Wednesday, August 30, 2017

Captain's Mast

As I mentioned in my last post, I spent the better part of three weeks working on the great flybridge project. I am happy to report that it's done now, and I have moved on to other things. The rest of this post concerns that project and nothing else, so if you're not interested in project details and photos you can safely ignore it, and I will be back to regular blog updates in my next post.


Vector's sporty new look, with repaired canvas and all hardware relocated to the mast.

To recap, Vector has a very, very nice canvas top over the flybridge, stretched over a custom-made, permanently mounted aluminum frame. This is not original to the boat, having instead been added by her last owner and our good friend John, who wrote about it in his blog at the time (the photo, apparently, is no longer available). That blog post, incidentally, also details the incredible list of upgrades John made to the boat to get her ready for cruising, all of which made her very attractive to us when we were shopping.


Vector, then called Acadian, before the top was added.

On that list you will find a satellite TV system, a new chart plotter, and an AIS receiver. Not mentioned on the list is the cellular booster antenna also added. These items were added at the same time as the top and frame, and the electronics firm designed the implementation to take advantage of the frame for mounting the sat dome (and an empty twin for visual symmetry), the AIS antenna, the cell antenna, the new GPS receiver for the plotter, and to relocate of the broadcast TV antenna in order to fit the GPS receiver for the AIS to its previous spot on the mast. They opted to use the enormous hollow mast as a cable chase for all of the above, and while they were at it, the cables for the six lights installed in the frame to light the flybridge deck. The frame maker added reinforcement to support all this.


Another view of the mast and flybridge before the addition of the top.

The consequence of using the mast as a cable chase meant that the mast was now married to the top, whereas previously it was hinged and could be lowered to reduce the air draft for low bridges. Reflecting this, the installers drilled a pair of holes in the mating flange of the mast section and bolted it in place "permanently." The mast and the aluminum top frame were not mechanically connected in any way; only the signal and power cables exiting the mast and entering the frame's built-in cable chase connected the two. The installers dressed up the cables crossing the gap with sections of white vinyl sanitation hose (really).

I'm not sure what the air draft was with the mast lowered, but I know that when John brought the boat down the rivers from Sturgeon Bay, Wisconsin, he lowered the mast in Chicago and had no trouble passing under the low bridges on the canal system, and specifically the 19'-3" (nominal) fixed bridge on the Illinois River at Lemont, IL, which is the lowest fixed clearance on the "Great Loop" route. The weight of the lowered mast posed a problem, inasmuch as he could then not raise the mast himself until getting help from a yard several weeks and hundreds of miles later, in Fulton, Mississippi.

With the mast locked upright, our minimum air draft is 24'-8", which is the top of the anchor light. That was only achievable if I climbed up the back end of the flybridge far enough to drop the four antennas affixed to the mast and the flybridge top first. We did that once, to clear a 25' bridge that was having trouble opening for us, and it was a real pain. The highest point on the aluminum flybridge frame is at 19'-8", and short of removing the whole frame at a boatyard, this is really Vector's absolute minimum air draft.

It has been a goal of mine, ever since getting the boat, to relocate antennas and reroute wires until the mast could once again be lowered. This would give us a high-water clearance of 19'-8" and let us clear a number of 20' bridges in the northeast US (including the one that stopped us at Troy, NY), go all the way around the Great Loop (timing the BNSF bridge in Lemont for something other than high pool), and eventually cruise rivers and canals further afield that have fixed clearances of six meters.

While that conceptually seemed quite simple, as I delved further and further into the wiring while we were at our first yard stay in Deltaville, Virginia back in 2013, it became increasingly clear that it would be a major undertaking. Already overwhelmed with a growing scope of yard work, we shelved the idea until some undetermined future date, when we'd either need to do it in order to get someplace, or one of the major systems involved needed to be replaced anyway.

In the meantime, anytime I needed to add something aloft, I made certain to avoid the temptation to run more wires between the mast and the top. For example, when the GPS "mushroom" mounted to the top quit working back in 2015, rather than simply install the replacement on the same mount, I instead added a new mount to the mast itself for the purpose.

Fast forward to Tropical Storm Cindy, which we rode out in Biloxi, Mississippi just two months ago. As I wrote on our way out, the storm was the last straw for the seam down the center of the canvas, which at that point had been on the top, unchanged, for a full ten years. In that post I explained why simply undoing the laces and removing the canvas was never really an option for us, due to all of the aforementioned antennas being essentially bolted right through the canvas into the aluminum frame. Now, we had no choice: to repair (or replace) the canvas, every one of those antennas would need to come down, and wiring would need to be cut, threaded back out of the chases, and repaired and replaced afterward.

The removal of all this gear alone is probably 20% of the whole job, and if I simply replaced it all as-is that might have been perhaps 50% of the effort, still leaving me with 100% for some future date to do the work as intended. Plenty of incentive to just bite the bullet and do it now. I detailed most of the work in removing all the gear in my first post from Charleston a few weeks ago, so I will not repeat it here.

Only one canvas shop quoted on actually repairing the material we already had, a quote of just $500. Considering a replacement top is five times that amount, and would take three months to schedule and complete, we felt repair was the right way to go if we could get even another 18 months out of the material we already had. Eight to ten years is the expected life of one of these tops. The canvas shop opted not to come remove the top until they were ready to actually do the repair, and so much of my work thus had to be done with the canvas in place, adding a bit to the time.


The splice in the galley ceiling for the KVH gyroscopically stabilized satellite dish power and control wiring.

After removing the active satellite dome and all remaining antennas, I traced all the cables back to their respective splices in the galley ceiling. The VHF antenna and cellular antennas needed their connectors cut off to fish the wires back out undamaged. I was disturbed to find that vibration had worn through the jacket of the VHF cable down to the braid in one spot, but it was salvageable with application of some heat shrink.


Abrasion in VHF cable. With no connector on the end I was able to slide a tight-fitting heat shrink over this and repair it.

With the top in place I was able to remove the six flybridge lights, but not the custom HDPE ("Starboard") trim rings for them. I wrote about these lights and rings back in 2016, when I was trying to replace two which had failed. I never succeeded, and we opted just to live without the two forward red lights working, since all four white ones still worked. The mast project meant all six would need to be rewired, so now was the time to replace them all with something newer.

This technology has changed a great deal in a decade, and I was able to find compact LED recessed lights that would fit the existing holes in the aluminum and eliminate the trim rings entirely, giving a lower-profile look. I worried one of the trim rings off and jury-rigged a new light in place to see how it would look with the top still on, as these newer lights "leak" a great deal of light out the back as well (they have transparent housings). We actually liked the glow reflecting back from the canvas, and I set the lights aside until the top could be removed.


One of the new lights, flush mounted in the aluminum with a "back glow" reflecting off the Weblon.

Having, by this time, already removed all the antenna wiring, the six power wires for these lights were the last holdouts keeping me from lowering the mast. With the lights out but the top still on I was able to fish out the four aftermost cables entirely, pulling new, smaller wires through in their place, and removed them intact back to the junction box at the base of the mast. The two forwardmost lights, the red ones which have been inoperative for a long time, would not yield their cables until the top was removed and I could access a pair of tiny holes in the top of the frame, so I just cut those two cables between the frame and the mast.

That let us remove the bolts and the pin-and-cotter arrangement that held the mast in place before the bolts were added, set up our new portable winch, and begin a test-lowering of the mast. The same beefy "arch" structure that the frame fabricators had included to support the loads of the satellite domes and other antennas would be our strongback for winching the mast up and down, using an inexpensive one-ton winch meant for ATVs ($70 on Amazon).


New winch, mounted to a heavy-duty mending plate, with U-bolt to affix it to the frame. 50-amp Anderson connector is at upper left.

I rigged our digital crane scale between the mast and the winch to see how quickly the force would escalate as the mast approached its nearly-horizontal "down" position. John had estimated the force at 600-800 pounds, so I was a bit surprised to see the scale top out at right around 200. Well within the rating of the one-ton winch and also not too much horizontal stress on the very beefy aluminum frame. I knew I would be adding another 30 to 40 pounds of antennas to the mast, but still within reason.


Test-lowering of mast. Crane scale is black box just to right and winch is behind starboard flag halyard.

With the mast lowered for the first time in a decade, I was able to get a good look inside, straighten out some of the cabling, and clean out a whole lot of mud-dauber nests. Sealing the new cable entries to keep the mud daubers out went on the priority list. Inexplicably, the installers chose to use carriage bolts when they bolted the mast in place, but did not square out the holes, so the square shoulders did considerable damage to the paint. I replaced the bolts with hex-head ones with washers to cover up the damage.


Base of mast showing cable entry and plenty of mud dauber detritus.

Next up was figuring out how to re-install the satellite antenna. All the other antennas could easily and appropriately be installed on the mast with a little bit of work. The sat dome, however, was more problematic. It's heavy, and it really wants a clear view of the sky from 15° above horizontal in all 360° of the compass. I really wanted to install it above the boat deck rail near the aft hatch, where it would be closer to the DirecTV receiver, closer to the boat's center of roll, and have a mostly unobstructed sky view, with the mast subtending only a small bit of arc and probably not obstructing the signal much.

That was great in theory, and we even jury-rigged a mounting platform across the rail, set the empty dome up, and had a good long look at the boat from the dock to be sure it didn't look too much like a wart back there, or an amateur afterthought. I was all set to start fabricating mounting hardware when a problem presented itself. In spite of being much closer to the receiver (by at least 50' or so, as the cables run), there was just no way to get the cables from the boat deck down to the receiver cabinet. The only vertical "chases" in the walls are obstructed by horizontal framing members and/or tightly packed hard-batt insulation. The wires that already run up that way, such as the power cables for the davit, were installed long before the walls went on, and there's just no way to fish anything through.

Reluctantly, I decided to install the sat dome on the mast. The only way to get a 360° clear view would be to put it right on top, where the anchor light is, and move the anchor light to a strut which is made for that purpose. I had all the hardware for this (except the anchor light strut, maybe $200), but it presents a few problems:

  • It increases our mast-up air draft by almost two feet. Yes, we can now lower the mast, but this addition would mandate doing just that in far more places, and would make us wait for bridge openings we currently can clear closed.
  • It moves 30 pounds or so of weight almost four feet higher from the center of roll than where it had been, increasing the moment of inertia.
  • It adds a lot of movement to the antenna itself under way as the boat rolls.
  • It looks a bit topheavy visually.

Instead I opted to mount the dome on a platform attached to the back of the mast, with the top of the dome just below the sweep of the radar array. That would mean the mast itself would partially obstruct the signal any time the TV satellite is directly ahead of the boat. We decided that was an acceptable trade-off.

If this was being done as part of the original build of the boat, the platform would have been constructed as a fixed part of the mast, in the same way that the platform for the radar set is integrated. Without wanting to weld and paint on the existing mast, an expensive task which would also require removing most of the existing equipment and wiring, I turned instead to aftermarket mounts made for the purpose.

These mounts are intended for sailboat masts and other masts with circular or oval cross-sections, and the "ears" that attach to the mast are curved. The manufacturers assured me the curved ears could be affixed to our mast's flat surface, but recommended a compressible gasket to take up the void. They have a plethora of holes because they are intended to be attached with numerous pop rivets; most masts are made of relatively thin material.


Seaview SM-18 sat dome mount with my home-made brackets attached.

I ended up finding a used take-off on eBay for $130 (the full kit, new, is $330) that had no ears at all. Instead I fabricated a flat-surface mounting bracket using a section of aluminum square tubing and some stainless bolts and washers. The square tubing is attached to the mast with 1/4" bolts into drilled-and-tapped threads in the 1/4" aluminum plate of the mast itself. There is no way to get a nut onto a bolt inside the mast. If I find over time that these threaded holes are not adequate. I will have to cut an access hole in the front of the mast and cover it with a Beckson Plate, and I'd rather avoid that f I can.


New mount attached to mast. Black Ethernet cable from Ubiquiti Bullet will get rerouted and shrouded in white slit loom.

Only after getting the mounting plate fully installed and heaving the dish assembly on top of it did I discover that the nice, factory-finished, powder-coated hole in the plate intended for the cables is too small for my dish. The dish calls for a 3" hole and the plate provides a 2" hole. With the dish mounted to the (perfectly aligned) factory holes for the mounting screws, the plate partly obstructs two of the four cable connectors.

Down came the dish (which I had already carefully mounted with all four bolts) and the mounting plate so I could enlarge the hole. Fortunately, I have a 3" hole saw capable of cutting aluminum. If you've used a hole saw, you'll know it depends for centering on a "pilot" bit in the middle of the material to be cut. When you want to enlarge an existing hole, you need to first cover it with material for the pilot to drill into. My first two attempts at this were inadequate and I ended up with a messy hole that needed some white paint later to hide the gaffe. It all worked out in the end, though.


Hole enlarged and dish mounted.

Once I had the dish back in place and all the cables hooked up at both ends, it fired right up and locked onto the bird. It all looks almost "factory installed" up there and I'm pretty happy with the way it turned out. I mounted the platform even with the mast "wings" for best appearance, which has the beam of the radar just grazing the top of the dome. That has it missing the actual dish in all but the northernmost latitudes, and we should have no trouble even using the dish under way.

I would normally have drilled a hole in the mast just below the bracket to run all the cables. But there are already two large (1.5" diameter) holes just on the opposite side of the mast, where the cables used to come out and head toward the chase in the top. Rather than cut yet more holes, I wrapped the cable bundle in some white slit-loom and fed them around the mast and through one of the existing holes, by way of a 90° sanitary elbow (seems we can't get away from sewer fittings here) to dress it and keep the water out of the mast.


Cable entry via a sanitary ell. Stainless cover to the left is made for unused holes in sinks; it barely fit.

I added yet another vertical mount to the mast wings, on the port side this time to match the one I added a year or so ago to starboard. I centered it between the port VHF antenna and an existing GPS antenna so I could mount the Shakespeare broadcast TV antenna there. It looks a bit crowded but it all works.


Completed mast installation with new sat dome mount and relocated broadcast TV antenna.

Of the two antennas that were removed from the top, one was the cell antenna which we're simply getting rid of, as it no longer supports all the bands now in use. The other, fortuitously, turned out to be connected to the flybridge VHF radio. I bought a bracket to mount this to the outside rail of the top frame, then drilled a hole in the frame and fished the lead wire through the frame and down into the coaming where it was short reach to the VHF radio. Fishing the cable was the hardest part, since there's a right-angle turn and the weld seams inside the aluminum frame are rough and inhospitable to pulling wires.



Ultimately I used a combination of fish tapes, magnets (just like those old children's toys where you moved a race car around a game board with a magnet under the board) and coat hangers to get a string through, and then used that to pull the wire. Soldering a new PL-259 connector on the cable completed the job. All told, it took me nearly four hours to run this one single cable. If I fold the antenna down, the bracket is still below the uppermost part of the frame, and unlike the previous antenna mounts, there are no holes in the canvas and no need to remove anything to remove or replace the canvas.


Cable enters the frame through grommeted hole at right. At left is bottom of mount bracket.

Eventually the canvas shop sent a strapping young man to remove the top and bring it back to the shop. The two of us had it down in about fifteen minutes. It mostly came down and folded up without drama, although we had been warned that the ten-year-old Weblon had a good chance of cracking when we did this.


Topless Vector. The mast work is mostly done in this photo.

Vector looked oddly naked with her top off. The canvas shop had figured less than a week, and so I moved quickly to finish the work that could only be done while the top was off. That included removing the other five HDPE trim rings for the old flybridge lights, removing and replacing the last two lighting power wires, and fishing the new supply wires from the flybridge coaming and up through the aluminum top frame.

Once again all the wire fishing took many more hours than it should have. I am grateful that the frame installers actually cut holes in the coaming to get wires into the frame from there, but they did little to make fishing easy. I did end up drilling a couple of small holes to run my fish tape through for part of the process, which I later covered with metal tape made for repairing ducts.


Fishing wires for lights. You can see the tails of new cables hanging down in the light mounts.

At one point my fish tape got caught on a weld seam and Louise and I spent over an hour trying to free it; eventually I had to use my endoscope to find the snag and a coat hangar to free it. All told I think I spent more than six hours fishing wires for six puck lights. When I was done, though, I was able to wire up all six new lights to one of the two existing flybridge switches. The old "red" light switch got retasked for some blue LED strip lighting down the center top support; this will be used to supplement our anchor light for additional visibility in dark anchorages.


Six new white lights and the blue light special. Much more impressive at night.

Making a safety stand for the mast from five feet of 1-1/2" PVC pipe and some fittings completed the overall project; this will support the mast in its lowered position, with the winch cable remaining safely attached until the mast is again raised.


Lowering the completed mast with the winch.

With all of my "must do's" for the canvas and mast project thus done, I turned my attention to yet another project that has been languishing on my to-do list. At some level it is unrelated to the top project, but it involves the mast, and as long as I was up there on the ladder it made sense to do it now. That would be relocation of our remote-control spotlight.

The spotlight is another expensive item that John had added to the boat when getting it ready to cruise. It's an ACR, generally considered the gold standard of the industry, and it works really, really well. Control stations at both the pilothouse and flybridge helms allow it to be switched on or off and aimed from either station. It rotates 360° and adjusts up and down by 15°. It's heretofore been mounted on a very nice, very beefy, very expensive custom mounting stanchion attached to the forward end of the flybridge coaming.


Our fancy ACR spotlight on its custom perch at the front of the flybridge coaming.

That puts it at a great height for lighting anything up, but there is one big problem. Mounted here, it also illuminates the inside of the foredeck and its gunwales, a massive expanse of white paint which reflects thousands of candlepower right back into the pilothouse windows, and to a lesser extent onto the flybridge.  It's all but useless when driving from the pilothouse in darkness, as it immediately kills the helmsman's night vision and obscures the view ahead; it can be used with care from the flybridge so long as you remember to step back a bit before turning it on, so you can't see the foredeck.

After a couple of nighttime runs we gave up on using it at all, buying instead a cordless handheld model which we could use by stepping outside and holding it over the gunwales, where it could not reflect back to us from any part of the boat. Effective, but a pain, and requiring two of us if someone needs to actually be at the helm.

The ideal place for the spotlight would be on a bracket above the anchor and forward of the bow, but it would take too much salt water there, and there's really no easy way to run the massive seven-wire cable to it in that location. A good second choice would be bolted to the flybridge top, just far enough back that the forward portion of the top puts the foredeck in full shadow. But remember, we're trying to get things off the flybridge top, not put more things on. And thus we have our third choice, atop the mast, just below the anchor light. From here it can illuminate in almost 360°, is completely shaded from the foredeck, and still illuminates most objects within two or three boatlengths of the bow.

I spent a good deal of time noodling on how to make a bracket for it to attach it to the mast, until I realized there was already a very beefy welded-aluminum bracket up there, which was holding an LED steaming light weighing just a few ounces. A sketch, some geometry, and a bit of math revealed I could use that bracket for both the spotlight and the steaming light together if I just made a fairly light-duty, flat extension plate for it.


New bracket extension, and the rest of the cutting board from whence it came.

Aluminum would be the best choice, but sourcing and fabricating aluminum is something of a challenge on board. I chose instead to use HDPE, which is sold for marine use under the trade name StarBoard®. One of our dirty little secrets is that we know food-service-grade cutting boards are made of basically exactly the same material (the level of UV-resistance being one distinguishing factor), and I ordered a large, 1/2" thick cutting board on Amazon Prime for $15.


Extension in place with steaming and spotlights mounted. The spotlight is rotated to its closest-to-mast position, to make sure it was going to clear.

HDPE is easy to work using conventional tools, and cutting the extension to shape and adding appropriate mounting and cable holes took just a few minutes. The extension moves the steaming light forward by ten inches, leaving room behind it for the spotlight, which is tall enough that it shoots right over the steaming light. Leaving room for the spotlight to rotate through 360° meant only the aftmost two mounting screws go all the way through the original welded aluminum bracket, but the HDPE is plenty strong enough to support the remaining cantilevered part of the light.


New hole for the control cable (gray, at right). Installing the cable gland and its backing nut was a challenge. Yellow cable is for the steaming light.

The aforementioned seven-wire control cable from the spotlight runs just a few feet to a fancy electronic control box. The remote control stations for the spotlight connect to this box with regular 75-ohm cable TV coax. In its original location, the control box was mounted in the pilothouse overhead, between two of the windshield wipers. I had to move it to somewhere in the mast for the cable from the spotlight to reach.


Control box mounted to HDPE attached to existing radar mounting bolt.

Fortunately there is a convenient cavity below the radar array, with a nice big access plate, easy access to the inside of the mast, and a good mounting location in the form of the lower part of the radar mounting bolts. With some ingenuity I could mount the control box without drilling any more holes. I used another piece of cutting board, this one much smaller and thinner, as a mounting substrate for the controller, and mounted this to one of the radar bolts with an appropriate nut and a pair of stainless washers. 30' or so of CATV coax, a couple of F-connectors, and another 30' of power cable completed the installation.


Broader view of the under-radar access plate, with new control box at right. Cable in center is from radar. You can see my pull strings zip-tied to it.

The spotlight is working great in its new location, but the proof in the pudding will be when we can try it out at sea, in full darkness. I've left the old, beefy bracket in place in front of the flybridge. It looks a bit odd there with nothing on it, but it will give us a good mounting location for an additonal radar array or other equipment in the future. I'll probably mount a work light of some sort to it in the interim, for those times when we really do want to light up the foredeck (one of the things we used the spotlight for), and so it doesn't look so out of place.

It is somewhat ironic that we did all of this work right after completing our big loop of the western rivers, a trip we undertook because we could not go the full way around on the Great Loop trip. With these modifications and a bit of fortuitous timing in Chicago we can now, in fact, complete the loop, and we'll plan to do that at some point, picking up where we left off in Troy, going through the lakes to Chicago, and down the Illinois and Upper Mississippi to cross our wake at the confluence of the Ohio.

2 comments:

  1. Nice work! Why not add a spacer below the spot so it can shine over the mast behind the boat?

    Mike

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