Dry and wet risers - Revision history

Jan: Remove links to pages that do not exist; retain displayed text (wiki-wide link audit).

2026-11-02T21:32:48Z

Remove links to pages that do not exist; retain displayed text (wiki-wide link audit).

← Older revision		Revision as of 22:32, 2 November 2026
Line 82:		Line 82:
	* [[Hose reel]]		* [[Hose reel]]
	* [[Fire extinguisher]]		* [[Fire extinguisher]]
	* [[Positive pressure ventilation]]		* Positive pressure ventilation

	== Notes ==		== Notes ==

Lisa: Add Intermediate SVG figures with Fire Safety Academy watermark at planned locations; preserve article text

2026-11-02T17:14:49Z

Add Intermediate SVG figures with Fire Safety Academy watermark at planned locations; preserve article text

← Older revision		Revision as of 18:14, 2 November 2026
Line 12:		Line 12:
	== Wet, dry and other types ==		== Wet, dry and other types ==
	NFPA 14, as summarised in the NIST report on the World Trade Center suppression systems, describes standpipe systems by their water supply as wet, damp or dry.<ref name="H-21" /> Wet systems are the preferred arrangement. They are filled with water at all times and connected directly to an automatic water supply, such as the public water main, a tank with a pump, an elevated tank or a pressure tank.<ref name="H-21" /> Because the pipes are full, every part of the building that contains them must be heated to prevent freezing.<ref name="H-21" />		NFPA 14, as summarised in the NIST report on the World Trade Center suppression systems, describes standpipe systems by their water supply as wet, damp or dry.<ref name="H-21" /> Wet systems are the preferred arrangement. They are filled with water at all times and connected directly to an automatic water supply, such as the public water main, a tank with a pump, an elevated tank or a pressure tank.<ref name="H-21" /> Because the pipes are full, every part of the building that contains them must be heated to prevent freezing.<ref name="H-21" />

			[[File:fse-dry-and-wet-risers-v1.svg\|thumb\|upright=1.5\|alt=Two building sections: left, a water-filled riser fed by a tank and pump; right, an empty riser fed by a fire appliance at a street-level inlet.\|A wet riser (left) is always full and connected to an automatic water supply; a manual dry riser (right) contains air until the fire service pumps water in through the inlet at street level. Based on Hopkins et al. (2005), pp. 19 and 21.]]

	Dry systems contain air at atmospheric pressure or under pressure, and NFPA 14 divides them into manual, automatic and semi-automatic types.<ref name="H-21" /> A manual dry standpipe has only fire department connections and no connection to an automatic water supply: water reaches the outlets only when a fire service pump feeds the inlet.<ref name="H-21" /> An automatic dry standpipe holds pressurised air or nitrogen behind a dry-pipe valve; when a hose valve is opened, the air escapes and the water supply opens the valve and fills the pipe.<ref name="H-21" /> A semi-automatic dry standpipe has a connection to an automatic water supply that is kept closed until it is needed.<ref name="H-21" />		Dry systems contain air at atmospheric pressure or under pressure, and NFPA 14 divides them into manual, automatic and semi-automatic types.<ref name="H-21" /> A manual dry standpipe has only fire department connections and no connection to an automatic water supply: water reaches the outlets only when a fire service pump feeds the inlet.<ref name="H-21" /> An automatic dry standpipe holds pressurised air or nitrogen behind a dry-pipe valve; when a hose valve is opened, the air escapes and the water supply opens the valve and fills the pipe.<ref name="H-21" /> A semi-automatic dry standpipe has a connection to an automatic water supply that is kept closed until it is needed.<ref name="H-21" />
Line 45:		Line 47:

	The pump must therefore supply at least 689 + 897 ≈ 1,590 kPa, about 230 psi, before any friction loss is added (rounded up). The height of 300 ft is the limit used in the New York City building code, which allows an automatic fire pump to serve only the lowest 300 ft of a taller building.<ref name="RG-48">Razza and Grill (2005c), p. 48.</ref> Zones above that height must be supplied by gravity or pressure tanks.<ref name="RG-48" />		The pump must therefore supply at least 689 + 897 ≈ 1,590 kPa, about 230 psi, before any friction loss is added (rounded up). The height of 300 ft is the limit used in the New York City building code, which allows an automatic fire pump to serve only the lowest 300 ft of a taller building.<ref name="RG-48">Razza and Grill (2005c), p. 48.</ref> Zones above that height must be supplied by gravity or pressure tanks.<ref name="RG-48" />

			[[File:fse-dry-and-wet-risers-v2.svg\|thumb\|upright=1.5\|alt=Straight line of static pressure against height, rising about 9.8 kPa per metre, with a marker at 91.4 m and 897 kPa.\|Static pressure of a water column against height, about 9.8 kPa per metre; the marker shows the worked example at 300 ft (91.4 m). Friction losses and the outlet pressure come on top. Based on Titus (2002), p. 4-45.]]

	The same physics explains the vertical zoning of tall buildings. The standpipes in each World Trade Center tower were divided into four vertical water supply zones: floors 1 to 8, 9 to 41, 42 to 76 and 77 to 110.<ref name="H-38" /> Check valves between the zones stopped water from flowing down from one zone into the next.<ref name="H-38" /> Because the working pressure varied with elevation, the riser pipes were heavier at the bottom. The lowest zone had extra-strong steel pipe with fittings rated at 1,000 psi, the top zone standard pipe with 350 psi fittings.<ref name="H-37">Hopkins et al. (2005), p. 37.</ref> Adjustable pressure-restricting devices were fitted to the hose racks on floors 77 to 94.<ref name="H-40" />		The same physics explains the vertical zoning of tall buildings. The standpipes in each World Trade Center tower were divided into four vertical water supply zones: floors 1 to 8, 9 to 41, 42 to 76 and 77 to 110.<ref name="H-38" /> Check valves between the zones stopped water from flowing down from one zone into the next.<ref name="H-38" /> Because the working pressure varied with elevation, the riser pipes were heavier at the bottom. The lowest zone had extra-strong steel pipe with fittings rated at 1,000 psi, the top zone standard pipe with 350 psi fittings.<ref name="H-37">Hopkins et al. (2005), p. 37.</ref> Adjustable pressure-restricting devices were fitted to the hose racks on floors 77 to 94.<ref name="H-40" />

			[[File:fse-dry-and-wet-risers-v3.svg\|thumb\|upright=1.5\|alt=Tall tower schematic split into four standpipe zones, with water tanks near the top of zones, pumps on mechanical floors and inlets at street level.\|Vertical zoning of the standpipe system in a World Trade Center tower: four supply zones, gravity tanks for the first minutes, manual fire pumps on mechanical floors and fire department connections at street level. Based on Hopkins et al. (2005), pp. 10, 30 and 38.]]

	High pressures also limit what the fire service can supply. The 1997 high-rise firefighting procedures of the Fire Department of the City of New York require building fire pumps to deliver their rated capacity at 50 psi (345 kPa) at the highest outlet.<ref name="LV-I">Lawson and Vettori (2005), Appendix I.</ref> The same procedures warn that these pumps, and gravity tanks, may not give adequate nozzle pressure on the upper floors, so the fire service's own pumpers are the primary supply in most operations.<ref name="LV-I" /> As a rule of thumb, they recommend one pumper supplying the standpipe for each hand line in use.<ref name="LV-I" />		High pressures also limit what the fire service can supply. The 1997 high-rise firefighting procedures of the Fire Department of the City of New York require building fire pumps to deliver their rated capacity at 50 psi (345 kPa) at the highest outlet.<ref name="LV-I">Lawson and Vettori (2005), Appendix I.</ref> The same procedures warn that these pumps, and gravity tanks, may not give adequate nozzle pressure on the upper floors, so the fire service's own pumpers are the primary supply in most operations.<ref name="LV-I" /> As a rule of thumb, they recommend one pumper supplying the standpipe for each hand line in use.<ref name="LV-I" />

Daan: New FSE wiki article: Dry and wet risers (written by Claude Opus 5.5)

2026-11-01T22:54:15Z

New FSE wiki article: Dry and wet risers (written by Claude Opus 5.5)

New page

'''Dry and wet risers''' are fixed vertical water pipes in a building with a hose outlet on each floor. They allow firefighters to connect their hoses close to a fire instead of laying hose from the street.<ref name="H-19">Hopkins et al. (2005), p. 19.</ref> A wet riser is filled with water at all times and connected to an automatic water supply. A dry riser contains air, and in its simplest form has no water supply of its own: the fire service pumps water in through an inlet at street level.<ref name="H-21">Hopkins et al. (2005), p. 21.</ref> In the United States the same installations are called standpipe systems, and the vertical pipes in them are called standpipe risers.<ref name="H-19" />

Risers exist because laying hose from an appliance in the street to an upper or underground floor takes time and effort.<ref name="VdG-66" /> Removing the need for long hose lays from the appliance to an upper floor is generally accepted to improve the initial attack, even though no performance statistics are kept for these systems.<ref name="H-21" /> In a [[high-rise building]], the fire service depends on fire pumps and standpipe systems that can supply enough water for fires beyond the reach of appliances on the ground.<ref name="LV-76">Lawson and Vettori (2005), p. 76.</ref> The pressure needed rises by about 9.8 kPa for each metre of height, which is why tall buildings divide their risers into vertical zones with tanks and pumps.<ref name="T-4-45">Titus (2002), p. 4-45.</ref><ref name="H-38">Hopkins et al. (2005), p. 38.</ref>

== Terminology and components ==
A standpipe system is a fixed piping system that delivers water to designated areas of a building to support manual [[firefighting]].<ref name="H-19" /> In a high-rise building it consists of risers with hose connections at each floor, supplied by pumps and by at least one fire department connection at street level.<ref name="H-19" /> The connections may or may not have hoses permanently attached, depending on the type of system and the local code.<ref name="H-19" /> The number of risers depends on the size and layout of the building, and the systems are usually pressure-monitored to show that they are ready for use.<ref name="H-19" />

The main parts are the riser itself, the hose valve or outlet on each floor, and the inlet through which the fire service pumps water into the system. In American usage this inlet is called a fire department connection or "siamese" connection.<ref name="H-19" /><ref name="H-35">Hopkins et al. (2005), p. 35.</ref> In the World Trade Center towers, each hose station had a valve, a 125 ft (38 m) hose and a nozzle, and the racks were mounted about 4.5 ft (1.4 m) above the stair landing.<ref name="H-10">Hopkins et al. (2005), p. 10.</ref><ref name="H-40">Hopkins et al. (2005), p. 40.</ref> This height allowed firefighters to reach the valve without walking up half a flight of stairs.<ref name="H-40" />

The basic concept has changed little in about 90 years. NFPA 14, the American standard for the installation of standpipe and hose systems, was first adopted in 1915.<ref name="H-19" /> New Zealand documents speak of "fire hydrant systems for buildings" and of an internal [[fire hydrant]] designed to NZS 4510.<ref name="MBIE-53">Ministry of Business, Innovation and Employment (2025b), p. 53.</ref><ref name="MBIE-54">Ministry of Business, Innovation and Employment (2025b), p. 54.</ref> A Dutch guideline for car parks, translated into English, uses the term "dry riser".<ref name="VdG-51">Van der Graaf et al. (2021/2023), p. 51.</ref>

== Wet, dry and other types ==
NFPA 14, as summarised in the NIST report on the World Trade Center suppression systems, describes standpipe systems by their water supply as wet, damp or dry.<ref name="H-21" /> Wet systems are the preferred arrangement. They are filled with water at all times and connected directly to an automatic water supply, such as the public water main, a tank with a pump, an elevated tank or a pressure tank.<ref name="H-21" /> Because the pipes are full, every part of the building that contains them must be heated to prevent freezing.<ref name="H-21" />

Dry systems contain air at atmospheric pressure or under pressure, and NFPA 14 divides them into manual, automatic and semi-automatic types.<ref name="H-21" /> A manual dry standpipe has only fire department connections and no connection to an automatic water supply: water reaches the outlets only when a fire service pump feeds the inlet.<ref name="H-21" /> An automatic dry standpipe holds pressurised air or nitrogen behind a dry-pipe valve; when a hose valve is opened, the air escapes and the water supply opens the valve and fills the pipe.<ref name="H-21" /> A semi-automatic dry standpipe has a connection to an automatic water supply that is kept closed until it is needed.<ref name="H-21" />

The choice between wet and dry involves a trade-off. A wet riser gives water at once, but needs a reliable automatic supply and protection against frost.<ref name="H-21" /> A manual dry riser needs no permanent supply, but delivers nothing until the fire service has connected a pumping appliance to its inlet.<ref name="H-21" /> Its use therefore depends on [[fire service access]] to the inlet. The New York City building code, in both editions compared by NIST, provides for wet standpipes.<ref name="RG-46">Razza and Grill (2005c), p. 46.</ref>

Standpipe systems are also classified by user.<ref name="H-19" /> Class I systems have 2½ in. (63.5 mm) hose valves for heavy streams used by the fire service in advanced stages of a fire.<ref name="H-20">Hopkins et al. (2005), p. 20.</ref> Class II systems have 1½ in. (38 mm) hose stations with hoses and nozzles for trained occupants or fire brigades to fight small fires.<ref name="H-20" /> Class III systems combine both and serve the fire service, trained occupants and fire brigades.<ref name="H-20" />

Whether occupants should rely on pre-connected hoses has long been debated.<ref name="H-21" /> Some jurisdictions permit only Class I systems, for use by the fire service alone.<ref name="H-21" /> The pre-connected hoses of the World Trade Center towers were intended for the trained fire brigade or the fire department.<ref name="H-10" />

== Pressure and building height ==
Water in a vertical pipe presses down with its own weight, so the pressure at the bottom of a riser is higher than at the top.<ref name="T-4-45" /> The pressure caused by a column of water alone is called static pressure, and the height of the column is called the head.<ref name="T-4-45" /> The SFPE handbook gives this relation from fluid statics: the pressure difference between two points equals the density of the water, times the acceleration of gravity, times their difference in height.<ref name="T-4-45" />

<math display="block">\Delta p = \rho\, g\, \Delta h</math>

{| class="wikitable"
! Symbol !! Description !! Unit
|-
| <math>\Delta p</math> || static pressure difference between two levels || Pa
|-
| <math>\rho</math> || density of water (about 1,000 kg/m³) || kg/m³
|-
| <math>g</math> || acceleration of gravity (9.81 m/s²) || m/s²
|-
| <math>\Delta h</math> || difference in height between the two levels || m
|}

The relation applies to water at rest or to the elevation part of the pressure in a flowing system; friction losses in pipes and fittings come on top of it.<ref name="T-4-45" /><ref name="H-20" /> Titus gives the same rule in American units: a column of water of ''h'' feet corresponds to 0.433''h'' psi, and 1 psi corresponds to 2.3 ft (0.7 m) of water.<ref name="T-4-45" /> In SI units this is about 9.8 kPa per metre of height. The pump ratings of the World Trade Center standpipe system follow this rule: a pump rated at 360 psi was also listed as 831 ft of head, and 0.433 × 831 ≈ 360.<ref name="H-34">Hopkins et al. (2005), p. 34.</ref>

'''Worked example.''' A standpipe must deliver its design flow at 100 psi (689 kPa) at the most remote outlet.<ref name="H-20" /> If that outlet is 300 ft (91.4 m) above the pump, the height alone costs:

<math display="block">\Delta p = 1000 \times 9.81 \times 91.4 \approx 897\ \mathrm{kPa}\ (130\ \mathrm{psi})</math>

The pump must therefore supply at least 689 + 897 ≈ 1,590 kPa, about 230 psi, before any friction loss is added (rounded up). The height of 300 ft is the limit used in the New York City building code, which allows an automatic fire pump to serve only the lowest 300 ft of a taller building.<ref name="RG-48">Razza and Grill (2005c), p. 48.</ref> Zones above that height must be supplied by gravity or pressure tanks.<ref name="RG-48" />

The same physics explains the vertical zoning of tall buildings. The standpipes in each World Trade Center tower were divided into four vertical water supply zones: floors 1 to 8, 9 to 41, 42 to 76 and 77 to 110.<ref name="H-38" /> Check valves between the zones stopped water from flowing down from one zone into the next.<ref name="H-38" /> Because the working pressure varied with elevation, the riser pipes were heavier at the bottom. The lowest zone had extra-strong steel pipe with fittings rated at 1,000 psi, the top zone standard pipe with 350 psi fittings.<ref name="H-37">Hopkins et al. (2005), p. 37.</ref> Adjustable pressure-restricting devices were fitted to the hose racks on floors 77 to 94.<ref name="H-40" />

High pressures also limit what the fire service can supply. The 1997 high-rise firefighting procedures of the Fire Department of the City of New York require building fire pumps to deliver their rated capacity at 50 psi (345 kPa) at the highest outlet.<ref name="LV-I">Lawson and Vettori (2005), Appendix I.</ref> The same procedures warn that these pumps, and gravity tanks, may not give adequate nozzle pressure on the upper floors, so the fire service's own pumpers are the primary supply in most operations.<ref name="LV-I" /> As a rule of thumb, they recommend one pumper supplying the standpipe for each hand line in use.<ref name="LV-I" />

== Design requirements ==
In the United States, NFPA 14 sets the design flow for Class I and Class III systems at 500 US gal/min (about 1,900 L/min) at 100 psi at the most hydraulically remote standpipe.<ref name="H-20" /> Each additional standpipe adds 250 US gal/min (about 950 L/min), up to a total of 1,250 US gal/min (about 4,700 L/min).<ref name="H-20" /> This assumes two 2½ in. hose lines on the most remote standpipe and one on each of the others.<ref name="H-20" /> "Remote" means hydraulically remote: the outlet needing the highest pressure at the source, which may be the top floor or the far end of a building, so the design is checked with a hydraulic analysis.<ref name="H-20" /> Class II systems are designed for 100 US gal/min (about 380 L/min) at 65 psi (448 kPa).<ref name="H-20" />

The spacing of the outlets is expressed in lengths of hose. When the World Trade Center was built, NFPA 14 required Class I hose valves to be placed so that every part of a building lay within 30 ft (9.1 m) of a nozzle. That nozzle was assumed to be on a 100 ft (30.5 m) hose.<ref name="H-20" /> The New York City building code, in its 1968 and 2003 editions, requires that every point on every floor can be reached by a 20 ft (6.1 m) stream. The stream comes from a nozzle on not more than 125 ft (38 m) of hose.<ref name="RG-46" /> The risers and their 2½ in. hose valves must be inside the stair enclosures, with an outlet on each floor 5 to 6 ft above the landing.<ref name="RG-46" /><ref name="RG-47">Razza and Grill (2005c), p. 47.</ref>

The same code sets the riser size by height: at least 4 in. (about 100 mm) in diameter up to 150 ft (46 m) from the entrance floor to the highest outlet, and 6 in. (about 150 mm) above that.<ref name="RG-48" /> Where a system has several risers, they must be cross-connected at or below street level.<ref name="RG-47" /> Buildings over 300 ft (91 m) high need an additional water supply for their standpipes, supplemented by manually operated fire pumps.<ref name="RG-49">Razza and Grill (2005c), p. 49.</ref>

In New Zealand, the second edition of C/VM2 (2025) requires vehicle access to a hard-standing from which an unobstructed path leads to within 20 m of the inlets to sprinkler or fire hydrant systems.<ref name="MBIE-53" /> It also requires the means to deliver water for firefighting to all parts of the building.<ref name="MBIE-53" /> That water comes either from a pumping appliance parked so that every point in the building lies within 75 m, about three hose lengths, or from an internal hydrant installed to NZS 4510.<ref name="MBIE-54" /> For intermediate floors, a commentary in the same document accepts a hydrant in a safe path within 40 m, about two hose lengths, of the most remote point.<ref name="MBIE-55">Ministry of Business, Innovation and Employment (2025b), p. 55.</ref>

In the Netherlands, guidance on indoor car parks advises placing a dry riser where the fire service enters, because it shortens the hose to be laid out and so the attack time.<ref name="VdG-66">Van der Graaf et al. (2021/2023), p. 66.</ref> It recommends a smoke-free stairwell as an attack route to underground storeys, with a connection point for a dry riser, and notes that most car parks have such a stairwell.<ref name="VdG-51" /> The International Fire Engineering Guidelines (2005) list the location of hydrants and other fire service facilities, and the amount of firefighting water available, among the factors that govern the efficiency of fire service intervention.<ref name="IFEG-1.9-5">National Research Council of Canada et al. (2005), p. 1.9-5.</ref>

== The World Trade Center, 2001 ==
The towers of the World Trade Center show how a large riser system works and how it can fail. Each tower had three standpipe risers per zone, one in each exit stair, with Class III hose stations on every floor.<ref name="H-10" /><ref name="H-37" /> In the initial operating mode, water came by gravity from 5,000 US gal (about 19,000 L) tanks placed above each zone, enough for 500 US gal/min for about 10 minutes.<ref name="H-30">Hopkins et al. (2005), p. 30.</ref><ref name="H-39">Hopkins et al. (2005), p. 39.</ref> During that time, staff were expected to start manual 750 US gal/min fire pumps on the 7th, 41st and 75th floors, which drew on the city [[fire water supply]].<ref name="H-10" /><ref name="H-39" /> Fourteen fire department connection stations at street level allowed the fire service to add water and pressure.<ref name="H-10" />

On 11 September 2001 the aircraft impacts damaged the stairwells around the risers. In WTC 1, NIST concluded that two of the three standpipe risers were probably lost and the third possibly, so the standpipe water supply would have been lost after a limited time.<ref name="E-37">Evans et al. (2005), p. 37.</ref><ref name="E-38">Evans et al. (2005), p. 38.</ref> Isolation valves on the 88th and 99th floors could in principle have allowed a partial restoration, but the status of the systems was unknown.<ref name="E-38" /> The fire service's first size-up found the standpipe systems inoperable at the impact zones.<ref name="LV-77">Lawson and Vettori (2005), p. 77.</ref> Restoring them would have required building staff to close an isolation valve between the towers and to go up with firefighters to seal the broken pipes and run the pumps.<ref name="LV-77" />

The scale of the task shows why risers matter. NIST estimated that about 4,700 L/min would be needed to extinguish half a floor of a tower, using about five 63.5 mm hose lines, and about 9,400 L/min and ten lines for a whole floor.<ref name="LV-77" /> Such an operation would involve at least 15 to 20 engine companies, and if the building's pumps were not working, special high-rise pumpers would have to feed the standpipes.<ref name="LV-77" /> Fire departments also rely on lifts, such as a [[firefighting lift]], to carry personnel and equipment up tall buildings, and lifts are often an integral part of high-rise firefighting.<ref name="LV-77" /> In 7 World Trade Center later that day, a chief officer opened a standpipe on the 4th floor and found no water.<ref name="LV-110">Lawson and Vettori (2005), p. 110.</ref>

== Limitations ==
No performance records are kept for standpipe and hose systems, so their reliability cannot be quantified from the sources.<ref name="H-21" /> They are not an alternative to automatic sprinklers.<ref name="H-21" /> A riser only supplies water if its source works. In the World Trade Center towers the extra water depended on manually started pumps, whereas NFPA 14 requires an automatic supplementary supply as current best practice.<ref name="H-10" /><ref name="E-xxxi">Evans et al. (2005), p. xxxi.</ref> A dry riser depends entirely on the fire service reaching and charging its inlet.<ref name="H-21" />

Because risers run through the stairs, damage that affects the stair cores can disable several risers at once, as it did in 2001.<ref name="E-37" /> The NIST emergency response report lists the distance between stairwells containing standpipes, and redundant standpipe and water supply systems, among the difficulties seen in the responses of 1993 and 2001.<ref name="LV-l">Lawson and Vettori (2005), p. l.</ref> Sectional isolation valves, such as those on floors 88 and 99 of the World Trade Center risers, offer a way to shut off a damaged section and restore part of a system.<ref name="H-39" /><ref name="E-38" />

== See also ==
* [[Hose reel]]
* [[Fire extinguisher]]
* [[Positive pressure ventilation]]

== Notes ==
<references />

== References ==
* Evans, D. D., Peacock, R. D., Kuligowski, E. D., Dols, W. S., & Grosshandler, W. L. (2005). ''Active fire protection systems'' (NIST NCSTAR 1-4). National Institute of Standards and Technology.
* Hopkins, M., Schoenrock, J., & Budnick, E. (2005). ''Fire suppression systems'' (NIST NCSTAR 1-4B). National Institute of Standards and Technology.
* Lawson, J. R., & Vettori, R. L. (2005). ''The emergency response operations'' (NIST NCSTAR 1-8). National Institute of Standards and Technology.
* Ministry of Business, Innovation and Employment. (2025b). ''Verification Method C/VM2: Framework for fire safety design'' (2nd ed.).
* National Research Council of Canada, International Code Council, Department of Building and Housing, & Australian Building Codes Board. (2005). ''International fire engineering guidelines'' (2005 ed.). Australian Building Codes Board.
* Razza, J. C., & Grill, R. A. (2005c). ''Comparison of the 1968 and current (2003) New York City Building Code provisions'' (NIST NCSTAR 1-1F). National Institute of Standards and Technology.
* Titus, J. J. (2002). Hydraulics. In P. J. DiNenno, D. Drysdale, C. L. Beyler, W. D. Walton, R. L. P. Custer, J. R. Hall Jr., & J. M. Watts Jr. (Eds.), ''SFPE handbook of fire protection engineering'' (3rd ed., pp. 4-44–4-71). National Fire Protection Association; Society of Fire Protection Engineers.
* Van der Graaf, J., Hessels, T., & Rosmuller, N. (2023). ''Fire safety of indoor car parks accommodating electrically powered vehicles''. Nederlands Instituut Publieke Veiligheid. (Original work published 2021)

[[Category:Firefighting & Fire Service]]