Cable Neatenization

Is that a word?  I don't think so, but I'm using it anyway.

When last we spoke about the mutiny of our Radar Officer, I had gotten the new radar working in the cockpit. But the cables, tho strung to near their final location, were looped from inside the cockpit coaming in a decidedly NOT ship-shape manner. I mentioned that I had ordered a cable grommet - well that grommet has arrived, and it was time to finish up the installation.

All I had to do was make a 2" diameter hole in the top surface of the coaming.  How hard could that be?  I got out my trusty drill and a 2" holesaw and went to work, expecting to take maybe 15 minutes.

Getting thru the teak coaming cap was a piece of cake.  And I knew that the actual structural fiberglass construct was under the teak.  What I did not know was that it was a full inch thick of solid fiberglass - Downeast certainly cannot be faulted for skimpy construction!

My poor holesaw was really not up to the task.  The narrow slot that the teeth made did not clear itself of fiberglass dust well, meaning that as the hole deepened the dust accumulated...  and melted.  Stopping frequently (after maybe 10 revolutions of the saw) and vacuuming out the debris, followed by picking off the melted and now solidified resin from the teeth of the holesaw made for very slow going.  It was a two-beer hole. 

But patience and perseverance won out, and eventually the coaming was breached.   Yes, you can see that I drilled some holes down thru the saw cut in an attempt to provide a chip clearance path.  It helped, a little.  But I had to keep clearing out the holes too.  Like I said, two beers.

And there is the finished product.  Looks pretty good, doesn't it?

When the radar unit is dismounted and stored down below, the cables go back thru the grommet, inside the coaming where they are protected from the weather.  I will eventually re-route the GPS cable to this grommet too, but that means re-making more than a half dozen connections.  A good task to do while at anchor on a quiet sunny day next summer.

Oh, and the old radar unit has sold.

Cable Neatenization

The Mutiny of the Radar Officer

I've talked about our Radar setup aboard Eolian before.  And that setup worked out very well for us...  as long as it was a rare occasion that required Radar.  Down in Puget Sound, it was indeed a rare occasion.

But not so rare up here north of the Strait of Juan de Fuca, when crossing Rosario Strait.  In fact, I think we may have put more hours on the Radar set this summer than in all our previous time on Eolian.

A consequence fell from this.  Jane, our Radar Officer, mutinied.

She said that she didn't like having to stay below and shout up to me the "hits" on the screen, especially when the engine was running, making the communication essentially one-way (it being difficult for me to make myself heard by Jane sitting down below, almost directly above the engine).

So, I did what any self-respecting Captain would do having received permission to spend money:  Notwithstanding all those things I said before, I scurried off to craigslist and found a used Furuno Radar with an LCD screen that is water resistant and daylite readable, and can therefore be mounted in the cockpit next to the GPS.  No Radar Officer required.

For sale - any takers?

Yesterday and today I spent removing the old Radar. A trip up the mizzen was required to disconnect the interconnect cable and remove the radome (boy that sucker is heavy!). Next, I tied a string to the end of the cable and lowered it thru the mizzen to the cockpit.

Then the big job started - unthreading the interconnect cable from the path the original installer had used between the base of the mizzen mast and the display unit that used to hang overhead in the navigator's station.  It would have been much easier if I had cut the cable, but I didn't want to do that because the interconnect cables are very expensive, and the lack of a cable would seriously impair the old unit's resalability.

Then the next day was spent on:

• Ascend the mizzen mast again, this time with electric drill in hand so that I could drill new mounting holes in the mounting plate on the mast.  Layout the new holes that were needed, since neither of the two sets on the mount matched up.
• Drill those holes, starting with a 1/8" drill bit and ending with a 7/16" bit.
• Hoist the new radome up and bolt it in place.  Working up the mast is scary...  you want to always have everything tied off, either to you or to the mast, because gravity is such a bitch.  So this was a very scary action, because the radome is a curvy beast, leaving only a bolt thru one of the mounting holes to use as the hoist point.  This meant that I had to disconnect the only thing securing the radome up there in order to mount it.  Until I got the first bolt in place, it was just my hands fending off the depridations of gravity.  Every motion was thought out ahead of time, and somehow every task had to be done with just one hand, the other being designated as the "keep the radome from falling" hand.
• Thread the new interconnect cable (already attached to the radome) down the mizzen mast, using the pull string I left in place.

So this is where things stand at the moment:

It works!

There it sits, just as pretty as can be, right next to the GPS (or where the GPS would be, if it were mounted).

Still to do for a complete installation:

• Permanently mount the new display on the coaming next to the GPS
• Drill a hole thru the coaming for the cables

I have a stainless steel "desk grommet" on order for the cable penetration of the coaming - you've seen these on newer office furniture, intended for computer cables.  Hopefully this will give a finished appearance when the displays are mounted and when they are not.

The Mutiny of the Radar Officer

The old ways are still good

There is a lot of commercial traffic on Puget Sound.  There are big container ships, cruise ships, ferries, tugs towing barges, and military ships.  And all of these move faster than we do in Eolian - much much faster.   Whenever we cross the traffic lanes, I feel a little like the frog in Frogger.

There is a strong tendency on my part to be attracted to the latest new, shiny "gee whiz" gadget.  I'm pretty sure that I am not alone in this.  But you have to go pretty far up the gadget cost scale to get something that can top the good old hand bearing compass. 

A recent crossing from Port Madison to Shilshole provides the case in point.  Just as we cleared Jefferson Head, a tug and tow became visible, heading south in the southbound traffic lane.   I pulled out our trusty old hand bearing compass and took bearings on the bow of the tug and the stern of the barge it was towing.  Then after a few minutes I took the bearings again.

The old adage is that if the bearing is not changing, then you are going to collide.   And tug-'n-tows are long enough that you need to keep track of both ends of the combination (NEVER try to go between a tug and its tow!).

But when I took the second set of bearings, I noticed that a second tug and tow had  appeared from behind the first - he was in the process of passing!   The problem just got more complicated.

Clearly one tug was going faster than the other (he was passing, after all).  Now the choices had become:

1. Pass in front of the entire parade
2. Pass between the barge in the first tow and the tug in the second
3. Wait for the whole parade to pass and cross behind the last barge.

More study with the compass as we continued, our courses converging, convinced me that choice #2 was available to us, but that we were going a little too slowly to make it possible.  So I increased our speed (there was no wind - we were under power), and confirmed that we could pass between the first barge and the second tug.  A little more fiddling with the speed got us into the sweet spot.  And indeed, we cleared both tug-'n-tows nicely, with no drama at all.

We did this bit of piloting with a lowly hand compass. 

To do it with electronics, you'd need to have a GPS-interfaced AIS receiver, or a multi-thousand dollar radar with MARPA capability.

Or a hand compass.

The old ways are still good

Potentially useful fact

Tonight I learned something while reheating dinner in the microwave: the wonderful stuffed green pepper Jane had made a couple of days ago.

The stuffing got hot, but the pepper did not.

Think about it:  green peppers are invisible to radar!

(Now what great invention can I make with this discovery?)

Potentially useful fact

Altered Reality: Navigating with radar

Navigating with radar is an exercise in perception in an altered reality.

Instead of seeing with light, you are seeing with radio waves.  Things are different (on purpose!) - there are some consequences:

• Things reflect radio waves differently than light.  Some things which are opaque to light are essentially transparent to radio waves (eg. wood, fiberglass).
• Surface roughness matters.  Rough surfaces (with feature size down to say 3-4 inches) will appear brighter than smooth surfaces.
• Size on the radar screen will be related to reflection efficiency more than physical size.  A canoe with a good radar reflector will appear bigger than a 30' wood cabin cruiser with the engine below the waterline.  In fact, that cabin cruiser may be invisible.
• The radar beam does not continuously illuminate the surroundings like the sun.  Instead, it is a narrow beam which is swept around the horizon - imagine trying to understand your surroundings by swinging a flashlight around your head in a circle.  This means that you are very obviously viewing a series of snapshots rather than continuous video.
• In most cases, the radar antenna will be mounted near a mast.  This arrangement will cause a blind sector - a wedge-shaped area on the radar screen in which nothing can ever appear.  Think of it as a shadow.  But there will be no evidence on the screen of this.  

For these and other reasons, it is very disorienting for the helmsman to switch back and forth between the radar display and looking out over the bow.  A far, far better arrangement is to have a radar officer (on Eolian this is Jane) who lives continuously in the altered reality of the radar world, and a helmsman who remains in the real world.  To complete the link, a communication protocol needs to be worked out between the radar officer and the helmsman.  Not surprisingly, we fell into the one where angles are identified as a clock position on the screen, and distance is in miles or fractions of a mile.  For example, Jane might say, "You have something which appears to be stationary, out about 1/2 mile at 2 o'clock."  And then I squint in that direction.

Try it in broad daylight first.  In this way, you will be able to link up the altered reality of the screen with the one out the window.  And do not be surprised if several of the boats in your vicinity are completely invisible on radar.  (Do you have a radar reflector?).  Try out all your controls to learn how they affect what you see (or don't see).

Do not spend all of your observation time at short distance scales.  Switch to longer range scales frequently - big ships move quickly (and you don't). 

Illustrating some of these points, here are two stores from our logs:

Cruising north in thick fog just off of Apple Tree Cove, we knew we were in the ferry lanes.  I was having no luck seeing, but I could hear a ferry out there somewhere.  I kept asking Jane where it was, and she kept telling me that she could not see it at any range.  Seemingly very quickly, he sounded like he was right behind us.  And suddenly Jane shouted - There he is - on both sides of us! 
The ferry had been approaching us from astern, and was in the shadow wedge created by our mizzen mast.  When he got close enough that his ends extended outside the shadow, indeed, he did appear to be on both sides.  He also was turning into Apple Tree Cove to the Kingston ferry terminal, so the story had a happy ending.  Im pretty sure he had us on his radar.

And another:

Cruising again in thick fog, we were entering Port Ludlow.  Now, this is is a little scary in good weather. Having the fog did nothing to make it easier.  Jane began to report that the area beyond the ledge was filled with boats, all apparently stationary.  "Hmmm...," I thought, "a bunch of fishing boats?"  I asked her for a safe course, and she said there were too many blips to pick one.   I ducked down the companionway to see for myself, and try to get a feel for things.  Yikes!  They were everywhere!

I throttled way back, hoping to slow to the point where I'd be able to see boats and be able to avoid them.  As I approached the first one, Jane kept telling me how close I was, and kept asking me if I could see it.  Then why I couldn't see it, as we were right on top of it.  And about then, we passed a crab pot buoy with a little flag on it.  And then a whole lot more of them.  It seems that there was a wire in the flag, to hold it out - a wire that made an excellent radar reflector.

This story too has a happy ending. As we rounded the little sandy hook and entered the inner bay, we drove out of the fog into bright sunshine.

Altered Reality: Navigating with radar