Sonic Booms

[Piers]

Anyone been caught out by Concorde's sonic booms over the Channel as the leaves Paris for the States?

I've been caught unawares twice, and what a jump I had both times. Both happened just to the north of the Alderney Race.

The first time, a really flat crossing, all relaxed, enjoying the sun and its warmth, when the enormous double 'Ber-bang' made us all jump out of our skins. Throttles back, gauges check, look around to see what we may have hit, examine the engine room, look in the saloon - nothing. Until it began to dawn on me. Looking high to the West, there she was streaking to the States.

The second time was not flat at all. Emotional would be a better description, and it had been 'a bit of an endurance run and a challenge to a chap's sense of humour' all the way from the Little Russel up to Alderney and through the Race. Rain had replaced the sun and the family was in a state of denial, trying to sleep it out in the cockpit.

We were just clearing the Race, heading north and home, when suddenly, 'Ber-bang'.

I can assure you my immediate thoughts were not charitable. This could not be a worse place for a problem. A sea on the ebb, the wind from the NE and the race just behind me...

Throttles back, gauges, engine room, and then, a vague memory seemed to ease itself into my mind courtesy of adrenalin...I wonder?

A quick consultation with the family (which by now was wide awake) brought agreement - Concorde again. Relieved, we drove on.

But that's twce I've been caught. Hopefully, not a third time, but with her airborne again, I'm not so sure.

Have you been caught? And what happened?

Piers du Pre
MBM Cruising Club enthusiast
www.dupre.co.uk

 

[Col]

The Alderney race ? You hero !!
I prefer to go about 2-3 miles W of the Casquets, much smoother, although the race is ok at slack.

 

[hlb]

No but I once went through the races and thought it was rough, and then met thick fog with yachts all around. The experience was very similar.

Haydn

 

[Guest]

not sure if ber-bang is a sonic boom. They don't reach supersonic whilst over land, only out beyoun st davids head, for example, so fastnet racers get it. It's a loud single crack.

 

[ToMo]

heckscuse moi!....we suffer the retched thing twice a day...every day (almost!) here in SE Cornwall, and where we are it is definately a ber-bang....it does depend on where youj are in relation to where Concord winds it up...there has been a long running campaign to get the speed up moved futher out....but you know low population density = few votes = bog off and stop bothering us!
Happy whatsits!
TôMö

 

[Piers]

Hi Matt - yes, it's a sonic boom. The ber-bang comprises the leading and trailing edge of the shock wave as it passes over you.

And the Air France Concordes are allowed to accelerate down the Channel and can be supersonic by the time they reach the Channel Islands.

Hence, a favorite place for the booms!

Piers du Pre
MBM Cruising Club enthusiast
www.dupre.co.uk

 

[Piers]

Where do you keep your boat?

Piers du Pre
MBM Cruising Club enthusiast
www.dupre.co.uk

 

[DepSol]

Piers is right, in the summer we usually get the ba boom about 9pm when we are waiting for the sunset off Herm Island.

By the way Col the race and the swinge are real pussycats, you just have to pick the ride state of tde to go through them. Usually when one is rough the other is smooth.

Dom

 

[Col]

Re: Channel Islands.

Hi Depsol, hope to be back down your neck of the woods mid-late march, whats diesel prices like at the moment ?

 

[ToMo]

Hi Piers, I trailer my Boat, she's only a small day boat with a cuddy - I often launch from the Millpool at Looe as its only 4 miles from my home
Comps of the thingy
TôMö

 

[DepSol]

Re: Channel Islands.

Hi Col

Would be good to see you and share a few beers. Diesel is about 25p litre through my Shell card. Give me a shout when you have set a date, weather depending of course.

Dom

 

[johndf]

Re: Channel Islands, Concorde, Aldernet Race

We hear Concorde's ber-bang every day around 1615 here in Jersey and I don't mind a bit. Despite being both a raggie and a green, I was delighted when Concorde took to the air again a few weeks ago - a beautiful aircraft imho. The sonic boom is not a problem. The same has been true of the Alderney Race both times I've been through. The second time, there was no wind but a large swell and a big spring tide. The Race was like a millpond, but the sea off the French Coast two or three miles East of Cap de la Hague was very unpleasant. I think it was due to there being a good three knots of tide against a large swell passing over a very uneven and rather shallow bottom. there was virtually no wind at the time. Anyone else had problems there?

 

[Guest]

Re: Channel Islands, Concorde, Aldernet Race

Yes had a hel of a ride from Cherbourg to Guernsey through race last August, weather was given at C herbourg 2-3 but of Cap dela Hague it was horendous, steep chop, seas from every direction, only got better at top of little Russel.

Return was as bad, planned to go straight back to uk, west of Casquets, again, weather given 3-4 4 miles north of Alderney troughs were higher than my flybride, boat is a princess 388, weather on other side giving sixes off needles, made a quick bolt to Cherboug, surfing and twisting all the way, never mind a great learning curve.
As they say the boat can take more than its crew, but when the oil light and buzzers show you know that your'e at the wrong angle!.

Paul js.

 

[Col]

Re: Channel Islands.

I will give you a call nearer the time when I Know what my plans are.


Col.

 

[Dave_Snelson]

Piers, I was caught fast asleep on the sun deck of a cross channel ferry. Talk about jump!! I leapt up and looked around and found all manner of pandemonium with kids cying (mine included) and bewildered looking adults. It was like the report of a cannon, only twice.

Cheers.

 

[Piers]

And it's always the Air France Concorde! BA's standard departure routes do not route over the Channel. Depending on the winds over the Atlantic she will head out over Cornwall, Wales, or Scotland and wait until she's clear of land before accelerating.

Seeing the fright the ber-bang causes, I just wonder how long before something happens. It always seems to take people by surprise - do we need another Waterloo per-chance?

Piers du Pre
MBM Cruising Club enthusiast
www.dupre.co.uk

 

[Piers]

Re: Channel Islands, Concorde, Aldernet Race

I always route well clear of the Cap, far further out than most boats seem to take. The waters further out seem to be far nicer.

Piers du Pre
MBM Cruising Club enthusiast
www.dupre.co.uk

 

[DepSol]

Re: Channel Islands, Concorde, Aldernet Race

If you are approaching Alderney at 1 hour either side of half tide forget the race go through the swinge it'll be flat but keep a look out for 'Corbet' and miss it by 100 feet.


Dom

 

[Piers]

Re: Channel Islands, Concorde, Aldernet Race

Understood - I take it that Corbet is the rock half way up the Swinge on the Alderney side, pronounced 'Kirby'? And if I remember correctly, the rock used to have a beacon / mark on it which has since been lost!

Piers du Pre
MBM Cruising Club enthusiast
www.dupre.co.uk

 

[tony_brighton]

Had the same problem about 15 miles N of Alderney - was single-handing back across under engine (no wind for the sails!) and plotting a position on the chart when it happened. Leapt out of the cabin thinking the engine had let go and was going to have to pump up the dinghy. In retrospect - definitely a sonic boom as I've heard it again.