First of all, the concept of Lining Off and the details of how it was/is done are skimpy at best and require a lot of reading to locate and discern. I know because it has been a real chore collecting the info for the book I am writing about Lining Off. I know the Royal Navy worked hard at breaking down the trade secrets held by the Guilds and Liners who would only pass their trade secrets to their sons. It was their livelihood, that was at stake. The older books frequently used the term "brought to rule" to describe this quest for control. I think the RN failed, because we still do not have one single resource to describe the Lining Off Process properly.
Most of the early writers I have read that even mention Lining Off, wrote about what they thought they were seeing, not realizing they really didn't know. At best they left clues that I have used in reverse engineering the process. Lining off in my opinion should always be done on a one-off hull. naturally when you've already done one hull, the next similar hull will be easier because you know what compromises are needed.
The process plans for the breadths of seam locations, always with the intent of minimizing twist and having strake widths that will hold fasteners without splitting. Interestingly, in the older texts, the term strake is used until they actually start getting planks out of boards, at which point they start calling it a plank. Today, out of ignorance, we use the terms plank and strake synonymously. Not knowing this makes discernment difficult when reading the older books.
It is correct about the Garboard Stealer. Its real advantage is that it allows the Garboard to rise (to sny) as the stress of simultaneous bending and twisting is applied. The Garboard Stealer eliminates the need to edgeset the garboard plank downward.
The use of the terms "add and drop" can also be confusing. For whatever reason, the older convention seems to be to call these girth-adjustment-planks Stealers at the Stems and Drop Planks amidships. When you consider that it is ultimately plank thickness and the thumb rules for fasteners that determines the minimum width of hoodends, you can quickly see that only a limited number of hoodends can be planned for the stem forward. The hoodend of the stealer uses one of those spots, and the adjustment for the difference in the number of strakes amidships occurs aft of this point whether you go from a stealer to two planks or allow the stealer to become a through plank that receives a drop plank. And for the opposite reason you probably couldn't fit the number of strakes determined for the amidships section of the hull to the stem aft. Drop Strakes (not full length) planned amidships reduce the number of full length strakes reaching the stem forward, and as such reduce the number of stealers needed above the Shutter Strake, which really controls the flow of all strakes if properly planned.
Drop planks increase the number of strakes reaching aft and solves some of the problems there. As I said earlier, Stealers properly installed are not an issue.
Having opened this smelly can of musty information. You can of course find a
unique hull that will make a lie of any one statement, but the rules of thumb
developed empirically must be used or your hull will not be the scale replica
you might have wanted it to be.
{Bob Giles}
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