[Code of Federal Regulations]
[Title 49, Volume 2]
[Revised as of October 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR174.67]

[Page 703-706]
 
                        TITLE 49--TRANSPORTATION
 
   CHAPTER I--PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, 
                      DEPARTMENT OF TRANSPORTATION
 
PART 174_CARRIAGE BY RAIL--Table of Contents
 
           Subpart C_General Handling and Loading Requirements
 
Sec.  174.67  Tank car unloading.

    For transloading operations, the following rules must be observed:
    (a) General requirements. (1) Unloading operations must be performed 
by hazmat employees properly instructed in unloading hazardous materials 
and made responsible for compliance with this section.
    (2) Each hazmat employee who is responsible for unloading must apply 
the handbrake and block at least one wheel to prevent movement in any 
direction. If multiple tank cars are coupled together, sufficient hand 
brakes must be set and wheels blocked to prevent movement in both 
directions.
    (3) Each hazmat employee who is responsible for unloading must 
secure access to the track to prevent entry by

[[Page 704]]

other rail equipment, including motorized service vehicles. This 
requirement may be satisfied by lining each switch providing access to 
the unloading area against movement and securing each switch with an 
effective locking device, or by using derails, portable bumper blocks, 
or other equipment that provides and equivalent level of safety.
    (4) Each hazmat employee who is responsible for unloading must 
display caution signs on the track or on the tank cars to warn persons 
approaching the cars from the open end of the track and must be left up 
until after all closures are secured and the cars are in proper 
condition for transportation. The caution signs must be of metal or 
other durable material, rectangular, at 30.48 cm (12 inches) high by 
38.10 cm (15 inches) wide, and bear the word ``STOP.'' The word ``STOP'' 
must appear in letters at least 10.16 cm (4 inches) high. The letters 
must be white on a blue background. Additional words, such as ``Tank Car 
Connected'' or ``Crew at Work,'' may also appear in white letters under 
the word ``STOP.''
    (5) The transloading facility operator must maintain written safety 
procedures (such as those it may already be required to maintain 
pursuant to the Department of Labor's Occupational Safety and Health 
Administration requirements in 29 CFR 1910.119 and 1910.120) in a 
location where they are immediately available to hazmat employees 
responsible for the transloading operation.
    (6) Before a manhole cover or outlet valve cap is removed form a 
tank car, the car must be relieved of all interior pressure by cooling 
the tank with water or by venting the tank by raising the safety valve 
or opening the dome vent at short intervals. However, if venting to 
relieve pressure will cause a dangerous amount of vapor to collect 
outside the car, venting and unloading must be deferred until the 
pressure is reduced by allowing the car to stand overnight or otherwise 
cooling the contents. These precautions are not necessary when the car 
is equipped with a manhole cover which hinges inward or with an inner 
manhole cover which does not have to be removed to unload the car, and 
when pressure is relieved by piping vapor into a condenser or storage 
tank.
    (b) After the pressure is released, the seal must be broken and the 
manhole cover removed as follows:
    (1) Screw type. The cover must be loosened by placing a bar between 
the manhole cover lug and knob. After two complete turns, so that vent 
openings are exposed, the operation must be stopped, and if there is any 
sound of escaping vapor, the cover must be screwed down tightly and the 
interior pressure relieved as prescribed in paragraph (a)(4) of this 
section, before again attempting to remove the cover.
    (2) Hinged and bolted type. All nuts must be unscrewed one complete 
turn, after which same precautions as prescribed for screw type cover 
must be observed.
    (3) Interior type. All dirt and cinders must be carefully removed 
from around the cover before the yoke is unscrewed.
    (c) When the car is unloaded through a bottom outlet valve, the 
manhole cover must be adjusted as follows:
    (1) Screw type. The cover must be put in place, but not entirely 
screwed down, so that air may enter the tank through the vent holes in 
threaded flange of the cover.
    (2) Hinged and bolted type. A non-metallic block must be placed 
under one edge of the cover.
    (3) Interior type. The screw must be tightened up in the yoke so 
that the cover is brought up within one-half inch of the closed 
position.
    (d) When unloading through the bottom outlet of a car equipped with 
an interior manhole type cover, and in each case where unloading is done 
through the manhole (unless a special cover with a safety vent opening 
and a tight connection for the discharge outlet is used), the manhole 
must be protected by asbestos or metal covers against the entrance of 
sparks or other sources of ignition of vapor, or by being covered and 
surrounded with wet burlap or similar cloth material. The burlap or 
other cloth must be kept damp by the replacement or the application of 
water as needed.
    (e) Seals or other substances must not be thrown into the tank and 
the contents may not be spilled over the car or tank.

[[Page 705]]

    (f) The valve rod handle or control in the dome must be operated 
several times to see that outlet valve in bottom of tank is on its seat 
before valve cap is removed.
    (g) The valve cap, or the reducer when a large outlet is to be used, 
must be removed with a suitable wrench after the set screws are loosened 
and a pail must be placed in position to catch any liquid that may be in 
the outlet chamber. If the valve cap or reducer does not unscrew easily, 
it may be tapped lightly with a mallet or wooden block in an upward 
direction. If leakage shows upon starting the removal, the cap or 
reducer may not be entirely unscrewed. Sufficient threads must be left 
engaged and sufficient time allowed to permit controlled escape of any 
accumulation of liquid in the outlet chamber. If the leakage stops or 
the rate of leakage diminishes materially, the cap or reducer may be 
entirely removed. If the initial rate of leakage continues, further 
efforts must be made to seat the outlet valve (see paragraph (f) of this 
section). If this fails, the cap or reducer must be screwed up tight and 
the tank must be unloaded through the dome. If upon removal of the 
outlet cap the outlet chamber is found to be blocked with frozen liquid 
or any other matter, the cap must be replaced immediately and a careful 
examination must be made to determine whether the outlet casting has 
been cracked. If the obstruction is not frozen liquid, the car must be 
unloaded through the dome. If the obstruction is frozen liquid and no 
crack has been found in the outlet casting, the car may, if 
circumstances require it, be unloaded from the bottom by removing the 
cap and attaching unloading connections immediately. Before opening the 
valve inside the tank car, steam must be applied to the outside of the 
outlet casting or wrap casting with burlap or other rags and hot water 
must be applied to melt the frozen liquid.
    (h) Unloading connections must be securely attached to unloading 
pipes on the dome or to the bottom discharge outlets before any 
discharge valves are opened.
    (i) Throughout the entire period of unloading and while a tank car 
has unloading equipment attached, the facility operator must assure that 
the tank car is:
    (1) Attended by a designated hazmat employee who is physically 
present and who has an unobstructed view of the unloading operation; or
    (2) Monitored by a signaling system (e.g., video system, sensing 
equipment, or mechanical equipment) that is observed by a designated 
hazmat employee located either in the immediate area of the tank car or 
at a remote location within the facility, such as a control room. The 
signaling system must--
    (i) Provide a level of surveillance equivalent to that provided in 
subparagraph (1) of this paragraph (i); and
    (ii) Provide immediate notification to a designated hazmat employee 
of any system malfunction or other emergency so that, if warranted, 
responsive actions may be initiated immediately.
    (j) Attendance is not required when piping is attached to a top 
outlet of a tank car, equipped with a protective housing required under 
Sec.  179.100-12 of this subchapter, for discharge of lading under the 
following conditions:
    (1) All valves are tightly closed.
    (2) The piping is not connected to hose or other unloading equipment 
and is fitted with a cap or plug of appropriate material and 
construction.
    (3) The piping extends no more than 15.24 centimeters (6 inches) 
from the outer edge of the protective housing.
    (k) In the absence of the unloader, a tank car may stand with 
unloading connections attached when no product is being transferred 
under the following conditions:
    (1) The facility operator must designate a hazmat employee 
responsible for on-site monitoring of the transfer facility. The 
designated hazmat employee must be made familiar with the nature and 
properties of the product contained in the tank car; procedures to be 
followed in the event of an emergency; and, in the event of an 
emergency, have the ability and authority to take responsible actions.
    (2) When a signaling system is used in accordance with paragraph (i) 
of this section, the system must be capable of alerting the designated 
hazmat employee in the event of an emergency

[[Page 706]]

and providing immediate notification of any monitoring system 
malfunction. If the monitoring system does not have self-monitoring 
capability, the designated hazmat employee must check the monitoring 
system hourly for proper operation.
    (3) The tank car and facility shutoff valves must be secured in the 
closed position.
    (4) Brakes must be set and wheels locked in accordance with 
paragraph (a)(2) of this section.
    (5) Access to the track must be secured in accordance with paragraph 
(a)(3) of this section.
    (l) As soon as a tank car is completely unloaded, all valves must be 
made tight by the use of a bar, wrench or other suitable tool, the 
unloading connections must be removed and all other closures made tight.
    (m) Railroad defect cards may not be removed.
    (n) If oil or gasoline has been spilled on the ground around 
connections, it must be covered with fresh, dry sand or dirt.
    (o) All tools and implements used in connection with unloading must 
be kept free of oil, dirt, and grit.

[Amdt. 174-26, 41 FR 16092, Apr. 15, 1976, as amended by Amdt. 174-26A, 
41 FR 40685, Sept. 20, 1976; Amdt. 174-43, 48 FR 27699, June 16, 1983; 
Amdt. 174-68, 55 FR 52678, Dec. 21, 1990; 56 FR 66280, Dec. 20, 1991; 
Amdt. 174-81, 60 FR 49111, Sept. 21, 1995; Amdt. 174-83, 61 FR 28678, 
June 5, 1996; 68 FR 61941, Oct. 30, 2003; 70 FR 20034, Apr. 15, 2005; 72 
FR 55693, Oct. 1, 2007]