Posts In The “Technical” Category
This post discusses the reasons a boat owner might choose to carry deck fuel and the impact of deck fuel on the vessel’s stability. We start by explaining why a boat’s “real ocean” range is actually far less than the ranges advertised, and sometimes even less than the ranges carefully measured by owners. Then we…
The Marine Automatic Identification System is a simple yet effective means of reducing the risk of collision at sea. These systems work on a reserved VHF frequency and each boat using the system has an AIS transceiver on board that transmits the vessel’s position, speed, and course, and other data including the vessel size and…
We’ve had three pendants fail on our Steelhead Marine crane over the last 9 years. The proportional switch proximity sensor is very fragile but there are other failure points as well. These pendants cost just under $1000 each, so we really needed a longer lasting and more economical solution. Steelhead does sell a remote-control for this crane,…
At 1:30:34 AM on Jun 17, 2017 the USS Fitzgerald and the container ship ACX Crystal came together just south of Yokosuka Japan. The ACX Crystal is a 730’ modern containership built in 2008 and capable of carrying 2,858 TEU of containers at a 23-knot service speed. The Fitzgerald is a $1.8B US Navy Arleigh Burke-Class…
Isolating shore power from on-board electrical systems is important to avoid excess corrosion and, even more importantly, to avoid risk of shock in and around the boat. Two common approaches to isolation are galvanic isolators and isolation transformers. Isolation transformers have many advantages and often are installed in Nordhavns, but have one potential downside though:…
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River bar crossings require great care and in some conditions they simply can’t be safely crossed. Earlier this week, the crew of the commercial fishing vessel Mary B requested help from the US Coast Guard in a night crossing of the Yaquina Bay bar at Newport, Oregon. Sea conditions were reported to be 14 to…
In May of this year, while cruising Arctic Norway, we ordered two new Accu-Steer HPU 200-24 steering pumps from Emerald Harbour Marine in Seattle after our Accu-Steer HPU212 steering pump developed serious bearing noise. This actually was our secondary pump that we’d switched to when the primary started leaking. Both pumps were still fully-operational, but…
We have an Inca TV Lift on Dirona and we’re generally very happy with it. The lift is powerful, so it doesn’t get stuck when friction on the slide surfaces increases over time, as it invariably does. It’s built from heavy parts, so it keeps working even in the high vibration environment of a boat….
Reliable black water levels make the boat easier to operate and lower costs by reducing the number of pump-outs required. We have sufficient black water tankage to go for two weeks in normal use and, with some care, we can go much more than a month between pump outs. However, when using inaccurate level sensors,…
On Dirona, we aim to always run the boat using a single power source. When we are plugged into shore, we aim to drive the entire boat off of shore-side power and never run the generator. This may sound easy, but in Europe you frequently won’t find more than a 16A shore power service and…
A few years back we posted the Excel-based spreadsheet we wrote for our maintenance log, along with instructions on how to use it. The spreadsheet has continued to serve us well, and still is our main tool for managing maintenance items. While it’s fairly easy to add new maintenance items for a given piece of…
Most fish boats run both deck lights and forward lights. They use the deck lights for working at night and the forward-facing lights to see further in front of the boat better. Our experience from operating around commercial fishing vessels at night is their forward-facing spotlights can be seen from great distances. We sometimes find…
It’s hard to believe, but our “new” John Deere 6068AFM75 is now nearly 9 years old, has been around the world, and has now clocked up over 10,000 engine hours: Hours: 10075.1 Nautical miles traveled: 69,187 Fuel burn: 59,257.4 gallons Load factor: 44.2% Longest ocean crossing: 3,689 nautical miles (St. Helena to Barbados) Over the…
When considering fuel quality, we’ve always thought first about water, rust, and other impurities in the fuel. Knowing we intended to travel the world and expecting poor quality fuel in the many less-developed countries we would visit, we left Seattle with 48 primary filters on board. What we have learned is that fuel quality is…
Most battery manufacturers specify battery life expectancy in terms of number of cycles at a certain maximum discharge level. Transforming this data into the expected or remaining battery life for a house bank is challenging. In measuring the number of cycles, for example, what depth of discharge qualifies as a “cycle”? Our house bank consists…
Frequent readers of this blog know we like NMEA2000 and have become very dependent upon Maretron N2KView at the core of our monitoring and control system on Dirona. The screens above are our underway and at rest monitoring displays for Dirona. They are repeated in the pilot house, salon, and master stateroom. Knowing how much…
After 9 years of hard use and over 550 hours, we decided to purchase a new tender and we picked it up in Harlingen, Netherlands. It was long past time to replace our tender with the final straw being an eight-inch complete seam blow-out in the cold Orkney Islands group in Scotland. Our goal was…
The dry exhaust system on Dirona is well-built and reliable. The way it works is the stack heads up through the boat in a 5-inch pipe to release exhaust gas at the top of the stack. The exhaust pipe is enclosed in a larger pipe where it passes through the boat. This larger pipe provides…