PROMOTIONAL STUDY COURSE
Herein is presented a series of definitions, questions and answers designed to aid fire department officers in preparing themselves for promotional examinations. In this department, which appears monthly, will be included questions typical of examinations held throughout the country.
Self-closing Fire Door: A self-closing fire door is a door which is normally kept in a closed position by some mechanical device.
Automatic Fire Door: An automatic fire door is one which is normally kept opened, and is arranged to close when automatically released by the action of heat on a fusible link or in some other approved manner.
Standpipe (Fire Line): An arrangement of vertical pipes with tanks and hose connections at each floor level, allowing a stream of water to flow at an outlet when valve is turned on at that floor.
Risers: The vertical lines of pipe in a standpipe system, to which hose outlets are attached on each floor.
(To be answered in next issue)
- (a) A fire occurs in the basement of a three-story brick building constructed with steel trusses and having gable end walls, and stocked on the upper floors with machinery and merchandise in crates and cases. What part of the building would be most dangerous and require the special attention of the commanding officer?
- (b) Fire has enveloped the entire basement and is spreading up the elevator wells, mushrooming on the upper floors and roof. There is the danger of the floor beams and roof trusses giving away. What precautions should be taken? Explain fully and give your reasons therefor. The open elevator wells are on the center line of the building and one near each end wall.
False and True Questions
(Is each question false or true? Answers in next issue)
- T F—Back-draughts are usually encountered in cases where fires have been smouldering and gases forming for some time.
- T F—Fires which have consumed most of the air within a building frequently continue to give off inflammable gases and thereby create conditions favorable to back-draughts.
- T F—Buildings are sometimes equipped with scuppers (floor drains to the outside of the building) and it is important for the men to see that they are clear of obstructions when overhauling.
- T F—Acid and chemical fumes are always heavier than air and require only floor ventilation.
- T F—Nitric acid fumes, if inhaled for any length of time, may prove fatal.
- T F—Pipes in the plumbing system of buildings are sometimes broken as a means of getting rid of the water after fires.
- T F—The removal of gases usually requires venting at both the top and bottom levels of buildings.
- T F—Steel shutters furnish positive protection against exposure fires.
- T F—Materials and buildings not involved are sometimes wet down as a means of preventing fire through lessening the danger from exposure.
- T F—The friction loss in a line of 3-inch hose with 2 1/2-inch couplings is as great as the loss in a line of 2-inch hose of the same length with 2 1/2-inch couplings because in the former case couplings smaller than the hose break up the smoothly flowing stream of water.
- T F—The net water pressure of a fire engine at work is affected by the length of hose and by the size of the hose and nozzle.
- T F—A 700-gallon pumper can be made to deliver at least its full rated capacity at 120 pounds net pump pressure through two 100foot 2 1/2-inch hose lines siamesed into a one and three-quarters-inch nozzle.
- T F—The stream of water from a chemical tank is much more effective in putting out a fire on a wooden roof than a stream of hydrant water of the same size and velocity.
- T F—If 2 1/2-inch couplings are used with both 3-inch hose and with 2 1/2-inch hose, the advantages of using uniform couplings offsets the disadvantages of the greater friction loss that results from the use of 2)4inch instead of 3-inch couplings in the 3-inch hose.
- T F—A pressure of 60 to 70 pounds at a 2-inch nozzle will throw a stream of water the maximum distance for that nozzle.
- T F—Battered threads on the Siamese of a standpipe make it useless as soon as the water that was in the tank has been used.
- T F—Engine pressure is always equal to nozzle pressure plus friction loss in the hose and at connections.
- T F—A fire engine standing on a street pavement 40 feet above the surface of a river can draw water from the river, if engine has been kept in proper condition, and if it is not more than 200 feet from the river.
- T F—Automatic relief valves are absolutely necessary on pumpers of the centrifugal type.
When backing a line out of a building, the first step usually taken is to …….. the hose just outside of the building.
The pipe of a standpipe system which carries the water up to the various floors is called a ……..
Where a standpipe is to be used for fighting a fire which is spreading, …….. lines are usually stretched by the fire department to supply it.
Radiant heat travels only in …… lines.
Answers to Questions in Previous Issue
- Fire occurs at the hour when the store will be most crowded, namely, 3 o’clock on a Saturday afternoon. The hazards include the crowds, highly inflammable materials in the store, large open areas, and the possibility of panic.
Unless proper action is promptly taken, fire will spread up stairway and elevator shafts (if not properly closed in) to upper floors, and at the same time cutting the people on the upper floors off from escape by means of these channels. There will be extreme danger from loss of life from fire or from panic if fire is permitted to spread. A secondary possibility is the fire extending across the alley at the rear to buildings exposed to fire building.
Immediately upon my arrival and noting the conditions of the fire, I would transmit a call for additional apparatus, sending in second and third alarms at once. In order to delay the spread of the fire I would order members first truck company to go to the roof at once to ventilate, as well as ventilate on the fire floor by opening windows.
If building is equipped with sprinklers, first engine company would be ordered to connect to sprinkler system, and at the same time make sure that the valves controlling the sprinkler pipes in the basement are open. If standpipes are present, second engine would be connected to standpipe and men sent to third floor to connect to standpipe and to operate on fire, in order to keep it away from stairway if such operation would be faster in this particular case than stretching from street. Stores of large areas and of this height usually have several stairways, so that in the event that one stairway is used for department operations, the other stairways can be held for use of occupants in escaping. If elevator shafts are not cjosed in, ventilation can be very effectively produced by opening up over elevator shafts. On the other hand, if they are closed in, it will be necessary to draw the bulk of smoke and heat up one of the stairwells.
Third engine company would be ordered to stretch line from second floor standpipe outlet up stairway to fire floor, or if such a line would obstruct the escape of persons coming down stairs, this line would be stretched from the street up ladders to third floor, to assist line already in operation on this floor in holding the fire from spreading until all persons have gotten out of the building, and additional apparatus is on hand.
Of first concern is the getting of the people in the store to the street. Where such a large number are congregated, it will be a slow process to get them to the street by way of ladders, so that every effort should be devoted toward saving one or more of the stairways and the passenger elevators for the purpose.
As additional engines arrive, lines would be sent up to the fire floor, and floors above by way of ladders to head off fire, and confine it. Lines going to upper floors would operate chiefly around vertical passageways, such as elevator shafts and stairwavs, to prevent fire from getting out on any of the floors above the fire floor. After rescue work has been completed, then attention may be given to exposure across alley at rear, providing the fire in the fire building is being properly covered.
Problem does not state height of buildings on either side of fire building. If such buildings are lower than the fire building, it may be possible to direct some of the people in the fire building to the roofs of adjoining buildings. This would be done in the event that crowds were too great to get to the street by way of stairways, or it there were danger of any being cut off on the upper floors of the department store.
It is believed the foregoing procedure will hold the fire, as well as assure rescue of all persons in the building.
- (1) The usual rule for calculating necessary nozzle pressure, to produce an effective stream when the distance of travel of stream is known, is to allow one pound nozzle pressure for each foot range of stream.
(2) If the horizontal range of stream were to be 100 feet, then 100 pounds pressure would be required at the nozzle.
3. True; 4. True; 5. False; 6. True: 7. True; 8. False; 9. True; 10. False; 11. True; 12. True; 13. True; 14. True: 15. True; 16. True; 17. True: 18. True; 19. True; 20. True; 21. False.
22. . . . gas mask.
23. . . . petroleum . . . vegetable.
24. . . . slow-burning.
25. . . . practically harmless.
26. . . . 1 1/4-inch.