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	<id>https://fire-safety.academy/w/index.php?action=history&amp;feed=atom&amp;title=Fire_hydrant</id>
	<title>Fire hydrant - Revision history</title>
	<link rel="self" type="application/atom+xml" href="https://fire-safety.academy/w/index.php?action=history&amp;feed=atom&amp;title=Fire_hydrant"/>
	<link rel="alternate" type="text/html" href="https://fire-safety.academy/w/index.php?title=Fire_hydrant&amp;action=history"/>
	<updated>2026-11-04T12:25:38Z</updated>
	<subtitle>Revision history for this page on the wiki</subtitle>
	<generator>MediaWiki 1.43.11</generator>
	<entry>
		<id>https://fire-safety.academy/w/index.php?title=Fire_hydrant&amp;diff=2800&amp;oldid=prev</id>
		<title>Mark: Revise against the FSE wiki writing guidelines: corrections after independent fact-check (revised by Claude Opus 5.5)</title>
		<link rel="alternate" type="text/html" href="https://fire-safety.academy/w/index.php?title=Fire_hydrant&amp;diff=2800&amp;oldid=prev"/>
		<updated>2026-11-02T18:36:31Z</updated>

		<summary type="html">&lt;p&gt;Revise against the FSE wiki writing guidelines: corrections after independent fact-check (revised by Claude Opus 5.5)&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
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				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 19:36, 2 November 2026&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l62&quot;&gt;Line 62:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 62:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Rescue work, care for the injured and the loss of hydrant water meant that the fire department could not consider fighting the WTC 7 fires until about 1:00 p.m.&amp;lt;ref name=&amp;quot;McA-627&amp;quot;&amp;gt;McAllister et al. (2008), p. 627.&amp;lt;/ref&amp;gt; At about 2:30 p.m. it ordered its personnel to withdraw from the building. The reasons included growing fires, possible structural damage, the loss of many fire department assets and the lack of usable water in the hydrant system.&amp;lt;ref name=&amp;quot;McA-304&amp;quot; /&amp;gt; The city mains had also been the only supply for the sprinklers on the lowest 20 floors. Fires on the 7th to 13th floors therefore went unchecked by sprinklers.&amp;lt;ref name=&amp;quot;McA-77&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;McA-78&amp;quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Rescue work, care for the injured and the loss of hydrant water meant that the fire department could not consider fighting the WTC 7 fires until about 1:00 p.m.&amp;lt;ref name=&amp;quot;McA-627&amp;quot;&amp;gt;McAllister et al. (2008), p. 627.&amp;lt;/ref&amp;gt; At about 2:30 p.m. it ordered its personnel to withdraw from the building. The reasons included growing fires, possible structural damage, the loss of many fire department assets and the lack of usable water in the hydrant system.&amp;lt;ref name=&amp;quot;McA-304&amp;quot; /&amp;gt; The city mains had also been the only supply for the sprinklers on the lowest 20 floors. Fires on the 7th to 13th floors therefore went unchecked by sprinklers.&amp;lt;ref name=&amp;quot;McA-77&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;McA-78&amp;quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;== Maintenance, information and &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;misconceptions &lt;/del&gt;==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;== Maintenance, information and &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;limits &lt;/ins&gt;==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;A hydrant only helps if crews can reach it and it works when needed. The International Fire Engineering Guidelines list perimeter roads for fire service access and equipment such as hydrants among the items whose design and maintenance effective intervention needs.&amp;lt;ref name=&amp;quot;IFEG-1.9-8&amp;quot;&amp;gt;National Research Council of Canada et al. (2005), p. 1.9-8.&amp;lt;/ref&amp;gt; In some jurisdictions, essential safety provisions may secure that maintenance.&amp;lt;ref name=&amp;quot;IFEG-1.9-8&amp;quot; /&amp;gt; The guidelines also note that the fire service part of a design may change over a building&amp;#039;s life, through changes in fire stations, budgets, equipment and traffic.&amp;lt;ref name=&amp;quot;IFEG-1.9-2&amp;quot;&amp;gt;National Research Council of Canada et al. (2005), p. 1.9-2.&amp;lt;/ref&amp;gt; The 2013 commentary on C/VM2 reads New Zealand Building Code clause C5.8 as requiring hydrants and other fire safety systems to meet acceptable standards for design, construction, installation and maintenance.&amp;lt;ref name=&amp;quot;MBIE13-35&amp;quot;&amp;gt;Ministry of Business, Innovation and Employment (2013), p. 35.&amp;lt;/ref&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;A hydrant only helps if crews can reach it and it works when needed. The International Fire Engineering Guidelines list perimeter roads for fire service access and equipment such as hydrants among the items whose design and maintenance effective intervention needs.&amp;lt;ref name=&amp;quot;IFEG-1.9-8&amp;quot;&amp;gt;National Research Council of Canada et al. (2005), p. 1.9-8.&amp;lt;/ref&amp;gt; In some jurisdictions, essential safety provisions may secure that maintenance.&amp;lt;ref name=&amp;quot;IFEG-1.9-8&amp;quot; /&amp;gt; The guidelines also note that the fire service part of a design may change over a building&amp;#039;s life, through changes in fire stations, budgets, equipment and traffic.&amp;lt;ref name=&amp;quot;IFEG-1.9-2&amp;quot;&amp;gt;National Research Council of Canada et al. (2005), p. 1.9-2.&amp;lt;/ref&amp;gt; The 2013 commentary on C/VM2 reads New Zealand Building Code clause C5.8 as requiring hydrants and other fire safety systems to meet acceptable standards for design, construction, installation and maintenance.&amp;lt;ref name=&amp;quot;MBIE13-35&amp;quot;&amp;gt;Ministry of Business, Innovation and Employment (2013), p. 35.&amp;lt;/ref&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l68&quot;&gt;Line 68:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 68:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Firefighters also need to know what each connection serves. New Zealand&amp;#039;s clause C5.7 requires clear information so that firefighters can locate the fire and identify the fire safety systems in the building.&amp;lt;ref name=&amp;quot;MBIE-53&amp;quot; /&amp;gt; It also requires information on any hazardous substances or processes in the building.&amp;lt;ref name=&amp;quot;MBIE-53&amp;quot; /&amp;gt; In New York, colour-coded caps showed whether a fire department connection fed a standpipe, a sprinkler system, a combined system or a high-pressure supply.&amp;lt;ref name=&amp;quot;McA-77&amp;quot; /&amp;gt; The operations and maintenance manual of WTC 7 included a riser diagram showing the arrangement of the valves.&amp;lt;ref name=&amp;quot;McA-78&amp;quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Firefighters also need to know what each connection serves. New Zealand&amp;#039;s clause C5.7 requires clear information so that firefighters can locate the fire and identify the fire safety systems in the building.&amp;lt;ref name=&amp;quot;MBIE-53&amp;quot; /&amp;gt; It also requires information on any hazardous substances or processes in the building.&amp;lt;ref name=&amp;quot;MBIE-53&amp;quot; /&amp;gt; In New York, colour-coded caps showed whether a fire department connection fed a standpipe, a sprinkler system, a combined system or a high-pressure supply.&amp;lt;ref name=&amp;quot;McA-77&amp;quot; /&amp;gt; The operations and maintenance manual of WTC 7 included a riser diagram showing the arrangement of the valves.&amp;lt;ref name=&amp;quot;McA-78&amp;quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;A common misconception is that hydrants guarantee an attack from inside the building. &lt;/del&gt;&#039;&#039;Introduction to Fire Safety Engineering&#039;&#039; stresses that a positive result of a fire safety engineering analysis does not mean the fire service will attack from inside.&amp;lt;ref name=&quot;VR-9.3&quot;&amp;gt;Van Rossum (2027), §9.3 (Results from zone models).&amp;lt;/ref&amp;gt; That decision always rests with the crews at the scene.&amp;lt;ref name=&quot;VR-9.3&quot; /&amp;gt; The International Fire Engineering Guidelines likewise state that the analysis of occupant evacuation should not rely on fire service intervention.&amp;lt;ref name=&quot;IFEG-1.9-1&quot;&amp;gt;National Research Council of Canada et al. (2005), p. 1.9-1.&amp;lt;/ref&amp;gt; It is &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;also &lt;/del&gt;misleading to give hydrants a fixed score in a risk checklist. The SFPE Handbook notes that the relative value of hydrants, sprinklers and extinguishers depends on other features of a building&#039;s form and use.&amp;lt;ref name=&quot;WH-5-5&quot;&amp;gt;Watts and Hall (2002), p. 5-5.&amp;lt;/ref&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&#039;&#039;Introduction to Fire Safety Engineering&#039;&#039; stresses that a positive result of a fire safety engineering analysis does not mean the fire service will attack from inside.&amp;lt;ref name=&quot;VR-9.3&quot;&amp;gt;Van Rossum (2027), §9.3 (Results from zone models).&amp;lt;/ref&amp;gt; That decision always rests with the crews at the scene.&amp;lt;ref name=&quot;VR-9.3&quot; /&amp;gt; The International Fire Engineering Guidelines likewise state that the analysis of occupant evacuation should not rely on fire service intervention.&amp;lt;ref name=&quot;IFEG-1.9-1&quot;&amp;gt;National Research Council of Canada et al. (2005), p. 1.9-1.&amp;lt;/ref&amp;gt; It is misleading to give hydrants a fixed score in a risk checklist. The SFPE Handbook notes that the relative value of hydrants, sprinklers and extinguishers depends on other features of a building&#039;s form and use.&amp;lt;ref name=&quot;WH-5-5&quot;&amp;gt;Watts and Hall (2002), p. 5-5.&amp;lt;/ref&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;== See also ==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;== See also ==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Mark</name></author>
	</entry>
	<entry>
		<id>https://fire-safety.academy/w/index.php?title=Fire_hydrant&amp;diff=2685&amp;oldid=prev</id>
		<title>Mark: Revise against the FSE wiki writing guidelines: verified and corrected citations, new sources, See also, links, style (revised by Claude Opus 5.5)</title>
		<link rel="alternate" type="text/html" href="https://fire-safety.academy/w/index.php?title=Fire_hydrant&amp;diff=2685&amp;oldid=prev"/>
		<updated>2026-11-02T17:52:44Z</updated>

		<summary type="html">&lt;p&gt;Revise against the FSE wiki writing guidelines: verified and corrected citations, new sources, See also, links, style (revised by Claude Opus 5.5)&lt;/p&gt;
&lt;a href=&quot;https://fire-safety.academy/w/index.php?title=Fire_hydrant&amp;amp;diff=2685&amp;amp;oldid=1168&quot;&gt;Show changes&lt;/a&gt;</summary>
		<author><name>Mark</name></author>
	</entry>
	<entry>
		<id>https://fire-safety.academy/w/index.php?title=Fire_hydrant&amp;diff=1168&amp;oldid=prev</id>
		<title>Sanne: Add diagrams fse-fire-hydrant-v1.svg, fse-fire-hydrant-v2.svg, fse-fire-hydrant-v3.svg (level-1 visual plan)</title>
		<link rel="alternate" type="text/html" href="https://fire-safety.academy/w/index.php?title=Fire_hydrant&amp;diff=1168&amp;oldid=prev"/>
		<updated>2026-11-02T07:24:45Z</updated>

		<summary type="html">&lt;p&gt;Add diagrams fse-fire-hydrant-v1.svg, fse-fire-hydrant-v2.svg, fse-fire-hydrant-v3.svg (level-1 visual plan)&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
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				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 08:24, 2 November 2026&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l8&quot;&gt;Line 8:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 8:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;The hydrant&amp;#039;s primary function is to make water available to a pumping appliance. The appliance and its crew then deliver water through their hose systems. This makes the hydrant one part of a chain that includes municipal or private supply, connection, pumping, hoses and nozzles.&amp;lt;ref name=&amp;quot;NUREG-F25&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;Hopkins-xxxv&amp;quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;The hydrant&amp;#039;s primary function is to make water available to a pumping appliance. The appliance and its crew then deliver water through their hose systems. This makes the hydrant one part of a chain that includes municipal or private supply, connection, pumping, hoses and nozzles.&amp;lt;ref name=&amp;quot;NUREG-F25&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;Hopkins-xxxv&amp;quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[File:fse-fire-hydrant-v1.svg|thumb|upright=1.5|alt=Source, hydrant, pumper, hoses and nozzle form a chain to the fire.|A hydrant supplies a pumping appliance rather than extinguishing directly. Based on U.S. Nuclear Regulatory Commission (2005), p. F-25 and Hopkins, Schoenrock, and Budnick (2005), pp. xxxi–xxxv.]]&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Fire water supply]] includes the sources and infrastructure needed to provide that flow. NIST&amp;#039;s WTC analysis describes municipal distribution, reserve tanks, pumps and fire department connections as different components. Those sources can have different capacities and failure modes.&amp;lt;ref name=&amp;quot;Hopkins-xxxii&amp;quot;&amp;gt;Hopkins, Schoenrock, and Budnick (2005), pp. xxxii–xxxv.&amp;lt;/ref&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Fire water supply]] includes the sources and infrastructure needed to provide that flow. NIST&amp;#039;s WTC analysis describes municipal distribution, reserve tanks, pumps and fire department connections as different components. Those sources can have different capacities and failure modes.&amp;lt;ref name=&amp;quot;Hopkins-xxxii&amp;quot;&amp;gt;Hopkins, Schoenrock, and Budnick (2005), pp. xxxii–xxxv.&amp;lt;/ref&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l28&quot;&gt;Line 28:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 29:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Redundancy can involve more than one source or supply route. NIST describes municipal connections, reserve tanks and fire department connections as supporting provisions. Their independence must be assessed, because shared mains, power or valves can still create common failure points.&amp;lt;ref name=&amp;quot;Hopkins-xxxv&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;Hopkins-xli&amp;quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Redundancy can involve more than one source or supply route. NIST describes municipal connections, reserve tanks and fire department connections as supporting provisions. Their independence must be assessed, because shared mains, power or valves can still create common failure points.&amp;lt;ref name=&amp;quot;Hopkins-xxxv&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;Hopkins-xli&amp;quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[File:fse-fire-hydrant-v2.svg|thumb|upright=1.5|alt=Municipal, tank, pump and fire-department supplies feed hydrants, with shared failure points.|Redundant supplies require independent availability when needed. Based on Hopkins, Schoenrock, and Budnick (2005), pp. xxxiv–xxxv and pp. xli–xlii.]]&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;== Firefighting access ==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;== Firefighting access ==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l36&quot;&gt;Line 36:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 38:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Access includes more than vehicle arrival. Personnel must reach the fire floor, search the area and protect their means of egress. Building information should help them identify the fire location, available systems and hazardous substances or processes.&amp;lt;ref name=&amp;quot;CVM2-53&amp;quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Access includes more than vehicle arrival. Personnel must reach the fire floor, search the area and protect their means of egress. Building information should help them identify the fire location, available systems and hazardous substances or processes.&amp;lt;ref name=&amp;quot;CVM2-53&amp;quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[File:fse-fire-hydrant-v3.svg|thumb|upright=1.5|alt=Pumper at hard-standing connects to hydrant and hoses reach fire through protected access.|Firefighting access includes vehicles, connections, internal routes and safe egress. Based on Ministry of Business, Innovation and Employment (2025), pp. 53–55.]]&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Hose deployment can determine whether a connection is practically usable. C/VM2 offers one provision based on reaching any point within a building within 75 m of a pumping appliance, approximately three hose lengths. That is a scenario-specific method, not a guarantee of safe or direct hose routing.&amp;lt;ref name=&amp;quot;CVM2-54&amp;quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Hose deployment can determine whether a connection is practically usable. C/VM2 offers one provision based on reaching any point within a building within 75 m of a pumping appliance, approximately three hose lengths. That is a scenario-specific method, not a guarantee of safe or direct hose routing.&amp;lt;ref name=&amp;quot;CVM2-54&amp;quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Sanne</name></author>
	</entry>
	<entry>
		<id>https://fire-safety.academy/w/index.php?title=Fire_hydrant&amp;diff=725&amp;oldid=prev</id>
		<title>Jan: New FSE wiki article: Fire hydrant (written by Kimi Code CLI)</title>
		<link rel="alternate" type="text/html" href="https://fire-safety.academy/w/index.php?title=Fire_hydrant&amp;diff=725&amp;oldid=prev"/>
		<updated>2026-11-02T03:56:53Z</updated>

		<summary type="html">&lt;p&gt;New FSE wiki article: Fire hydrant (written by Kimi Code CLI)&lt;/p&gt;
&lt;p&gt;&lt;b&gt;New page&lt;/b&gt;&lt;/p&gt;&lt;div&gt;A &amp;#039;&amp;#039;&amp;#039;Fire hydrant&amp;#039;&amp;#039;&amp;#039; is a device that provides water to fire department pumpers for firefighting. It forms a connection point between the available water infrastructure and the equipment used to deliver water to a fire. Its usefulness depends on access, flow, pressure, valve condition and the complete supply network.&amp;lt;ref name=&amp;quot;NUREG-F25&amp;quot;&amp;gt;U.S. Nuclear Regulatory Commission (2005), p. F-25.&amp;lt;/ref&amp;gt;&amp;lt;ref name=&amp;quot;CVM2-53&amp;quot;&amp;gt;Ministry of Business, Innovation and Employment (2025), p. 53.&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
A hydrant does not itself extinguish a fire. Water must be transported through suitable hoses and applied by trained personnel, while the supply must remain available during operations. The hydrant&amp;#039;s location and condition therefore need to be assessed together with vehicle access, hose deployment and fire conditions.&amp;lt;ref name=&amp;quot;CVM2-54&amp;quot;&amp;gt;Ministry of Business, Innovation and Employment (2025), pp. 53–55.&amp;lt;/ref&amp;gt;&amp;lt;ref name=&amp;quot;Hopkins-xxxi&amp;quot;&amp;gt;Hopkins, Schoenrock, and Budnick (2005), pp. xxxi–xxxv.&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Hydrants are also distinct from sprinkler inlets and standpipes, although these provisions can be located close together. A fire department connection can supplement an installed system, while a standpipe distributes water to hose outlets within a building. Each provision has its own function and dependencies.&amp;lt;ref name=&amp;quot;NUREG-F61&amp;quot;&amp;gt;U.S. Nuclear Regulatory Commission (2005), pp. F-61–F-62.&amp;lt;/ref&amp;gt;&amp;lt;ref name=&amp;quot;Hopkins-xxxv&amp;quot;&amp;gt;Hopkins, Schoenrock, and Budnick (2005), p. xxxv.&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
== Function and system boundary ==&lt;br /&gt;
&lt;br /&gt;
The hydrant&amp;#039;s primary function is to make water available to a pumping appliance. The appliance and its crew then deliver water through their hose systems. This makes the hydrant one part of a chain that includes municipal or private supply, connection, pumping, hoses and nozzles.&amp;lt;ref name=&amp;quot;NUREG-F25&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;Hopkins-xxxv&amp;quot; /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
[[Fire water supply]] includes the sources and infrastructure needed to provide that flow. NIST&amp;#039;s WTC analysis describes municipal distribution, reserve tanks, pumps and fire department connections as different components. Those sources can have different capacities and failure modes.&amp;lt;ref name=&amp;quot;Hopkins-xxxii&amp;quot;&amp;gt;Hopkins, Schoenrock, and Budnick (2005), pp. xxxii–xxxv.&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
A hydrant&amp;#039;s static condition does not demonstrate adequate flow during an incident. Pressure can change as demand increases and as losses occur in the distribution network. The relevant assessment therefore includes the operating condition and not only the presence of a connection.&amp;lt;ref name=&amp;quot;Hopkins-xli&amp;quot;&amp;gt;Hopkins, Schoenrock, and Budnick (2005), pp. xli–xlii.&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Water supply can be affected by physical damage or loss of power. NIST identifies city-main damage, pump-power loss and infrastructure failure as possible interruptions in its scenarios. A hydrant at a usable location can consequently be unable to support the intended operation.&amp;lt;ref name=&amp;quot;Hopkins-xli&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;Hopkins-xlii&amp;quot; /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
The complete boundary also includes valves and isolation arrangements. Valves can allow parts of a network to be isolated, but an incorrect position can prevent supply. Inspection and operational information should make those dependencies visible to the responding personnel.&amp;lt;ref name=&amp;quot;Hopkins-xxxv&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;NUREG-10-2&amp;quot;&amp;gt;U.S. Nuclear Regulatory Commission (2005), p. 10-2.&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
== Municipal and private supplies ==&lt;br /&gt;
&lt;br /&gt;
Municipal networks distribute water through underground mains. NIST describes a gridded lower-Manhattan network with several possible flow paths, which reduces sensitivity to restrictions in any one path. That description is specific to the WTC area and is not a universal municipal arrangement.&amp;lt;ref name=&amp;quot;Hopkins-xxxiii&amp;quot;&amp;gt;Hopkins, Schoenrock, and Budnick (2005), p. xxxiii.&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
The same account reports expected flows in the local mains with little recognisable pressure reduction under normal conditions. Those values are observations for that system and period. They cannot be used to infer available flow or residual pressure in another network.&amp;lt;ref name=&amp;quot;Hopkins-xxxiii&amp;quot; /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Reserve tanks can provide an initial or secondary supply. NIST describes tanks that allowed time for personnel to start pumps manually, while also providing a finite quantity. The intended response must account for how that finite duration interacts with pump activation and subsequent supply.&amp;lt;ref name=&amp;quot;Hopkins-xxxv&amp;quot; /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Fire pumps can increase pressure to the required distribution system. They depend on suitable power, operation and maintenance. A pump that fails to start or loses power can make an otherwise intact pipe network unavailable.&amp;lt;ref name=&amp;quot;Hopkins-xxxv&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;NUREG-10-2&amp;quot; /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Redundancy can involve more than one source or supply route. NIST describes municipal connections, reserve tanks and fire department connections as supporting provisions. Their independence must be assessed, because shared mains, power or valves can still create common failure points.&amp;lt;ref name=&amp;quot;Hopkins-xxxv&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;Hopkins-xli&amp;quot; /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
== Firefighting access ==&lt;br /&gt;
&lt;br /&gt;
[[Fire service access]] must allow a pumping appliance to reach a position from which personnel and hoses can be deployed effectively. C/VM2 uses a hard-standing and an unobstructed path to the building as part of its New Zealand firefighting scenario. The relevant connections must also remain accessible.&amp;lt;ref name=&amp;quot;CVM2-53&amp;quot; /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
C/VM2 refers to access within 20 m of firefighter entry points and installed sprinkler or hydrant inlets in its cited clause. This is a requirement of the second-edition New Zealand method, not a universal hydrant spacing rule. Other jurisdictions and building layouts must use their own criteria.&amp;lt;ref name=&amp;quot;CVM2-53&amp;quot; /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Access includes more than vehicle arrival. Personnel must reach the fire floor, search the area and protect their means of egress. Building information should help them identify the fire location, available systems and hazardous substances or processes.&amp;lt;ref name=&amp;quot;CVM2-53&amp;quot; /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Hose deployment can determine whether a connection is practically usable. C/VM2 offers one provision based on reaching any point within a building within 75 m of a pumping appliance, approximately three hose lengths. That is a scenario-specific method, not a guarantee of safe or direct hose routing.&amp;lt;ref name=&amp;quot;CVM2-54&amp;quot; /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Structural stability also affects access. C/VM2 calls for specified structures supporting firefighter access and rescue to remain stable during and after fire. A hydrant and hard-standing may be usable initially but become inaccessible if the building&amp;#039;s condition changes.&amp;lt;ref name=&amp;quot;CVM2-53&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;CVM2-54&amp;quot; /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
== Hydrants and standpipe systems ==&lt;br /&gt;
&lt;br /&gt;
A [[Dry and wet risers]] system distributes water vertically within a building to hose outlets. NUREG-1805 defines a standpipe as piping, risers, valves and connections used by occupants or fire department personnel. Wet standpipes are permanently charged with water, while manual standpipes rely on the fire service to supply them.&amp;lt;ref name=&amp;quot;NUREG-F61&amp;quot; /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
A hydrant can provide water to a pumping appliance, while a fire department connection can feed a standpipe or sprinkler system. These functions should not be conflated merely because they share a location or connection hardware. Their downstream networks and intended users differ.&amp;lt;ref name=&amp;quot;Hopkins-xxxv&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;NUREG-F61&amp;quot; /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
NUREG-1805 describes standpipe classes according to intended use. Class I serves fire service or personnel trained in heavy streams, Class II concerns incipient-fire hose use, and Class III combines those features. Those classes are not the same as fuel-based fire classes.&amp;lt;ref name=&amp;quot;NUREG-F61&amp;quot; /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
NIST&amp;#039;s WTC account describes standpipes in stairwells supplying pre-connected hoses on each floor. It also describes ground-level fire department connections that could supplement those systems. This illustrates how internal distribution and external supply can work together.&amp;lt;ref name=&amp;quot;Hopkins-xxxiv&amp;quot;&amp;gt;Hopkins, Schoenrock, and Budnick (2005), pp. xxxiv–xxxv.&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
A [[Firefighting]] assessment must therefore identify the complete path. Municipal or reserve water reaches the hydrant or inlet, passes through pumps and risers, and reaches hose teams or fixed outlets. A failure at any stage can change the water available at the fire.&amp;lt;ref name=&amp;quot;Hopkins-xli&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;NUREG-F61&amp;quot; /&amp;gt;&lt;br /&gt;
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== Flow, pressure and hose deployment ==&lt;br /&gt;
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Hydraulic assessment considers available flow and pressure after losses through the network. NIST used minimum delivered density and pressure requirements to evaluate installed systems under specified conditions. Those criteria and design areas belong to the cited standards and analysis, not to every building.&amp;lt;ref name=&amp;quot;Hopkins-xli&amp;quot; /&amp;gt;&lt;br /&gt;
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The analysis found capacity to control several small fires under normal operating assumptions, but performance degraded as the assumed operating area increased. This illustrates the difference between available hydraulic capacity and the fire&amp;#039;s actual demand. A system can have excess capacity for one scenario and be overwhelmed by a larger one.&amp;lt;ref name=&amp;quot;Hopkins-xli&amp;quot; /&amp;gt;&lt;br /&gt;
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NIST also found one booster pump undersized relative to the cited NFPA 14 requirement, while noting it met the local code. This shows the importance of distinguishing different acceptance bases. A component can satisfy one code and still fall below another engineering benchmark.&amp;lt;ref name=&amp;quot;Hopkins-xli&amp;quot; /&amp;gt;&lt;br /&gt;
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Hose length and route add operational losses and deployment time. C/VM2 uses approximate hose lengths in its method to address whether water can reach all parts of the building. Actual routes can be indirect and must be considered with the firefighters&amp;#039; access and exit conditions.&amp;lt;ref name=&amp;quot;CVM2-54&amp;quot; /&amp;gt;&lt;br /&gt;
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The fire environment affects whether water can be applied safely. C/VM2 sets conditions for radiation and smoke-layer height at first water application in particular unsprinklered firecells. Those criteria apply to the specified New Zealand scenario and do not guarantee safe conditions later.&amp;lt;ref name=&amp;quot;CVM2-53&amp;quot; /&amp;gt;&lt;br /&gt;
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== Reliability and common failures ==&lt;br /&gt;
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A hydrant and its connection can be physically intact while water is unavailable. NUREG-1805 lists empty tanks, broken headers, closed valves and pump failures as possible sprinkler-supply failures. The same systems-thinking is necessary when evaluating hydrant-supported manual firefighting.&amp;lt;ref name=&amp;quot;NUREG-10-2&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;Hopkins-xli&amp;quot; /&amp;gt;&lt;br /&gt;
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Shared infrastructure can defeat apparent redundancy. Several outlets connected to one damaged main or pump can lose supply together. NIST&amp;#039;s evaluation considers initial damage to risers and water-supply components when estimating system performance during the incident.&amp;lt;ref name=&amp;quot;Hopkins-xlii&amp;quot; /&amp;gt;&lt;br /&gt;
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Reserve arrangements need realistic timing. A tank with limited duration may support only the period before pumps or alternative supplies operate. That duration must be compared with detection, response, deployment and activation times rather than treated as unlimited backup.&amp;lt;ref name=&amp;quot;Hopkins-xxxv&amp;quot; /&amp;gt;&lt;br /&gt;
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Damage to distribution outside the building can matter as much as damage within it. NIST describes water-system damage in the streets around the WTC after the collapses. Access to an external hydrant therefore does not guarantee that the municipal supply remains available.&amp;lt;ref name=&amp;quot;Hopkins-xxxi&amp;quot; /&amp;gt;&lt;br /&gt;
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Reliability assessment should distinguish availability, delivered flow and suppression outcome. A source can be available without providing sufficient pressure, and water can reach the fire without controlling it. Each stage needs relevant evidence rather than one general reliability claim.&amp;lt;ref name=&amp;quot;Hopkins-xli&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;Fleming-4-73&amp;quot;&amp;gt;Fleming (2002), p. 4-73.&amp;lt;/ref&amp;gt;&lt;br /&gt;
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== Inspection and operational information ==&lt;br /&gt;
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Inspection should confirm the hydrant&amp;#039;s identity, access and supply arrangement. A connection that is blocked by vehicles or altered surroundings can be unavailable even if its mechanical condition is satisfactory. Access should be reviewed as part of the operating building, not only on the original plan.&amp;lt;ref name=&amp;quot;CVM2-53&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;IFEG-1-8-14&amp;quot;&amp;gt;Australian Building Codes Board et al. (2005), pp. 1.8-13–1.8-14.&amp;lt;/ref&amp;gt;&lt;br /&gt;
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Operational information should identify which parts of the network each connection serves. Isolation valves and multiple inlets can create different supply paths. Responding personnel need clear information about available systems and hazardous conditions to use those paths appropriately.&amp;lt;ref name=&amp;quot;CVM2-53&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;Hopkins-xxxv&amp;quot; /&amp;gt;&lt;br /&gt;
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Maintenance should preserve valves, pumps, tanks and connections as a functioning chain. Testing only one component can miss a failed common path. Restoration after impairment should verify the supply at the relevant outlet and operating condition.&amp;lt;ref name=&amp;quot;NUREG-10-2&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;ABCB-130&amp;quot;&amp;gt;Australian Building Codes Board (2020), pp. 129–130.&amp;lt;/ref&amp;gt;&lt;br /&gt;
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Documentation should include the source, supply route and relevant standards of record. NIST reconstructed these arrangements from drawings, specifications, procedures and other collected records. Such records make it possible to evaluate capability and interpret changes over time.&amp;lt;ref name=&amp;quot;Hopkins-xxxii&amp;quot; /&amp;gt;&lt;br /&gt;
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Changes to roads, hard-standing, building entrances and internal routes can alter effective access. A hydrant that was once easy to reach may become difficult to use without any change to the hydrant itself. Periodic review should include those physical and operational changes.&amp;lt;ref name=&amp;quot;CVM2-54&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;IFEG-0-3-8&amp;quot;&amp;gt;Australian Building Codes Board et al. (2005), p. 0.3-8.&amp;lt;/ref&amp;gt;&lt;br /&gt;
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== Evaluation and common misunderstandings ==&lt;br /&gt;
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A hydrant is not a guarantee of unlimited water. Available flow depends on the municipal or private source, pumps, tanks, distribution and continued operation. The duration and independence of each source must be evaluated for the scenario.&amp;lt;ref name=&amp;quot;Hopkins-xxxv&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;Hopkins-xli&amp;quot; /&amp;gt;&lt;br /&gt;
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A hydrant is also not the same as a standpipe or a sprinkler inlet. These provisions can share connections and water sources, but they serve different downstream purposes. The system being supplied must be identified before assessing performance.&amp;lt;ref name=&amp;quot;NUREG-F61&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;Hopkins-xxxv&amp;quot; /&amp;gt;&lt;br /&gt;
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Location alone does not prove accessibility. Vehicle hard-standing, unobstructed paths, hose deployment and fire conditions all affect whether water can be applied. C/VM2&amp;#039;s scenario addresses these as connected firefighting requirements rather than as a simple distance check.&amp;lt;ref name=&amp;quot;CVM2-53&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;CVM2-54&amp;quot; /&amp;gt;&lt;br /&gt;
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Historical calculations and case studies do not establish universal flow or pressure. NIST&amp;#039;s WTC analysis uses building-specific infrastructure, design criteria and fire assumptions. Those conditions must be retained when drawing lessons from its results.&amp;lt;ref name=&amp;quot;Hopkins-xli&amp;quot; /&amp;gt;&lt;br /&gt;
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The useful assessment therefore traces water from source to application. It checks connection access, supply reliability, pressure, hose deployment and firefighter safety. A hydrant provides valuable protection only when that complete sequence remains functional.&amp;lt;ref name=&amp;quot;NUREG-F25&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;CVM2-53&amp;quot; /&amp;gt;&lt;br /&gt;
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Hydrant assessment should also distinguish normal system availability from incident conditions. A routine flow test may demonstrate performance at one demand, while a larger fire or damaged main produces a different result. The scenario used for assessment should state the demand, supply route and any impairments being considered.&amp;lt;ref name=&amp;quot;Hopkins-xli&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;Hopkins-xlii&amp;quot; /&amp;gt;&lt;br /&gt;
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Operational maps should support the connection between source and destination. They can show which valves, risers and zones supply a particular area and where alternative connections are located. This helps responders understand whether a failed path can be isolated and another used without assuming that every connection is equivalent.&amp;lt;ref name=&amp;quot;Hopkins-xxxv&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;CVM2-53&amp;quot; /&amp;gt;&lt;br /&gt;
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For fire service planning, the time to establish supply belongs in the response sequence. Detection, appliance travel, hose deployment and pump activation occur before water reaches the fire. C/VM2 provides method-specific intervention times for its scenarios and also permits another time supported by a brigade intervention model.&amp;lt;ref name=&amp;quot;CVM2-54&amp;quot; /&amp;gt;&lt;br /&gt;
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The review should end with a clear statement of the conditions under which the hydrant can deliver its intended function. That statement should identify source, access, pressure and flow evidence, operating assumptions and any remaining uncertainty. It should not imply that the connection alone proves successful fire control.&amp;lt;ref name=&amp;quot;Hopkins-xli&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;NUREG-F25&amp;quot; /&amp;gt;&lt;br /&gt;
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== See also ==&lt;br /&gt;
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* [[Dry and wet risers]]&lt;br /&gt;
* [[Fire water supply]]&lt;br /&gt;
* [[Firefighting]]&lt;br /&gt;
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== Notes ==&lt;br /&gt;
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&amp;lt;ref name=&amp;quot;Hopkins-xlii&amp;quot;&amp;gt;Hopkins, Schoenrock, and Budnick (2005), pp. xli–xlii.&amp;lt;/ref&amp;gt;&lt;br /&gt;
&amp;lt;references /&amp;gt;&lt;br /&gt;
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== References ==&lt;br /&gt;
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* Australian Building Codes Board. (2020). &amp;#039;&amp;#039;Fire safety verification method data sheets&amp;#039;&amp;#039; (Version 1.1). Author.&lt;br /&gt;
* Australian Building Codes Board, National Research Council of Canada, International Code Council, &amp;amp; Department of Building and Housing New Zealand. (2005). &amp;#039;&amp;#039;International fire engineering guidelines&amp;#039;&amp;#039; (2005 ed.). Australian Building Codes Board.&lt;br /&gt;
* Fleming, R. P. (2002). Automatic sprinkler system calculations. In P. J. DiNenno (Ed.), &amp;#039;&amp;#039;SFPE handbook of fire protection engineering&amp;#039;&amp;#039; (3rd ed.). National Fire Protection Association.&lt;br /&gt;
* Hopkins, M., Schoenrock, J., &amp;amp; Budnick, E. (2005). &amp;#039;&amp;#039;Fire suppression systems&amp;#039;&amp;#039; (NIST NCSTAR 1-4B). National Institute of Standards and Technology.&lt;br /&gt;
* Ministry of Business, Innovation and Employment. (2025). &amp;#039;&amp;#039;C protection from fire: Verification method C/VM2&amp;#039;&amp;#039; (2nd ed.). New Zealand Government.&lt;br /&gt;
* U.S. Nuclear Regulatory Commission. (2005). &amp;#039;&amp;#039;Fire dynamics tools: Quantitative fire hazard analysis methods for the U.S. nuclear regulatory commission fire protection inspection program&amp;#039;&amp;#039; (NUREG-1805). Author.&lt;br /&gt;
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[[Category:Firefighting &amp;amp; Fire Service]]&lt;/div&gt;</summary>
		<author><name>Jan</name></author>
	</entry>
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