[Milsurplus] AC Power on Ships

[Ray Fantini]

Cool, there hulls would dissolve! Sounds like the Philadelphia experiment gone wrong!, Sorry just had to say that. I always assumed DC power was distributed on pre WW2 ships because producing reliable AC in terms of frequency control and transition between two different generators would be a issue with primitive shipboard technology where DC was easy to produce being not generator speed dependant, easy to regulate and had the advantage of using batteries for backup. In the twenties and thirties what electronic devices did you have on a ship? Maybe a radio and a DF set, but by the forties than you had radio, DF , depth finders, radar and many servo systems like master compasses that all work better from AC. Yea, sure you had motor generator sets and dynamotors for small stuff but none of that begins to compare with the reliability of AC distribution and transformers.
Ray Fantini KA3EKH

-----Original Message-----
From: milsurplus-bounces at mailman.qth.net [mailto:milsurplus-bounces at mailman.qth.net] On Behalf Of Richard Brunner
Sent: Monday, October 25, 2010 9:40 AM
To: jfor at quik.com
Cc: milsurplus at mailman.qth.net
Subject: Re: [Milsurplus] AC Power on Ships

One last word on grounded vs ungrounded AC power systems.  For years the
NEC has been pushing grounded systems for, I believe, entirely specious
reasons.  Today you will only see ungrounded systems used where
continuity of service is very important, such as refineries, chemical
factories, cement works, etc.  On a ship grounded is ok until you
connect to shore power, then stray currents go through sea water to the
hull and the hull starts to dissolve.

Richard, AA1P