Building Stacer Plate boats

[Fed]

I contacted Telwater about it and they did not muck around.

I reckon you got lucky Davidson, I would have politely told you to take it back to where you bought it from or another authorised dealer if it was under warranty.

[PB]

PB, what Cat is those photos from?

Its an 8m we built for gippsland ports, currently building them another one at the moment.

[Chris Tucker]

Here's a photo Lovey..



Boat is in survey as a work boat but would make an awesome fishing platform.

[PB]

Dan (PB), do you have any build photos of the 490 Interceptor? Probably a better comparison for the stacer?

Not really a comparison at all being that has full height transverse frames and full length longitudinal stringers, built exactly the same way as our much larger commercial boats.

Chris your probably a better one to discuss the difference in build methods and how they differ from builder to builder and what truly defines a true plate boat.

[aussiebasser]

I guess I'm one of the lucky ones. I've had 6 Telwater boats, my brothers and nephews have had another 4 or 5. We've never had one crack or do anything apart from be a bloody good boat. My next tin boat would probably be a Sea Jay, but I cannot fault any of the Quinnies or Stacers I've had.

[Chris Tucker]

Not really a comparison at all being that has full height transverse frames and full length longitudinal stringers, built exactly the same way as our much larger commercial boats.

Chris your probably a better one to discuss the difference in build methods and how they differ from builder to builder and what truly defines a true plate boat.

The problem is there is no clear and absolute definition. Telwater obviously define it as meaning using 5083 (or similar) for hull bottoms and topsides and the majority of the market place appear happy to let them get away with that definition. If it were my money I'd want something like the photo above. Plate frames (doesn't worry me if they're longitudinal or transverse). Some sort of support for side plates (there are a lot of ali boats out there that don't have enough topside support). But most importantly a transom structure that ties into the rest of the boat.

There are too many under built/designed ali boats in the market place that people are happy to just weld up without asking "why has my boat broken?" Someone even posted a few pages back about there being "two types of ali boats those that have cracked and those that will" and no one said a word. A properly designed and built boat should last a lifetime and manufacturer's should be made to stand behind their products.

[patrol50]

I guess I'm one of the lucky ones. I've had 6 Telwater boats, my brothers and nephews have had another 4 or 5. We've never had one crack or do anything apart from be a bloody good boat. My next tin boat would probably be a Sea Jay, but I cannot fault any of the Quinnies or Stacers I've had.

mate with that kind of incredibly fortunate run ( have had 2 quins and both have had the odd issues but hey they are what they are - a mass produced pressed alloy boat built allegedly to a price point ) - and yes i also like the sea jays particularly their plate built units from what i have seen of them but anyway reckon with that amazing good fortune you should probably invest in a few lotto tickets

cheers

[creat]

The Quintrex Trident 690 looks almost the same as the Stacer Ocean Ranger 679

Is the substructure in the quintrex the same as the stacer?


nevermind, found it.
https://www.youtube.com/watch?featur...mMZmlLAw#t=100

[Nick H]

The Quintrex Trident 690 looks almost the same as the Stacer Ocean Ranger 679

Is the substructure in the quintrex the same as the stacer?


nevermind, found it.
https://www.youtube.com/watch?featur...mMZmlLAw#t=100

There is a reason they are at the price point they are, compared to my platey there looks to be about half the Aluminium in the substructure. Lucky they weld the keel!! Most people probably don't keep a boat long enough to worry about the build quality. There's an old pro with a profish that lives across from Labalsa ramp and I reckon the boat is at Least 15 years old still going strong.

[Andy56]

Why is it I have a sense of De Ja Vu.

Isnt this exactly the same discussion we had when holden went from full chassis rails in the HQ to integrated chassis/body in the commodore? Its now standard across every car except 4wd SUVs

Are we discussing making a boat that everyone can afford or are we discussing making a bullet proof barge? Surely, a 23-30ft commercial boat needs to be fabricated that way were as a 15-18 ft boat doesnt need that much? Horses for coarses?

I dont understand this fettish about having to be upto Military spec.
If they werent safe, wouldnt they be on the 7.30 report?

Nobody has given us any engineering insite yet. Sure nice pictures of one big boat with massive ribbing and another with not so big ribbing but welded floor. Unless the ribbing is tighter, the plate is subjected to the same stresses in either method, I would have thought. To me the stacer has tighter ribbing, the other one has massive ribs but to a larger pitch. But logitudinal stresses are much larger on bigger boats. I have never seen an aluminium boat of any construction bowing in the middle. Have I missed something?

Which begs the question, what ARE we really arguing about? I can equally be pedantic and say a true plate boat is usually a displacement hull. Wont that set the rabbits....lol

We should be happy that stacer are willing to show us how they are made. I for one appreciate the clip.

[Lovey80]

Andy, I think we all appreciate the clip that is for sure.

Actually we have had some engineering insights from Chris Tucker, who I believe is one of the premier naval architects in Australia (willing to stand corrected). But I guess what has people curious is the build methods used. When you start talking plate boats you're usually associating that with a boat that is capable offshore. As you know offshore boats take a beating whether we like it or not. Ally doesn't like too much stress or it cracks. The stronger the reinforcement and the less flex that the plate gets the longer it is going to last before it cracks.

When I look at the frames PB posted, it gives me confidence that if build quality is good then the boat is likely to get corrosion pin holes well before structural problems begin in the boat. Only time will tell if we can have confidence in the telwater system. I certainly would be curious to see one of these rigs after a couple of thousand hours on the water.

[Chris Tucker]

I'm really concious of not criticising other people's products on forums like this so I'm not going to embark on a detailed analysis of the Stacer's structure which isn't intrinsically different to many of the cheaper "Plate boats" on the market. So I won't be calculating whether individual members are up to spec or not. Traditional boat structures are designed as grids.

Bottom plate thickness is defined by weight, speed, and stiffener spacing.
Bottom stiffener size is defined by all of the above plus the unsupported span of the stiffener. Typically this is the distance between the frames.
Frames (or floors in the case of the stacer build) are then defined by their spacing and unsupported span.
On big boats the next links in the chain are the Kelson then the bulkheads. On small boats it is not unusual to use the sides of the boat as the next component (similar to Andy's Holden chassis). This is the case on both the Stacer and PB's interceptor

Now here is where it gets complicated.
Most of the applicable standards say that if a member is more than 12x its thickness without a flange it will buckle so a 4mm flat bar stringer can only be 48mm high and a 5mm 60mm high. You can go beyond that but only for build-ability reasons and only if it would actually be ok if built at 48mm.
When you look at the Stacer video the transverse members appear to be joint right on the keel this is the location of the maximum bending moment in the stiffeners. The same structure using bottom stringers that span from side to side in one piece would have significantly higher safety factors. Stacer appear to get around this using a doubler welded over the joint. It is interesting that at a glance the the Stacer's interior structure is very similar to many of the cheaper plate boats on the market but details like those brackets on the keel line make all the difference and actually make it a superior product. Of more interest is the fact that we don't see any form of floatation go into it. Now the boat may be bigger than the size where this is required but still is safety where you want to save money. It might also be shoved in at the same time a the fuel tank but as it would be easier to install before welding down the deck plates I find it hard to believe this is done.

The boat is built a lot lighter than many of the "premium platies" on the market and lacks the chines and details seen on many of them so I suspect it handles, rides and bangs more like a traditional ali boat or tinny than a modern plate boat so their traditional market coming up from a pressed tinnie will be impressed, but owners of glass boats will go for a ride and say "see ali boats still can't compete".

That's all you ll get from me on this one.

[PB]

Why is it I have a sense of De Ja Vu.

Isnt this exactly the same discussion we had when holden went from full chassis rails in the HQ to integrated chassis/body in the commodore? Its now standard across every car except 4wd SUVs

Are we discussing making a boat that everyone can afford or are we discussing making a bullet proof barge? Surely, a 23-30ft commercial boat needs to be fabricated that way were as a 15-18 ft boat doesnt need that much? Horses for coarses?

I dont understand this fettish about having to be upto Military spec.
If they werent safe, wouldnt they be on the 7.30 report?

Nobody has given us any engineering insite yet. Sure nice pictures of one big boat with massive ribbing and another with not so big ribbing but welded floor. Unless the ribbing is tighter, the plate is subjected to the same stresses in either method, I would have thought. To me the stacer has tighter ribbing, the other one has massive ribs but to a larger pitch. But logitudinal stresses are much larger on bigger boats. I have never seen an aluminium boat of any construction bowing in the middle. Have I missed something?

Which begs the question, what ARE we really arguing about? I can equally be pedantic and say a true plate boat is usually a displacement hull. Wont that set the rabbits....lol

We should be happy that stacer are willing to show us how they are made. I for one appreciate the clip.

I get what you are saying mate and yes I do believe there is a place in the market for what Telwater do 100% we need boats like this and secondly they are Australian built and another big plus in my book.
The big problem in the industry is the way these and a lot of other so called plate boats are marketed and how they are automatically compared to what me and a lot of other hard working boat builders do when its simply not the case.
In their build clip it shows the build times and what stage they are up to. At the 11 hour mark for us to get to the same stage would take about 3-4 weeks on a similar size boat. Yes I did post a pic of a larger commercial boat but the second pic of the mono hull is only a 4.3m (4.9 LOA) tiller steer and we were showing that it is built the exact same way as our much larger models.
The way Stacer build there "plate" range is almost identical to their pressed range the only real difference is that the bottom and side sheets don't have pressed ribs in them.

[scottar]

After having used a pressed tinnie for the better part of 20 years offshore with no cracking, I see no reason the Stacer won't give a good service life. Sure, it is probably not as strong as a survey built commercial boat but it won't typically see the same sort of use either. While the other boats displayed in this thread are in all likelihood stronger (I'm no engineer and without destructive testing or a whole heap of complicated maths can we be sure??), if we are to say the Stacer is not a "plate" boat, then what is it - it sure isn't a pressed boat. It has a fully internal frame that is in both axis. I doesn't rely on hull pressings for longitudinal rigidity like a tinnie does. All I can see is a plate boat using a different construction technique.

Just as a side note - plenty of "true" plate boats have failed over time from a variety of manufacturers. Owner usage patterns, fit of components and the abilities of the man on the welder play a big part in alloy boat longevity.

[patrol50]

I'm really concious of not criticising other people's products on forums like this so I'm not going to embark on a detailed analysis of the Stacer's structure which isn't intrinsically different to many of the cheaper "Plate boats" on the market. So I won't be calculating whether individual members are up to spec or not. Traditional boat structures are designed as grids.

Bottom plate thickness is defined by weight, speed, and stiffener spacing.
Bottom stiffener size is defined by all of the above plus the unsupported span of the stiffener. Typically this is the distance between the frames.
Frames (or floors in the case of the stacer build) are then defined by their spacing and unsupported span.
On big boats the next links in the chain are the Kelson then the bulkheads. On small boats it is not unusual to use the sides of the boat as the next component (similar to Andy's Holden chassis). This is the case on both the Stacer and PB's interceptor

Now here is where it gets complicated.
Most of the applicable standards say that if a member is more than 12x its thickness without a flange it will buckle so a 4mm flat bar stringer can only be 48mm high and a 5mm 60mm high. You can go beyond that but only for build-ability reasons and only if it would actually be ok if built at 48mm.
When you look at the Stacer video the transverse members appear to be joint right on the keel this is the location of the maximum bending moment in the stiffeners. The same structure using bottom stringers that span from side to side in one piece would have significantly higher safety factors. Stacer appear to get around this using a doubler welded over the joint. It is interesting that at a glance the the Stacer's interior structure is very similar to many of the cheaper plate boats on the market but details like those brackets on the keel line make all the difference and actually make it a superior product. Of more interest is the fact that we don't see any form of floatation go into it. Now the boat may be bigger than the size where this is required but still is safety where you want to save money. It might also be shoved in at the same time a the fuel tank but as it would be easier to install before welding down the deck plates I find it hard to believe this is done.

The boat is built a lot lighter than many of the "premium platies" on the market and lacks the chines and details seen on many of them so I suspect it handles, rides and bangs more like a traditional ali boat or tinny than a modern plate boat so their traditional market coming up from a pressed tinnie will be impressed, but owners of glass boats will go for a ride and say "see ali boats still can't compete".

That's all you ll get from me on this one.

very interesting and relevant comments chris and no question you know your game i would say ( while i am an engineer i am not a naval architect / engineer so you would buy and sell me in this game ) but imho the way that some alloy boats allegedly are simply built more to a common industry price point and not necessarily specified approved design standards is probably a crux of the matter really - and so when comparing alloy boats of similar size and claimed performance but with varied construction methods that aint necessarily comparing apples with apples unless the design standards and materials specification / construction methods are relatively comparable - and it appears the spin doctors or marketing gurus do like to muddy those comparison waters

cheers