Conventional Steel (Chapter 9) Flashcards Preview

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

P = D^2


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

P = .375 x AREA OR 3/8 x AREA
(I beams, built up girders steel plates, columns, and other structural steel sections)


11. What are the volumes of unit explosives?

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


15. What is TNT requirement for Rails?

5” or higher use 1lb of TNT
Less than 5” use ½ lb of TNT


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

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.


6. What is minimum RE factor for steel cutting?

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


17. What is TNT requirement for frogs?

2 lbs of TNT


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

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


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

Target to charge contact


16. What is TNT requirement for Crossovers and switches?

1 lb of TNT


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

Up to 1” diameter = 1 lb of explosive

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

Over 2” diameter : P=D^2 formula


8. What is maximum thickness of steel charge?

No more than 6” thick


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

Thermite, acetylene, or electrical cutting


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

Type, size, and placement of charge


9. How to calculate width of steel charge?

Width of charge is 1 to 3 times charge thickness


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

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)


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

Charge/Target contact
RE factor
Type of steel


What does target configuration determine?

The type and amount of explosives necessary.

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


What determines the size of a steel cutting charge?

Type and size of steel target
Each configuration requires a unique charge


Rules of thumb for placement of charges

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.