[Rhodes22-list] The Cat

[Arthur H. Czerwonky]

Robert,
Where would you find the plotting radar ping detector?  Would it cover the normal bandwidths fully?
Art

-----Original Message-----
>From: Robert Skinner <robert at squirrelhaven.com>
>Sent: Sep 18, 2007 10:20 PM
>To: Rhodes 22 mail list <rhodes22-list at rhodes22.org>
>Subject: [Rhodes22-list] The Cat
>
>I'm thinking that a major radar reflector AND plotting 
>radar ping detector might be a damn good idea.  We Maine 
>cruisers now have to deal with a 55 MPH catamaran ferry:
>
>See http://www.catferry.com/the-ship/general-paticulars.php
>
>>From http://www.catferry.com/press-room/press_2006_05_01.php :
>
>"The CAT is a wave-piercing catamaran car and passenger ferry, 
>manufactured by INCAT of Australia. The vessel is 320 feet 
>long, and is powered by four 9,500 horsepower marine diesel 
>engines that drive a water jet propulsion system that could 
>fill an Olympic sized swimming pool in 33 seconds.  The CAT 
>can travel at speeds up to 55 mph, while its trim tab and 
>T-Foil ride control system ensures a comfortable ride for 
>passengers. Constructed of enough high-strength aluminum to 
>produce 32 million beverage cans, The CAT is a technological 
>marvel."
>
>Or from a coastal cruiser's point of view, a HOLY TERROR!
>
>I am considering having a ping detector hooked up with an 
>alarm to wake me if I'm snoozing.  At 55 mph, it is 
>traveling just a bit less than a mile a minute, or 88.5 
>KPH.  So what's the problem?
>
>The straight line of sight distance d in kilometers to the 
>true horizon on earth is approximately
>
>         d = (13 x h) * 0.5
>
>where h is the height in meters of the observer.
>
>Given a radar unit on the Cat 20 meters above waterline, a 
>reflector and/or detector on the top of my sailboat mast 6 
>meters above waterline, and the curvature of the sea 
>surface, I would be visible from a distance of about 25 Km.
>At 88 KPH, that would allow 17 minutes to see my tiny blip 
>and avoid my being sliced in half then ground into lobster 
>bait.
>
>I question the wisdom of expecting a coffee-swilling deck
>hand on night watch to spot my little blip, get permission 
>to take evasive action, and do it in time to save my butt.
>
>So Edith P. better be able to detect the ping, sound an 
>alarm, and plot a constant bearing closing.  Especially if 
>I am (was) hove to for a nap.
>
>Puts me in mind of "Bert & I"'s Bangor Packet story.*
>
>/Robert "What Cat?" Skinner
>
>* http://www.bertandi.net/
>  http://www.bluewaterweb.com/BosunsLocker/Locker.asp?SKU=001015&TopicID=168
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