[Code of Federal Regulations]
[Title 46, Volume 1]
[Revised as of Octobery 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 46CFR38.05-10]

[Page 490-491]
 
                           TITLE 46--SHIPPING
 
         CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY
 
PART 38_LIQUEFIED FLAMMABLE GASES--Table of Contents
 
                  Subpart 38.05_Design and Installation
 
Sec. 38.05-10  Installation of cargo tanks--general--TB/ALL.

    (a)(1) Cargo tanks shall be supported on foundations of steel or 
other suitable material and securely anchored in place to prevent the 
tanks from shifting when subjected to external forces. Each tank shall 
be so supported as to prevent the concentration of excessive loads on 
the supporting portions of the shell or head as prescribed under Sec. 
38.05-2(d).
    (2) Cargo tanks installed in barges shall comply with the 
requirements of Sec. 32.63-25 of this subchapter.
    (b) Foundations, and stays where required, shall be designed for 
support and constraint of the weight of the full tank, and the dynamic 
loads imposed thereon. Thermal movement shall also be considered.
    (c) Foundations and stays which may be exposed to the cargo shall be 
suitable for the temperatures involved and be impervious to the cargo.
    (d) The design of the foundations and stays shall consider the 
resonance of the cargo tank, or parts thereof, and the vibratory forces, 
found in the tank vessel. If necessary, effective damping arrangements 
shall be provided.
    (e) Independent containment systems shall be so arranged as to 
provide a minimum clearance of not less than 24 inches from the vessel's 
side and not less than 15 inches from the vessel's bottom to provide 
access for inspection of the hull. Clearances for collision protection, 
where required by other parts of the regulations in this subchapter, may 
increase the clearances specified here.
    (1) For pressure vessel type tanks the distance between adjacent 
tanks and between tanks and vessel's structure shall be adequate to 
permit access for inspection and maintenance of all tank surfaces and 
hull structure as approved by the Commandant. Alternate provisions may 
be made for inspection and maintenance of the vessel's structure and 
tanks by moving such tanks or by providing equivalent acceptable means 
for remote inspection.
    (2) For nonpressure vessel type containment systems, access shall be 
arranged to permit inspection of one side each of the primary tank and 
secondary barrier, under normal shipyard conditions. Containment systems 
which, because of their peculiar design, cannot be visually inspected to 
this degree, may be specially considered provided an equivalent degree 
of safety is attained.
    (f) Cargo tanks may be installed on deck, under deck, or with the 
tanks protruding through the deck. All tanks shall be installed with the 
manhole openings located in the open above the weather deck. Provided an 
equivalent degree of safety is attained, the Commandant may approve 
cargo tanks installed with manhole openings located below the weather 
deck.
    (g) For pressure vessel type cargo tanks, the following conditions 
apply:
    (1) Liquefied flammable gas cargo tanks may be located in cargo 
tanks or in spaces which meet the requirements for cofferdams as defined 
in Sec. 30.10-13 of this subchapter. When liquefied flammable gas cargo 
tanks are installed in cargo tanks, such cargo tanks may be used 
simultaneously or separately for the carriage of flammable or 
combustible liquids up to and including the grade for which the cargo 
tanks are otherwise certified in accordance with the requirements of 
this subchapter.
    (2) Where the liquefied flammable gas tanks are installed in cargo 
tanks and a portion of the liquefied flammable gas tanks extend above 
the weather deck, the penetration shall be made gastight and watertight, 
and shall be such as to provide full compliance with the structural 
requirements including

[[Page 491]]

testing for the hull and integral tanks. In the application of the 
requirements for the hydrostatic test of the cargo tanks, the 
hydrostatic test shall in no case be less severe than the worst 
anticipated service condition of the cargo loading. In the design and 
testing of independent cargo tanks and integral cargo tanks 
consideration shall be given to the possibility of the independent tanks 
being subjected to external loads.
    (3) Where the liquefied flammable gas tanks are installed in nontank 
hull spaces and a portion of the tank extends above the weather deck, 
provision shall be made to maintain the weathertightness of the deck, 
except that the weathertightness of the upper deck need not be 
maintained on:
    (i) Vessels operating on restricted routes which are sufficiently 
protected; or,
    (ii) Open hopper type barges of acceptable design.
    (h) No strength welding employed in the attachment of supports, 
lugs, fittings, etc., shall be done on tanks that require and have been 
stress relieved, unless authorized by the Commandant.