Tag Archives: garboard Strake
Rabbet for Garboard Strake
Just chiseled out some Rabbets for the Garboard Strake…
On a vessel’s hull, a strake is a longitudinal course of planking or plating which runs from the boat’s stempost (at the bows) to the sternpost or transom (at the rear). The garboard strakes are the two immediately adjacent to the keel on each side.
A clinker-built Viking longship, whose overlapping planks constitute “strakes”.
Garboard strakes and related near-keel members
Diagram of typical modern metal-hulled ship’s exterior plating, with a single strake highlighted in red
The word derives from traditional wooden boat building methods, used in both carvel and clinker construction. In a metal ship, a strake is a course of plating.
In small boats strakes may be single continuous pieces of wood. In larger wooden vessels strakes typically comprise several planks which are either scarfed, or butt-jointed and reinforced with a butt block. Where the transverse sections of the vessel’s shape are fuller, the strakes are wider; they taper toward the ends.
In a riveted steel ship, the strakes were usually lapped and joggled (one strake given projections to match indentions in the one adjoining), but where a smoother finish was sought they might be riveted on a butt strap, though this was weaker. In modern welded construction, the plates are normally butt-welded with full penetration welds all round to adjoining plates within the strake and to adjoining strakes.
In boat and ship construction, strakes immediately adjacent to either side of the keel are known as the garboard strakes or A strakes. The next two are the first broad or B strake and second broad or C strake. Working upward come the bottom strakes, lowers, bilge strakes, topside strakes, and uppers also named sequentially as the D strake, E strake, etc. The uppermost along the topsides is called the sheer strake. Strakes are joined to the stem by their hood ends.
A rubbing strake was traditionally built in just below a carvel sheer strake. It was much less broad but thicker than other strakes so that it projected and took any rubbing against piers or other boats when the boat was in use. In clinker boats, the rubbing strake was applied to the outside of the sheer strake. Many current pleasure craft reflect this history in that they have a mechanically attached (and therefore replaceable) rub rail at the location formerly occupied by a rubbing strake, often doubling to cover the joint between a GRP hull and its innerliner. Inflatable dinghies and RIBs usually have a rubbing strake (typically a glued-on rubber extrusion) at the edge.
A “stealer” is a short strake employed to reduce the width of plank required where the girth of the hull increases or to accommodate a tuck in the shape. It is commonly employed in carvel and iron/steel shipbuilding, but very few clinker craft use them.
Planking from Keel up
I’m slowly working my way up. ..
On the Stern, I calculated that I need to taper the 5mm Planks down to 3.88mm in order for all of them to fit.
I had to make the Garboard Strake in 2 Sections.
See how I had to make that bend at the forward part.
It is true what they say about Garboard planks. That it’s the toughest Plank to be able install. It does go through some rather radical twisting… Around 90° worth from Bow to Stern.
Here I’m gluing the forward part in before I do the rest of the twisting.
One of the main things about Garboard Planks is that you don’t want to let it come up the Bow. This is so you don’t get Plank crowding as you progress up the Bow with the rest of the Planks on the lower band.
The lip of the Plank comes over the Kelson, where the Keel will be glued.
The Keel acts like a Rabbet groove. If it wasn’t like this or had a false Keel, I would have carved some Rabbet grooved along it but it wasn’t necessary with this ship.
Also I’m keeping the overhang on the front of the Garboard Plank… just to have someplace to be able to clamp on to.
Looking at the forward part of it… I’m kind of cursing myself right now for now thinning it out a bit, and to have cut a Rabbet into it. Oh well… I’ll remember to do it next time. It’s too late. The clue on Starboard side is already set and it would be a big messy pain in the ass to take it apart and redo it.