Television—Blessing or Bane to the Fire Service
Either Way, Nation’s Fastest Crowing Industry Presents Fire Service With New Problems
A FIRE ENGINEERING SPECIAL REPORT
Editor’s Note: Does television, electronic giant of the times, offer new or special fire hazards? Does this new product and new industry portend new headaches for the fire service?
If you believe the radio industry, the answer is “no.” Television, they insist, is safer than good old-fashioned radio. If you accept the judgment of fire officers who have come to grips with this electronic wonder on the fire ground, you’ll want to know more about video, and all it means as friend or foe of firemen.
Thus far, little has been written about television from the fire fighter’s standpoint. As a forerunner to the televison bibliography to be, FIRE ENGINEERING is pleased to submit this study, with accounts of actual fires involving television receivers and studios.
In so doing grateful acknowledgment is made to Fire Chiefs Stackpole of Lowell, and Benjamin E. Chase of Haverhill, Mass. Lieutenant Rowell C. Currier, Haverhill Superintendent of Fire Alarm and Mr. Ralph Anderson, radio expert, for data on actual fires, to the National Board of Fire Underwriters, Mr. George Booth, general manager, and the Underwriters Laboratories, New York, Mr, K. S. Geiges, associate electrical engineer; to the Television Broadcasters Association, DuMont Laboratories and Mr. O. H. Caldwell, editor “Electronic Industries.”
NEWEST and fastest growing giant in American industry is television. Just what this newcomer in the electronic field will mean to the fire service can only be conjectured, at this writing. That it will have a double influence, however, appears feasible. The first is in education and instruction within the fire service itself; the second is its value as a medium for interpreting the fire service, and its work, to the public.
A year ago there were an estimated 17,000 television sets in the country. In August last, there weye more than half a million; of these, 278,896 were produced in the first half of 1948. Production in 1949 should total around 1,600,000 receivers, it is predicted by authorities. By the end of 1948 there should be more than 850,000 receivers and over sixty television broadcasting stations in operation. It is further prophesied that by 1952 there should be 13,570,000 sets in operation.
In the last six months the Federal Communications Commission has experienced a flood of applications for permission to construct and operate commercial television stations. A recent check (Sept. 1948) showed 299 applications pending, almost all filed since January 1, 1948. At present there are only thirty stations operating on the air, seven licensed and twentythree operating on “special temporary authority.” In addition, 104 construction permits for stations have been authorized.*
Whether or not this review of applications for video stations, and further radio channels, pressure for which is persistent in Washington, will result in re-opening the entire subject of allocations presently made the fire and other emergency services is problematical. It is certain however, that the fire service and related interests all vitally concerned in retaining the frequencies allocated by the Commission will have to reckon with this persistent pressure upon the FCC by commercial interests who plead, for more channels, and do not care from whom they take
The mushroom growth of television has everybody concerned: manufacturers who have difficulty getting materials; service organizations, unable to get experienced personnel; the FCC, which has allocated seven channels for television and is trying to find many times that number (some television and FM interests have appealed for some of the radio channels presently allocated the emergency services, including fire); broadcasters, who are testing new studio and field techniques.
The Fire Hazard
There is at present considerable difference of opinion over television as a fire hazard. Within the radio industry it is contended that video (television) is no more of a hazard than conventional radio sets. O. H. Caldwell, Editor, Electronics Industries and a nationally known electronic authority, says “I have been inquiring among television repair men and have not been able to get, any report of a television set setting fire to anything (of course, sometimes a resister burns out inside the set, putting it out of commission, but that’s all).” His belief was shared by engineers of DuMont and other television comoanies and the broadcasters’ association.
Within the fire services and insurance circles there is more doubt inspired, evidently by reports of a number of fires, accidents and lightning episodes involving radio installations.
Interest of the fire service was first directed to the hazards of television early in. 1947 when antennas first began to sprout upward front rooftops in increasing numbers. Most fire officers are not technically radio-wise but they are perfectly conscious of the possibilities for trouble when metal conductors are projected above structures. The” have also had to run the gauntlet of wire aerials of every kind in operating on roof tops—particularly of multiple occunancies. With knowledge of the accidents resulting from this latter kind of antenna installation, they were naturally concerned over just how much video was going to add to their woes.
About Television Antennas
At this point a word or two about television aerials might not be amiss. According to K. S. Geiges, electrical engineer with the Underwriters’ Laboratories, hack in the 1920’s when radio broadcasting fi,rst became popular, the hazards of outdoor receiving antennas had the attention of authorities, including fire protection engineers, who were guided by the installation requirements of the National Electrical Code. As radio developed, and the number of transmitting stations increased, more powerful transmitters were employed and more sensitive receiving equipment was developed, until at present time the indoor receiving antenna has largely replaced the outdoor type for conventional radio.
With the advent of television, it has again been found necessary to locate the antenna outdoors for suitable reception. This is necessitated by the use of higher frequencies for these services. A characteristic of transmission at these higher frequencies is the limited range, which is only somewhat greater than the line-of-sight distance under normal Conditions (line-of-sight is the distance the eye travels to the horizon). Another characteristic is the screening effect of intervening metal structures. For cases where the antenna is not within the line-of-sight of the transmitter, the obvious remedy for both effects is to get the antenna as high as possible.
On 30, 1948, the FCC announced suspension temporarily of action on pending or prospective applications for television authorizations as a result of evidence presented at the Industry-Commission conference in Washington, Sept. 13-14. Serious questions were raised as to the merits of present or proposed allocations. Officials of the FCC said an engineering conference would be called “to consider and recommend any necessary or desirable revision of its television rules, regulations and standards, and possible channel allocations.” Following the survey and report of the engineering conference, it is said “industry conferences will be arranged by the Commission for discussion of its findings and proposed revisions based thereon of its rules and allocations”
The results of this tendency can be seen in any community located in the fringe area of an existing television service center.
The antenna masts extend well above the roof line of supporting structures and vary in height from five to forty Or more feet. As to whether this condition will continue when the number of transmitting stations is increased and higher powered transmitters are available, Mr. Geiges believes this is a matter of opinion. Some electronic engineers contend a large number of television installations will continue to require elevated outdoor antennas for suitable reception.
The hazards of the mast or elevated antenna, are basically the same regardless of the radio frequencies involved although it should be borne in mind, Mr. Geiges says, that the high frequency antenna uses a single mast, often erected on the building itself, with height a factor of performance. Any high metal structure being a likely target for lightning, with consequent danger of fire or lightning damage to the structure and to the electrical equipment as well, naturally concerns the fire protection engineer.
In the case of high masts, there is also the hazard of their being improperly anchored or supported so that they might fall in a windstorm or when weakened by a fire in their underpinning. Such fall or collapse might contact nearby overhead power wires to cause further hazards.
The other hazard, of the antenna previously mentioned, is its obstruction to fire fighting operations. If and when “master antennas” are installed on multiple occupancies, in place of the almost limitless individual television aerials now being permitted in some municipalities, this hazard will be reduced, if not eliminated.
Over a period of the past thirty years or more, provisions of the National Electrical Code affecting grounding of antennas have been revised as necessary to meeting changing conditions. The present Code covers receiving station antenna systems, but not television installations. It was obviously written for the conventional (AM) broadcasting type of installation. Revisions are now under consideration to further modify the requirements to include television antennas.
The Code requires radio lightning arresters designed to provide a ground path for static discharge and induced surge currents. Although the older designs of arresters are not suitable for FW and television antennas, there are new models available which are built for this purpose. It should be pointed out that the arrester is not intended to protect the building in the event of a direct lightning stroke to the antenna.
It is the opinion of some authorities that grounding of the mast itself is an essential of safe installation because the masts are generally of metal and extend well above the roof line of the building. However, there is a difference of opinion over the method of grounding and this question is under advisement at present. Some types of high-frequency (FM) antennas can be grounded at a point on the antenna itself without affecting the proper operation of the receiver. Consideration, said Mr. Geiges, is being given to the possibility of grounding both antenna and mast through a single grounding conductor.
It is reported that where lightning rods are used on a building, the installation of the antenna would affect the protection afforded by the rods. In such cases the mast is tied to the rod system by a grounding conductor of suitable size.
Television Antenna Agreements
One of the first cities to question the wisdom of permitting unlimited television antennas on apartment houses was New York. Following considerable controversy between apartment house tenants and their landlords, the Television Broadcasters Association, Inc., prepared a “model” form of Apartment House agreement designed to be signed jointly by landlord and tenant. This rather formidable looking document, covers nearly three legal size pages of solid text and embodies these essentials:
The landlord will pe.rmit the tenant to erect and install by the installer at the tenant’s expense, on the roof or other suitable place, an outdoor television antenna, including lead-in cable, upon certain terms and conditions (which follow in abbreviated form) —
- Before outdoor antenna can be installed, the landlord must have first approved in writing a sketch and specincations showing location, method of installation, etc. Landlord reserves the right to withhold installation.
- If a suitable outdoor television antenna already has been erected and is available for use on the premises, the landlord has the right to insist that tenant’s receiver and lead-in cable be connected to the previously erected antenna installation.
- Installer agrees to safe workmanlike installation, to be approved by the landlord and that the installations “satisfy the requirements of, and will not be in violation of, any applicable fire regulation or law, building code, safety law, regulation or ordinance issued under the authority of any federal, state or municipal government having jurisdiction over the premises, or any standard or requirement set by the National Board of Fire Underwriters, and tenant agrees to maintain the same at all times at his own expense.” The landlord may require installer within one year from date of installation to procure certificates of the appropriate state or municipal agencies which ordinarily supply such certificates, certifying that the installation does not violate any fire, safety or building ordinance or regulation.
- The installer will indemnify the landlord and tenant for and uphold them harmless from any and all liability resulting from property damage, personal injury, etc., caused by or resulting from the erection, installation and maintenance of the antenna installation. The installer must warrant “adequate experience” in installing television antennas.
- Installer and tenant agree that the installation shall become the sole property of the landlord upon installation, to connect tenant’s receiver so long as it is located at the apartment occupied by the tenant. If tenant’s receiver is removed from his apartment continuously for seven months or more, exclusive of the time required for repairs, the tenant loses the right to connect a receiver to the outdoor antenna as if the tenant had vacated the premises.
- The landlord will not be liable to maintain or repair the antenna or leadin cable or other attachments.
- Tenant must agree to permit other tenants on the premises to connect their receivers to his antenna as long as his own set’s sound and vision is not impaired.
- Agreement is off unless the tenant has commenced to install his receiver and to connect it to an outdoor antenna, as provided, within thirty days from date on which the tenant’s television receiver is delivered to his apartment.
- Tenant agrees to pay and to be liable jointly and severally with owners of other television receivers connected with his antenna for the cost of repairs and replacements made by them, and the work to be done by service agency approved by landlord.
- Provides for penalties in the event the outdoor television antenna installation is not installed or made in a safe and workmanlike manner or if it violates the provisions of any applicable fire regulation or law, building code, etc. Landlord, on serving notice, may remove the installation. He may also refuse to permit further antennas to lie installed on any tenant’s installation until all regulations are complied with.
- Provides that in the event the installation shall increase the insurance rate on the premises, the tenant shall reimburse the landlord accordingly. The same applies if any federal, state or local tax is imposed on the set or installation.
- Tenant agrees that in the event an outdoor multiple television antenna system for the use of all tenants and such installation is a type approved by the Television Broadcasters Association Inc., the tenant will at his own expense, remove the outdoor antenna installation to which his receiver is connected. If he fails to do this within stated time, the landlord may remove it at the tenant’s expense.
- Landlord may add costs of doing work which the tenant failed to perform under the agreement, to the tenant’s rent bill.
- Failure of the tenant to live up to his obligations under the agreement and make payments as required shall constitute a breach of terms of the tenant’s lease and permit landlord to institute remedies of “summary dispossess,” etc.
- Upon the tenant’s removal from premises, or discontinuance of his outdoor installation, he will remove installation at his own expense, and through landlord’s selected service agency. Landlord may permit installation to remain on premises if some other receiver is connected to it. If tenant fails to remove it, the landlord may do so at the tenant’s expense.
- Upon tenant’s removal from premises or the installation’s removal 30 days from date of discontinuance of antenna and landlord notified, all liabilities of tenant shall terminate, provided tenant has lived up to the terms of agreement.
- No modification of the agreement shall be effective unless agreed to and signed by each of the parties.
- Rights of parties to the agreement shall belong and inure to the successors and assigns of each and any of them, but the agreement shall not be assignable by tenant without prior written consent of landlord.
It will be noted that emphasis was placed upon adherence to federal, state and local laws and ordinances governing fire and other safety provisions. Many authorities believe that such an agreement is too stringent and will never be universally adopted.
A number of more simple regulations have been instituted by municipalities. The City of Hartford has published (June 15, 1948) “Requirements for Radio Receiving Antenna Work in Connection With Commercial, Industrial and Apartment House Installations.” This document has only nine short paragraphs and appears to cover the details.
In smaller communities, the Town of Mamaroneck, N. Y.—which as a New York City suburb has a number of apartments, adopted brief regulations covering the question as follows:
“III-A TELEVISION AERIALS OR ANTENNAS
The installation of aerials or antennae for television sets in the Town of Mamaroneck, N. Y., on multiple dwellings as defined in Article II of the Building Code of the Town of Mamaroneck, shall be subject to the following rules and regulations:
- No aerial or antenna shall be less than ten (10) nor more than twenty (20) feet in height above the roof-line.
- All such aerials or antennae shall be constructed of metal, or other material equivalent as to strength and fire resistance.
- Where the installation of such aerials or antennae is on a flat type roof, no guy wires shall be used, but such aerials or antennae shall be carried on self-supporting brackets, or masts, supported only by metal brackets at the base thereof. Where space is available along a parapet wall, such aerial or antenna may be placed upon the parapet wall, or anchored to its side if the wall is approved by the inspector as sufficiently strong.
- The supporting mast shall be permanently grounded by means of a copper conductor not smaller than #6 American Wire Guage.
- All aerials or antennae shall be either permanently grounded or provided with a lightning arrester which shall be properly grounded and approved by the inspector.
- Lead-in wires from such aerials or antennae shall not be installed so as to pass through dumbwaiter, elevator shafts or other interior shafts or enclosed passage-ways, except where leadin wire or wires are in a metal shield or tube which is permanently grounded.
- No aerial or antenna shall be installed without a permit to be issued by the inspector nor maintained without an inspection and certification evidencing compliance with these regulations.
The National Board of Fire Underwriters and the Underwriters’ Laboratories have both been active in checking the fire and other hazards of television. The National Board has not published standards embodying the fire hazard of television installations but radio installations are covered in Article BIO of the National Filectrical Code; this article applies also to television equipment. The Electrical Department of the New York Office of the Underwriters’ Laboratories (K. S. Geiges) has made a specific study of this problem and has issued “Proposed Requirements for Television Receiving Appliances” (Feb., 19481 together with the “Underwriters’ Standard for Radio Receiving Appliances”—of which the first-named is a supplement.
According to the UL, the most serious hazard is the electrical shock hazard. Any radio operated from household current uses or generates voltages which, under certain conditions, may cause serious or fatal shock. Such accidents are not in fact peculiar to television or radio but can result from almost any electrical appliance. Television reception, however, requires the generation and use of voltages far higher than needed for conventional radios. Voltages up to 30,000 may be used in video equipment, although in the average video home receiver the voltage is probably only about one-third that figure, according to investigators.
Equipment presently being sold the public is for the most part equipped with interlocks on the access panel to prevent persons from coming in contact with a high voltage point while it is energized. At the same time, persons repairing or servicing equipment will have occasion to circumvent the interlocks, exposing themselves to the energized circuits. Therefore, only thoroughly qualified persons should undertake repair of video sets, authorities stress. Firemen and consumers should never tamper with the interlock when, for any reason, they want to poke a.round the inside of a set.
Fire hazard ranks next in importance to shock. Some fires, it is reported, have resulted from blocking off the avenues of ventilation of the set, as provided by the manufacturer or installer. One such incident is described in the following:
At last summer’s convention of the New England Association of Fire Chiefs held at the Hotel Wentworth, Portsmouth, N. H., one topic which occupied a prominent part in the educational program’s symposium was television.
Assembled fire chiefs heard Chief Chas. E. Stackpole of Lowell, Mass, describe the fire of June 18 last, in his city, which did damage in excess of $500,000 and which he believed started in a television studio located in the destroyed building. It was conceivable that the fire originated in a television set in the studio.
This is said to be the first large scale fire in which television was advanced as a possible or probable cause. Chief Stackpole’s report heightened the interest of New England chiefs in the possible hazards of television. That interest was further whipped by a subsequent report of another, although less serious fire, involving a television set, given the open session by Fire Chief Benjamin L. Chase of Haverhill, Mass.
Haverhill Television Fire
There was no room for doubt about the cause and resulting outcome of this blaze, one of the first television fires to be fully reported, and painstakingly investigated by competent fire officers. At the request of the New England Association, Chief Chase submitted his own report, together with the opinions of Ralph Anderson, radio engineer who, with Chief Chase and Lieutenant Rowell C. Currier, Haverhill Superintendent of Fire Alarm, conducted the investigations.
In his communication to FIRE ENGINEERING Chief Chase writes:
“On June 24, 1948, at 4:21 A.M. we received a box ala.rm for a fire at 43 Washington Street (Haverhill). Upon arrival we found the radio store which was located on the street floor heavily charged with a white smoke and two sprinkler heads in operation.
“A further investigation showed that the fire originated in a table model television set, from which the fire communicated to the wall and traveled to the ceiling, setting off two sprinkler heads which had completely extinguished the fire.
“While I was tracing out the wires in order to determine which sets were connected, the owner arrived and I saw him reach for the switch on the radio set; I feel sure that the set was on and that he unconsciously shut it off. He stales that he does not ycmcmbcr whether he did or not.
“After the clean-up and sprinkler system restored, I ordered the set removed front the store to my office for further investigation. I left for the convention later in the morning. While at the convention I met Ralph Anderson, a radio engineer who, after hearing about the fire, volunteered to assist me in my investigation. He returned to Haverhill with me and together with Lieutenant Rowell O. Currier, my own Superintendent of Fire Alarm, we instituted the investigation. I employed a photographer to take pictures as we proceeded. Copies of these pictures are supplied herewith; they are numbered and referred to in Mr. Anderson’s report, a full copy of which is enclosed. We all know Mr. Anderson to be a radio expert.”
We are privileged to quote Mr. Anderson’s report. He states:
“Probable cause of fire in television set (giving the name of the manufacturer, model and serial number of the set.)
“Fire alarm box 3113 at 4:21 A.M. for fire at 43 Washington Street, Haverhill, Mass. The above mentioned radio was burned very badly and also was the cause of the fire. The sprinkler system put out the fire.
(Continued on page 734)
(Continued from page 687)
“The last known time the radio was used was at approximately 8:00 P.M. the previous evening. All indications show that the radio was left on. Owner admits that he did not know whether or not he shut it off. The lapse of time between 8:00 P.M. and 4:21 A.M. was 8 hrs. and 21 min.
“The radio was set on a table, the top of which was 21 in. x 16 in., and the measurements between legs on set is 21 in. and is 18 in. wide.
“There are two ports in the bottom of the set for ventilation but these were covered, by the table top, thus eliminating any ventilation on bottom of set. There weye two burned spots on table top; also, a cardboard poster was against back of set which further stopped ventilation there.
“There are no fuses in set on the A.C. line: also the A.C. source for set was fused at 30 amps.
“Pictures were taken at each step in the investigation. Fig. 1 shows the set as it was taken from the fire before anything was disturbed. Fig. 2 was taken with set tipped so that the bottom of cabinet shows and also the underside of top of cabinet.
“Fig. 3 is a close-up of the start of the fire. Fig. 4 is of the underside of the set itself after being removed from the cabinet. Fig. 5 shows section of set housing high voltage supply. Fig. 6 shows the inside of cabinet with set removed, indicating fire started underneath high voltage supply. Fig. 7 is high voltage Section with cover removed.
“Fig. 8 is of the tube that apparently caused the fire. It was determined before set was removed from cabinet that the start of the fire was in the lower right hand corner looking from the back. It was also noted that the picture tube had been broken before the arrival of fire department. Upon careful check of glass it was determined that cold water from sprinkler system falling on the hot tube shattered it.
“The high voltage section cover has a port from which tubes can be removed. In looking into this section the oscillator tube plate had a burned spot on it. This can be seen in Figs. 5, 7, and 8. The set was then removed from the cabinet and turned over. It was very evident then that the fire started under the high voltage section.
“The position of the wires and their color and the condition of chassis indicated the exact location where the fire started. This section was near the base of the 5 V 4 G rectifier tube. The fire started here and ignited cabinet base, then in turn crept under chassis (right hand edge) to the open space at the right and on to the top of the cabinet.
“There were no resistors on condensors attached to this particular section as they had all been burned so badly that they were on the bottom of the set. No check could be made to see if they were shorted.
“The oscillator tube of the high voltage supply had burned spots on the plate. These spots were caused by arcing in the tube. In this type of circuit when burn spots occur the tube will draw more current.
“This higher current places a greater load on the rectifier J V 4 G tube. The rectifier tube will also draw more current and after a period of time will become heated and probably be shorted, thereby causing wires leading to the tube to become very hot.
“This finding indicates that the set was definitely left on, as it would take two to three hours to start a fire under these conditions. There is no way of knowing the exact time that elapsed between the time the owner left store and the time the set broke down.
“I believe that had the A.C. line been properly fused and also set had been allowed proper ventilation, this fire might not have occurred.”
Preventive measures are: Keep sets well ventilated in all installations, including the demonstrating sets in the store.
Most insulation on the high voltage parts is flammable and recent recommendations call for enclosing them in metal, to prevent spread of a fire within the component. However, enclosed parts develop heat, which complicates this problem.
Limits for the maximum temperatures of individual components have been established by the UL, so that in case of a ground or short within the set, the temperature will not climb so high as to set fire to the cabinet or to any object, such as curtains in contact with the set.
Since cathode ray tubes are relatively large and are operated at high vacuum, another hazard listed is “implosion”— i.e.: the inward rupture of the tube, with resultant possibility of flying glass. For this reason, protection of the tube on all sides is advised. The tube face should be screened with a sheet of shatterproof glass and all enclosures should be in place when the set is in operation. Breakage in the case of smaller tubes is relatively rare.
In a sharp implosion, the force of the external air impels the glass into the tube and out the other side. It might result in ripping out the back of the set. Because the prosphor powder in video tubes contains a beryllium compound, it is also considered advisable for anyone who is cut by the flying glass to have the wound promptly treated by a physician, and to explain to him that the cut resulted from glass treated with a beryllium compound.
Inasmuch as masts are placed as high as possible, the lightning hazard may be increased as a result of antenna installations unless the proper precautions are taken. Such installation should be in accordance with Article 810 of the National Electrical Code. Metal towers should be properly grounded, preferably with at least a No. 6 American wiregauge conductor. The shield of the concentric or coaxial cable should also be grounded, where used.
Modification of present standards are reported to be under advisement and it is expected that a prescribed set of standards will be evolved at an early date.
Thus far we have discussed television from the standpoint of hazards. There is another important side of the picture.
Television, because it has video, or eye appeal as well as audio, opens up an entire new field of promotion for the fire service. This very factor, which can make it such a boon, can likewise, convert television into a curse for the fire fighter.
The fire service has already complained about haphazard and thoughtless broadcasting of fires and other emergencies. Resolutions have been passed by the International Association of Fire Chiefs and its affiliates decrying mass newscasting which has resulted in mass movements of the curious to the scene of emergencies, with resultant traffic jams, blockades, and interference with fire fighting operations.
The thought was advanced by one fire chief that television would be a blessing in this respect, because it would enable the curiosity seekers to remain at home and watch the progress of a fire or other incident. That reasoning may have weight but, on the other hand, no telebroadcast can hope to picture the disaster, whether fire, flood or hurricane, as it really is, and as an observer hopes to see it. It is possible, therefore, that the televising of a fire for example, may sufficiently whet the appetites of the video audiences, to encourage them to hop in their cars and head for the scene. Time will tell.
Already television is broadcasting the picture story of how fires are fought. Firemen’s tournaments, and parades are finding their way onto the television image. Much, if not most of this is “good public relations” for the fire service. It can be made still better by some careful cooperation between television studios and heads of our fire departments.
Television has proved a boon in furthering fire prevention programs. It goes much further than radio could ever help to go, in taking the video audience right into the plant, or home or store, where fire occurred, and showing them the actual evidence of carelessness and thoughtlessness, rather than merely telling them about it. Television dramatises the story. It can dramatize the fire service, if properly used.
Another great unexplored field is in firemanship training. Television may eventually prove the greatest training tool the fire service has ever had.
Perhaps it is a good augurv that the first oudoor television newscast ever made was that of a fire on the banks of the East River, New York City not so many years ago!