Document ID: chunk:federal_register_of_legislation:C2004A04507:schedule:2:p21
Version: federal_register_of_legislation:C2004A04507
Segment Type: schedule
Provision Reference: sch 2 (pt 21/26)
Character Range: 74825–77560

tank length. Additional segregated ballast capacity provided for reducing longitudinal hull girder bending stress, trim, etc., may be located anywhere within the ship.

  (e) Suction wells in cargo tanks

    Suction wells in cargo tanks may protrude into the double bottom below the boundary line defined by the distance h provided that such wells are as small as practicable and the distance between the well bottom and bottom shell plating is not less than 0.5 h.

  (f) Ballast and cargo piping

    Ballast piping and other piping such as sounding and vent piping to ballast tanks shall not pass through cargo tanks. Cargo piping and similar piping to cargo tanks shall not pass through ballast tanks. Exemptions to this requirement may be granted for short lengths of piping, provided that they are completely welded or equivalent.

    (4) (a) Double bottom tanks or spaces as required by paragraph (3)(b) may be dispensed with, provided that the design of the tanker is such that the cargo and vapour pressure exerted on the bottom shell plating forming a single boundary between the

SCHEDULE—continued

     cargo and the sea does not exceed the external hydrostatic water pressure, as expressed by the following formula:

     f . hc . ρc . g + 100Δp ≤ dn . ρs . g

     where:

          hc = height of cargo in contact with the bottom shell plating in metres

     ρc = maximum cargo density in t/m3

          dn = minimum operating draught under any expected loading condition in metres

     ρs = density of sea water in t/m3

     ∆p = maximum set pressure of pressure/vacuum valve provided for the cargo tank in bars

     f = safety factor =1.1

     g = standard acceleration of gravity (9.81 m/s2).

    (b)     Any horizontal partition necessary to fulfil the above requirements shall be located at a height of not less than B/6 or 6 metres, whichever is the lesser, but not more than 0.6D, above the baseline where D is the moulded depth amidships.

    (c)     The location of wing tanks or spaces shall be as defined in paragraph (3)(a) except that, below a level 1.5 h above the baseline where h is as defined in paragraph (3)(b), the cargo tank boundary line may be vertical down to the bottom plating, as shown in figure 2.

(5)     Other methods of design and construction of oil tankers may also be accepted as alternatives to the requirements prescribed in paragraph (3), provided that such methods ensure at least the same level of protection against oil pollution in the event of collision or stranding and are approved in principle by the Marine Environment Protection Committee based on guidelines developed by the Organization.

(6)     For oil tankers of 20,000 tons deadweight and above the damage