Tube Separation

[Chris]

It does not look like the glue has come apart at the front you can see from the bbc footage that it actually tore free at the front which then caused the bow to peel back.

I can't believe how little meat there is at the front for the tube to attach to. I remember Rogue Wave telling me this was a weak spot with Ribcraft now I can see why

[BogMonster]

Originally Posted by wavelength

or a Humber for that matter?

No the tubes just fall to bits at the other end instead

[wavelength]

Given the number of humbers knocking about around the world, and the age of a lot of them, used and abused by various dive clubs and commercial operators, they do not seem to figure in the "tube ripping off from the bow due to stuffing into a wave" scenarios, or indeed any detubing situations. I've used them of all ages and all sizes, all over the world, including the Falklands and I have never had a prob with tubes coming unstuck from the front, back or indeed the middle .

[alystra]

Originally Posted by wavelength

Given the number of humbers knocking about around the world, and the age of a lot of them, used and abused by various dive clubs and commercial operators, they do not seem to figure in the "tube ripping off from the bow due to stuffing into a wave" scenarios, or indeed any detubing situations. I've used them of all ages and all sizes, all over the world, including the Falklands and I have never had a prob with tubes coming unstuck from the front, back or indeed the middle .

Phew! That's a relief. Thought for a while I'd got something else to worry about. Now I can concentrate on thinking that my engine block might be turning into a colander.

[wavelength]

Phew! That's a relief. Thought for a while I'd got something else to worry about. Now I can concentrate on thinking that my engine block might be turning into a colander.

I hope not-we still have one of our humbers from 2001 with that same model engine! The boat has been as good as gold but it had three engines in the first year due to problems. Keep it in regular use -the best combined maintainance plan for both the outboard and its owner

[BruceB]

There was one incident when a tube ripped off a Humber all on one side that I can remember. It was a few years ago in the Clyde on a RIB used by a diving club that shall remain nameless to protect the guilty. The boat lost one whole sides worth of Tube from the bow right back.
I think it may have been caused ever so slightly by abuse though, probably hitting the channel bouy in the dark at 25-30 knts may just have been a contributing factor
This thread is really giving me a nice warm glow despite my concern for the folk involved in the various incidents, I very near bought a Ribcraft instead of the Humber, mainly because it was supposed to be of a higher build quality. I hadn't realised it wasn't unknown for them to self destruct!

[Pete7]

Originally Posted by BruceB

I hadn't realised it wasn't unknown for them to self destruct!

Shoking isn't it, well the only solution then is that ribs have a fibreglass nose cone to help keep the tubes on

It may be possible to retro-fit so feel free to chat to Leeway as I gave him a GRP nose cone moulding.


Pete

[tinker]

they do not seem to figure in the "tube ripping off from the bow due to stuffing into a wave" scenarios, or indeed any detubing situations.

IMHO it depends how badly they have been used and in what conditions, every craft has a weak point, just that some people have more luck in finding it The forces involved must be very high, try and push an inflated football underwater then imagine 20+ times the boyancy hitting a wall of water at 20 knotts, the pressure on the front bow of the tubes would surely be very high.

[Rodan]

Originally Posted by tinker

IMHO it depends how badly they have been used and in what conditions, every craft has a weak point, just that some people have more luck in finding it The forces involved must be very high, try and push an inflated football underwater then imagine 20+ times the boyancy hitting a wall of water at 20 knotts, the pressure on the front bow of the tubes would surely be very high.

but isnt that what a tough rib is supposed to or should be capable of doing! done it a couple of times by accident and watched the tube take the strain but it held beautifully - like it should!

[prairie tuber]

I while I can easily see how this can happen to a RIB when being used commercially as a lifeboat (going full throttle into very heavy seas day after day), it is completely unacceptable that it does happen. If a manufacturer is going to build a RIB, they should do it right. People choose RIBs because of their supposed ability to handle conditions that a hard boat can't.

Codprawn asked a good question about whether anyone has heard of this happening on an Avon. I haven't heard of this happening to a Hurricane, Polaris or a Titan Rib. All of which get continuous use as CG and Rescue boats in extremely severe sea conditions in North America. Sure they all may eventually may need retubing after alot of heavy use, but a a catastrophic separation of the tubes at the bow from a hard stuffing?

For a brand such as Ribcraft (which I thought was supposed to be a premier British brand) to have this happen even once, let alone several times (based on all the other accounts I've read of in this thread) is absolutely brutal. They clearly need to redesign, and re-evaluate their construction methods.

Have RIBs become a victim of their own success in the UK? By that I mean, has their popularity drawn so many outfits to get into the manufacturing of Ribs, that alot of them really don't know (or care) about how to build it properly? It seems that RIB evaluations in magazines (particularly that one dedicated to RIBs with the beautiful glossy photos and the very poorly written articles), always talk about the dryness of the ride, lay out of the deck, whether the cupholders are ergonomically located etc..., but I never see anything written about what really matters, which is long term durablity after continuous severe use.

What advantage does a RIB that falls apart and sinks when used in severe conditions have over a hardboat that gets swamped and sinks when used in severe conditions? May as well save the money and get the hardboat, or better still, eliminate the middle man and just have someone throw you overboard while you are a passenger on a boat that does float.

[tinker]

IMHO a sub 5m hard boat would have sank or have being so swamped it would not have been possible to get the draft back in order to re-start the engine and shift the water. I had to reach into about 14 inches of sea water to release the drain plug.
As stated in my earlier post it was a 7 year old rib at the time of failure and it was the hypalon tearing rather than the joint failing. That however led to the joint failing when returning to base with the waves then putting pressure on the seam/joint. No boat is indestructible, especially a sub 5m one with 7 years of use, a heavy handed idiot at the helm and a heavy sea.

[Searider]

Suffered a tear in the attachment strip on the bow of my 5.4m Searider the first time I used it.

Was a 50mm tear from stuffing into the back of one wave.

Spotted it when the boat went back on its trailer later that day so there was no repetitive impacts to elongate the tear or cause further damage.

Easily fixed with a patch and no further issues in 4 more years of ownership.

1978 boat and the incident was in about 1998 - so a 20 year old boat.

Could happen to anyone!

[RJH]

As a Ribcraft owner this may be construed as being a touch defensive but I have little or no experience of these very rough conditions ( nor do I want to test my tubes in them!) but the following was included on the YBW newsletter today. May help to explain the mystery.


Lifeboat rescues lifeboat
Portishead independent lifeboat had to be rescued yesterday after colliding with a submerged object while on exercise in heavy seas. The 22ft RIB 'Denbar Sage', carrying two crewmen and a trainee, sustained structural damage, and the crew members issued a Mayday.

Swansea Coastguard despatched two RNLI lifeboats from Weston-super-mare, the Independent Lifeboat from SARA, and a SAR Helicopter from RAF Chivenor to assist, and 'Denbar Sage' was towed back to its base. A Portishead lifeboat spokesman said, "We do not know what the boat hit, but we think it may have been a large tree."

[Poly]

to rip the tubes off by hitting a submerged tree seems a bit tricky to me.

[Bigmuz7]

Originally Posted by Polwart

to rip the tubes off by hitting a submerged tree seems a bit tricky to me.

Dont agree.. on the contrary.. due to the density of the soaked wood, most of it is submerged. On my way to Campbelltown a couple of years ago in September, I came across an entire trunk after some storms, with all its branches under the water and only a few showing above, presumably due to other impacts,.. waves were about 2.0m so.. given the right speed at the wrong time ... a strike would have been a bad experience. Happened that visibility was good and we could see it coming, but I've been in plenty where it could have appeared at a moments notice !

[Poly]

Originally Posted by Bigmuz7

Dont agree.. on the contrary.. due to the density of the soaked wood, most of it is submerged. On my way to Campbelltown a couple of years ago in September, I came across an entire trunk after some storms, with all its branches under the water and only a few showing above, presumably due to other impacts,.. waves were about 2.0m so.. given the right speed at the wrong time ... a strike would have been a bad experience. Happened that visibility was good and we could see it coming, but I've been in plenty where it could have appeared at a moments notice !

I quite believe that a tree trunk can be mostly submerged, would be difficult to see even in reasonable conditions and virtually impossible in bad weather. And I have no doubt that hitting one would be a very unpleasant experience, probably resulting in substantial damage.

I could see a big trunk putting a whole in the hull. I could see a sharp branch sticking out of a large submerged tree tearing the tube. But the video shows an intact tube detached from an intact (or certainly not substantially damaged) bow.

If the trunk was submerged how does the tube get to it unless by some massive coincidence the trunk is in the centre of a wave AND the boat stuffs the wave at exactly that point. Even then to pull the tube off the hull rather than burst the bow section?

[Bigmuz7]

Originally Posted by Polwart

If the trunk was submerged how does the tube get to it unless by some massive coincidence the trunk is in the centre of a wave AND the boat stuffs the wave at exactly that point.

Thats a possible scenario, it all looks similar when regular waves hit you, time after time after time.. Not saying it was the case here, but its perfectly plausible ,as its what I have seen myself.

If I had a finger and thumb for every event I'd never think I would ever see at sea....I never ceased to be amazed

[Bigmuz7]

Just occurred to me .. We have a loft supported by an old log split in four, lifted from the North Minch coast line 55 or so years ago. About 8 years ago whilst at sea , I observed some gulls that looked like they were standing on the water, when I got closer, they were resting on one of the very same logs (as it appeared) in the same area, so, to prevent myself and others hitting this timber I dragged its huge weight to shore and beached it,and as yet I have not moved it from where I left it. Its 14 feet long by about 15 inches in diameter, and absolutley none of it, was visible in the water. Once on dry land ,.. only my tractor could move it up the beach to where it sits now to this day

[Poly]

but that was my point - a submerged log is much more likely to do hull or leg damage than rip the tubes off when the tubes are normally sitting out the water. even if you did stuff a log - the forces don't seem to me like they would be mainly upwards as necessary to cleanly rip off the tubes. Press said y'day that MAIB were investigating so maybe we will find out.

[jwalker]

I've seen examples of Bigmuz's logs and I wouldn't want to meet one in a wave but I agree with Polwart that this is unlikely to be the cause of the damage. You are both right so stop bickering.....

If you look carefully at the video, it's pretty obvious that the front of the tube folded back and tore the cross piece at the bow over the rather sharp corner of the flange. After that the glue simply came apart. As I said before, bad gluing. A good glue joint will not separate at the glue line, the glue amalgamates into one. It's clear to see that there have been a few good patches where adhesion appears to be ok but mostly the glued area has just separated. It's interesting to note that there are multiple layers of joint reinforcing but even these have not stayed together.