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:
Social count:
0

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

180615-01 Lead

A Dramatic Comeback in the Volvo

After winning three of the last four legs in the Volvo Ocean Race (and coming in second in the fourth), Dutch-flagged Brunel is now tied for first overall with Spanish-flagged Mapfre and Chinese-flagged Dongfeng following the completion of Leg 10 from Cardiff, Wales, to ...read more

MFS-5-2018-Propan-SP02

Tohatsu LPG-powered 5hp Propane Motor

Gassing it UpTired of ethanol-induced fuel issues? Say goodbye to gasoline. Japanese outboard maker Tohatsu has introduced an LPG-powered 5hp kicker that hooks up to a propane tank for hours of stress-free running. Available in short-, long- or ultra-long-shaft versions, the ...read more

TOTW_PromoSite

SAIL's Tip of the Week

Presented by Vetus-Maxwell.Got a tip? Send it to sailmail@sailmagazine.comThink Deeply When chartering, I am always maddened to be told that the echo sounder is calibrated “to depth under the keel, plus a bit for safety.” Such operators seem to imagine that the instrument’s sole ...read more

180612-01 Landing lead

Painful Sailing in Volvo Leg 10

It’s looking to be a case of feast or famine for the 2017-18 Volvo Ocean fleet as it continues the epic struggle that has been Leg 10, with it having been all famine thus far. Painful is the only word to describe the light-air start in Cardiff, Wales, on June 10, as the 11-boat ...read more

01-13_07_180304_JRE_03695_4605

Tips From the Boatyard

Within the Volvo Ocean Race Boatyard sits a communal sail loft which provides service and repairs for all seven teams sailing in the 2017-18 edition of the race. The sail loft employs only five sailmakers who look after 56 sails in each stopover. If you’re thinking, “wow, these ...read more

sailCarwBasicsJuly18

Sail Care for Cruisers

Taking care of your canvas doesn’t just save you money, it’s central to good seamanship  Knowing how to take care of your sails and how to repair them while at sea is an important part of overall seamanship. The last thing any sailor needs is to get caught on a lee shore with ...read more

Ship-container-2048

The Danger of a Collision Offshore

This almost happened to me once. I was sailing singlehanded between Bermuda and St. Martin one fall, and one night happened to be on deck looking around at just the right time. The moon was out, the sky was clear and visibility was good. Still, when I thought I saw a large ...read more

New-MHS-Promo

Multihulls on the Horizon

Fountaine Pajot New 42The French cat powerhouse has been on a roll these last few years, cranking out new models that not only replace their older line but take a step forward in design and user-friendliness. The New 42’s “real” name had not been revealed as we went to press, but ...read more