[Code of Federal Regulations]
[Title 46, Volume 2]
[Revised as of October 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 46CFR62.30-5]

[Page 303-304]
 
                           TITLE 46--SHIPPING
 
   CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED)
 
PART 62_VITAL SYSTEM AUTOMATION--Table of Contents
 
   Subpart 62.30_Reliability and Safety Criteria, All Automated Vital 
                                 Systems
 
Sec. 62.30-5  Independence.

    (a) Single non-concurrent failures in control, alarm, or 
instrumentation systems, and their logical consequences, must not 
prevent sustained or restored operation of any vital system or systems.
    (b)(1) Except as provided in paragraphs (b)(2) and (b)(3) of this 
section, primary control, alternate control, safety control, and alarm 
and instrumentation systems for any vital system must be independent of 
each other.
    (2) Independent sensors are not required except that sensors for 
primary speed, pitch, or direction of rotation control in closed loop 
propulsion control systems must be independent and physically separate 
from required safety control, alarm, or instrumentation sensors.
    (3) The safety trip control of Sec. 62.35--5(b)(2) must be 
independent and physically separate from all other systems.
    (c) Two independent sources of power must be provided for all 
primary control, safety control, instrumentation and alarm systems. 
Failure of the normal source of power must actuate an alarm in the 
machinery spaces. One source must be from the emergency power source 
(see part 112 of this chapter, Emergency Lighting and Power Systems) 
unless one of the sources is--

[[Page 304]]

    (1) Derived from the power supply of the system being controlled or 
monitored;
    (2) A power take-off of that system; of
    (3) An independent power source equivalent to the emergency power 
source.