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@It doesn't add up, Aug 30, 2016 at 4:18 PM
Pcar:
Cetane is only relevant to diesel engines. Technically it is measured in a laboratory diesel engine, although there are shortcut methods that are usually used (distillation and density measurements combined in a formula to produce "cetane index") that are simpler to measure and correlate well with engine performance.Cetane appears nowhere in the a href="http://www.petrostar.com/assets/downloads/Jet_A.pdf">specification for jet fuel.
Thanks for info.
My experience is IC engines, thus obvious BBC was confusing octane with cetane. Assumed jet kerosene was similar to diesel in specs as USA military vehicles like Abraham MBT can use either.
Does jet kerosene need to have lubrication properties for the injector pump(s)?
Pcar
Pcar. Lightning strikes per square kilometre may be low, but thunderstorms are not. We have experienced three in the past month. Metal sticky-up things on higher ground will build up electrical charges and thus initiate upward strikes or preferentially attract downward strikes. Thus average lightning strikes per unit area may not be a suitable metric.
ACK
Pcar. Lightning strikes per square kilometre may be low, but thunderstorms are not. We have experienced three in the past month. Metal sticky-up things on higher ground will build up electrical charges and thus initiate upward strikes or preferentially attract downward strikes. Thus average lightning strikes per unit area may not be a suitable metric.
ACK
@AK, Aug 30, 2016 at 2:03 PM
Several people here have suggested that lightning strikes causing fires are terminal for wind turbines. A simple question then is why doesn't the metal nacelle act as a Faraday Cage for the elctronic innards, and the speed of passage of the current through the nacelle covering prevent overheating of other parts like the gearbox?
Nacelle may act as a Faraday cage. However, it has a large hole containing the metal prop shaft passing through it. This will transmit the strike through the bearings - probably welding some of them creating partial seizures and overheating.
@AK, Aug 30, 2016 at 3:44 PM
Then the question becomes the opposite one - if wind turbines are so susceptible to lightning strikes, why aren't more of them taken out? The article linked indicated that only a tiny percentage of the world's turbines have been destroyed. Commonly placed on high ground and being the tallest objects around, wind turbines should act as the perfect lightning attractors. They themselves should also build up significant charge during thunderstorms.
Lightning strikes per square mile pa are very low in Europe & North America.
How many have you seen where you live?
Pcar
@stewgreen, Aug 30, 2016 at 1:22 PM
But one wonders how it gets to the point, where suddenly vested interests have hijacked charities from inside. Seems the same happned with the COOP, RSPB, RSPCA and BBC.
SSPCA seems to be still sane based on lack of news about them killing animals or launching politically motivated prosecutions.
RNLI & PDSA are my favourite charities.
Imagine if green blob hijacked RNLI - new mission statement:
. "We rescue those on vessels with no engines using our state of the art rowing boats."
Pcar
@SandyS, Aug 30, 2016 at 6:27 AM
I almost purchased a Countach replica with V12 Jag engine at auction, bidding went over my limit.
I passed a burnt out Reliant Robin on way to Uni one morning. From where it was, looked like it overheated waiting at a red light.
All that was left was chassis, engine etc and a large pile of glassfibre covering everything.
Pcar
Re jet fuel:
Thank you for the comments. I have complained to the BBC about Mr McGrath and his ignorant reporting. Incidentally, one of the most important qualities of jet fuel is its freeze point. "High octane" jet fuel is a meaningless concept. When will the BBC employ properly educated reporters rather than green activists?
Mike Post
ACK, perhaps increased costs for insurance, and restrictions on liability, are one of those unforeseen extras, that they did not take out insurance for, and tax payers are not going to cover it either.
It is also possible that Underwriters were badly advised about the risks they were taking on, by the experts in wind turbines, ie the industry.
golf charlie
ACK 4:03 North East Passage and North West Passage
I would love to have a go at a well financed publicity stunt like that. I do respect the crew, and wish them the best of luck, but I do not understand what they achieve if they succeed, and what they will have achieved if they don't.
Europeans, particularly the Brits, have been dying to find the North West Passage navigable for 300 years. The rewards for a short cut to the Pacific and Orient would have been rich. But what convinced them there was a route? Possibly stories about those who had done it before?
The Polar Ocean yacht "Northabout" is 49ft Length Over All, so Length on the Water Line is a bit shorter. Her maximum speed under sail or engine is just over 8 Knots. She is 49ft LOA, because at 50ft, Maritime Law on skippers/crewing/chartering changes for non privately owned boats. She looks sturdy and capable, but is no " lightweight built for speed" racer, so may struggle to cruise at more than 7 knots. Even without an engine, I would prefer to be aboard Northabout than any of Franklins ships, from the survival if it goes wrong angle, and chance of success if it doesn't go wrong.
I really and genuinely wish them luck. The crew and yacht seem capable of the task, ice willing.
Shipping companies and the Canadians got quite excited 10-15 years ago about the financial possibilities, but have now lost interest. Oil companies have given up dreaming of drilling through Arctic water, it is too hard.
golf charlie
9:02 PM Pcar
I too saw the remains of a Reliant (Delboy) van at a set of lights in the 1980s - there was a clear air above it up to about 100ft - then a pillar of smoke (still summer's day). It must have gone off like a firework! - a skeleton and a pile of charred fibre.....