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.