Railroad - Tank Cars

Specifications within §174.63 encompass portable tanks, IM portable tanks, IBCs, large packagings, cargo tanks, and multi-unit tank car tanks.

A bulk packaging can be transported inside a fully closed transport vehicle or freight container if it is properly secured with a restraint system.

Unless authorized by the FRA or regulations listed in §174.63, you must not transport bulk packaging containing a hazardous material in container-on-flatcar (COFC) or trailer-on-flat-car (TOFC) service. You must not transport a cargo tank or multi-unit tank car containing a hazardous material in COFC or TOFC service unless approved by the FRA. However, in the event of an accident or incident, approval is not required for HAZMAT in TOFC service under the following conditions:

• An emergency need for the cargo tank is needed to mitigate the consequences of an incident.
• The movement of the cargo tank is limited to transportation necessary for emergency purposes.

Tank Car Unloading

Unloading operations must be performed by HAZMAT employees properly trained in unloading hazardous materials. The transloading facility operator must maintain written safety procedures in a location that is easily accessible to HAZMAT employees responsible for transloading operations.

HAZMAT employees involved in unloading must comply with the following rules:

• The handbrake must be applied and one wheel must be blocked to prevent movement in any direction. If multiple tank cars are coupled together, ensure that sufficient handbrakes are set and wheels blocked.
• Access to the track must be secured to prevent entry by other rail equipment.

Caution Signs

Caution signs must be displayed 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 cars are in proper condition for transportation. Caution signs must be:

• Made of metal or other durable material
• Rectangular
• At 30.48 cm (12 inches) high by 38.10 cm (15 inches) wide
• Marked with the word "STOP" in white letters on a blue background, and with letters at least 10.16 cm (4 inches) high

Manhole Covers

Before a manhole cover or outlet valve cap is removed from a tank car, the car must be relieved of all interior pressure by cooling or venting. However, if venting will cause a dangerous amount of vapor to collect outside the car, venting and unloading must be deferred until the pressure is reduced. Seals or other substances must not be thrown into the tank. Procedures for unloading processes after the pressure is released are found in §174.67(b-h).

Attendance

Throughout the entire period of unloading processes and while unloading equipment is attached, the tank car operator must be physically attended by a HAZMAT employee who has an unobstructed view of the unloading operation, or is monitored by a signaling system that meets the provisions in §174.67(i)(2).

Attendance is not required when piping is attached to a top outlet of a tank car equipped with protective housing for discharge of lading under the following conditions:

• Valves are tightly closed.
• The piping is not connected to a hose or other unloading equipment and is fitted with a cap or plug of appropriate material and construction. The piping does not extend more than 15.24 cm (16 in) from outer edge of the protective housing.

In the absence of an unloader, a tank car can stand with unloading connections attached when no product is being transferred under the following conditions:

• The facility operator must designate a HAZMAT employee responsible for on-site monitoring of the transfer facility.
• If a signaling system is used, the system must be capable of alerting the designated HAZMAT employee in the event of an emergency, and provide immediate notification of any monitoring system malfunction. If the monitoring system does not have self-monitoring capability, the designated HAZMAT employee must check it hourly.
• The tank car and facility shutoff valves are secured in the closed position.
• Brakes, wheels, and access to track are in accordance with §174.67(a)(2-3).

As soon as a tank car is unloaded, tighten all valves, whether via bar, wrench, or other suitable tool. Remove the unloading connections, and tighten all other closures. Railroad defect cards must not be removed. In addition, if oil or gasoline has been spilled on the ground around connections, cover with fresh, dry sand or dirt. Keep all tools used in unloading free of oil, dirt, and grit.

Tank car specifications and unloading are found in §174.63 and §174.67.

To learn more about Railroad HAZMAT visit our DOT Railroad HAZMAT Online Training web page.