Ladder Satellite Runs as Second Piece For Floodlighting and Salvage

Ladder Satellite Runs as Second Piece For Floodlighting and Salvage

Light unit with boom being cranked up manually from rest position.

Photos by Guy Newgren, San Jose Fire Department

Two-piece engine companies have been around since steamer days, but there is one fire department which has converted eight of its nine aerial or elevating platform companies into two-piece units.

As the second rig in these companies, San Jose, Calif., operates a vehicle carrying heavy rescue tools, salvage covers, and a large light plant. Called simply “light units,” each such truck serves these purposes:

  1. To function as a satellite of the aerial at working fires. While the specialized ladder truck is positioned for rescue or elevated stream operations at a fire building, the light unit can be moved to any convenient point to provide a high level of fireground illumination or carry out salvage work. The covers and other equipment carried on the light unit reduce the load the aerial must carry.
  2. The much smaller, lighter, less costly light unit can be dispatched alone, leaving its companion piece behind, to auto rescue or similar calls, particularly on expressways which are considered too risky for aerials.

Manning and equipment

San Jose’s ladder companies normally have a crew of five. Four men ride with the aerial while the fifth drives the light unit. When the latter responds by itself, it carries two men while the other three stay with the aerial.

Light units carry these tools: submersible pump, electric rescue saw, gas-cutting outfit, hydraulic power extrication kit, and 20 salvage covers. They have also been carrying 120 gallons of foam, but this is being phased out in favor of aqueous film-forming foam for use with hand-held or builtin eductors on the engine companies. The lighting plants, driven by a separate engine, range in size from 5 kw on the older rigs to 12.5 kw on the three newest ones which went in service at the end of April 1974.

The first of San Jose’s light units was built for downtown use in 1961 by the fire department shop on a converted 1952 GMC chassis. An army surplus generator was installed, and the new apparatus was designated “Salvage 1.” Two more similar rigs were built during the next three years. Later, they came to be known as “light, salvage and rescue” vehicles, and then came the idea of making them integral parts of ladder companies.

Run with ladder companies

Originally, light units were assigned only to the central high-value district. But during the 1970s, San Jose’s largest area and largest-loss fires established a pattern of occurrence far from downtown—such as the $2 million blaze in October 1973 which destroyed 12 apartment buildings under construction on a 10-acre tract. So the newest, largest light units now run with ladder companies in outlying districts 5 miles or more from the center of the city.

Typical of them is LU 14. To begin its construction, the fire department purchased a 1-ton International V8392 chassis with 132-inch wheelbase, 9000 pounds gross weight, for $6300. It was equipped with a 3-speed automatic transmission, 2-speed transfer case, and non-slip rear axle.

The compartmented body, built by Westates Co. of nearby Redwood City, contains five transverse closed compartments accessible from both sides of the truck. The two rearmost compartments do not extend all the way across the bed, leaving an open area in the center for mounting the base of an elevating mast with five floodlights at its tip. One of the full-width compartments completely encloses the engine-generator set. Its top opens up for ventilation when the engine is running. Older rigs had the set mounted in the open on the truck bed, which gave less protection from dirt and weather. Other compartments contain the covers and tools.

Metal halide lamps

LU 14’s lighting equipment makes use of the latest area-lighting techniques now being used on large-scale construction projects, including metal halide (MH) high-intensity discharge lamps. Functioning somewhat like a modern rear-mount aerial ladder, the elevating mast or boom has a base section extending over the truck’s cab. At a fire scene, this is cranked up manually into a vertical position, and the remainder of the boom is extended hydraulically to a maximum of almost 40 feet above the ground.

Topmost of the five lamps is a fixed-position 1000-watt quartz-iodide unit with a light output of 50,000 lumens. This gives instant light with no “warmup” period. Next below it, to either side of the boom, is a pair of narrow beam MH lamps which can be rotated 45 degrees upward or 45 degrees downward by electric motors controlled from an operator’s panel on the truck. These lamps have a 125-foot beam width 350 feet from the truck. Next below them are two wide-angle MH lamps which can be manually rotated through a smaller angle sidewise, but not up or down. These two can light up a large area to either side of the truck with the boom down (see diagram). Total light output for the five-lamp cluster is 950,000 lumens.

Boom controls are simple—updown rotation for the two movable lamps, and extend-retract for the boom itself. Limit switches automatically stop the movements at each extreme and prevent extension of the boom unless the base section has been raised.

Engine and generator

The electrical system was designed and installed by Electro-Motion Pacific of Redwood City, Calif., which also mounted the boom on the truck body. This firm supplied the 120/ 240-volt, three-wire, single-phase generator with a 4-cylinder air-cooled engine developing 26 hp at 1800 rpm. The rest of the construction and wiring was done in the SJFD shop. The total cost of the apparatus was $17,595.

Besides the boom lamps, LU 14 carries four portable floodlights plus four 125-foot reels of cable. The aerials also carry lights and small generators. At wide-area blazes, however, it is often impractical to set up complete illumination with portable sets. There may not be enough cable. Also, the cables get in the way and are easily damaged, and the manpower needed to set things up may not be available.

Using the elevated boom, on the other hand, LU 14 and its companion units can illuminate a vast area.

“They light up a whole city block,” claims San Jose’s Deputy Chief Tony Sapena. “You just have to see one at night to appreciate what they can do. One captain decided to try his unit out at quarters one night, and it was so bright that when all the candlepower hit the photocell control units for the neighborhood street lights, they thought the sun was coming up, and all the street lights went out.”

Older light units also have extended masts, with single lamps of less power, which reach a few feet upward from the truck bed.

Three more LUs are on order for 1975 completion. These will be diesel-powered for assignment to stations where other apparatus is already diesel, so those locations can store a single fuel. That will give San Jose a total of 10 such rigs, one of which will run with newly activated Truck 9, while at least one of the oldest will probably go into reserve.

Light unit can be raised or lowered as indicated.With boom lowered, lowest cluster of lamps lights area around truck. Beams from raised boom can reach a block or more to both sides and front.

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