[Code of Federal Regulations]

[Title 49, Volume 2]

[Revised as of October 1, 2005]

From the U.S. Government Printing Office via GPO Access

[CITE: 49CFR177.840]



[Page 788-792]

 

                        TITLE 49--TRANSPORTATION

 

   CHAPTER I--PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, 

                      DEPARTMENT OF TRANSPORTATION

 

PART 177_CARRIAGE BY PUBLIC HIGHWAY--Table of Contents

 

                     Subpart B_Loading and Unloading

 

Sec. 177.840  Class 2 (gases) materials.



    (See also Sec. 177.834 (a) to (j).)

    (a) Floors or platforms essentially flat. Cylinders containing Class 

2 (gases) materials shall not be loaded onto any part of the floor or 

platform of any motor vehicle which is not essentially flat; cylinders 

containing Class 2 (gases) materials may be loaded onto any motor 

vehicle not having a floor or platform only if such motor vehicle be 

equipped with suitable racks having adequate means for securing such 

cylinders in place therein. Nothing contained in this section shall be 

so construed as to prohibit the loading of such cylinders on any motor 

vehicle having a floor or platform and racks as hereinbefore described.



[[Page 789]]



    (1) Cylinders. Cylinders containing Class 2 gases must be securely 

restrained in an upright or horizontal position, loaded in racks, or 

packed in boxes or crates to prevent the cylinders from being shifted, 

overturned or ejected from the motor vehicle under normal transportation 

conditions. However, after December 31, 2003, a pressure relief device, 

when installed, must be in communication with the vapor space of a 

cylinder containing a Division 2.1 (flammable gas) material.

    (2) Cylinders for hydrogen, cryogenic liquid. A Specification DOT-4L 

cylinder containing hydrogen, cryogenic liquid may only be transported 

on a motor vehicle as follows:

    (i) The vehicle must have an open body equipped with a suitable rack 

or support having a means to hold the cylinder upright when subjected to 

an acceleration of 2 ``g'' in any horizontal direction;

    (ii) The combined total of the hydrogen venting rates, as marked, on 

the cylinders transported on one motor vehicle may not exceed 60 SCF per 

hour;

    (iii) The vehicle may not enter a tunnel; and

    (iv) Highway transportation is limited to private and contract 

carriage and to direct movement from point of origin to destination.

    (b) Portable tank containers containing Class 2 (gases) materials 

shall be loaded on motor vehicles only as follows:

    (1) Onto a flat floor or platform of a motor vehicle.

    (2) Onto a suitable frame of a motor vehicle.

    (3) In either such case, such containers shall be safely and 

securely blocked or held down to prevent shifting relative to each other 

or to the supporting structure when in transit, particularly during 

sudden starts and stops and changes of direction of the vehicle.

    (4) Requirements of paragraphs (1) and (2) of this paragraph (b) 

shall not be construed as prohibiting stacking of containers provided 

the provisions of paragraph (3) of this paragraph (b) are fully complied 

with.

    (c) [Reserved]

    (d) Engine to be stopped in cargo tank motor vehicles, except for 

transfer pump. No Division 2.1 (flammable gas) material shall be loaded 

into or on or unloaded from any cargo tank motor vehicles with the 

engine running unless the engine is used for the operation of the 

transfer pump of the vehicle. Unless the delivery hose is equipped with 

a shut-off valve at its discharge end, the engine of the motor vehicle 

shall be stopped at the finish of such loading or unloading operation 

while the filling or discharge connections are disconnected.

    (e) Chlorine cargo tank motor vehicles shall be shipped only when 

equipped:

    (1) With a gas mask of a type approved by the The National Institute 

of Occupational Safety and Health (NIOSH) Pittsburgh Research Center, 

U.S. Department of Health and Human Services for chlorine service; and

    (2) With an emergency kit for controlling leaks in fittings on the 

dome cover plate.

    (f) A cargo tank motor vehicle used for transportation of chlorine 

may not be moved, coupled or uncoupled, when any loading or unloading 

connections are attached to the vehicle, nor may it be left without the 

power unit attached unless the vehicle is chocked or equivalent means 

are provided to prevent motion. For additional requirements, see Sec. 

173.315(o) of this subchapter.

    (g) Each liquid discharge valve on a cargo tank motor vehicle, other 

than an engine fuel line valve, must be closed during transportation 

except during loading and unloading.

    (h) The driver of a motor vehicle transporting a Division 2.1 

(flammable gas) material that is a cryogenic liquid in a package 

exceeding 450 L (119 gallons) of water capacity shall avoid unnecessary 

delays during transportation. If unforeseen conditions cause an 

excessive pressure rise, the driver shall manually vent the tank at a 

remote and safe location. For each shipment, the driver shall make a 

written record of the cargo tank pressure and ambient (outside) 

temperature:

    (1) At the start of each trip,

    (2) Immediately before and after any manual venting,

    (3) At least once every five hours, and

    (4) At the destination point.



[[Page 790]]



    (i) No person may transport a Division 2.1 (flammable gas) material 

that is a cryogenic liquid in a cargo tank motor vehicle unless the 

pressure of the lading is equal to or less than that used to determine 

the marked rated holding time (MRHT) and the one-way travel time (OWTT), 

marked on the cargo tank in conformance with Sec. 173.318(g) of this 

subchapter, is equal to or greater than the elapsed time between the 

start and termination of travel. This prohibition does not apply if, 

prior to expiration of the OWTT, the cargo tank is brought to full 

equilibration as specified in paragraph (j) of this section.

    (j) Full equilibration of a cargo tank transporting a Division 2.1 

(flammable gas) material that is a cryogenic liquid may only be done at 

a facility that loads or unloads a Division 2.1 (flammable gas) material 

that is a cryogenic liquid and must be performed and verified as 

follows:

    (1) The temperature and pressure of the liquid must be reduced by a 

manually controlled release of vapor; and

    (2) The pressure in the cargo tank must be measured at least ten 

minutes after the manual release is terminated.

    (k) A carrier of carbon monoxide, cryogenic liquid must provide each 

driver with a self-contained air breathing apparatus that is approved by 

the National Institute of Occupational Safety and Health; for example, 

Mine Safety Appliance Co., Model 401, catalog number 461704.

    (l) Operating procedure. Each operator of a cargo tank motor vehicle 

that is subject to the emergency discharge control requirements in Sec. 

173.315(n) of this subchapter must carry on or within the cargo tank 

motor vehicle written emergency discharge control procedures for all 

delivery operations. The procedures must describe the cargo tank motor 

vehicle's emergency discharge control features and, for a passive shut-

down capability, the parameters within which they are designed to 

function. The procedures must describe the process to be followed if a 

facility-provided hose is used for unloading when the cargo tank motor 

vehicle has a specially equipped delivery hose assembly to meet the 

requirements of Sec. 173.315(n)(2) of this subchapter.

    (m) Cargo tank motor vehicle safety check. Before unloading from a 

cargo tank motor vehicle containing a liquefied compressed gas, the 

qualified person performing the function must check those components of 

the discharge system, including delivery hose assemblies and piping, 

that are readily observed during the normal course of unloading to 

assure that they are of sound quality, without obvious defects 

detectable through visual observation and audio awareness, and that 

connections are secure. This check must be made after the pressure in 

the discharge system has reached at least equilibrium with the pressure 

in the cargo tank. Operators need not use instruments or take 

extraordinary actions to check components not readily visible. No 

operator may unload liquefied compressed gases from a cargo tank motor 

vehicle with a delivery hose assembly found to have any condition 

identified in Sec. 180.416(g)(1) of this subchapter or with piping 

systems found to have any condition identified in Sec. 180.416(g)(2) of 

this subchapter.

    (n) Emergency shut down. If there is an unintentional release of 

product to the environment during unloading of a liquefied compressed 

gas, the qualified person unloading the cargo tank motor vehicle must 

promptly shut the internal self-closing stop valve or other primary 

means of closure and shut down all motive and auxiliary power equipment.

    (o) Daily test of off-truck remote shut-off activation device. For a 

cargo tank motor vehicle equipped with an off-truck remote means to 

close the internal self-closing stop valve and shut off all motive and 

auxiliary power equipment, an operator must successfully test the 

activation device within 18 hours prior to the first delivery of each 

day. For a wireless transmitter/receiver, the person conducting the test 

must be at least 45.72 m (150 feet) from the cargo tank and may have the 

cargo tank in his line of sight.

    (p) Unloading procedures for liquefied petroleum gas and anhydrous 

ammonia in metered delivery service. An operator must use the following 

procedures for unloading liquefied petroleum gas or anhydrous ammonia 

from a cargo tank



[[Page 791]]



motor vehicle in metered delivery service:

    (1) For a cargo tank with a capacity of 13,247.5 L (3,500 water 

gallons) or less, excluding delivery hose and piping, the qualified 

person attending the unloading operation must remain within 45.72 meters 

(150 feet) of the cargo tank and 7.62 meters (25 feet) of the delivery 

hose and must observe both the cargo tank and the receiving container at 

least once every five minutes when the internal self-closing stop valve 

is open during unloading operations that take more than five minutes to 

complete.

    (2) For a cargo tank with a capacity greater than 13,247.5 L (3,500 

water gallons), excluding delivery hose and piping, the qualified person 

attending the unloading operation must remain within 45.72 m (150 feet) 

of the cargo tank and 7.62 m (25 feet) of the delivery hose when the 

internal self-closing stop valve is open.

    (i) Except as provided in paragraph (p)(2)(ii) of this section, the 

qualified person attending the unloading operation must have an 

unobstructed view of the cargo tank and delivery hose to the maximum 

extent practicable, except during short periods when it is necessary to 

activate controls or monitor the receiving container.

    (ii) For deliveries where the qualified person attending the 

unloading operation cannot maintain an unobstructed view of the cargo 

tank, when the internal self-closing stop valve is open, the qualified 

person must observe both the cargo tank and the receiving container at 

least once every five minutes during unloading operations that take more 

than five minutes to complete. In addition, by the compliance dates 

specified in Sec. Sec. 173.315(n)(5) and 180.405(m)(3) of this 

subchapter, the cargo tank motor vehicle must have an emergency 

discharge control capability that meets the requirements of Sec. 

173.315(n)(2) or Sec. 173.315(n)(4) of this subchapter.

    (q) Unloading procedures for liquefied petroleum gas and anhydrous 

ammonia in other than metered delivery service. An operator must use the 

following procedures for unloading liquefied petroleum gas or anhydrous 

ammonia from a cargo tank motor vehicle in other than metered delivery 

service:

    (1) The qualified person attending the unloading operation must 

remain within 7.62 m (25 feet) of the cargo tank when the internal self-

closing stop valve is open.

    (2) The qualified person attending the unloading operation must have 

an unobstructed view of the cargo tank and delivery hose to the maximum 

extent practicable, except during short periods when it is necessary to 

activate controls or monitor the receiving container.

    (r) Unloading using facility-provided hoses. A cargo tank motor 

vehicle equipped with a specially designed delivery hose assembly to 

meet the requirements of Sec. 173.315(n)(2) of this subchapter may be 

unloaded using a delivery hose assembly provided by the receiving 

facility under the following conditions:

    (1) The qualified person monitoring unloading must visually examine 

the facility hose assembly for obvious defects prior to its use in the 

unloading operation.

    (2) The qualified person monitoring unloading must remain within 

arm's reach of the mechanical means of closure for the internal self-

closing stop valve when the internal self-closing stop valve is open 

except for short periods when it is necessary to activate controls or 

monitor the receiving container. For chlorine cargo tank motor vehicles, 

the qualified person must remain within arm's reach of a means to stop 

the flow of product except for short periods when it is necessary to 

activate controls or monitor the receiving container.

    (3) If the facility hose is equipped with a passive means to shut 

off the flow of product that conforms to and is maintained to the 

performance standard in Sec. 173.315(n)(2) of this subchapter, the 

qualified person may attend the unloading operation in accordance with 

the attendance requirements prescribed for the material being unloaded 

in Sec. 177.834 of this section.

    (s) Off-truck remote shut-off activation device. For a cargo tank 

motor vehicle with an off-truck remote control shut-off capability as 

required by Sec. Sec. 173.315(n)(3) or (n)(4) of this subchapter, the 

qualified person attending the unloading operation must be in



[[Page 792]]



possession of the activation device at all times during the unloading 

process. This requirement does not apply if the activation device is 

part of a system that will shut off the unloading operation without 

human intervention in the event of a leak or separation in the hose.

    (t) Unloading without appropriate emergency discharge control 

equipment. Until a cargo tank motor vehicle is equipped with emergency 

discharge control equipment in conformance with Sec. Sec. 173.315(n)(2) 

and 180.405(m)(1) of this subchapter, the qualified person attending the 

unloading operation must remain within arm's reach of a means to close 

the internal self-closing stop valve when the internal self-closing stop 

valve is open except during short periods when the qualified person must 

activate controls or monitor the receiving container. For chlorine cargo 

tank motor vehicles unloaded after December 31, 1999, the qualified 

person must remain within arm's reach of a means to stop the flow of 

product except for short periods when it is necessary to activate 

controls or monitor the receiving container.

    (u) Unloading of chlorine cargo tank motor vehicles. After July 1, 

2001, unloading of chlorine from a cargo tank motor vehicle must be 

performed in compliance with Section 3 of the Chlorine Institute 

Pamphlet 57, ``Emergency Shut-off Systems for Bulk Transfer of 

Chlorine'' (IBR, see Sec. 171.7 of this subchapter).



(Approved by the Office of Management and Budget under control number 

2137-0542)



[29 FR 18795, Dec. 29, 1964. Redesignated at 32 FR 5606, Apr. 5, 1967]



    Editorial Note: For Federal Register citations affecting Sec. 

177.840, see the List of CFR Sections Affected which appears in the 

Finding Aids section of the printed volume and on GPO Access.