Appendix A to Part 179 - Procedures for Tank-Head Puncture-Resistance Test
49:3.1.1.1.2.8.1.1.7 : Appendix A
Appendix A to Part 179 - Procedures for Tank-Head
Puncture-Resistance Test
1. This test procedure is designed to verify the integrity of
new or untried tank-head puncture-resistance systems and to test
for system survivability after coupler-to-tank-head impacts at
relative speeds of 29 km/hour (18 mph). Tank-head
puncture-resistance is a function of one or more of the following:
Head thickness, jacket thickness, insulation thickness, and
material of construction.
2. Tank-head puncture-resistance test. A tank-head
puncture-resistance system must be tested under the following
conditions:
a. The ram car used must weigh at least 119,295 kg (263,000
pounds), be equipped with a coupler, and duplicate the condition of
a conventional draft sill including the draft yoke and draft gear.
The coupler must protrude from the end of the ram car so that it is
the leading location of perpendicular contact with the impacted
test car.
b. The impacted test car must be loaded with water at six
percent outage with internal pressure of at least 6.9 Bar (100
psig) and coupled to one or more “backup” cars which have a total
weight of 217,724 kg (480,000 pounds) with hand brakes applied on
the last “backup” car.
c. At least two separate tests must be conducted with the
coupler on the vertical centerline of the ram car. One test must be
conducted with the coupler at a height of 53.3 cm (21 inches),
plus-or-minus 2.5 cm (1 inch), above the top of the sill; the other
test must be conducted with the coupler height at 79 cm (31
inches), plus-or-minus 2.5 cm (1 inch), above the top of the sill.
If the combined thickness of the tank head and any additional
shielding material is less than the combined thickness on the
vertical centerline of the car, a third test must be conducted with
the coupler positioned so as to strike the thinnest point of the
tank head.
3. One of the following test conditions must be applied:
Minimum weight of attached
ram cars in kg (pounds) |
Minimum velocity of impact in
km/hour (mph) |
Restrictions |
119,295
(263,000) |
29 (18) |
One ram car only. |
155,582
(343,000) |
25.5 (16) |
One ram car or one car plus
one rigidly attached car. |
311,164
(686,000) |
22.5 (14) |
One ram car plus one or more
rigidly attached cars. |
4. A test is successful if there is no visible leak from the
standing tank car for at least one hour after impact.
[Amdt. 179-50, 60 FR 49078, Sept. 21, 1995, as amended by Amdt.
179-50, 61 FR 33256, June 26, 1996; 66 FR 45390, Aug. 28, 2001]