A cruise ship has been in contact with the air span over the Nordfjord at Bryggja, and Linja reports that there is visible damage to the power line.
Thursday night at 22:04, the cruise ship Mein Schiff 4 touched our fjord span over the Nordfjord. We received a message from a witness who saw it, in addition to the fact that the collision affected our monitoring system, says CEO of Linja, Asgeir Aase, to Fjordenes Tidende.
During Friday, Linja made visual inspection with a drone on the fjord span to the 132kv line between Ă…lfoten and Bryggja.
There are visible injuries, but there are minor injuries that are not critical, Aase states.
After the collision with the cruise ship, the fjord span has sagged somewhat. This means that the Norwegian Coastal Administration now reduces the sailing height under the fjord span from 60 meters to less than 50 meters.
It does not block the fjord, but it means that tall ships must sail closer to land to avoid catching up in the fjord span, says Asgeir Aase.
The line owner will start repairing the power line in August.
Shocking! Absolutely shocking that a cruise ship would conduct such an operation. It must have created some high tension on the bridge. I am sure the situation will be rectified shortly.
I didn’t realize that the ship had this capacity, and I’m surprised that not one officer on the bridge was grounded enough in reality to offer resistance to this circuit of the fjord.
I thought that “Electric puns” was limited to the Ukraine thread??
Actually it is shocking (no pun intended) that a ship touches a 132kv fjord crossing transmission line.
Free sailing height at the lowest point is marked on the navigation charts and well know to the pilots.
There are also markers that is visible from ships (or air crafts) approaching the line. (No it was not dark at 22:04 hrs.)
In this case free height was declared as 60 m. at the lowest point and the Mein Schiff 4 has an air draft of >45m. The declared free sailing height has now been reduced to <50m. at the lowest point.
Taller ships can still get in and out of Nordfjorden by staying closer to either side of the fjord.
(No they don’t risk running aground, unless they get closer than 5-10 m. from shore)
BTW; the length of the crossing is 2400 m., with 13 m.t. tension in each of the 3 lines (phases).
PS> The warm weather and bright sunshine the last few days MAY have caused the lines to sag more than calculated.
Global warming and larger ships MAY require somebody to have a second look at how temperature affects elongation of these type of fjord spans, of which there are many in Norway.
The Verrazano Narrows Bridge in New York is only 1298m between spans, but between the design temperature range of 10F and 103F, the bridge has a designed vertical clearance change of 12 feet.
I’m sure they have allowed for sagging because of temperature swings, incl. high summer temperatures and low winter temperatures, before issuing their figures to the Coastal Authorities that publish “free sailing height”.
PS> We are talking about three electric cables here, not a major structure, like a bridge.
Yes indeed they do, that is why the traffic in and out of Nordfjord is not hampered by this.
Ships with air draft exceeding xx (45?) m. just have to sail closed to one side of the fjord, or the other, to make sure they are able to clear the cables.
PS> Towing the Troll A Condeep out from Stord they had to ballast down to clear one of these fjord crossing cabler spans, which made for a bottom clearance of only a few meters:
[quote=“ombugge, post:6, topic:63510, full:true”]
I’m sure they have allowed for sagging because of temperature swings, incl. high summer temperatures and low winter temperatures, before issuing their figures to the Coastal Authorities that publish “free sailing height”.
PS> We are talking about three electric cables here, not a major structure, like a bridge.
[/quote
A professor of mine told me that one of the biggest problems he has seen is the inability of intelligent people designing things to understand the level of ignorance of the people who may be using their design. “Keep this in mind lest some moron make you look like an idiot. Make allowances for them and yourself because you also not infallible.”
Who do you see as “the people who may be using their design”? The ships that sail under, or the people who consume the power?
Maybe I should explain this with “sagging in low winter temperatures”:
One of the main issues are ice forming on the cables during certain winter conditions, causing the lines to sag more than expected from elongation on warm summer days.
The other issue is ice dropping from the lines when it thaws, which happens frequently with the changing weather here on the NW coast of Norway.
