metal watertight bow, with the advantages of cushining and flex and front end boyancie you get with a tube.

As far as a hard nose is concerned then it doesnt have the same boyancie area as a tube or flex when inverted,but does give you a big bow locker and will cut through a sea dependant on its design.

I am not saying that a hard nose is crap as it gives more room in the bow and slices but can crack if wacked hard.

They are using tubes with no problems commercialy in Canada as they are here, and they push twin 250s all day long at crazy speeds.

Last wk I spoke to a commercial opperater who was in my oppinion being straight with me, he said that his normal tubed bow alli ribs had done 80,000 offshore miles with no problems and the boats are out every day and he owns three of them.

The tubes are machanicly fixed into a half moon shapes cradle at 6oclock all the way round to 12 oclock with bolted strips running there full length top and bottom and can be detached if required by unbolting.

I think of you sell hard nose ribs then you will say its very important to have one ?, if you dont then you have to decide and look into the fixing arangments/attachment method of tubes to the boat .

After that look at the boats that the tube came off or detached and then take a rational view as to the reason this happend?

There could be several reasons for it.

Its not IMHO as simple as one is better than another.

[Manos]

Thought that Canada will feature somehow CH
Still reading RIB Int'l June edition about what is the best RIB to get and still 'understand noooothing'. Will keep loooooking

[crazyhorse]

Manos the best rib to get is the one that makes you happy.