Thursday, March 14, 2019

Hjortie Installs a Bulwark Door


Hjortie 37VT33 is getting a bulwark door.  The work is being done by Pete and Alan Hansen, Hansen's Harbor, Lake City, MN.

The Hansen's have taken care of as many as three LNVTs at once and have done many repairs and modifications to them.  This was their comment after having cut the bulwark door:

If the manufacture would have used closed cell foam one would have a lot more strength and no water [accummulating in the bulwark]



Tuesday, March 12, 2019

Beware the Brass

Steve D'Antonio's excellent article explains the deterioration being discovered in some LNVT intermediate support bearing hose fittings and plugs (see also this 14 May 2018 LNVT blog post).

In April 2018 Mike McCoy, Tug E. Bear 37VT62, found this badly corroded fitting. 



Beware the Brass

ATD12_BewareBrass01
Not all copper alloys are created equal, so it's important to verify their composition when using them in raw-water applications.
A colleague recently described to me the unusual loss of a large, relatively new motoryacht that sank at the dock as a result of a failed raw-water plumbing fitting in its HVAC system. The fitting, which had been installed by the builder, was made from brass. On the strength of the contract's "corrosion exclusion," the owner's insurance company refused to pay for the loss. The owner filed a suit against the insurer, and lost. Setting the legal drama aside, the anecdote is a reminder to builders and service yards to beware of brass when selecting or replacing below-the-waterline marine hardware.

Brass

Brass is an alloy of copper, and copper has been a boatbuilding material for centuries, most notably as cladding on hull bottoms to keep teredo worms out of the timbers, and as a natural antifoulant. It is an excellent biocide, which contributes to its popularity for plumbing in onboard freshwater systems. Also, copper pipes are opaque, which denies plant-based biological growth the light necessary to proliferate.
In some engines, copper pipe carries raw water to and from cooling pumps. This usually works well, although the tubing is often of proprietary alloys and shapes, which can be expensive and difficult to source. Additionally, copper is susceptible to two forms of corrosion likely to be seen aboard seagoing vessels:
  • Impingement attack, or erosion corrosion, is caused by swiftly moving water in a copper pipe or tube. Because copper is relatively soft, it can literally be worn away by swiftly moving seawater, especially at 90° turns and restrictions, where turbulence and velocity are greater.
  • Copper can also fall prey to decay from exposure to hydrogen sulfide, a common constituent of polluted water.
Brass, a metal that is almost synonymous with the sea, is actually a family of copper alloys whose primary ingredients, in varying ratios, are copper and zinc. In fact, some brasses are composed of as much as 50% zinc. Some of the more common "seagoing" brasses are: red brass with 85% copper, 15% zinc; cartridge brass, 70% copper, 30% zinc; Muntz metal, 60% copper, 40% zinc; admiralty brass, 70 copper, 30% zinc; naval brass, 60% copper, 40% zinc; aluminum brass, 76% copper, 22% zinc, 2% aluminum; and finally, manganese "bronze," 60% copper, 40% zinc. Manganese bronze is bronze in name only; because of its zinc content, it resides squarely in the brass family.
ATD12 BewareBrass02
Regardless of labeling, pipe fittings smaller than ½" (12mm) are often brass rather than bronze. Sourcing these components in bronze is often challenging.

While brass has many familiar uses aboard—from clocks and joinerwork trim to lamps and electrical components—it should never be used in raw-water applications. It's worth noting that many small (1/4″–3/8″ NPT) plumbing fittings, such as pipe-to-hose adaptors, pipe plugs, and bushings, are made of brass, while their larger cousins are bronze. Although most bronze seacock and sea strainer drains utilize 1/8″ NPT plugs, under no circumstances should these be replaced with brass. Appropriately sized bronze plugs can be obtained from the equipment manufacturer. And if you're unsure of the plug material, avoid using it below the waterline or in raw-water applications. Another location where brass is often inadvertently used is in water injection ports on stuffing boxes. These frequently call for a threaded pipe-to-hose adaptor of 1/4″ or 3/8″.
In my experience, many chandlery clerks and marine equipment vendors cannot be relied upon to provide accurate alloy information. Many are unaware of the important distinction between brass and bronze, and prohibitions for use of the former in raw-water systems. It's up to you to know that if you replace a lost or damaged bronze plug with a brass one, you may suffer the consequences.

What's Behind the Weakness

Why is brass so susceptible to corrosion?
Because many brass alloys contain a substantial amount of zinc, they are especially susceptible to "dezincification," whereby the zinc selectively corrodes and leaves a porous copper shell that retains its shape but has little strength. A dezincified brass propeller, for instance, can be identified by its splotchy reddish or pink coloring. Many propellers (and propeller nuts) are fabricated from so-called manganese bronze, a brass alloy, and as such are especially susceptible to dezincification. That's why it's so important to protect this often-substantial investment with sacrificial anodes, and to vigilantly monitor and renew them when necessary. In a conventional assembly, which combines a stainless steel alloy shaft and a brass (manganese bronze) propeller, once the anode is gone, the metal most likely to corrode is the prop. Besides dezincification, brasses are susceptible to other forms of corrosion. Ammonia, a common ingredient in household cleaners, will readily attack brass, causing it to weaken and crack; and mercury will do the same.

ATD12_BewareBrass03
By definition, brass alloys include zinc as one constituent element. When that zinc selectively corrodes, in a process known as dezincification, it is easily identifiable by the pinkish hue of the copper left behind.

Bronze

Bronze, although it's a copper alloy, is different from brass in that it's free of any appreciable amount of zinc, and so is not susceptible to dezincification. Bronze's parent alloying element is copper, but its primary alloying element is tin. As a result, pound for pound, bronze is often more expensive than brass, which contains less costly zinc.
Gunmetal, as its name suggests, was employed in firearms manufacture. It is a bronze alloy of 88% copper, 10% tin, and 2% zinc. It is not especially strong, but it is corrosion resistant and perfectly acceptable for below-the-waterline use. It is often cast into items such as cleats, chocks, and shaftlogs.
ATD12_BewareBrass04
This pipe-to-hose adapter on a seacock failed as a result of dezincification. Fortunately, the failure occurred during winterization, after the vessel had been hauled.

Another bronze alloy, aluminum bronze, is strong but susceptible to de-aluminification. This vulnerability is avoidable with the addition of nickel. The resulting strong, corrosion-resistant alloy, typically called nibral (nickel, bronze, aluminum), is often used to make propellers. Prop repair shops sometimes charge a premium for reworking nibral props due to the metal's tendency to take on a set, or memory. Manganese is sometimes added to this already complex soup of metals to further increase strength.
Silicon-bronze is by far the most popular alloy for underwater hardware, including seacocks. It is 96% copper, the remainder being silicon and other trace elements—sometimes very small amounts of zinc, often measured in single percentage points. Bronze hardware such as nuts, bolts, and screws is often made of this alloy and can be expected to give long, corrosion-resistant service.
Phosphor bronze is typically made up of 85%–95% copper and 5%–10% tin, with the addition of a small amount of phosphorous, which improves the hardening characteristics of the bronze, making it a good choice for bearings and springs.

Conclusions

Above all else, remember: particularly for generic plumbing components, brass is ill-suited for any application where it's called upon to convey, direct, or stem the flow of seawater, regardless of whether it's used above or below the waterline. This includes plumbing associated with raw-water strainers, stuffing boxes, seacocks, and sanitation and air-conditioning systems. Your clients rely on you to know what materials are suitable in which applications. While brass, bronze, and similar alloys may look the same, that's not a defense you'll want to rely on if you have to explain a catastrophic failure.

About the Author: For many years a full-service yard manager, Steve now works with boat builders and owners and others in the industry as "Steve D'Antonio Marine Consulting Inc." He is the technical editor of 
Professional BoatBuilder, and awaits publication (by McGraw-Hill/International Marine) of his book on marine systems.

Friday, March 8, 2019

Tuggers Pay Tribute to Debbie Steplock, Pet Tug 37VT60

Debbie Steplock, 14 October 1969 - 26 February 2019

On 4 March 2019 an LNVT Rendezvous was held in Casper, Wyoming, to support Lou Steplock, Pet Tug 37VT60, and to say goodbye to Debbie.

(L to R) Ted and Kim Shann, Barb Lawrence, Tom Blackwood, Lou Steplock, Bicki Howell, Janice Bialko, Mike Dunn, and Dave Howell.  Also attending, but not pictured were Pat and Ken Smith.

Lou asked Tom Blackwood, Thistle Dew, 37VT46 to speak at Debbie's memorial and to focus on her life afloat.  This is the address that Tom gave on 5 March 2019, to 400-plus of Debbie's family, friends, and shipmates.  

-------

Good morning,

I am a tugboater like Captain Steplock.  My name is Tom Blackwood and I own a tug just like his.  As I look before me I see a man, an apparent impersonator, because the Lou Steplock I know always wears the scrubs of a doctor, sadly worn deck shoes of a poor sailor, and has a rumpled train schedule stuffed in his back pocket.   So who are you?

Inside, he has a mind of clarity, an unbridled passion to do good and a heart, that has been smashed, smashed into pieces....and if you could hear those pieces they're putting out a code, a signal:  ... --- ...     ... --- ...   S O S  Save Our Souls.   And by gosh, the code has been heard.  Here today are eight fellow Tuggers from as far east as the shores of Maryland and Atlantic waters and as far west as Seattle and Puget Sound filled with waters of the Pacific Ocean.  So all of them, and all of us, are here, and answering that same call, and because there are so many, I have absolutely no doubt we can bring function back to that broken heart.   And oh, by the way, it would be a big help in putting this repair team together: does anyone, anyone, know where we can get a good cardiac thoracic surgeon? 

Funny thing about hearts, and this is a teaching moment, so Doc, you've got to pay attention, you might learn something, is that hearts like other hearts and this one more than liked.  He, like each and every one of us, loved that massive heart of Debbie.

So let's get started on that repair.  We all know Debbie, that's why we are here.  She was the pretty girl, ahh, but more than that, she was the pretty girl that was nice to everyone.  That's rare and that is special.  She gave, gave, gave right to the last and now, though gone, she is continuing to give through all the organs and parts she was able to donate.  [If I can pause for a commercial break, I'd like to say sign up today.]

But let's go back to boating.  It took Debbie a little while to cotton up to this lot of Tuggers.  That's Tennessee talk.   Boating wasn't really her thing, but shopping was!  So, how do we put the two together?  Ah ha!  There is an upcoming rendezvous of tugs in Seattle, right downtown and directly up from the docks is   Nordstroms.

Picture this:  The boats are gathered and we're all busy crawling over tugs and checking out engines when you glance up to see Debbie, on her return, walking down the dock.  A bouquet of fresh flowers from the Pike Place Market cradled in one arm and the hand of the other toting one of those fancy, cord handled, crisp white shopping bags with gold letters on it saying....come on now....Nordstrom.   She now thinks, "Tugging is for me.  Yipee!"

In time we would see this play out again at some distant island.  Lopez I think, in Fisherman Bay.  For some reason Lou was absent and my job was to get her on an afternoon departing float plane, for some important reason, like, an opera that night in Seattle.  The plane arrived.  On this day Debbie was dressed in a summer outfit of pastel yellow, which coincidentally matched the yellow paint scheme of the awaiting Kenmore float plane, she carried a small case and sported a smart, very smart summer sun hat.  And of course, madly stylish sunglasses.  With such grace and poise she glides over the sun bleached timbers of the dock with her head high and shoulders back.   As in the image of Marilyn Monroe there is a brief catch of wind at the hemline but nary a break in stride.  Now coming her way is the Captain.  He greets her in his professional, polished and rehearsed manner, takes her case and  deftly guides her aboard.  All's well until he sees me, dragging the rest of the luggage toward the plane.  There is a bit of a sigh and he says "Oh, we have even carried canoes."


All settled in now, that throaty big radial engine of secure strength, starts up and the planes eases into a smooth water taxi.  Debbie turns to look out the window, with eyes a sparkle, and oh how we know those eyes, gives her signature wave then the engine comes to roar and once again Debbie thinks, "I like this tugging stuff."  
I must fast forward to say, in the end, she had her own, well broken in deck shoes, would get soaking wet in a dinghy ride, stand in the rain for a bus, or hop in the trunk of a Good Samaritan ashore offering a ride.   She was the best and yes, without a waiver, Debbie liked Tugging..


So, as it was when that floatplane took to flight, we now wave good bye to you, Debbie, to watch you climb to greater heights, knowing you will go on, over the horizon and out of sight, to touch the hearts of oh so many more.  Good bye.
And you, Lou, here we are, your mending team is in place.  Let the landlubbers fill your arteries with strength and will and let your Tugger buddies keep the saltwater in your veins.

I'll see you back aboard Pet Tug, Petunia Tug, where the spirit of your First Mate ever waits.  


And remember, remember.......every now and again, you're  gonna have to take her shopping, listen to some piano music at Nordstroms, and when cooking aboard, in the galley, wear your pearls..


Tom Blackwood
Presented: 5 March 2019
Highland Park Community Church
Casper, Wyoming 
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A video of Debbie's memorial service.  Tom's address starts at the 29 minute mark.

Debbie's obituary, Casper Star Tribune, 4 March 2019.




Thursday, March 7, 2019

Deck-Fill-Plate, Cap Replacement




Has the cap to your fuel, water, or pumpout deck plate been lost overboard? Good news, Bruce Griffiths, Tess II 37VT22, has found a replacement that fits on our tugs:

CH5930/WATER DECK FILL HOSE BARB 1- 1/2" S.S. WITH KEY ($34.99 Tax included).

VICTORY PRODUCTS # 8194 Ontario Street, Vancouver BC Canada V5X 3E3
Fax (604) 325-0326
Phone (604) 325-5233

Bruce reports that, "I just replaced the cap and chain. Perfect fit and the chain attachment screw thread fits the existing hose barb base."