« iepriekšējāTurpināt »
STATEMENT OF FACTS
It appears that on March 2, 1944, a boiler exploded at property owned by the United States located at 219 North Lee Street, Alexandria, Va., and caused considerable damage to the Smoot property. It seems that the boiler was located in the boilerhouse on the east side of the building. The Smoot mill is situated on a direct east line with rear of the building and caught full direct force of the explosion. Also, the roofs of the lumber sheds on the south were damaged by debris.
The Federal Works Agency in its report of July 6, 1944, states that, it had made an investigation and that the damages done to the Smoot Co.'s property amount to approximately $1,210. They acknowledge liability in that "there were undoubtedly certain deficiencies in the training of the personnel and inadequate safety devices which caused this accident."
Your committee disagrees with the recommendation of the Federal Works Agency as to the amount of damages, as attached hereto and made a part of this record is an estimate made by Eugene L. Anderson, contractor and builder, of Alexandria, Va., which sets the amount of the total damage at $2,397.19.
Therefore, your committee recommend favorable consideration to the proposed bill, as amended.
Appended hereto is the report of the Federal Works Agency, together with other pertinent information.
Hon. DAN R. MCGEHEE,
Chairman, Committee on Claims,
FEDERAL WORKS AGENCY,
House of Representatives, Washington, D. C.
MY DEAR MR. MCGEHEE: This agency is in receipt of your letter of May 10, 1944, by reference from the War Department, enclosing a copy of H. R. 4737, entitled "A bill for the relief of W. A. Smoot, Incorporated," and requesting a report thereon.
This proposed legislation would authorize and direct the Secretary of the Treasury to pay to W. A. Smoot, Inc., of Alexandria, Va., the sum of $2,417.19, in full settlement of all claims of that company against the United States for damages caused to its lumber and millwork plant located at Cameron and Union Streets, Alexandria, Va., as the result of an explosion on March 2, 1944, in a nearby building occupied by the Records Division of the Adjutant General's office of the War Department and operated by this agency.
The records on file in this office indicate that the accident occurred under the circumstances as outlined in the bill and that there were undoubtedly certain deficiencies in the training of the personnel and inadequate safety devices which caused this accident. A further investigation by an official of this agency, however, indicates that damages to the Smoot Co.'s property total approximately $1,210.
Although the damage to the Smoot Co.'s property resulted from the improper operation of the Government building, this Agency cannot recommend favorably on the claim in the sum of $2,417.19 inasmuch as our estimate approximates only $1,210.
A copy of the report of the investigating board pertaining to this accident, together with an estimate of the representative of the Technical Division pertaining to the damages incurred by the Smoot Co., is transmitted herewith.
This report has been referred to the Bureau of the Budget and that Bureau has advised that there would be no objection to its submission to your committee.
PHILIP B. FLEMING,
ALEXANDRIA, Va., April 10, 1944.
W. A. Smoot & Co., Inc., Cameron and Union Streets, Alexandria, Va., in account with Eugene L. Anderson, contractor and builder:
Mar. 6, 1944. Repairs to mill damaged by explosion at King's Warehouse Bldg., as per contract...
Received payment in full as of this date.
EUGENE L. ANDERSON.
Washington, D. C., April 19, 1944.
W. A. SMOOT & Co., Inc.,
(Attention: Mr. Albert Smoot.)
GENTLEMEN: We take pleasure in quoting you on one No. 5071⁄2, 60 x 34 inches walnut flat-top desk, immediate delivery $74.50.
in about 90 days.
Very truly yours,
PUBLIC BUILDINGS ADMINISTRATION,
Washington, D. C.
If oak finish is desired delivery
CHAS. G. SOTT Co., INC.,
Office Furniture Department.
Alexandria, VA., March 4, 1944.
I hereby agree to do the following work at W. A. Smoot & Co., lumber and millwork, located at Cameron & Union Streets, Alexandria, Va., damaged by boiler explosion at King's Warehouse building:
Repair sheathing 7 places on mill roof building No. 1 to span rafters.
Reflash fire walls where needed.
Repair sheathing, 3 places on lumber shed east of mill, building No. 3.
Repair sheathing, 4 places on lumber shed, west of mill building 4.
Patch west end section No. 1 roof.
New roof on middle section No. 2 161⁄2 squares blue-black granite rolled roofing.
New roof on east end section No. 3, 20 squares blue-black granite rolled roofing.
Repair flashings at fire walls.
Furnish labor and materials.
This work will be done in first-class-workmanship manner for the sum of $577.70.
I will be able to start this work March 6, 1944. This work will be completed in 2 fair working days.
EUGENE L. ANDERSON.
ALEXANDRIA, VA., March 14, 1944.
W. A. Smoot & Co., Alexandria, Va., in account with Eugene L. Anderson, contractor and builder:
March 6, 1944. To repairs to roof (as per contract).
EUGENE L. ANDERSON.
APRIL 12, 1944.
To: Buildings Manager, Public Buildings Administration.
Subject: Boiler explosion, 219 North Lee Street, Alexandria, Va.
The Public Buildings Administration Board appointed to investigate the boiler explosion which occurred March 2, 1944, in the King's Warehouse located at 219 North Lee Street, Alexandria, Va., has made its investigation and submits the following report:
The Board made a number of trips to the site of the explosion and received and examined reports from many persons who had knowledge of the explosion. Copies of their statements are attached.
Â conference on this explosion was held on March 6, 1944, in the office of Mr. G. S. Barber, manager, Virginia district, Pentagon Building. It was attended by representatives of the Bureau of Standards and the Public Buildings Administration. Those having knowledge of the explosion were questioned and a transcription of the consultation was made.
Representatives of the National Bureau of Standards were requested to report on the cause of the explosion. They submitted two reports the substance of which has been considered in preparing this report.
Building: Four-story brick L-shaped of nonfireproof construction. was a one-story brick extension adjoining the main building.
Heating System: The building was heated by a closed forced hot-water heating system consisting of two steel boilers, two water circulating pumps, one closed expansion tank, piping, and radiators. Piping was divided into five zones, equipped with automatic temperature control.
Boilers: Each of the two boilers was a National Radiator Corporation steel firebox type, three pass, with rear smoke outlet. Manufacturer No. OB-436, 358 square feet heating surface, rated at 6,080 square feet steam or 9,720 square feet hot-water radiation. Boilers designed for 30 pounds working water pressure, tested at shop to 60 pounds hydrostatic (from manufacturer's catalog).
One boiler, the one in use at time of explosion, was stoker fired, with bituminous coal. The other boiler, which had not been used during this heating season, was provided with an oil burner.
Boiler trimmings: Each boiler had a combined temperature- and pressureindicating gage which showed pressure in both pounds per square inch and in feet of water, in addition to the temperature of the water. Dial was 4-inch diameter. In addition to the gages there was one Watts 54-a 1⁄2 inch combined temperature and pressure relief valve fitted with a fusible plug set to open at 212° F. and a spring loaded pressure release set at 100 pounds. This relief valve was installed on the pipe connection between the boiler and the expansion tank which may be considered a dead-end line without circulation. Water feed to boiler was manually controlled.
Smokestack: Both boilers were connected to a steel smokestack 40-inch diameter by 75 feet in height, above boiler room floor.
Stoker: Stoker was a Whiting Corporation "Whiting" underfeed stoker having three speeds of 132, 176, and 220 pounds of coal per hour, respectively, rated for 13,300 square feet hot water radiation at 150 British thermal units per square feet (2,000,000 British thermal units).
The variation in speed of stoker was controlled by hand. The motor circuit was controlled automatically on and off by an immersion-type aquastat installed in the flow main just above boiler. In addition to the aquastat control of the stoker motor, there was a timer that would automatically start and stop the motor as required to hold a minimum fire on the stoker.
Circulating pumps: There were two circulating pumps for circulating the water through the heating system. Each pump was a Buffalo Pump Co. 221⁄2-inch single-stage type having a rating of 225 gallons per minute against a total head of 12 feet of water.
Each pump was manually controlled from a knife switch so that either or both pumps could be placed in service. In addition, the main electric service line was automatically controlled from outside temperature as described under "Automatic controls."
Expansion tank: A closed expansion tank 30 inches diameter by 48 inches long (150 gallons) was installed with bottom of tank about 5 feet above top of boiler. Tank was connected to flow main at boiler with 14-inch pipe, with gate valve in line and a combined pressure and water temperature relief between the gate
valve and boiler. Tank was provided with a valved drain, gage glass and a valved tap in top of tank.
Radiation: Radiation consisted of 10,502 square feet of small-tube hot-water radiation. Flow and return connections to each radiator were at bottom ends on top floor; and on all other floors flow connection was at top end and return connection at bottom end of radiators.
Automatic control of the heating system: The system was equipped with a Minneapolis-Honeywell Co. compensated control system.
The building was divided into five zones, the temperature in each zone being controlled by an "M. H. Weatherstat" located on the roof of the building. The "Weatherstat" is designed to operate on the combined effect of all four outside weather factors; i. e., temperature, wind direction, wind velocity, and solar radiation.
The "Weatherstat" was connected electrically through a flow water controller to a motor driven three-way mixing valve installed in the flow line of the heating main supplying that zone. This mixing valve also was connected to the return main of the zone so that the water delivered to the radiators could be all hot directly from the boiler, or could be tempered by mixing hot water from the boiler with return water from the zone piping. See attached sketch of boiler room piping detail.
Normal operation: When starting the system cold the hot water from the boiler would flow through the three-way valves to the flow mains and radiators and would return from the radiators through a pump to the boiler. As the building became warmer, the position of the three-way valves would be changed so that a portion of the cooler water in the return would mix with the hot water from the boiler thereby varying the temperature of the water being delivered to the radiators, as required to compensate for the heat loss of the building. This variation was automatically controlled for each zone by the "Weatherstat" on the roof acting in conjunction with the flow-water controllers.
The temperature of water in the radiators normally would be 160° to 170° in extreme cold weather. In case the water in the boiler would rise to 173° the aquastat would open the electric circuit to the stoker which would shut the stoker down and would then close the circuit when the temperature of water in the boiler dropped to 163°.
Explosion: The stoker fired boiler exploded at approximately 11:40 p. m., March 2, 1944. The outside sheet of the boiler which weighed approximately 1,800 pounds landed on the roof of the torpedo station about 60 feet above ground and 270 feet from the boiler room. The tubes, heads, and crown sheet of the boiler were located about 20 feet from the original settings, with the tubes resting on ground and the crown sheet on top, indicating that these sections had been lifted into the air by the explosion.
The boiler tubes in most cases were separated from the heads, but were not otherwise damaged, and all tie rods, braces and stays had been pulled through either the inner or outer casing of the boiler. The shape of the heads seems to indicate that the explosion took place inside the water space of the boiler. The other boiler, which was not being fired but which was on the line with valves open, had been lifted from its foundation and was found free of all connections a few feet from its setting.
The entire boiler room was demolished to a point about 18 inches above the floor and the side wall of the main building had collapsed, leaving the ends of the floor joists unsupported.
The steel smokestack, which was supported from the boiler-room floor and extended through roof of the boilerhouse and then on outside of the main building to above the roof, was only slightly damaged although the breeching had been blown away.
Possible cause of explosion: While there were certain deficiencies in the boiler plant which very evidently contributed to the boiler failure, the extreme severity of the explosion, which totally demolished the boilerhouse, also destroyed the stoker control, pump switches, and other equipment that are essential as evidence in determining the exact operating condition of the plant at the time of the explosion.
From the evidence available after the explosion, it appears that the failure of the boiler was due to: (1) Faulty welding; (2) inadequate relief valve; (3) complicated type of automatic heating system control; and (4) uninformed operating personnel.
1. Faulty welding. The entire outside sheet which enclosed the water space of the boiler separated from the water legs and tube sheets at the welds. Both edges of the weld that failed were examined for their entire length.
The American Society of Mechanical Engineers Code for Low Pressure Heating Boilers requires that welding "shall insure a joint of sound metal thoroughly fused and to a thickness in excess of the maximum thickness of the plate." The weld that failed showed practically no fusion of metal and it was not more than onequarter the thickness of the plate.
Report of Mr. Nicholas P. Setchkin, National Bureau of Standards, on the faulty welding is attached.
2. Inadequate relief valve.-The American Society of Mechanical Engineers Code requires that each boiler of the size in this plant must have a 12-inch diameter relief valve set to open at pressure not above 30 pounds per square inch and without a shut-off between boiler and relief.
The system which failed had one relief valve for both boilers set to open at 100 pounds per square inch pressure located in the connection to expansion tank and with boiler stop valves between the boilers and the relief. The original installation had a 4-inch relief valve which failed about 2 weeks before the explosion and was replaced by a 1⁄2-inch relief by one of our operating engineers. See sketch of Boiler Room Piping Detail.
3. Complicated type of automatic heating system control. The automatic control for each individual zone has advantages in fuel saving. However, it also has certain dangers from a safety standpoint. When the temperature in the boiler is low the three-way valves are wide open to flow from the boiler. As the temperature in the boiler rises and the zone flow-water controllers are satisfied, the three-way valves gradually change position until they are almost closed on the flow and almost open on the return. If the stoker control does not operate, the three-way valves will assume a full closed position in the flow main cutting off circulation through the boiler. If this occurred, and it is entirely possible, the boiler water would have become dangerously hot, contributing to the boiler failure.
4. Uninformed operating personnel. It appears from Mr. Huckaba's statements at the conference in Mr. Barber's office that he was not familiar with the details of the system and also was lax in checking the stoker control after Mr. Douglas reported the stoker would not come on. Mr. Huckaba said he "first tested the
fuses; they were all right. Then I suspected the building was too warm for the stoker to come on. I turned the aquastat to 180°, about, and I turned it back down to original position. It went off. I decided it was the room temperature that had cut the stoker off."
To check the aquastat merely by moving the adjustment both ways without knowing the temperature of the water in the boiler is an incomplete test. If the heat-sensitive element which actuates the aquastat had been out of commission this test would not necessarily have detected the failure. With this element out, there was nothing to stop the stoker from running away.
In addition to the aquastat, the stoker was provided with a timer whose function was to start and run the stoker a short time at predetermined intervals regardless of room or boiler water temperature to prevent the fire from becoming too low or going out entirely. With the timer in proper working order it should have come on often enough during Fireman Douglas' shift to eliminate his handfiring of the boiler.
When Mr. Douglas reported that the stoker would not come on it is believed that Mr. Huckaba, among other tests, should have determined whether or not the timer was functioning properly, which he did not do.
Other possibilities which were considered.—(a) Gas explosion in firebox; (b) low water in boiler; (c) main stop valve on boiler shut. Each of these possible causes is commented on in order:
(a) The condition of the tubes, tube sheets, crown sheet, and outer shell after the explosion was conclusive that the explosion was caused by internal pressure. (b) With low water, steam would have been generated for some time before the explosion. This would have caused considerable noise which undoubtedly would have been heard by the fireman in the boiler room and guards in the main building. Fireman Bates testified there was no unusual noise in the system previous to the explosion.
(c) Fireman Bates left the boiler room about 5 minutes before the explosion. There was insufficient time for anyone to have closed these valves and escaped in that time.
Operating conditions.-The exact operating condition under which the boiler exploded could not be determined. Normally, the boiler was operated under a pressure of about 25 feet of water at gage, equal to a pressure of about 10.8 pounds per square inch. The boiling point of water under this pressure is approximately 241° F. It is obvious that the temperature of water in the boiler reached