Posted by: towmasters | March 24, 2011

Good Design: It Never Goes Out Of Style

Truly excellent design is more rare than you might think and often rather slow to catch on. But it does occasionally happen. So was I pleasantly surprised to see a brand-new barge with a design feature that I’ve been hoping to see for years? Absolutely.

The barge pictured below is a bunker barge: designed primarily for bunkering ships. That is, to come alongside ships that are moored or at anchor and pump fuel to them. Ships don’t go to fuel docks – the fuel dock comes to them. These bunker barges may be pushed or towed alongside and will carry varying types and amounts of cargo (fuel) depending upon the needs of the ships they serve.

What makes this one different than other bunker barges? Rather than having the typical unprotected sharp corners, this barge’s bow curves gracefully around and is protected by built-in, wrap-around fendering…..

…..which also wraps around the 90° corners at the stern…..

…..as well.

The ends of each section are finished with wedges that help prevent them from catching on obstructions and being peeled off the barge.

Why does any of this matter? Because currents flow, the winds blow, and ships weave back and forth while at anchor. Tugboating, as the old saying goes, is a contact sport. Notwithstanding tractors, most tugs doing bunker work don’t handle like a helicopter. We very seldom get to come in exactly “flat” (parallel) to the ship’s hull unless there is an assist boat. So one must angle over, by the bow or stern, and “crab” or wiggle to close the distance and get alongside. In so doing you always run the risk of striking the ship, or the ship striking you, at one of the corners and having metal-to-metal contact. Maybe it results in just a bit of chipped or scraped paint, or maybe there’s a dent, or maybe worse. Like a crumpled hull, a crack, or a hole. In any case it’s bad for business and easily avoidable, just by using good design principles. The obvious questions should always be asked and answered while still in the design phase. What is this thing meant to do? What can we do to make it work better? What is the cost-benefit ratio?

The curved bow, almost always the first point of contact, gives you a broader and, therefore, stronger area on which to land. It spreads any impact forces out over a greater area, making it more durable and less damaging to whatever you’re landing against. The rubber fendering prevents or minimizes any cosmetic damages that might occur. Maybe nothing at all, or just a little scuff, when you otherwise would have had a small dent. Maybe just a small dent when you would normally have had a great big dent, and so on. You get the picture…..

When departing from shipside the fendered stern (and bow) corners will allow you to fearlessly twist off to a steep angle if need be before pulling away. So even if there’s a fairly strong wind blowing you’re empty barge against the ship you can still make a clean getaway without necessarily needing an assist. How much is that capability worth to a company?

Don’t the barges have big Yokohama fenders? Yes, they do. But contrary to the belief of some tankermen (and others) those Yokohamas aren’t really meant for protecting the barge while maneuvering alongside to get the first line, or when pulling away. They’re primarily for protecting the barge and the ship from one another once the barge is parallel, or very nearly so, and made fast alongside. Their location, well away from the bow and stern, means that they provide little or no protection when landing and sailing at angles to the ship’s hull, which is the norm.

Can’t the tankermen and deckhands just use deck lines or hand fenders instead? A big, fat NO on the lines. They are a poor substitute for real fenders (they’re easily squeezed or pulled out of position by friction, leaving you with nothing), and using them as such usually damages them, which can lead to their “unexpected” failure later. How about hand fenders? Sure, and I make sure that my deckhands use them. But, like it or not, many of the old-school skills are dying: it’s not uncommon to see barges with no “preventive” woven-rope fenders hanging alongside at all. The small aircraft tires that make such good portable “handy” fenders (there should always be one for each corner of a barge, kept ready on station at all times, plus a spare “rover”) are also becoming a rarity these days. And even they can be pulled out of position when sliding along a ship’s hull to get into position.

No, this built-in fendering is definitely the way to go and will ultimately pay for itself, and then some, in damages avoided and customers who are kept happy ‘cuz you don’t dent ’em up or ruin their nice paint jobs. Not to mention avoiding the damage to your own equipment and personnel.

Are there any potential weaknesses or downsides to this set-up? Only one that I can see so far, and it certainly doesn’t outweigh the many benefits. Because the fendering sticks out a few inches from the hull there is the possibility that sometimes the top or bottom of it might catch, and get hung up on top of or underneath, the concrete decks, steels beams, or horizontal face timbers of docks as the barge goes up and down with the tides and/or loads and discharges cargo. The workaround would be very simple: install those same steel wedges you see at the ends of the fendering in an over/under configuration in a few key places so that they force the barge out and away from the timbers or framing when they come into contact with the dock. allowing the fendering to slip clear.

No one design can do everything perfectly. The very features that make something highly suited to one task may make it equally unsuitable for another. But if you think carefully about it first and do your homework in advance (and are willing to spend some extra money up front) you’ll usually come out ahead and learn more in the process. In general, I’m a believer in the sometimes-forgotten concept that form follows function. It’s nice to see the occasional revival of it.

 

 

 

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Responses

  1. now, as an outsider, i could have looked at this a kazillion times and not seen what an insider sees. merci!

  2. Thanks for sharing photos!

  3. […] Princess as well as  (near to far) Sassafras with DoubleSkin 303, Timothy L Reinauer with RTC 84, and Freedom Service with Energy […]


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