oops! tidal power collision

[Quandary]

So the yachty consensus is that it is better to try to maintain turbines underwater in a 10 kt. tide with 15mins. slack than ask the dozy bu**ers passing in their yachts twice a year while out on a jolly to navigate around them?????

 

[dunedin]

So the yachty consensus is that it is better to try to maintain turbines underwater in a 10 kt. tide with 15mins. slack than ask the dozy bu**ers passing in their yachts twice a year while out on a jolly to navigate around them?????

It can't be beyond the wit of engineering to have turbines which can be raised from below for maintenance above the surface, then being lowered again afterwards

 

[saltylegs]

It can't be beyond the wit of engineering to have turbines which can be raised from below for maintenance above the surface, then being lowered again afterwards

When the wings are down no big problem you will just hit the Light house style structure.
But if the wings are up then anything that gets swept under gets leveled as per in the OP.
As I have said above this lump is mid flow and if you are without power or you have no apparent wind as you are matching the tidal flow (maybe up to 10 knots) or maybe you are just in the shadow of the hill then you are likely to land on the "tower".
So if the wings are up and you are out of control as above then who is at fault, You who has taken taken all reasonable precautions or the idiots who put a huge "windmill" mid flow where you cannot avoid it.

 

[vyv_cox]

We have only visited once but the tidal flow was most memorable. I can quite imagine that someone not used to it could assume he had plenty of time to avoid the obstacle when in fact he didn't. We could not motor up- tide on an average tide and watching other boats going with it caused much merriment, as they travelled at seemingly impossible speeds past us.

 

[guernseyman]

T....
Presumably, though, there will be an exclusion zone while they instal it. Do you know when/where? I have just scanned current NtMs for the area and nothing came up, so I'm guessing the answer is "not just yet".

...

No, come to think of it, I don't think the location has been revealed.
A couple of years ago, on my way to Sark, I heard a Navigational Warning about tidal flow meters installed off Alderney, but didn't note the lat/long.
No doubt there will be similar warnings for the installation. There will be cable laying, too. To France, for onward selling of power to the UK I believe, eventually.
I hope it goes well. Currently (oops) the price of electricity in Alderney is crippling. Speaking to a cycle hire shop proprietor when I was there ten days ago, he remarked that he was struggling to pay off his bill after that cold winter.

 

[Quandary]

We came down through Kyle Rhea last week with the tide under us and a following breeze that was only a knot or two faster, as we cleared the ferry narrows a 60m. private motor yacht towing its 6m. tender complete with bimini about 50m. behind it, roared up through against the tide at about 30 kts. within about 20m. of us, laying us on our beam and almost washing the dog out of the cockpit. His wash went right up to the ferry lighthouse so it was fortunate there was no one on the slip.
I would be much happier avoiding a few static turbine towers than the eedjit driving 'Big Eagle'????
As for the idea of telescopic towers, if that would work they could do the maintenance in winter when us yachties are tucked up at home in bed with the electric fire on; be reasonable, most of the yachties that can not steer now have bow thrusters, (I saw a Sadler 34 with one in the canal yesterday), but if you can not steer your yacht in a broad fast tide flow you should not be anywhere near these waters.

 

[DaveS]

Yeah, and eedjits hit the Swellies beacon from time to time too, perhaps we should ban all navigation marks & blow up all rocks around our coasts too. Dredging all sandbanks to a minimum of 30' depth would help some sailors (& submarine captains) too.

FFS, the tidal flow is eminently clear around standing pillars & the things themselves are hard to miss - err as in not see - they are actually dead easy to stay well away from if you have a brain.

In addition to a brain, to avoid such obstructions one also requires a functioning means of propulsion which, as others have pointed out, might for various reasons not be available.

I don't think anyone is arguing for removing most natural hazards, but there is a considerable difference between that and condoning the deliberate introduction of new hazards - particularly when alternative technologies exist which can achieve the same results without creating hazards.

 

[Seajet]

Yeah, and eedjits hit the Swellies beacon from time to time too, perhaps we should ban all navigation marks & blow up all rocks around our coasts too. Dredging all sandbanks to a minimum of 30' depth would help some sailors (& submarine captains) too.

FFS, the tidal flow is eminently clear around standing pillars & the things themselves are hard to miss - err as in not see - they are actually dead easy to stay well away from if you have a brain.

Searush,

I'm with you on this comment;

what's so different between rocks distributed by the gods or turbines placed by man, except the latter are probably better marked ?!

 

[pmagowan]

We have a mooring in Strangford lough, lovely place with enough islands to go to a new one every day of the year. The tidal gate of the narrows is quite impressive. In a yacht you simply can not leave if you don't time it right. The turbine is interesting and a little scary. It is mid channel and the tide races past it at 9 or 10 knots. No matter how you try you always seem to end a little closer to it than you intended. That said, with a working source of propulsion it is not difficult to miss. You just have to realise that the bow may be pointed a completely different direction to your current line of travel. When raised it does pose a significantly larger target.

I am not altogether bothered by it and if it provides significant electricity at reasonable cost then fine. Personally I am pro nuclear when it comes to power since it seems to tick all the boxes without all these twiddly things dotted around our countryside and coast.

 

[Seajet]

Pmagowan,

well we have tidal gates around Chichester and the Solent too, we have to work the tides; no normal sailing boat gets in against the ebb without a struggle.

On holidays around the Channel Islands I remember the Decca clocking up 13+ knots in a Centaur in the Alderney Race, one uses it as a ' conveyor belt ' when it suits, if it doesn't suit don't try !