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ContinuousWave: Small Boat Electrical
Shore Power for Big Boats
|Author||Topic: Shore Power for Big Boats|
posted 12-06-2012 12:28 PM ET (US)
This topic area is called SMALL BOAT ELECTRICAL, but I wish to discuss an electrical topic that is completely the opposite: big-boat electrical and shore power.
When most small boats are at a dock, they typically make an electrical connection to shore power, obtaining 120-VAC from the marina or dock facility. Some larger boats may connect to 240-VAC shore power. It never occurred to me that in the realm of big boats--and here I mean really big boats like 1,000-footers--there typically would not be a connection to shore power. Big boats typically run their own power generation plant, and when connected to a dock during loading or unloading for a day or two, they just continue to run on electrical power they generate themselves. This practice is about to change.
I found this interesting article on the topic of big-boat shore power:
I think readers of SMALL BOAT ELECTRICAL will find the article interesting.
posted 12-06-2012 06:19 PM ET (US)
As a regular reader of the SMALL BOAT ELECTRICAL forum thread, I didn't find the article very interesting. It consists of about 450 words and three photographs, apparently provided to a trade publication by a shipping company and a manufacturer of electronic gear, to promote their respective interests.
posted 12-06-2012 11:09 PM ET (US)
Tom--I found the article fascinating, and that's why I mentioned it.
posted 12-07-2012 12:23 AM ET (US)
I also loved the jargon cold ironing. A great new term!
posted 12-07-2012 10:20 AM ET (US)
The US Navy has been doing this for many years at naval facilities, at least since 1978 if I remember correctly. Obviously the nuclear vessels with hot reactors need no shore power except when undergoing serious maintenance and perhaps refueling.
posted 12-07-2012 10:48 AM ET (US)
Cruise ships have been doing this in Juneau for years. Residents complained (and likely the EPA) of the emissions and tell-tale exhaust coming from the four to six cruise ships (200-feet to 1,000-fet) in port each day during the summer months. The cruise line agencies worked with the local electric authority to put in an electrical substation for at least some of the ships so they can go on shore power while in port.
FYI, on a busy summer cruise ship day in the summer, Juneau (population about 31,000) can receive over 15,000 visitors.
posted 12-08-2012 09:19 AM ET (US)
Just after coming across this article about big ship shore power, I happened come in out of the cold to watch an episode of MIGHTY SHIPS in which the featured vessel, a RoRo called NORTH STAR, was calling on Anchorage, Alaska. As soon as the NORTH STAR made up to the pier they switched to shore power using a 6,600-Volt source from a cabinet on the pier. Apparently this procedure has been in place at Anchorage for some time, as it was treated as a routine event. [You might call this a cold irony.--jimh]
posted 12-08-2012 08:01 PM ET (US)
Shore power delivered at 6.6 Kv indicates that the ship's generators may produce 6.6 Kv as well. That's pretty hot power for a ship. Normal distribution power in your neighborhood is probably 2.4 Kv of 4 Kv (4160 volt).
We made 15 Kv on a floating power plant but stepped it down to 440 volts for shipboard distribution and exported the 15 Kv to a station service substation where it was stepped up for transmission.
By distributing shipboard power at 6.6 Kv the NORTH STAR can save substantial distribution conductor weight at the price of a few extra transformers. Sounds like a good trade off.
posted 12-08-2012 08:15 PM ET (US)
In my neighborhood the primary power distribution is 13,200-VAC. It seems like 6.6-kVAC is exactly half of that voltage. Perhaps there is some sort of relationship there. I don't know much about this big-ship power stuff--I just heard of it two days ago!
There must be some sort of standard for the big-ship shore power, otherwise each port would be offering different voltages and, perhaps, different frequencies. In Europe it is common to find 50-Hz AC power, but in North American 60-Hz is the norm.
What is the normal ship power frequency? Is it 50 or 60-Hertz? [It turns out this answer depends on where the ship was built.--jimh]
posted 12-08-2012 08:18 PM ET (US)
On the ship there is probably a large step-down transformer, and the 6,600-VAC is probably stepped down to match the ship's primary power voltage, which is probably 440-VAC or something in that neighborhood. High-power AC power distribution is outside of my scope of experience. Once the line voltage is more than 120-VAC to ground, I am out of my depth.
Here is an interesting white paper on Cold Ironing:
It mentions that cold ironing was first adopted in Alaska, beginning as long as 20-years ago, influenced by the very low cost of energy on the shore there. This correlates precisely with Jim Potdevin's observation that cold ironing was old-hat in Alaska.
posted 12-09-2012 10:34 AM ET (US)
Re cold ironing of military ships: military ships tend to spend a lot of time in port at their home port or base location, and this makes cold ironing a very attractive alternative to keeping the ship's power generation engines running all the time.
Commercial ships do not spend very much time in port; they are at sea and underway almost all the time, and they often visit many different ports in their travels. The short duration of their port stays and the diversity of ports visited has reduced the trend to adopt cold ironing as a standard procedure when in port.
posted 12-09-2012 10:48 AM ET (US)
All good points and interesting stuff. Time in port is a huge factor.
My earlier claim of 15 kV should have been 14 kV which was actually 13,800 volts.
I have a fair bit of experience of using 50 Hz to drive 60 Hz rated equipment in Europe. There did not seem to be any real difficulties except that fans, for example, did not provide the same cooling or heating so refrigeration equipment was less efficient. Electric motor life may have been slightly diminished but the evidence of that was anecdotal. For frequency critical equipment we employed motor generator sets or precise power diesel generator sets.
posted 12-09-2012 11:06 AM ET (US)
Re 50-Hz v. 60-Hz power, I would think that a transformer designed for 50-Hz would work with 60-Hz power, but perhaps not the other way. In designing a transformer the primary winding needs to have enough reactance that the self-magnetizing current is not too much. As the frequency is lowered, the reactance decreases and there is more self-magnetizing current. Typically the increased reactance necessary with lower frequency current comes only from more iron in the transformer core.
In aircraft it was common to use 400-Hz AC power because it reduced the amount of weight in transformers.
In the early days of power generation at Niagara Falls, Ontario, the Canadian power was being generated at 25-Hz. I believe this was done to help with the transmission of the power over long distances. At 25-Hz there is a noticeable flicker to incandescent lighting. Eventually the Canadians moved to 60-Hz power from Niagara Falls. My father built some radio equipment back in the 1940's which used old transformers he obtained surplus, and these were transformers designed for 25-Hz power. These transformers were very heavy and had large iron cores. They worked just fine on 60-Hz power.
posted 12-09-2012 12:28 PM ET (US)
Naval ships run on 400Hz for the more efficient transformers.
And in the days before switching power supplies, the IBM
posted 12-09-2012 04:29 PM ET (US)
Frequency changing motor-generators are very common in the US military. Generator sets producing 400-Hz are also used though they are not common.
posted 12-14-2012 09:20 PM ET (US)
"Cold Iron" is an old term, stating the ship's main power plant is secured and has cooled down or is not hot. It originated on steam ships that have large boilers systems that took a while to heat up and get operating. When the ship was pier side for long periods and secures all the boilers, it was called going "cold iron". Remember on a steam ship (built circa 1930 to 1985), the ship's electrical power is typically derived from a steam turbine driving a generator, so the all the boilers rarely went cold. But nowadays diesel engines account for majority of ship electrical power, and steam generator plants are rarely used or installed.
In our modern world, 1960's and newer, the U.S. Navy still uses the term on nuclear powered ships. In lieu of large coal or oil burning boilers, a nuclear plant is creating steam. When the nuclear plant is shut down--which is rare--it is still called going "cold iron".
Going "cold iron" is still valid dock talk, as there are a lot of steam ships and nuclear powered ships out there. So "cold ironing" to me, simply represents an adaptation of the original term in a valid way.
Now, having all ships receive shore power while pier-side is a great idea, but it is expensive infrastructure upgrade. Major ports dream of this. And it is a hard project to sell, because the economics make it a tough deal. It's not like the Ports get a ton of money providing shore power--or the ships save a ton either. It's really environmental political action that gets this type of stuff done--barring the price of WTI crude going to $200/barrel.
posted 12-18-2012 12:36 AM ET (US)
On my drive to an from Detroit this past weekend, I noticed several of the truck stops I visited for diesel were advertising that they had shore power.
I had never seen this available at truck stops during any of my previous trips around the Midwest and this made me wonder why it has taken this long to catch on. It's a perfect solution that allows a driver to conserve fuel by not having to run the tractor all night just to have power and stay warm.
It's a good solution for large ships for the same reason.
posted 12-18-2012 10:26 AM ET (US)
David--those big rigs also use the shore power for air conditioning in the hot weather. Plus, in the winter, the shore power keeps the engine block and fuel line heaters going. I wonder what the service costs. I imagine cable TV is included. I'll bet the channel choices are interesting.
posted 01-23-2013 09:56 AM ET (US)
The Port of Halifax, Nova Scotia, has announced it will be building shore power facilities for visiting cruise ships. The project is anticipated to cost CAN-$10-million. When completed, Halifax will be the first Atlantic Canada port to offer shore power for visiting cruise ships.
posted 01-23-2013 01:31 PM ET (US)
The application of shore power or cold ironing for cruise ships merits some further discussion. In my experience with travel on cruise ships, a cruise ship usually remains in a particular port for less than 24-hours. Usually they arrive very early in the morning, and depart before sunset. Even cruise ships at their port of embarkation don't remain at the dock very long. They usually are in and out in 24-hours. The switch to shore power for such a short time would limit the savings to be obtained in reduce fuel consumption.
I think there is a corollary influence affecting cold ironing. Many ports appear to be enacting regulations preventing the burning of fuel oil in the port with a high-sulfur content. This causes the ships to switch to a higher-grade fuel oil when in port. The higher grade fuel oil is probably also more expensive. Perhaps this has influenced the trend.
posted 04-12-2013 12:40 PM ET (US)
Harper government to help more ships reduce emissions, improve air quality
For release - April 12, 2013
OTTAWA — The Honourable Denis Lebel, Minister of Transport, Infrastructure and Communities, and Minister of Intergovernmental Affairs, today announced that the Harper government is launching a second round of funding under the Shore Power Technology for Ports Program to improve air quality at Canadian ports.
Shore power is a highly effective way to reduce marine diesel air emissions by enabling ships to shut down their engines and connect to the local electrical grid in order to power their on-board systems while docked.
"This technology will improve local air quality by reducing air pollution from ships in some of Canada's largest urban centres," said Minister Lebel. "By funding more shore power projects, our government is taking concrete action to reduce air emissions and improve the health of Canadians."
Canadian port authorities and private organizations engaged in operating and/or owning marine ports and terminals in Canada are encouraged to apply for funding by September 30, 2013. A guide for applicants and additional information is available on Transport Canada's website at www.tc.gc.ca/sptp.
Announced in January 2012, the Shore Power Technology for Ports Program is a $27.2-million contribution program which supports cost-shared projects. The federal government will provide up to 50 per cent of the eligible costs – up to a maximum contribution of $5 million per project.
Under the first funding round announced in May 2012, the Government of Canada is contributing up to $5 million to the Port of Halifax to implement shore power for cruise ships, beginning with the 2014 cruise season. Also under the first funding round, Seaspan Ferries Corporation is receiving approximately $88,000 to install shore power at the Swartz Bay Terminal on Vancouver Island. Additional projects under the first round of funding will be announced in the coming months.
Funding for the Shore Power Technology for Ports Program was provided under the Clean Transportation Initiatives in Budget 2011 as part of the renewal of the Government of Canada's Clean Air Agenda. The Clean Transportation Initiatives focus on aligning Canadian regulations with those in the United States and with international standards, improving the efficiency of the transportation system, and advancing green technologies through programs such as Shore Power Technology for Ports. These initiatives will help Canada achieve its target of reducing greenhouse gas emissions by 17 per cent from 2005 levels by 2020.
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