Section 58.25-10 - Main and auxiliary steering gear(a) Vessels accepted by a recognized classification society as meeting class Rules for steering gear, and SOLAS Chapter II-1, Regulations 29 and 30 (incorporated by reference; see § 58.03-1 ) are considered to meet the requirements of this subpart.(b) Power-operated main and auxiliary steering gear must be separate and independent systems. Other arrangements of steering gear will be acceptable if the Commanding Officer, Marine Safety Center determines that they are equivalent to the requirements of this subpart.(c) The main steering gear and rudder stock must be-(1) Of adequate strength for and capable of steering the vessel at maximum ahead service speed, which must be demonstrated to the satisfaction of the cognizant Officer in Charge, Marine Inspection;(2) Capable of moving the rudder from 35° on either side to 35° on the other with the vessel at its deepest loadline draft and running at maximum ahead service speed, and from 35° on either side to 30° on the other in not more than 28 seconds under the same conditions;(3) Operated by power when necessary to comply with paragraph (c)(2) of this section or when the diameter of the rudder stock is over 12 centimeters (4.7 inches) in way of the tiller, excluding strengthening for navigation in ice; and(4) Designed so that they will not be damaged when operating at maximum astern speed; however, this requirement need not be proved by trials at maximum astern speed and maximum rudder angle.(d) The auxiliary steering gear must be- (1) Of adequate strength for and capable of steering the vessel at navigable speed and of being brought speedily into action in an emergency;(2) Capable of moving the rudder from 15° on either side to 15° on the other in not more than 60 seconds with the vessel at its deepest loadline draft and running at one-half maximum ahead service speed or 7 knots, whichever is greater; and(3) Operated by power when necessary to comply with paragraph (d)(2) of this section or when the diameter of the rudder stock is over 23 centimeters (9 inches) in way of the tiller, excluding strengthening for navigation in ice.(e) No auxiliary means of steering is required on a double-ended ferryboat with independent main steering gear fitted at each end of the vessel.(f) When the main steering gear includes two or more identical power units, no auxiliary steering gear need be fitted, if- (1) In a passenger vessel, the main steering gear is capable of moving the rudder as required by paragraph (c)(2) of this section while any one of the power units is not operating;(2) In a cargo vessel, the main steering gear is capable of moving the rudder as required by paragraph (c)(2) of this section while all the power units are operating;(3) In a vessel with an installation completed on or after September 1, 1984, and on an international voyage, and in any other vessel with an installation completed after June 9, 1995, the main steering gear is arranged so that, after a single failure in its piping system (if hydraulic), or in one of the power units, the defect can be isolated so that steering capability can be maintained or speedily regained in less than ten minutes; or(4) In a vessel with an installation completed before September 1, 1986, and on an international voyage, with steering gear not complying with paragraph (f)(3) of this section, the installed steering gear has a proved record of reliability and is in good repair. Note 1 to paragraph (f)(4):
The place where isolation valves join the piping system, as by a flange, constitutes a single-failure point. The valve itself need not constitute a single-failure point if it has a double seal to prevent substantial loss of fluid under pressure. Means to purge air that enters the system as a result of the piping failure must be provided, if necessary, so that steering capability can be maintained or speedily regained in less than ten minutes.
(g) In each vessel of 70,000 gross tons or over, the main steering gear must have two or more identical power units complying with paragraph (f) of this section.