Width of garboard strake?

[Louie da fly]

Well, I'm almost ready to start planking below the waterline on the Great Harry. I've only ever done one previous pair of garboard strakes, and they weren't all that successful.

 

I've read the tutorials and looked at various builds but I just can't figure out  - I know the garboard strake is different widths at different points along its run; but is it the same as the widths of the adjoining planks, (the only difference being that the garboard has one edge that is straight)? For example, if there are (say) 15 strakes between the keel and the other reference point you're measuring to, is the width of the garboard at any given frame 1/15th of the distance measured along that frame ?

 

This has always been a puzzle to me , and I don't want to start planking before I'm sure I know what I'm doing.

 

Thanks,

 

Steven 

[druxey]

I think, depending on era and country, this varied. You'd probably be safe to go with your assumption. However, usually the garboard widened as it neared the stern post.

[Jim Lad]

Goodwin gives the width of the garboard strake as 2/3 the moulded depth of the keel for building after 1700.  I don't know whether that's helpful or more confusing.  I've always treated the garboard as 'just another strake of planking', but then I've never built a model of anything as early as the 'Great Harry'.  Perhaps a study of the 'Vasa' might give a few clues.

 

John

[Jaager]

My thinking on the situation is that the two important strakes for a successful bottom planking are the wale and the garboard.  It is important that the garboard absorb the first part of the arc from the baseline horizontal at the bow and what it can of the excess at the sternpost rabbet ( or arc if double ended).  All this while keeping its outer edge a straight line.  Because of this, I propose that a sacrifice of economy was made and the garboard was often cut from a plank that was often up to twice the width of the other planking stock.  In the spirit of pay me now, or pay me a lot more later.

Given that the seam at the stem-keel-stern rabbets are at the intersection of two different planes of force/flex/stress and failure is difficult to repair, a dinky garboard could be a disaster.

[Louie da fly]

So there's no hard and fast rule - doing it the way I described above is at least as good as any other. Now I feel ready to go ahead.

 

Thanks for your help, people.

 

Steven

Edited May 7, 2020 by Louie da fly

[Bob Cleek]

On 5/5/2020 at 7:01 PM, Jaager said:

Because of this, I propose that a sacrifice of economy was made and the garboard was often cut from a plank that was often up to twice the width of the other planking stock.  In the spirit of pay me now, or pay me a lot more later.

Yes. It was and still is shipyard practice to reserve select wide planking stock for garboard strakes. In some constructions, the garboard and perhaps the broads are also of thicker planking stock than the rest of the hull.

[Mark P]

Good Morning Gentlemen;

 

Further to the above comments, and as Bob says above, the garboard is often shown in sections as thicker than other planks at the edge where it meets the keel, tapering off at the outer/upper edge. In the 17th century it was also common practice to have thicker planks at the turn of the bilge. This was because of the need to grave, or clean, the ship's bottom, ideally twice a year; and to do this she had to be beached and allowed to lie on her keel and bilge. However this would be undetectable on a model.

 

Sir Henry Manwayring, an experienced sailor who distributed one or two copies of his Seamans' Dictionary to influential patrons every year, around the 1630s, wrote that to spring a leak at the garboard was the worst disaster of its kind, 'as it cannot be got at'.  It would therefore seem reasonable to suppose that the garboard received special attention. 

 

Another factor is that the timber shortages of later centuries would not have affected the shipwrights building the Great Harry, so wide planks would have been fairly easy to obtain.

 

All the best,

 

Mark 

[Louie da fly]

Interesting - the garboard strake on the Lomellina, built between 1503 and 1516 (the Great Harry was built in 1512-14) was carved out of a tree trunk. Here's a cross-section:

 

Apparently the garboards of the Cattewater wreck and the Red Bay wreck have similar characteristics. However, Lomellina was a Genoese ship, and the Cattewater and Red Bay wrecks were Iberian (Portuguese and Basque). The garboard strake of the Mary Rose, effectively a sister ship to the Great Harry, is much more "normal" (number 11 on the diagram below), so I think that's the path I'll follow.

 

 

Steven