Sparkling Spars - Sail Magazine

Sparkling Spars

Janet Hartman of Beaufort, North Carolina, asks:"Recently I contacted the National Ocean Survey (NOS) to ask whether the authorized clearances for overhead cables shown on their charts include the extra distance needed to avoid arcing. I received an email from nautical.charting@noaa.gov stating 'The ‘authorized clearance’ for an overhead power cable does not include the
Author:
Publish date:

Janet Hartman of Beaufort, North Carolina, asks:

"Recently I contacted the National Ocean Survey (NOS) to ask whether the authorized clearances for overhead cables shown on their charts include the extra distance needed to avoid arcing. I received an email from nautical.charting@noaa.gov stating 'The ‘authorized clearance’ for an overhead power cable does not include the clearance necessary to avoid possible arcing. The clearance indicates the distance between the water level and the cable.'

An electrician friend of mine tells me the distance needed to avoid arcing varies depending on a cable’s voltage. So how can you know how much clearance you need when sailing under a cable? Local politicians tell me that, according to OSHA, a mast must not come within 10 feet of an overhead cable. I wonder whether local bridge tenders might refuse to open up for a sailboat whose mast might come within 10 feet of a cable on the other side of the bridge? I also thought the OSHA restriction applied only to construction and electrical equipment, not to sailboats that are underway. Can you shed any more light on what seems to be a problem with no apparent answer?"

Nigel Calder replies:

Although I hadn’t thought about the problem before you raised it, there’s no question this could be a matter of life or death in certain situations. In practice, of course, most of us don’t push our mast clearances to the limit. As for your local bridge operators, I strongly suspect cables near bridges are insulated, which means they are not an issue.

But high-voltage cables on major pylons in this country can carry up to 750,000 volts and they definitely are not insulated. They are potentially lethal, and I for one will make sure I give them a generous clearance from now on.

Related

Sun-Odyssey-490-Bertrand_DUQUENNE-aft

Boat Review: Jeanneau Sun Odyssey 490

True innovation in monohull sailboat design can be a bit elusive these days. That’s not to say that there are no more new ideas, but it does seem that many new tweaks and introductions are a bit incremental: let’s say evolutionary rather than revolutionary. Just when it seems ...read more

X3M-family

Gear: X3M Flight blocks

Block PartyThe elegance of these new X3M Flight blocks from Ubi Maior conceals the fact that they can handle loads of up to 15 tons. Designed to be used with a variety of textile loops, as fixed or snatch blocks, the X3M blocks have resin frames to carry the loops and anodized ...read more

03-BAVARIA-C34_Interior-2k_2

Ask Sail: The Right Cabin Sole Finish

Q: I am working on refinishing my cabin floorboards. I have brought them home and sanded the old finish off and would appreciate comments on using varnish or polyurethane for the sole.— Danny Love, Grand Rivers, KYDON CASEY REPLIES Polyurethane is the better choice for a cabin ...read more

shutterstock_peterisland

The Caribbean Charter Trade Rides Again

“The BVI is now a bit like it was 20 years ago,” Josie Tucci, vice president of sales and marketing for sister companies Sunsail and The Moorings, told me last December. “Instead of full bars, it may be a guy on the beach with a cooler and a barbeque, but the spirit of the place ...read more

Dragging01

Waterlines: Fear of Dragging

If you have a paranoid personality, anchoring out can be a validating experience. On the one hand, it seems rather simple. You amble up to the bow of your boat, drop a lump of metal overboard, let out some rode and secure it somehow. Then you stroll back to your cockpit and ...read more

TOTW_PromoSite

SAIL's Tip of the Week

Presented by Vetus-Maxwell.Got a tip? Send it to sailmail@sailmagazine.comTake it easy  Looks untidy, huh? Maybe it does, but I’ve hoisted a lot of mainsails over the years. A few go up easily. Many are a struggle. Sometimes it’s about turning blocks and nasty mast-tracks, but ...read more

boot2019

50th Boot Düsseldorf 2019

Do you love water sports? Then come to Germany from January 19 - 27, 2019 and visit boot Düsseldorf, the world's largest water sports trade fair! For the 50th time, more than 250,000 visitors will experience why sailing, diving or surfing is more than just a hobby.©October 2018 ...read more