[Code of Federal Regulations]
[Title 46, Volume 7]
[Revised as of October 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 46CFR173.025]

[Page 159-160]
 
                           TITLE 46--SHIPPING
 
   CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED)
 
PART 173--SPECIAL RULES PERTAINING TO VESSEL USE--Table of Contents
 
                           Subpart B--Lifting
 
Sec. 173.025  Additional intact stability standards: Counterballasted vessels.

    (a) Each vessel equipped to counterballast while lifting must be 
shown by design calculations to be able to withstand the sudden loss of 
the hook load, in each condition of loading and operation and at each 
combination of hook load and crane radius.
    (b) When doing the calculations required by this section, the hook 
load and counterballast heeling arms and vessel righting arms, as 
plotted on graph 173.025, must define areas that satisfy the following 
equation:

Area II  Area I + K

Where--

(1) K=O for operation on protected waters and 7 foot-degrees (2.13 
meter-degrees) for operation on partially protected and exposed waters.
(2) Areas I and II are shown on graph 173.025.

    (c) Each heeling arm curve must be defined by--

HA=HAO cos (T)

Where--

HA=heeling arm.
HAO=heeling arm at 0 degrees of heel.
T=angle of heel.

[[Page 160]]

[GRAPHIC] [TIFF OMITTED] TC01MR91.028

Where--

GZ(1) is the righting arm curve at the displacement corresponding to the 
vessel without hooking load.
GZ(2) is the righting arm curve at the displacement corresponding to the 
vessel with hook load.
HA(1) is the heeling arm curve due to the combined heeling moments of 
the hook load and the counterballast at the displacement with hook load.
HA(2) is the heeling arm due to the counterballast at the displacement 
without hook load.
Theta(c) is the angle of static equilibrium due to the combined hook 
load and counterballast heeling moments.
Theta(f) is the downflooding angle on the counterballasted side of the 
vessel.

[CGD 79-023, 48 FR 51045, Nov. 4, 1983, as amended by CGD 85-080, 61 FR 
945, Jan. 10, 1996]