The signal rocket is by far the best-known article of military pyrotechnics. Its importance is due to the fact that it is complete in itself, and may be carried with ease as the firework in its entirety does not weigh over 2 1/2 pounds.

Military signal rocket.

Fig. 1. - Military signal rocket.

The signal rocket consists of a case or carton approximately 12 inches long by 1 1/4 inches inside diameter. This case or rocket body contains the propelling charge which consists of approximately 7 1/2 ounces of powder formed into the case, almost filling it. The propelling charge operates by the rapid burning of the powder, producing a large volume of gas, which on issuing from the bottom of the case causes the rocket to be propelled. The case carries a rocket head, which is a carton shorter than the rocket body and slightly larger in diameter, containing the garniture. This consists of the parachute, attached to which is the signal. Attached to the rocket body is a small cylinder or carton containing a composition which is ignited at the same time as that of the propelling charge. This device is called a smoke tracer, and leaves behind it a trail of smoke that aids the observer in determining from what point the rocket made its flight. Attached to the rocket body by means of a socket is a long stick 5/8 inch square and 6 feet long, which serves as a balance for the upward flight of the rocket. The propelling charge is of such composition and of such weight that it will force the rocket upward in its flight to a height of from 800 to 1,000 feet. The rocket is so designed that when the propelling charge has completed its work and the rocket has reached the desired height a blowing charge is ignited which expels the garniture from the head, throwing the parachute and signal to a distance of about 40 feet.

During this flight the parachute frees itself and opens out, holding suspended the signal.

The signals are so designed that they are ignited by the blowing or expelling charge.

Sectional drawing of signal rocket.

Fig. 2. - Sectional drawing of signal rocket.

Signal Rocket

A. Rocket body:

1. Case.

2. Bottom heading.

3. Driving-charge composition.

4. Top clay heading.

5. Expelling-charge match.

6. Expelling-charge-match prime.

7. Expelling charge.

8. Muslin drumhead.

9. Prime.

10. Stick socket.

11. Stick spring.

12. Stick-socket binder.

13. Assembly band.

14. Match.

15. Match pipe.

16. Match staple.

17. Bottom drumhead.

18. Finishing band.

B. Auxiliary parts:

1. Stick.

2. Stick crate.

3. Directions label.

4. Name label.

5. Match packet.

6. Tearing string.

7. Tearing-string staple.

B. Auxiliary parts - Continued.

8. Wrapping carton.

9. Rocket wrapper.

10. Drumheads.

11. Outside label.

12. Identification Tag.

13. Rocket packing container.

14. Rocket packing case.

15. Ignition-match tie string.

16. Parachute tie string.

17. Extension cord.

18. Asbestos cord.

19. Parachute.

C. Tracer:

1. Shell.

2. Clay headings.

3. Yellow-smoke composition.

4. Match.

5. Match pipe.

6. Wrapper.

D. Rocket head:

1. Case.

2. Wadding.

3. Packing.

4. Cap.

5. Cap band.

6. Muslin head band.

E Yellow-smoke signal:

1. Case.

2. Case ends.

3. First-fire composition.

4. Smoke composition.

5. Match.

6. Match band.

7. Wrapper.

8. Tie strings.

9. Asbestos cord. 10. Parachute.

F. White light:

1. Case.

2. Bottom disk.

3. Muslin disk.

4. Match.

5. First fire.

6. Composition.

F. White light - Continued.

7. Top disk.

8. Muslin wrapper.

9. Wet prime.

10. Ignition match.

G. Red-and-green lights:

1. Case.

2. Bottom disk.

3. Muslin disk.

4. Match.

5. Composition.

6. Top disk.

7. Muslin wrapper.

8. Wet prime.

9. Ignition match.

10. Ignition-match tie string.

11. Parachute tie string.

12. Identification tag.