(1) Cylinders containing compressed gases may be loaded into steel gondola or flat cars or into stock cars, but must not be loaded into hopper bottom cars. (j) Radioactive materials:

(1) Shipments of low specific activity materials, as defined in § 173.389 (c) of this chapter, must be loaded so as to avoid spillage and scattering of loose material. Loading restrictions are prescribed in § 173.392 of this chapter.

(2) Storage and loading restrictions are prescribed in § 174.586 (h).

(3) Containers of radioactive material weighing 15,000 pounds or more may be loaded on flat cars. Gondola cars (drop-bottom cars not authorized) may be used for the following:

(i) Radioactive materials in containers weighing 5,000 pounds or more;

(ii) Strong wooden boxes with inside containers of solid radioactive material, securely braced and cushioned; and

(iii) Radioactive material in concretefilled metal drums or in concrete vaults weighing 700 pounds or more.

(4) Packages must be so blocked and braced that they cannot change position during conditions normally incident to transportation.

(5) Persons should not remain unnecessarily in a car containing radioactive materials.

(k) Nitrates, except ammonium nitrate having organic coating, listed in § 173.182(b) of this chapter must be loaded in clean closed cars, which shall be free of loose boards, cracks, holes, or exposed decayed spots. Interior of cars must be swept clean and be free of any projections capable of injuring bags when so packaged. Doors of cars must have tight closures. Ammonium nitrate or ammonium nitrate fertilizer, having no organic coating, ammonium nitrate mixed fertilizer, or ammonium nitratephosphate, in bulk may be loaded in clean covered hopper cars. Ammonium nitrate having organic coating must be loaded in all-wood box cars, or wooden box cars with steel roofs, or steel box cars with wooden floors and must not be loaded in all-metal cars. Journals and boxes must be in good condition. (See § 174.541(a) (1) and (2).)

(1) Poison gas; class A, by rail freight: Poison gases, class A, may be shipped by, for, or to, the Departments of the Army, Navy, or Air Force of the United States Government, when loaded and handled as follows:

(1) In metal drums, specification ICC 5A (§ 178.81 of this chapter) or WD 5A,1 in box cars, gondola cars, or stock cars (flat bottom) in carload lots.

(2) In tanks, specification ICC 106A (§§ 178.275 or 178.276 of this chapter), mounted on or secured to multi-unit cars or gondola cars (flat bottom) in carload lots only.

(3) In bombs, in box cars or gondola cars (flat bottom) in carload lots only.

(4) In projectiles or ammunition for cannon with gas filled projectiles in box cars in carload or less-than-carload lots.

(5) Gas handlers. Each shipment of one or more carloads, as described in subparagraphs (1), (2), (3), and (4) of this paragraph, shall be accompanied by a crew of qualified gas handlers, supplied with equipment to handle leaks or other container failure, which will permit the escape of gas. Gas handlers will remain with the shipment during the entire time that it is in the custody of the carrier. Gas handlers will, in the event of leakage or escape of gas, make repairs and perform decontamination, if necessary. If they need assistance they will advise the carrier's representative as to the nearest Chemical Warfare Service Depot and aid required.

(6) Loading and bracing in cars. Drums must be loaded in cars having level floors. Cars equipped with metal corrugated ends or cars having bowed ends must be supplied with end wall bulkheads constructed in accordance with requirements for center gates. (See Sketch 1, Bureau of Explosives Pamphlet No. 6.)

(7) Drums must be loaded not more than one tier (layer) high and with filling holes up. They must be loaded as closely together as possible both crosswise and lengthwise and so blocked and braced as to maintain their relative positions during transit.

1 War Department specification container.

(8) Drums with filling holes in heads must be loaded on their bottoms. They may be loaded in rows, lengthwise of the car and any space between the sides of car and the nearest row of drums must be "filled in" with wooden boards or lumber nailed to sides of car sufficient in length and width to contact both hoops of drums, or, drums may be loaded across car in staggered stacks of which the number of drums in alternate stacks is reduced by one drum. All drums in stacks following the first stack loaded in end of car must be placed tightly into the angle of space formed by the sidewalls of the drum in the preceding stack. Any space between the sides of car and the drums in stacks having the greater number of drums, must be "filled in" with wooden boards or lumber nailed to sides of car sufficient in length and width to contact both hoops of drums.

(9) Drums with filling holes in sides must be loaded on their sides with filling holes up. They must be loaded lengthwise of the car in rows and any space between sides of car and the nearest row of drums must be "filled in" with wooden boards or lumber nailed to sides of car sufficient in length and width to contact both hoops of drums.

(10) Drums must be loaded in box car from ends of car toward space between car doors, and there braced by center gates and wedges. (See Sketch 1, Bureau of Explosives Pamphlet No. 6.)

(11) Doorways of box cars must be protected by one of the methods prescribed in Sketch 1, Bureau of Explosives Pamphlet No. 6A.

(12) Tanks must be securely mounted on cars especially provided for them or on gondola cars prepared with substantial wooden frames and blocks.

(13) Bombs, projectiles, and cannon ammunition must be loaded, blocked and braced as shown in Bureau of Explosives Pamphlet 6A. When shipments are loaded in gondola cars they must be securely blocked and braced and not loaded higher than the sides of the car.

(m) Poisonous liquids or solids, class B, must not be transported in the same car with any foodstuffs, feeds, or any other material intended for consumption by humans or animals which are not

packaged in air tight nonpermeable containers.

[29 F.R. 18774, Dec. 29, 1964, as amended by Order 66, 30 F.R. 5747, Apr. 23, 1965; Order 74, 32 F.R. 5275, Mar. 29, 1967; Amdt. 67-1, 32 F.R. 20982, Dec. 29, 1967; Amdt. 174-1, 33 F.R. 14931, Oct. 4, 1968]

§ 174.533 Truck bodies or trailers on flat cars.

(a) Truck bodies or trailers containing explosives, class B, explosives, class C, or other dangerous articles as provided in Parts 171-179 of this chapter must be of such design and so loaded that they will not rupture or become seriously damaged under conditions normally incident to transportation and must be so secured on the flat car that they cannot permanently change position during transit. Packages of explosives and dangerous articles contained therein must be loaded and braced as provided by §§ 174.529, 174.530, and 174.532. Placards must be applied when prescribed by §§ 174.541 and 174.542.

(b) Truck bodies or trailers equipped with automatic heating or refrigerating equipment employing any fuel or article classed as a dangerous article in Parts 171-179 of this chapter may be loaded and transported on flat cars if such equipment is of a type approved by the Bureau of Explosives. They must be so braced and stayed on the flat car that they cannot permanently change position during transit.

(c) A truck body or trailer on which is mounted any cargo tank containing any dangerous article shall not be accepted for transportation or transported except under conditions approved by the Bureau of Explosives.

§ 174.534 Portable containers or tanks.

(a) Portable containers or tanks must be of such design and so loaded and stayed in closed cars, in gondola cars, on flat cars, or in truck bodies or trailers on flat cars so they cannot permanently change position, rupture, or become seriously damaged under conditions normally incident to transportation. Ends, sidewalls, or doors of truck bodies or trailers shall not be relied upon to prevent shifting of portable containers or tanks.