Gauging Interest for a Stitch & Glue Landing Craft

Hello all, first post but long time reader!

As the title states I am looking to gauge interest in a stitch and glue landing craft design. I am thinking of designing one for my own purposes, but figured I would see what ideas others had before beginning.

I design welded aluminum boats as my profession, but I am often struck by how incredibly expensive these craft are. For strictly commercial operators I understand the value of a welded aluminum craft - namely durability, safety (dents instead of hull breaches), customization, etc.

I am curious though if there is a market for people like me who would find a landing craft extremely useful for hauling gear or supplies to off grid cabins, but wouldn't use and abuse one enough to justify the cost of a welded aluminum craft. Having built a number of stitch and glue boats I am confident that a "medium-duty" landing craft could be built fairly straightforwardly with pretty basic tools/skills.

If you count yourself in this category please reply with what your design requirements would be. These would be like LOA, beam, what kind of payload you'd want to carry and what type of accommodations you'd expect (cabin vs side console etc).

For my own personal design, I would want a fairly simple 26-28 foot LOA with a 9' 6" beam. I would want to run twin outboards spaced fairly wide apart, with a modest deadrise to take advantage of smaller and cheaper outboard engines. I would be happy with a top speed in the mid twenty knot range, and would be primarily carrying building materials. Given the weather in Canada I would have at minimum an enclosed side console, but more likely a small cab offset to one side with the driver position on centre.

The old Sealander glass landing crafts are quite similar to what I'm envisioning, but with some modern comforts and design.

Please let me know what you would all want!

 

I guess if you want to get home fast ( empty ) then a light weight, stitch-and-glue barge is an advantage.
Oh, and there's the fast build advantage of SaG.

But the hard chines aren't really SaG attributes nor is the light construction conducive to heavy barge loading.

Buy a used 42' Sea Truck from the Canadian Coast Guard; if you can find one.
You can safely put a loaded pick-up truck on board.

Where on the west coast do you plan to operate your barge?

 

Thanks for the reply BlueBell.

I agree completely that stitch and glue would be inefficient for any craft expected to carry heavy loads (like a pickup). I am more interested in a general purpose workhorse for carrying lighter loads, like skids of plywood, 2x4s, bags of concrete etc. My family has a remote property near desolation Sound and I am thinking of building a small cabin/office, and would get a lot of utility out of a small landing craft especially one that could be built fairly easily/affordably.

My vision for this is the marine equivalent of a Ford Ranger, a utilitarian little runabout.

Buying a used barge would make the most financial sense for construction, but having a small and zippy landing craft would be a nice add on to an off grid lifestyle after the cabin is built.

 

Drove past that little yellow boat this morning I think. If memory serves its been short of freeboard and hard pounding in chop since the late 70s...

Been thinking about a landing craft in roughly that size for some time. Even put a fair whack of money aside for getting the project started.

My off the cuff thoughts are;

Rigging cost are universal to material, while hull cost is an issue its a smaller % than initial sticker price.

I guess if we're comparing professional welded hull vs home made stitch and glue were gonna see a big difference as Labor cost is the biggest these days. But thats not strictly an apples to apples comparison.

Aluminum just works so darn well for small landing crafts, gonna have extra work getting ply laminated thick enough or clad in plastic to equate to its single point load resistance.

My bias is a full kit out welding setup, so that cost doesn't factor into my brain nor the learning curve to weld. Local place makes some pretty little stitch and glue boats, they are a bit cheaper... but they devalue like crazy on the second hand market and when used hard age like ripe bananas.

Friend had a hull built last year, that was absolutely optimized for plate utilization and wastage during nesting and cutting. Its objectivity not as pleasing of lines, but its not terrible. For me Id be more inclined to purchase optimized aluminum plans over stitch and glue.

 

Yeah I think the cost to tool up a shop for welding would likely be one of the highest barriers to entry for constructing a DIY welded aluminum landing craft, aside from the welding experience required.For example at the company I work for, one of our welding machines carries a total cost of roughly 22k CAD, then add on top all of the various tools and consumables and your head starts to spin.

I agree that if you're paying a shop to build a boat, then material is naturally way less of a factor compared to labour.

The equation really changes though if you don't mind trading your time to build one yourself though, especially since building a SaG boat requires only basic tools.
For reference, the company I work for is about to start my most recent design, a 33' x 10.5' welded landing craft, which will be a very sturdy platform for commercial use, but carries a mid 6 figure price tag. This would be very hard to justify for any non commercial operators, which I think is where a DIY SaG craft could be quite useful.

Most aluminum landing craft support the deck with long and tall girders connecting the deck to the hull, with alternating longitudinals for the aft 2/3 and purely girders for the forward 1/3. I would go for a similar arrangement out of wood, using straight laminated stringers instead of longitudinals.

I'd have to run my structural arrangement through the ISO standards before trying anything, but I am confident you could alleviate the point load concerns by adding a wide flange to the top of the girders giving a generous pad to glass the edge of each deck section to rather than just glueing the decks to the girders as is commonly done.

This is still very much a thought experiment for me, so please keep the ideas, opinions etc coming!

 

Hi Lgrundy, I've been thinking of something similar, but trailerable, about 29 ' long X 8' wide, Stitch and Glue with 1" thick ply bottom with very shallow V (so bottom doesn't suck into mud completely), thinner sides, bow folding down for loading when rammed into shore, and with masts and sails at sides, leeboards, and OB. Idea is max space for sheltered waters, un-cluttered floor space so can pitch a tent or a few inside, as a mobile camp ground / fishing platform / barge. Shallow steel keel, and angle iron chines for grounding. Built in buoyancy at sides, poss false flat floor, and rudder pintles (and OB bracket) front and rear so can sail in reverse if need/able. Maybe big enough to transport a small Suzuki 4x4, and/or several dirt bikes. A do-all trailerable sailing barge, not fast or efficient, but very functional.

 

First of all, I’m not really in the market per se for such a craft, but have seen them requested on s&g forums, so your idea has merit and given the cost of ally production landing craft; there is definitely a place for the idea.

Secondly, and perhaps more important, your proposal screams design error from the start. Let me explain the harsh critique.

When you design a vessel; you never start by suggesting a size. You start by suggesting the requirements or more commonly stating them. In the case of your lc, you go right to the size above. Don’t. First, write the statement of requirements; perhaps you just jumped ahead, I don’t care.

Most of the people who would want a lc have a simple, simple goal in mind to bring gear ashore. The most common gear is a 4 wheel drive something.

The second most common thing (I could be wrong) would be hauling out fish or game or hauling in plywood or timber for a cabin.

Then a larger lc could offer room for two such 4 wheel devices so two friends can go trekking in the back country or all the way up to a side by side, I suppose.

And by suggesting 9’6”, you’ve destroyed about 80% of the market who want to trailer the lc. Clearly not needed for a 4 wheeler unless the front hits the beach too soon.

Another reason plywood dies on the vine for lc is it’ll only make four beach landings (as ply) before wood is exposed. So, you need to overcome that somehow. Maybe the bottom gets an aluminum plate? I don’t know, but I have an aluminum skiff and its been on lotsa rocks.

I cannot see how you don’t need at least two designs and/or ally plate option. One for the guy who wants to say haul out a moose and a four wheeler, and a bigger one.

And afa engines, again, twin engines is going to take about 80% of the people out. So this also pushes me to think the idea probably needs two designs.

I’d backup and write the SOR and perhaps write two of them, so the idea can get traction for more users.

Write two statements of requirements first. I cannot see how many of the people wanting an economical lc will want it over trailerable width or with twin engines.

 

@Lgrundy,

I get what you're after and I think it's a great idea.
Sort of a mini version of the Inlet Raider ( see below ).
Many of the contracted Park Rangers use aluminum equivalents here,
very similar to what you're proposing.

Have you done the cost comparison to aluminum?
It's hard to beat, especially when you consider longevity.
You're going to need a lot of epoxy.
Can't you get a "deal" at your work ( on aluminum )?
Have you priced your "small" o/b's yet?
I suspect your total cost difference between Al and S&G construction
overall is going to be smaller than you're thinking.

You're the boat designer, what have you come up with thus far?

Beautiful ( and exciting! ) part of the world we live in.

 

Dimensions make sense as its about as big as can be trailered conveniently, any wider or longer and it starts to be a pain. Any smaller and its gonna be a squeeze for the average sxs. Gonna need a bit of power to sling it all on step at a decent clip.

 

Agreed comfisherman.

 

I think there is merit in investigating the option of a riveted Al boat. Either with solid rivets or by using sealed pop rivets. Riveting doesn't have a high dollar and skill entry bar, all that's needed is a drill and a modified air chisel or a hydraulic pop rivet gun. Frugal builders can get by with a drill and a hammer and dolly. With the addition of a modern adhesive sealant this could be even less daunting for some of the home builders then mixing epoxy and fiberglassing. The unknown is cost, that's why I recommend a local market survey.

As to size I think there are two directions: a trailarable smaller boat that can take an ATV or small trailer and a bigger boat that could take a pick-up. I don't think a landig craft that relies on manual loading and unloading would have success, people are lazy, they want some form of ro-ro.

 

Just a little note of caution if "sealed pop rivets" means the bucket-style ones:

I'd advise to do some testing with the various sheet thicknes combinations involved, and have a close look or do pressure testing afterwards..

They are surprisingly watertight usually. We popped tens of thousands of them when i had a solar roofing business. But we had a few cases (fabrication divergences ? Bad application, tilted or something ?) where they developed micro-cracks at the bottom of the pot. The rivet head would still be tight against the sheet roofing, but water would find it's way along the mandrel head to the crack. You'd typically need good eyes if not a magnifying glass to see it from 10cm away (forget it in our case where they'd be 7m up in some dark barn, even with binoculars you couldn't see it from the ground). The dripping was only noticed by the clients the next rainy season. Needless to say it was no fun to pull a few hundred m2 of panels off the roofs just to replace a few dozen rivets and get things back to a rust-proof state .