Conventional Steel (Chapter 9)

Question 1

12. What is steel cutting formula for high carbon or alloy steel?

Answer 1

P = D^2

Question 2

7. What is the conventional steel cutting formula for structural steel members?

Answer 2

P = .375 x AREA OR 3/8 x AREA

I beams, built up girders steel plates, columns, and other structural steel sections

Question 3

11. What are the volumes of unit explosives?

Answer 3

M112: 20
M186: 9
C2 Prima Sheet: 9.96
M1 dynamite: 10
TNT: 21.43

Question 4

15. What is TNT requirement for Rails?

Answer 4

5” or higher use 1lb of TNT

Less than 5” use ½ lb of TNT

Question 5

5. What types of explosives are used for steel cutting?

Answer 5

Plastic and sheet explosives due to their high RE factor, and they can be cut, molded, or shaped to match the angles of the target.

Question 6

6. What is minimum RE factor for steel cutting?

Answer 6

1.0 (TNT) Steel cutting requires high RE explosive to cut precisely .

Question 7

17. What is TNT requirement for frogs?

Answer 7

2 lbs of TNT

Question 8

14. What is charge placement for malleable steel bar that is 3” thick or larger?

Answer 8

Offset the charge. Split the charge in half and place on each side of the target staggered to produce maximum shearing effect

Question 9

1. What is most critical factor for placement when working with a conventional steel charge?

Answer 9

Target to charge contact

Question 10

16. What is TNT requirement for Crossovers and switches?

Answer 10

1 lb of TNT

Question 11

What are the rules for cutting charges for malleable steel, steel bars, rods, chains, and cable up to 2 inches?

Answer 11

Up to 1” diameter = 1 lb of explosive

Between 1” to 2” diameter = 2 lbs of explosive

Over 2” diameter : P=D^2 formula

Question 12

8. What is maximum thickness of steel charge?

Answer 12

No more than 6” thick

Question 13

3. What is the preferred method to cutting hard metals?

Answer 13

Thermite, acetylene, or electrical cutting

Question 14

4. What are the three important factors in steel cutting?

Answer 14

Type, size, and placement of charge

Question 15

9. How to calculate width of steel charge?

Answer 15

Width of charge is 1 to 3 times charge thickness

Question 16

2. What is four types of conventional steel target material?

Answer 16

High-carbon (Very dense, metal working dies)
Alloy (Gears, shafts, less dense than high carbon)
Malleable (Ibeams, RR track)
Cast iron (Pipes, brittle and easily broken)

Question 17

What are three important factors when using the conventional method of steel cutting?

Answer 17

Charge/Target contact
RE factor
Type of steel

Question 18

What does target configuration determine?

Answer 18

The type and amount of explosives necessary.

Target configuration and materials in steel demolitions are more important than with other target materials.

Question 19

What determines the size of a steel cutting charge?

Answer 19

Type and size of steel target

Each configuration requires a unique charge

Question 20

Rules of thumb for placement of charges

Answer 20

Width of charge is between 1-3 times its thickness
Do not use charges more than 6” thick
Direction of initiation is perpendicular to the target

When the charge extends past the flange, split the charge and place it on two sides. Offset the charge the thickness of the web.