Forum › Forums › General Discussions › The Running Tide 10 minute filler after 1977 PBS broadcast of OL › RE: The Running Tide 10 minute filler after 1977 PBS broadcast of OL
Actually, in those days, some sailors didn't trust the captain – the superstition that the captain sailing them straight away from land, with no sign of land ahead after more than a month (sometimes even less) believed their captain was insane and would sail them of the edge of the world. Even Columbus had to deal with grumblings of that sort as he sailed for what he hoped (and thought) was India. His crew was on the verge of mutiny when they sighted land, now known as the Americas. Some crewmembers were loyal to the end, but not everyone was.
Markings on the wheel: There is what's called "the master spoke". This is the spoke on the wheel that is at the top of the wheel when the rudder is amidships, and that spoke is usually marked with what's called a Turk's Head Knot. (Just Google Turk's Head; it will be easier that way.) Some helms had a rudder angle indicator on them, but thus was very rare. Usually it was one of the qualifications of a helmsman to know where the rudder was by how many turns of the wheel were made. And as a side note, most of the major steering is done by trimming and moving the sails. The rudder is more of a "fine tuner" for the course, and is very useful in turning the ship enough to "spill the wind from the sails" as the ship makes large turns, thus making it easier for the crew to handle the sails. (Try to do something with a large picnic blanket when the wind is blowing hard into it; it's not easy, until you turn so the blanket doesn't catch the wind. So, too, with sails.)
Each ship is different, and each has a different steering mechanism. The Cutty Sark, for example, has (let me see if I can explain this) a huge opposing screw attached to the wheel such that when the wheel is turned, each end of the screw moves a rod towards the center of the screw, and the rods in turn move an arm that's attached to the rudder post, which moves the rudder in one direction. Turning the wheel the other way does the same thing in reverse. This whole mechanism is covered by a Steering Box. (See these photos of a sailing ship with its steering box cover, both in place, and removed and sitting off to the right with a large "1886" on it; its steering mechanism is very similar to that of Cutty Sark's and should make it easier to visualize what I tried with difficulty to explain above. Also note that the master spoke is marked on the wheel's upright spoke by a pin on the outer edge that's different than the other pins, though rather than having a Turk's Head on it, it's a differently-carved pin – best visible in the 3rd photo, as is the lashing on the wheel's bottom spoke to keep wayward hands from turning it:
In this final photo you can see the tiller under the steering mechanism; the tiller would be used if the mechanism suffered catastrophic failure. Then block and tackle would be brought out and made fast to the aft end of the tiller to it could be pulled to one side or the other, and the forward end – where the rudder post is just abaft the wheel – would be locked in place so the tiller could move the rudder.
In this case, the wheel wouldn't kick back on you too badly; the rudder would have to fight the huge screw first. Some ships, such as Cutty Sark's rival, Thermopylae, had a vertical steering post, meaning the wheel was attached to the rudder post via gears interlocking at about 90 degrees: the vertical gear attached to the wheel, the horizontal gear to the rudder post. This sort of steering mechanism is a more "direct connect" between the wheel and rudder, and therefor gives the rudder more "kicking power" against the wheel – like not having power steering.
With the steering, again each ship is going to be different when it comes to how many turns will move the rudder how far, and the size of the wheel will determine how many spokes it has. (The nominal number is 6 or 8 spokes.) On the buoy tender I was stationed on in the Coast Guard in the early 1980s we had a 3-foot diameter, 8-spoke wheel: all brass tubing with no pins on the outer edge, but a Turk's Head on the master spoke. One full 360-degree turn of the wheel gave you 6 degrees of rudder.
On most ships, 30 degrees is considered full rudder (35 is hard or emergency rudder, and yes, you can turn a rudder so far that it will jam, although most steering mechanisms have "stops" in them to prevent this). The number of turns from amidships to left/right full rudder will depend on the ship and her steering mechanism. As I mentioned each one is different. And the steering mechanism would determine how the wheel (and rudder) react if you just let go. A hydraulic mechanism wouldn't notice if you let go or not. A mechanism like the Cutty Sark's might start working its way back slowly, while a direct link like Thermopylae's would spin that wheel right around with the rudder as the water's resistance against it pushed it to amidships.
The rate at which the rudder answers the wheel will depend on the type of mechanism: a mechanism such as Cutty Sark's or Thermopylae's will have the rudder answer as soon as you start turning the wheel. If a ship has hydraulic steering machinery – as my buoy tender did – it will take several seconds for the rudder to answer the wheel. One quick turn of the wheel took one second, and the rudder took two seconds to answer, and the more you have to turn the wheel the longer the delay will be. (Of course if you turn the wheel slowly the rudder will move just as slowly.)
Even though I was an Electronics Tech (ET) I was still a qualified underway Quartermaster of the Watch (or QMOW), and to get that qual I had to learn the ship's helm. I got so good at it that I could keep track in my head where the rudder was by how many turns of the wheel I'd given her, and with rapid rudder commands such as from right full to left full ("Shift your rudder!") I could spin that wheel ten times, count in my head how many seconds went by, and then call out when the rudder was "Passing amidships!", and when the "Rudder is at Left 30 Degrees!" and BINGO! There she was. It got so that when we were in Refresher Training (war games with the Navy), when they killed the helmsman, the ship-riders who graded the drills would not let me take the helm because even though they put black covers over the wheel angle indicator, which was atop the helm and showed how far the wheel was turned, and the rudder angle indicator, which followed a servo attached to the rudderpost and let you know where the rudder was, I still knew it all because I could keep track of where my wheel was, and how long it took my rudder to answer a command such as above. (So I was no fun for the ship-riders; I knew too much!) So a helmsman aboard a sailing ship would not be at the wheel unattended (manning the wheel without someone breaking him in) if he didn't know his helm as well as that.
Heeling: That's how far a ship "leans" to one side; it's not a term used to describe the cross-section of the hull or its shape. The more she heels, the more of her hull comes into contact with the water, ergo the more resistance she has and the less efficient her speed-making is. Also, the more she heels, the less effective her rudder will be because the rudder is no longer "pushing" the water to one side or the other, but mostly "up" or "down" depending on which side she heels to and what direction the rudder is placed. (That one's kind of hard to show, but use a piece of paper, hold it upright (no heeling) and turn it left and right as if it was a rudder. Then angle the paper to one side and do the same thing, turning the paper in-line with itself; you'll see the paper is now acting more like a diving plane than a rudder.)
And as for "common" angles of heeling, once again each ship is going to be different and the sea and wind conditions will play a part in that as well. How hard is the wind abeam and how hard is it blowing? How many sails does she have set that are catching that wind? How well is she ballasted or how heavy is she with cargo? How top-heavy is she? (Most of our Coast Guard Cutters these days are quite top-heavy, and it doesn't take much to have them heeling.) Lots of factors to take into account, so there really is no "common" angle for heeling.
Heeling and taking water over the rail: Again that will depend on the design of the ship. How much freeboard (the amount of her sides above the waterline to the rail) does she have? Also, how loaded with cargo is she? (The more she's loaded, the more she'll settle and the less freeboard she'll have – hence the need for the Plimsoll Mark to prevent overloading.) It also depends on the seas; calmer seas will have water breaking over the rails far less often than choppy seas, as in one case she'll just glide over the water, and in the other she'll be pitching or rolling (or both, which gives her a sort of "cork screw" motion – a motion I never got used to!). And just because she might be heeling enough to take water over her rails doesn't mean she'll sink. Ships are built with things like that in mind. As she rolls, the water will find its way across the deck into the waterways, and then through the scuppers, and back into the sea.
Okay… my brain hurts right now, and my pain meds are taking their toll on me. I'm going to roll into bed now and turn the other items over to R. (And of course he can feel free to add to anything I've said because I'm sure I haven't covered EVERYTHING in my comments.)
From: Lee Bonnifield <firstname.lastname@example.org>
To: shiponedingroup <email@example.com>
Sent: Mon, May 13, 2013 10:22 pm
Subject: Re: [shiponedingroup] Re: The Running Tide 10 minute filler after 1977 PBS broadcast of OL
> Pre Harrison Longitude was guessed, it was common practise from the days
> of Columbus to sail South to a known Latitude, 'Sail South until the
> butter melts then head West',
this is hilarious, where would we be if pre-Harrison sailors didn't
trust captains with vague heuristics
> wind I felt a pull at the wheel, weather helm it's known as, ie the
> vessel wants to round up into the wind and you need to apply pressure on
> the wheel to stop her and all it took to hold her on course was one or
> at the most two spokes from midships,
That is astounding, precision engineering that allows such a huge mass
to be kept centered in an unstable equilibrium with such a small force.
I don't see any marker on the wheel that would let you know that the
rudder is directly in line with the keel. Is there one, how do you know
how many spokes you are from midships? I see 8 spokes on Soren Larsen
wheel. How many 360 degree turns of the wheel would move the rudder from
full left to full right? What angle to keel is full left? If you let go
of the wheel. will the rudder line up with the keel?
> as the further a vessel heels the slower she will be and more
> difficult she is to handle.
Because of the different shape of the hull cross section below water
when boat is heeling? I see that a symmetrical cross section (no
heeling) would be most sensitive to rudder direction. A horizontal deck
might happen only with sailing down wind, what deck angles from
horizontal are common?
> rest of us were in our bunks. During his watch the wind slowly increased
> in strength and due to his inexperience he let the ship
> heel more and more until she was taking water over the rail,
What angle from horizontal does the deck have to be to take water over
> the motion
> threw the very experienced Dutch skipper out of his bunk! He came on
> deck to find the owner with a huge grin saying "Man look at the old girl
> go!!". I can't repeat what the skipper said in reply……. !
Let's make this deck more horizontal please before we sink
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