[Code of Federal Regulations]
[Title 49, Volume 2]
[Revised as of October 1, 2006]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR179.220-8]

[Page 1089]
 
                        TITLE 49--TRANSPORTATION
 
   CHAPTER I--PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, 
                      DEPARTMENT OF TRANSPORTATION
 
PART 179_SPECIFICATIONS FOR TANK CARS--Table of Contents
 
 Subpart D_Specifications for Non-Pressure Tank Car Tanks (Classes DOT-
                            111AW and 115AW)
 
Sec.  179.220-8  Tank heads.

    (a) Tank heads of the inner container, inner container compartments 
and outer shell must be of approved contour, and may be flanged and 
dished or ellipsoidal for pressure on concave side.
    (b) Flanged and dished heads must have main inside radius not 
exceeding 10 feet and inside knuckle radius must be not less than 3\3/4\ 
inches for steel and alloy steel tanks nor less than 5 inches for 
aluminum alloy tanks.
    (c) Ellipsoidal heads must be an ellipsoid of revolution in which 
the major axis must equal the diameter of the shell and the minor axis 
must be one-half the major axis.

[Amdt. 179-9, 36 FR 21341, Nov. 6, 1971]