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911 Title: WTC 7 Building; Fuel Systems for Emergency Power I took the liberty of extracting, excerpting and editing from the original document: NIST NCSTAR 1-1J, "WTC Investigation" the following details concerning the make up of the emergency power fuel distribution system that was located inside WTC bldg number 7 (WTC 7). It is advantageous to know the details of this system such that when various known 'fire' scenarios are examined they may be understood knowing the systems and potential fuel sources that are/were present in WTC 7. The following is presented for educational purposes only. 1) the Base Building system and 1) The Base Building system consisted of four subsystems: - the Silverstein sub-system (original system), The Ambassador Construction and American Express sub-systems were supplied with fuel from the original Base Building storage tanks installed below the loading dock. The Mayor?s Office sub-system contained its own storage tank that was filled from the original system tanks. The other system (the Salmon Brothers system), was supplied by a separate set of fuel storage tanks, also located below the loading dock. The systems had differing design features with each system operating independently. The two systems combined with all of the sub-systems, contained more than an estimated 43,000 gal of fuel, assuming all tanks were filled near capacity. Since the owners had contracts with fuel delivery services to maintain the tanks full at all times, this assumption is considered reasonable. E.1 BASE BUILDING SYSTEM The Silverstein system was installed in 1987. The system contained two 12,000 gal capacity storage tanks located below the 1st floor loading dock. The tanks supplied no. 2 diesel fuel to a duplex fuel oil pump set located in the 1st floor Fuel Oil Pump Room situated between the west banks of passenger elevators. The pumps supplied fuel to a 275 gal capacity day tank (1) in the 5th floor Generator Room, which supplied fuel to two 900 kW generators. The fuel Oil Return (FOR) pipes ran in parallel with the Fuel Oil Supply (FOS) pipes returning fuel back to the day tank and storage tanks. In 1994, the Silverstein system was modified for the Ambassador Construction project. The Base Building system was extended by tapping off the existing FOS pipe to the duplex pump set in the 1st floor Footnote (1) A day tank is a small-capacity fuel storage tank located near the generator(s) and kept full by a transfer pump from a main tank at or below grade. The BCNYC limits fuel supplies to no more than one 275 gal (maximum) day tank on any floor above the 1st. Fuel Oil Pump Room. The pump supplied fuel to the engine mounted day tank (50 gal capacity) of the 125 kW generator located on the 9th floor. The FOR pipe ran back to the existing FOR at the 1st floor. Again in 1994, the Silverstein system was modified for the American Express project. The Base Building system was extended by tapping off the existing FOS suction pipe and adding another duplex pump set in the 1st floor Fuel Oil Pump Room. A 275 gal day tank was added on the 8th floor, which supplied fuel to the 350 kW generator. In 1999, the Silverstein system was modified for the Mayor?s Office of Emergency Management project. The system added two additional duplex pump sets. The 1st pump set was used to fill a new 6,000 gal above ground storage tank on the 1st floor. The second pump set was used to supply fuel from the new storage tank to the new 275 gal day tank and three 500 kW generators on the 7th floor. The four Base Building sub-systems were similarly designed, but were independently operated by the fuel pump set controllers for each system. The sub-systems included many similar devices, such as antisyphon valves, foot valves, fusible link gate valves, solenoid valves, fuel level switches, rupture basins and leak detectors, all performing specific operations. Although each sub-system was not designed exactly like the other, the four sub-systems operated and performed similarly. Each sub-system operated based on the liquid level in the day tanks. Each sub-system control panel (four total) started and stopped the respective pump set by the liquid level switch in each day tank. The various fuel devices listed above provided increased assurance that unwanted fuel discharge would not occur. The devices listed above would have prevented, in most if not all scenarios, unwanted fuel discharge unto the floor below. The devices were installed to isolate fuel from open piping breaks, prevent backflow and drainage of fuel unto the floor below and shut off the pump set to prevent fuel flow. E.2 SALOMON BROTHERS SYSTEM In 1990, a second fuel oil distribution system was installed for the Salomon Brothers project. The fuel for the system was supplied by two 6,000 gal storage tanks located under the loading dock. FOS pipes ran to the duplex pump set on the 1st floor. The FOS discharge pipes ran up to the 5th floor supplying fuel to nine 1,750 kW generators. The FOS discharge pipe ended at a valve rig where the FOR pipe started and ran back to the pump set and storage tanks. The Salomon Brothers fuel system had a similar but slightly different design than the Base Building system. Similar to the Base Building system, the pump set provided fuel from two underground storage tanks. However, there was already a day tank on the 5th floor associated with the base system and the BCNYC did not permit more than one day tank per floor. Thus, the Salomon Brothers system used a continuously pressurized fuel supply piping system without a day tank. The fuel pressure in the FOS discharge piping was maintained by a liquid level switch and back pressure regulator in the 5th floor valve rig. The liquid level switch started and stopped the pump set in accordance with the liquid level in the FOS discharge pipe. The pump was powered from the generators such that any time any one generator was running, the pump was powered. Any use of this material, including any legal action or in any lawsuit, are subject to the provisions as specified in 15 USC 281a; as amended by P.L. 107-231. Any readers are are urged to do their own research and study pursuant to doing "due diligence" on this subject matter or any other matter relating to this matter. Views expressed by this poster are not those of any particular agency or bureau, nor are these views represented to be part of any US, state or local gov't bureau e.g. NIST, PANYNJ, NYC, et cetera, but are soley those of the individual poster. 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