Posted by Mike Field on March 10, 2019 at 19:15:06 user mikefield.
In Reply to: Was John Walker a Competent Seaman? posted by Peter Hyland on March 08, 2019 at 09:45:46:
I don't think it's "the strongest pull on the anchor chain" that's of concern here. Rather, it's the shortest length of rode relative to depth of water, which occurs at the top of the tide.
Goblin had come back up-river and moored on the North Shelf on the last of the ebb, so she would have been facing upstream, with the rode pointing downstream, when the anchor was set.
As Magnus and Jon have said, even a few fathoms of chain at the anchor end of the rode (whether or not the rest of the rode is rope) would normally lie flat on the bottom, exerting a horizontal pull on a properly-embedded anchor and thus keeping it in place. If there are jerks on the rode, as with strong gusts of wind on the moored vessel, the length of chain can lift momentarily, but essentially it acts as a spring, falling back down again as soon as the gust is over. (In Goblin's case the entire rode is chain anyway, which of course is even better.)
If the effect of the rode's catenary is lost however because the rode is very short, then the weight of the chain has less effect and the pull on the anchor becomes more vertical, and eventually the anchor will be plucked out of the ground. This effect will be exacerbated should the pull of the rode start coming from a different direction at the same time.
Now, if Mike Bender's guess were correct and the anchor left the bottom at half-flood, then Goblin would indeed have drifted upstream until the tide turned. But we're told (by John, at the end of Chapter 7) that it was on or just after high tide when Goblin went adrift. So the anchor had held until just on high water, when the rode could have been very nearly vertical anyway (we don't have enough information to be sure), and it may well have been the change in direction of the pull on the rode when the tide turned that tipped the balance and tripped the anchor. In any case, Goblin would certainly have drifted seaward once she started dragging, exactly as AR put it.
So it seems to me that Bender hasn't read the text all that well, because he should have picked that up. And although I only read the first page of his article I noted two other errors in it -- one, that Roger was six in S&A (when the very first sentence in the book tells us that he was seven), and another when he mentions Goblin's length as being twenty feet, when as far as I know her length isn't mentioned in the book at all. But we do know she's a seven-tonner, which implies a length of about 30'. (And in fact, as we know but Bender might not, Goblin is actually the real-life Nancy Blackett, whose length on deck is 28'.)
None of this is to say that John didn't make mistakes. He did. After all, this was his first time on a vessel the size of Goblin, and his first experience of being in tidal waters. But I think Bender is drawing a pretty long bow if he concludes that John is therefore a poor seaman.
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