Coast Guard Conducts Tests on Engine Room Fires—Part III

Coast Guard Conducts Tests on Engine Room Fires—Part III

Carbon Dioxide and Fog Employed in Instructive Series of Demonstrations; Some Observations

THIS is the third installment of an article describing fire extinguishing tests made on the Liberty Ship, “Gaspar de Portola” at Fort McHenry, Md., by the Coast Guard under direction of Commander Lloyd Layman.

The first two installments, which appeared in the February and March issues, reviewed the scope and purpose of the tests, and outlined the procedure followed; they also included reports of the first six tests. The article resumes the review of individual tests.

Test No. 7

1. TIME—

On 29 November, 1944.

1. PURPOSES—
2. To investigate further the techniques and methods developed during previous test fires for extinguishing a major fire involving fuel oil under the floor plates by the control of air flows and the use of low velocity water fog applied from the upper level at one point only.
1. CONDITIONS BEFORE TEST—
2. The machinery space remained the same as reported after Test Fire No. 6 conducted on 13 November, 1944 with the following exceptions:
1. Five hundred gallons of Navy Special fuel oil were added to the 4,500 gallons of fuel oil remaining after Test Fire No. 6 (at the start of Test Fire No. 6 the fuel oil consisted of a mixture of 3,800 gallons of bunker “A” fuel oil and 1,200 gallons of Navy Special fuel oil). Due to the starboard list, approximately ten thousand gallons of water were allowed to remain in the bilge in order to obtain maximum oil coverage without raising the oil above the floor plates. This brought the oil level to within two inches of the floor plates on the starboard side. Oil coverage of the bilge was obtained with the exception of about one hundred and fifty square feet at the forward port corner. This volume of oil provided an oil depth of approximately five inches.
2. An asbestos cloth curtain, with small brass hooks along the upper edge, was provided for attachment to the grilled opening between the Engineer’s Storeroom and the second deck port side passage. This curtain was placed over the grill when the covering of air intake openings was started. The curtain is underwriter’s grade cloth, 95% asbestos, 40 by 46 inches in size. During Test Fire No. 6, this grilled opening was closed with an asbestos board previous to start of test.
3. Two 2 1/2 inch hose lines were laid from a 500 gallon skid pump unit, located on the pier, to the main deck to supply the 1 1/2 inch working lines. One 1 1/2 inch line equipped with a 2 1/2 inch low velocity fog head was laid to the port side of the skylight house on the boat deck. A similar line equipped with a 1 1/2 inch low velocity fog head was laid to the starboard side of the skylight house on the boat deck. Two 1 1/2 inch hose lines equipped with all-purpose nozzles were laid to the forward escape hatch of the shaft tunnel. Additional 1 1/2 inch lines equipped with all-purpose nozzles were located at various strategic points on the bridge and top decks for use in cooling the exterior of the ventilators, if necessary, before covering. From another 500 gallon skid pump unit, located on the pier, a 2 1/2 inch line was laid to a twin twenty-five gallon mechanical foam pressure proportioner also located on the pier. From the proportioner a 2 1/2 inch line was laid to the main deck to supply two 1 1/2 inch hose lines equipped with mechanical foam nozzles.
4. An electronic pyrometer was used to obtain the degree of heat at levels from three feet above the floor plates up to one foot down from the top of the stack and at all overheads within the space. Reference is made under Test Record to the termocouple terminals at the locations given below:

official U. S. Coast Guard Photos

No. 4—Projecting downward one foot into machinery space from galley deck, directly over engine.

No. 5—Projecting downward one foot into machinery space from carbon dioxide compartment, port side second deck, four feet forward of storeroom and workshop bulkhead and six feet inboard from port shell plating.

No. 14—Six inches below ridge and five feet aft of forward bulkhead of the skylight house.

No. 15—Three feet above floor plates and ten feet forward of shaft tunnel entrance.

No. 16—Projecting ten feet into machinery space from mid-point of forward bulkhead, three feet above floor plates.

1. TEST RECORD—
2. At 1420, the oil in the machinery space was ignited at six different locations after priming with gasoline. Smoke banked down quickly from the overhead forcing the priming parties to withdraw from the machinery space by way of the shaft tunnel immediately following ignition of the oil.
3. From the topside, it was noted that almost immediately after ignition smoke started to come from the stack casing, the open skylights, and the forward port main ventilator. During the following twenty minutes the smoke coining from these openings was very black and in large volume.
4. At 1442, the smoke coming from the stack casing changed to very dark gray in color. At this time the average temperature within the machinery space was 447° F. The highest temperature was 653° F. at thermocouple No. 4 and the lowest temperature 173° F. at thermocouple No. 14.
5. At 1500, forty minutes after start of test, covering of air intake openings was started. The smoke coming from the stack casing at this time was very dark gray with some dark brown smoke present. The average temperature within the space was 649° F. The highest temperature was 925° F. at thermocouple No. 4 and the lowest temperature 460° F. at thermocouple No. 16. Note: A hatch tarpaulin was used to cover the entire sky light housing including the two small ventilators. Specially designed oval canvas covers were used to cover the six main ventilators. Water fog was used to cool some of the ventilators and the skylight housing.
6. At 1509, forty-nine minutes after start of test, the covering of all air intake openings was completed. The average temperature within the space was 567° F. The highest temperature was 700° F. at thermocouple No. 4 and the lowest temperature 175° F. at thermocouple No. 14. During the covering operation, the emitting smoke constantly diminished in volume and changed to light gray and light brown in color.
7. At 1512, fifty-two minutes after start of test, a 1 1/2 inch hose line equipped with a 2 1/2 inch low velocity fog head was inserted under the canvas hatch tarpaulin, used to cover the skylight house, into an open skylight on the port side. The hose line was lowered approximately 15 feet and low velocityfog applied at this point. A similar line equipped with a 1 1/2 inch low velocity fog head was inserted into an open skylight on the starboard side and lowered approximately 15 feet down into machinery space. At this time the average temperature within the space was 551° F. The highest temperature was 682° F. at thermocouple No. 4 and the lowest was 145° F. at thermocouple No. 14.
8. At 1517, five minutes after start of the application of water fog, the average temperature within the space was 424° F. The highest temperature was 525° F. at thermocouple No. 5 and the lowest temperature was 210° F. at thermocouple No. 15. A very small amount of smoke with considerable steam apparent was emitting from the stack casing.
9. At 1522, ten minutes after start of the application of water fog, the average temperature within the space was 347° F. The highest temperature was 435° F. at thermocouple No. 5 and the lowest temperature was 157° F. at thermocouple No. 15.
10. At 1527, fifteen minutes after start of the application of water fog the average temperature within the space was 321° F. The highest temperature was 385° F. at thermocouple No. 5 and the lowest temperature was 140° F. at thermocouple No. 15. At this time a verysmall amount of steam was emitting from the stack casing.
11. At 1532, twenty minutes after start ot application of water fog, the average temperature within the space was 269° F. The highest temperature was 345° F. at thermocouple No. 5 and the lowest was 123° F. at thermocouple No. 15.
12. At 1537, twenty-five minutes after start of application of water fog, the average temperature within the space was 242° F. The highest temperature was 312° F. at thermocouple No. 5 and the lowest was 112° F. at thermocouple No. 15. At this time an extremely small amount of steam was emitting from the stack casing.
13. At 1542, thirty minutes after start of application of water fog, the average temperature within the space was 221° F. The highest temperature was 285° F. at thermocouple No. 5 and the lowest was 103° F. at thermocouple No. 15.
14. At 1547, thirty-five minutes after start of the application of water fog, the average temperature was 204° F. The highest temperature was 263° F. at thermocouple No. 5 and the lowest was 95° F. at thermocouple No. 15. At this time an extremely small amount of light vapors were coming from the stack casing.
15. At 1551, one hour and thirty-one minutes after start of test and thirtynine minutes after start of the application of water fog, entry to the machinery space was made by way of the door from the shaft tunnel. The fire fighting party was able to proceed in an upright position to any point at the floor level without physical discomfort. It was found that the only burning was in a small amount of class “A” material (wooden bench, wooden bulletin board, and wooden floor covering on electrical equipment platform). This fire was extinguished with a small amount of water from one 1 1/2 inch line equipped with an all-purpose nozzle.
16. At 1556, the application of water fog at the skylights was stopped and during the following two minutes the covers were removed from the skylights and all main ventilators. An inspection party entered the machinery space by the main door and proceeded down the ladders to the floor plate level. The inspection party experienced no more discomfort than would have been experienced in the machinery space under normal operating conditions.
17. Heat indicating lacquer showed that the following temperatures were reached:
1. On the aft bulkhead of No. 3 hold, a temperature of at least 300° F. was reached at all locations and a temperature of 500° F. was reached at some locations. None of the spots painted on the forward surface (15 inches from bulkhead) of a vertical “1” beam bulkhead stiffener reached 175° F.

Official U. S. Coast Guard Photo

1. In the No. 3 ’tween deck section, spots painted on the deck one inch from the aft bulkhead and on the bulkhead one inch above the deck reached 175° F. at the mid-point and on the port side. Spots painted on the bulkhead five feet above the deck did not reach 175° F.
2. In the No. 4 ’tween deck section, spots painted on the deck one inch from the forward bulkhead did not reach 175° F. on the port side and reached 250° F. at the mid-point and on the starboard side. Spots painted on the bulkhead at points one inch above the deck and five feet above the deck reached 300° F. at some locations.

1. The volume of water used during the test was estimated at approximately, 7,392 gallons.
2. Twelve hundred and ten temperature readings were recorded during this test.

1. CONDITIONS AFTER TEST-
2. The machinery space was in practically the same condition as reported after Test Fire No. 6 conducted on 13 November, 1944 with the following changes:
1. All surfaces coated with carbon except in lubricating oil tank area and where washed clean by water fog.
2. Additional warping of floor plates.

Wooden bench top and bulletin board in lubricating oil tank area partially consumed by fire.

1. It was estimated by measurement before and after test, that not more than 750 gallons of oil were consumed during the test.

1. TENTATIVE CONCLUSIONS°
2. A major fire involving fuel oil under the floor plates can be extinguished by the control of air flows and the use of low velocity water fog applied from the upper level at one point only.
3. An asbestos curtain, underwriter’s grade cloth, fitted with small brass hooks along the upper edge can be used to close the opening between the Engineer’s Storeroom and the Second deck port side passage.

Test No. 8

1. Time—December 1944.
2. PURPOSES°
3. The primary purpose: to investigate further the techniques and method? developed during previous test fires for extinguishing a major fire involving fuel oil under the floor plates by the control of air flows and the use of low velocity water fog applied from the upper level at one point only.
4. Secondary purposes were as follows:
1. To determine if a uniform cooling of the oil is effected durng the process of extinguishment.
2. To determine if sufficient volume of fuel oil vapors are present within the space, upon completion of extinguishment, to constitute a hazard.

1. CONDITIONS BEFORE TEST°
2. The machinery space remained the same as reported after Test Fire No. 7 conducted 29 November, 1944, with the following exceptions:

Official U. S. Coast Guard Photo

1. One thousand gallons of Navy Special fuel oil were added to the 4,500 gallon’s of fuel oil remaining after Test Fire No. 7. Due to the starboard list, approximately ten thousand gallons of water were allowed to remain in the bilge in order to obtain maximum oil coverage without raising the oil above the floor plates. This brought the oil level to within two inches of the floor plates on the starboard side. Oil coverage was obtained with the exception of one hundred and fifty square feet at the forward port corner. This volume of oil provided an oil depth of approximately five and one quarter inches.

1. Two 2 1/2 inch hose lines were laid from a 500 gallon skid pump unit located on the pier, to the main deck to supply the 1 1/2 inch working lines. One 1 1/2 inch line equipped with a 1 1/2 inch straight applicator and a 2 1/2 inch low velocity fog head was laid to the port side of the skylight house on the boat deck. Additional 1 1/2 inch lines equipped with all-purpose nozzles were located at various strategic points on the boat and too decks for use in cooling the exterior of the ventilators, if necessary, before covering. From another 500 gallon skid pump unit, located on the pier, a 2 1/2 inch line was laid to a twin twenty-five gallon mechanical foam pressure proportioner also located on the pier. From the proportioner a 2 1/2 inch line was laid to the main deck to supply two 1 1/2 inch hose lines equipped with mechanical foam nozzles.
2. An electronic pyrometer was used to determine the degree of heat at levels from three feet above the floor plates up to one foot down from the top of the stack and at all overheads within the space. Reference is made under Test Record to the thermocouple terminals at the locations given below:

No. 2—Projecting downward one foot into machinery space from second deck starboard side passage, sixteen feet aft of torward machinery space bulkhead and fourteen feet inboard from starboard shell plating.

No. 4—Projecting downward one foot into the machinery space from the galley deck, directly over engine.

No. 5—Projecting downward one foot into machinery space from carbon dioxide compartment, port side second deck, four feet forward of storeroom and workshop bulkhead and six feet inboard from port shell plating.

No. 6—Projecting downward one foot into machinery space from second deck, above electrical equipment platform, five feet forward of aft machinery space bulkhead and seven feet inboard from starboard shell plating.

No. 14—Six inches below ridge and five feet aft of forward bulkhead of the skylight house.

No. 15—Three feet above floor plates and ten feet forward of shaft tunnel entrance.

No. 16—Projecting ten feet into the machinery space from the mid-point of the forward bulkhead, three feet above floor plates.

1. TEST RECORD°
2. At 1410, the oil in the machinery space was ignited at nine different locations after priming with gasoline. Smoke backed down quickly from the overhead forcing the priming parties to withdraw from the machinery space by way of the shaft tunnel immediately following ignition of the oil.
3. From the topside, it was noted that almost immediately after ignition smoke started to come from the stack rasing, the open skylights, and the forward port main ventilator. During the following twelve minutes the smoke coming from these openings was very black and in large volume.

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(Continued from page 243)

1. At 1423, the smoke coming from the stack casing changed to very dark gray in color. At this time the average temperature within the machinery space was 383°F. The highest temperature was 620° F. at thermocouple No. 2 and the lowest was 183° F. at thermocouple No. 15.
2. At 1440, thirty minutes after start of test, covering of air intake openings was started. The smoke coming from the stack casing was very dark gray in color. The average temperature within the space was 669°F. The highest temperature was 965°F. at thermocouple No. 4 and the lowest was 455°F. at thermocouple No. 16. Note: A hatch tarpaulin was used to cover the entire skylight housing including the two small ventilators. Specially designed oval canvas covers were used to cover the six main ventilators. Water fog was used to cool some of the ventilators and the skylight housing. An asbestos cloth curtain, with small brass hooks along the upper edge, was used to cover the _____rilled opening between the Engineer’s Storeroom and the second deck port side passage.
3. At 1446, thirty-six minutes after start of test, the covering of all air intake openings was completed. The average temperature within the space w’as 599°F. The highest temperature was 790°F. at thermocouple No. 4 and the lowest was 250°F. at thermocouple No. 14. During the covering operation, the emitting smoke constantly diminished in volume and changed to light gray and light brown in color.
4. At 1448, thirty-eight minutes after start of test, a 1 1/2 inch hose line equipped with 1 1/2 inch straight applicator and a 2 1/2 inch low velocity fog head was inserted under the canvas hatch tarpaulin, used to cover the skylight house, into an open skylight on the port side. The hose was lowered approximately 15 feet and low velocity fog applied at this point. At this time the average temperature within the space was 588°F. The highest temperature was 823° F. at thermocouple No. 4 and the lowest was 235°F. at thermocounle No. 14.
5. At 1453, five minutes after start of application of water fog, the average temperature within the space was 452°F. The highest temperature was 565°F. at thermocouple No. 5 and the lowest was 238°F. at thermocouple No. 14. A small amount of smoke, with steam apparent, was emitting from the stack casing.
6. At 1458, ten minutes after start of application of water fog, the average temperature within the space was 363°F. The highest temperature was 470°F. at thermocouple No. 5 and the lowest was 160° F. at thermocouple No. 15.
7. At 1553, fifteen minutes after start of application of water fog, the average temperature within the space was 311°F. The highest temperature was 407°F. at thermocouple No. 5 and the lowest was 135°F. at thermocouple No. 15. A very small amount of steam and light gray and light brown smoke was emitting from the stack casing.
8. At 1508, twenty minutes after start of application of water fog, the average temperature within the space was 286°F. The highest temperature was 393°F. at thermocouple No. 6 and the lowest was 125°F. at thermocouple No. 15.
9. At 1513, twenty-five minutes after start of application of water fog, the average temperature within the space was 249° F. The highest temperature was 330°F. at thermocouple No. 5 and the lowest was 113°F. at thermocouple No. 15. At this time an extremely small amount of steam and light gray and light brown smoke was emitting from the stack casing.
10. At 1521, thirty-three minutes after start of application of water fog. the average temperature within the space was 213°F. The highest temperature was 287°F. at thermocouple No. 5 and the lowest was 100° F. at thermocouple No. 15. Application of water fog stonned.
11. At 1522, one hour and twelve minutes after start of test, an inspection party entered the machinery space by way of the shaft tunnel and was able to proceed in an upright position to any point at the floor plate level without physical discomfort. It was found the only burning was in a small amount of class “A” material (wooden bench and bulletin board). This was extinguished with a small amount of water from one 1 1/2-inch all-purpose nozzle.
12. At 1522, an Explosimeter was used to determine the presence of oil vapors within the space. Tests for vapors were made at various locations within the space at a level of one inch above the surface of the oil. There was no indication of vapors being present at any point.
13. At 1522, temperature readings of the oil were taken at the following locations:
1. One foot from the aft bulkhead, on the starboard side, the temperature was 120°F. at a point one-half inch below the surface and 110°F. at two inches below the surface.
2. One foot from the forward bulkhead, amidships, the temperature was 170°F. at a point one-half inch below the surface and 128°F. at two inches below the surface.
14. At 1528, and during the following two minutes the covers were removed from the skylight house and the main ventilators.
15. Heat indicating lacquer showed the following temperatures were reached:
1. On the aft bulkhead of No. 3 hold a temperature of at least 175°F. was reached at all locations and a temperature of 400°F. was reached at some locations. None of these spots painted on the forward surface (15 inches from bulkhead) of a vertical “I” beam bulkhead stiffener reached 175°F.
2. In the No. 3 ’tween deck section, spots painted on the deck one inch from the aft bulkhead and on the bulkhead one inch above the deck reached 175°F. at the mid-point only. Spots painted on the bulkhead five feet above the deck did not reach 175°F.
3. c. In the No. 4 ‘tween deck section, spots painted on the deck one inch from the forward bulkhead reached 175° F. only at the mid-point and on the starboard side. Spots painted on the bulkhead one inch above the deck reached 250° F. at the mid-point and on the starboard side. Spots on the port side did not reach 175°F. Spots painted on the bulkhead five feet above the deck reached 250°F. at all locations.

The volume of water used was estimated at approximately 3,762 gallons.

1. Eleven hundred and eleven temperature readings were recorded during the test.

1. WEATHER CONDITIONS DURING TEST—
2. The weather was cloudy with a south wind of six miles per hour. The relative humidity was 55% and the temperature 44° F. The barometer was 30.07 inches.

1. CONDITIONS AFTER TEST—
2. The machinery snace was in practically the same condition as reported after Test Fire No. 7 conducted 29 November, 1944 with the following changes:

1. All surfaces coated with carbon except where washed clean by water fog, at forward end of engine, and on forward bulkhead at starboard corner.

Additional warping of floor plates. Additional burning of wooden bench top in lubricating oil tank area.

Deck of electrical equipment platform warped.

1. TENTATIVE CONCLUSIONS—
2. A major fire involving fuel oil under the floor plates can be extinguished by the control of air flows and the use of low velocity water fog applied from the upper level at one point only.
3. Temperature readings of the oil indicate a uniform cooling of the oil is effected during the process of extinguishment.
4. Upon completion of extinguish— ment there is no indication of the presence of fuel oil vapors within the space.

EDITOR’S NOTE: See the May issue for fourth installment of Commander Layman’s tests.