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	<id>http://www.errorbar.net/rw/w/index.php?action=history&amp;feed=atom&amp;title=A_9_8</id>
	<title>A 9 8 - Revision history</title>
	<link rel="self" type="application/atom+xml" href="http://www.errorbar.net/rw/w/index.php?action=history&amp;feed=atom&amp;title=A_9_8"/>
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	<updated>2026-06-22T16:34:43Z</updated>
	<subtitle>Revision history for this page on the wiki</subtitle>
	<generator>MediaWiki 1.35.13</generator>
	<entry>
		<id>http://www.errorbar.net/rw/w/index.php?title=A_9_8&amp;diff=828&amp;oldid=prev</id>
		<title>Eli Bishop at 06:47, 18 March 2026</title>
		<link rel="alternate" type="text/html" href="http://www.errorbar.net/rw/w/index.php?title=A_9_8&amp;diff=828&amp;oldid=prev"/>
		<updated>2026-03-18T06:47:57Z</updated>

		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table class=&quot;diff diff-contentalign-left diff-editfont-monospace&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;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&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 06:47, 18 March 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-l3&quot; &gt;Line 3:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 3:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;In a treadwheel crane, people walk on the inside of a large wheel (think of a hamster wheel) and the weight of their bodies provides the lifting force. The extra large version described here also has several workers walking the opposite way on the top of each wheel. Treadwheel cranes have been used in England since Roman times.&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;In a treadwheel crane, people walk on the inside of a large wheel (think of a hamster wheel) and the weight of their bodies provides the lifting force. The extra large version described here also has several workers walking the opposite way on the top of each wheel. Treadwheel cranes have been used in England since Roman times.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;/td&gt;&lt;td class='diff-marker'&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;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;An earlier version of this note suggested that the crane had no brake and relied on the walkers' weight to keep the load from falling. {{By|H}} replies: &lt;del class=&quot;diffchange diffchange-inline&quot;&gt;&amp;quot;&lt;/del&gt;I believe this is not quite right, that it actually does have brakes on the wheels but that they failed because the load was too heavy and the mechanism broke. The brakes are referred to as &amp;quot;stoppers&amp;quot; and are probably like the [http://www.technologystudent.com/cams/ratch1.htm ratchet mechanism] in a clock, with the stopper being the pawl. On page 11 [after the accident], Fister says 'That load wer too much for that weal ... it wer the stoppers coming luce and the weal took charge.'&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;An earlier version of this note suggested that the crane had no brake and relied on the walkers' weight to keep the load from falling. {{By|H}} replies:&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot;&gt; &lt;/td&gt;&lt;td class='diff-marker'&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;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot;&gt; &lt;/td&gt;&lt;td class='diff-marker'&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 class=&quot;diffchange diffchange-inline&quot;&gt;: &lt;/ins&gt;I believe this is not quite right, that it actually does have brakes on the wheels but that they failed because the load was too heavy and the mechanism broke. The brakes are referred to as &amp;quot;stoppers&amp;quot; and are probably like the [http://www.technologystudent.com/cams/ratch1.htm ratchet mechanism] in a clock, with the stopper being the pawl. On page 11 [after the accident], Fister says 'That load wer too much for that weal ... it wer the stoppers coming luce and the weal took charge.'&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;/td&gt;&lt;td class='diff-marker'&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;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;[[File:crane-bruges-small.jpg|frame|right|link=|Medieval Belgian 2-wheel crane {{By|BJB}}]]&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;[[File:crane-bruges-small.jpg|frame|right|link=|Medieval Belgian 2-wheel crane {{By|BJB}}]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;The use of two stoppers per wheel would either be simply for more strength, to prevent just this from happening, or alternately having each of the two per wheel engage in an alternating fashion so that the wheel won't have as far to turn and won't build up as much momentum if it does start to turn backwards, also to keep it from failing. With these large loads and a crane built, I assume, out of wood, the working parts would have to be large for strength. This means using larger teeth on the ratchet wheel, and therefore possibly requiring the latter of these two configurations. Either way, when Riddley tripped and knocked over the others working his wheel the stoppers had to take the strain, which they failed to do, causing all the force to be held by the other wheel, and then it too failed. It is a small point, but might be significant because it permits Riddley to be absolved of any blame in the accident, at least by Fister and Straiter Empy. Chalker Marchman's reply puts the blame on the men ... though of course the management would want to avoid blame.&lt;del class=&quot;diffchange diffchange-inline&quot;&gt;&amp;quot;&lt;/del&gt;&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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 class=&quot;diffchange diffchange-inline&quot;&gt;: &lt;/ins&gt;The use of two stoppers per wheel would either be simply for more strength, to prevent just this from happening, or alternately having each of the two per wheel engage in an alternating fashion so that the wheel won't have as far to turn and won't build up as much momentum if it does start to turn backwards, also to keep it from failing. With these large loads and a crane built, I assume, out of wood, the working parts would have to be large for strength. This means using larger teeth on the ratchet wheel, and therefore possibly requiring the latter of these two configurations. Either way, when Riddley tripped and knocked over the others working his wheel the stoppers had to take the strain, which they failed to do, causing all the force to be held by the other wheel, and then it too failed. It is a small point, but might be significant because it permits Riddley to be absolved of any blame in the accident, at least by Fister and Straiter Empy. Chalker Marchman's reply puts the blame on the men ... though of course the management would want to avoid blame.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;/td&gt;&lt;td class='diff-marker'&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;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;[[Category:Chapter 2]]&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;[[Category:Chapter 2]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Eli Bishop</name></author>
	</entry>
	<entry>
		<id>http://www.errorbar.net/rw/w/index.php?title=A_9_8&amp;diff=827&amp;oldid=prev</id>
		<title>Eli Bishop at 06:46, 18 March 2026</title>
		<link rel="alternate" type="text/html" href="http://www.errorbar.net/rw/w/index.php?title=A_9_8&amp;diff=827&amp;oldid=prev"/>
		<updated>2026-03-18T06:46:57Z</updated>

		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table class=&quot;diff diff-contentalign-left diff-editfont-monospace&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;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&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 06:46, 18 March 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-l1&quot; &gt;Line 1:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 1:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;* {{PP|9|8}} &amp;quot;a 16 man treadl crane with 2 weals&amp;quot;&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;* {{PP|9|8}} &amp;quot;a 16 man treadl crane with 2 weals&amp;quot;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;[[File:crane-rome-small.jpg|frame|left|link=|1st-century Roman crane with a single wheel {{By|BJB}}]]&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;[[File:crane-rome-small.jpg|frame|left|link=|1st-century Roman crane with a single wheel {{By|BJB}}]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;In a treadwheel crane, people walk on the inside of a large wheel (think of a hamster wheel) and the weight of their bodies provides the lifting force. &lt;del class=&quot;diffchange diffchange-inline&quot;&gt;In the &lt;/del&gt;large version described here&lt;del class=&quot;diffchange diffchange-inline&quot;&gt;, each of the wheels &lt;/del&gt;also has several workers walking on top of &lt;del class=&quot;diffchange diffchange-inline&quot;&gt;it in the opposite direction&lt;/del&gt;. Treadwheel cranes have been used in England since Roman times.&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;In a treadwheel crane, people walk on the inside of a large wheel (think of a hamster wheel) and the weight of their bodies provides the lifting force. &lt;ins class=&quot;diffchange diffchange-inline&quot;&gt;The extra &lt;/ins&gt;large version described here also has several workers walking &lt;ins class=&quot;diffchange diffchange-inline&quot;&gt;the opposite way &lt;/ins&gt;on &lt;ins class=&quot;diffchange diffchange-inline&quot;&gt;the &lt;/ins&gt;top of &lt;ins class=&quot;diffchange diffchange-inline&quot;&gt;each wheel&lt;/ins&gt;. Treadwheel cranes have been used in England since Roman times.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;/td&gt;&lt;td class='diff-marker'&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;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;An earlier version of this note suggested that the crane had no brake and relied on the walkers' weight to keep the load from falling. {{By|H}} replies: &amp;quot;I believe this is not quite right, that it actually does have brakes on the wheels but that they failed because the load was too heavy and the mechanism broke. The brakes are referred to as &amp;quot;stoppers&amp;quot; and are probably like the [http://www.technologystudent.com/cams/ratch1.htm ratchet mechanism] in a clock, with the stopper being the pawl. On page 11 [after the accident], Fister says 'That load wer too much for that weal ... it wer the stoppers coming luce and the weal took charge.'&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;An earlier version of this note suggested that the crane had no brake and relied on the walkers' weight to keep the load from falling. {{By|H}} replies: &amp;quot;I believe this is not quite right, that it actually does have brakes on the wheels but that they failed because the load was too heavy and the mechanism broke. The brakes are referred to as &amp;quot;stoppers&amp;quot; and are probably like the [http://www.technologystudent.com/cams/ratch1.htm ratchet mechanism] in a clock, with the stopper being the pawl. On page 11 [after the accident], Fister says 'That load wer too much for that weal ... it wer the stoppers coming luce and the weal took charge.'&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Eli Bishop</name></author>
	</entry>
	<entry>
		<id>http://www.errorbar.net/rw/w/index.php?title=A_9_8&amp;diff=826&amp;oldid=prev</id>
		<title>Eli Bishop: crane detail</title>
		<link rel="alternate" type="text/html" href="http://www.errorbar.net/rw/w/index.php?title=A_9_8&amp;diff=826&amp;oldid=prev"/>
		<updated>2026-03-18T06:46:11Z</updated>

		<summary type="html">&lt;p&gt;crane detail&lt;/p&gt;
&lt;table class=&quot;diff diff-contentalign-left diff-editfont-monospace&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;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&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 06:46, 18 March 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-l1&quot; &gt;Line 1:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 1:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;* {{PP|9|8}} &amp;quot;a 16 man treadl crane with 2 weals&amp;quot;&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;* {{PP|9|8}} &amp;quot;a 16 man treadl crane with 2 weals&amp;quot;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;[[File:crane-rome-small.jpg|frame|left|link=|1st-century Roman crane with a single wheel {{By|BJB}}]]&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;[[File:crane-rome-small.jpg|frame|left|link=|1st-century Roman crane with a single wheel {{By|BJB}}]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;In a treadwheel crane, people walk on the inside of a large wheel (think of a hamster wheel) and the weight of their bodies provides the lifting force. Treadwheel cranes have been used in England since Roman times.&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;In a treadwheel crane, people walk on the inside of a large wheel (think of a hamster wheel) and the weight of their bodies provides the lifting force&lt;ins class=&quot;diffchange diffchange-inline&quot;&gt;. In the large version described here, each of the wheels also has several workers walking on top of it in the opposite direction&lt;/ins&gt;. Treadwheel cranes have been used in England since Roman times.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;/td&gt;&lt;td class='diff-marker'&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;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;An earlier version of this note suggested that the crane had no brake and relied on the walkers' weight to keep the load from falling. {{By|H}} replies: &amp;quot;I believe this is not quite right, that it actually does have brakes on the wheels but that they failed because the load was too heavy and the mechanism broke. The brakes are referred to as &amp;quot;stoppers&amp;quot; and are probably like the [http://www.technologystudent.com/cams/ratch1.htm ratchet mechanism] in a clock, with the stopper being the pawl. On page 11 [after the accident], Fister says 'That load wer too much for that weal ... it wer the stoppers coming luce and the weal took charge.'&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;An earlier version of this note suggested that the crane had no brake and relied on the walkers' weight to keep the load from falling. {{By|H}} replies: &amp;quot;I believe this is not quite right, that it actually does have brakes on the wheels but that they failed because the load was too heavy and the mechanism broke. The brakes are referred to as &amp;quot;stoppers&amp;quot; and are probably like the [http://www.technologystudent.com/cams/ratch1.htm ratchet mechanism] in a clock, with the stopper being the pawl. On page 11 [after the accident], Fister says 'That load wer too much for that weal ... it wer the stoppers coming luce and the weal took charge.'&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Eli Bishop</name></author>
	</entry>
	<entry>
		<id>http://www.errorbar.net/rw/w/index.php?title=A_9_8&amp;diff=623&amp;oldid=prev</id>
		<title>Eli Bishop at 07:08, 25 November 2013</title>
		<link rel="alternate" type="text/html" href="http://www.errorbar.net/rw/w/index.php?title=A_9_8&amp;diff=623&amp;oldid=prev"/>
		<updated>2013-11-25T07:08:07Z</updated>

		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table class=&quot;diff diff-contentalign-left diff-editfont-monospace&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;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&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 07:08, 25 November 2013&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-l1&quot; &gt;Line 1:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 1:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;* {{PP|9|8}} &amp;quot;a 16 man treadl crane with 2 weals&amp;quot;&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;* {{PP|9|8}} &amp;quot;a 16 man treadl crane with 2 weals&amp;quot;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;[[File:crane-rome-small.jpg|frame|left|link=&lt;del class=&quot;diffchange diffchange-inline&quot;&gt;First-century Roman crane&lt;/del&gt;|1st-century Roman crane with a single wheel]]&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;[[File:crane-rome-small.jpg|frame|left|link=|1st-century Roman crane with a single wheel &lt;ins class=&quot;diffchange diffchange-inline&quot;&gt;{{By|BJB}}&lt;/ins&gt;]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;In a treadwheel crane, people walk on the inside of a large wheel (think of a hamster wheel) and the weight of their bodies provides the lifting force. Treadwheel cranes have been used in England since Roman times.&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;In a treadwheel crane, people walk on the inside of a large wheel (think of a hamster wheel) and the weight of their bodies provides the lifting force. Treadwheel cranes have been used in England since Roman times.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;/td&gt;&lt;td class='diff-marker'&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;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;An earlier version of this note suggested that the crane had no brake and relied on the walkers' weight to keep the load from falling. {{By|H}} replies: &amp;quot;I believe this is not quite right, that it actually does have brakes on the wheels but that they failed because the load was too heavy and the mechanism broke. The brakes are referred to as &amp;quot;stoppers&amp;quot; and are probably like the [http://www.technologystudent.com/cams/ratch1.htm ratchet mechanism] in a clock, with the stopper being the pawl. On page 11 [after the accident], Fister says 'That load wer too much for that weal ... it wer the stoppers coming luce and the weal took charge.'&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;An earlier version of this note suggested that the crane had no brake and relied on the walkers' weight to keep the load from falling. {{By|H}} replies: &amp;quot;I believe this is not quite right, that it actually does have brakes on the wheels but that they failed because the load was too heavy and the mechanism broke. The brakes are referred to as &amp;quot;stoppers&amp;quot; and are probably like the [http://www.technologystudent.com/cams/ratch1.htm ratchet mechanism] in a clock, with the stopper being the pawl. On page 11 [after the accident], Fister says 'That load wer too much for that weal ... it wer the stoppers coming luce and the weal took charge.'&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;/td&gt;&lt;td class='diff-marker'&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;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;[[File:crane-bruges-small.jpg|frame|right|link=Medieval Belgian 2-wheel crane|&lt;del class=&quot;diffchange diffchange-inline&quot;&gt;Medieval Belgian 2-wheel crane&lt;/del&gt;]]&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;[[File:crane-bruges-small.jpg|frame|right|link=&lt;ins class=&quot;diffchange diffchange-inline&quot;&gt;|&lt;/ins&gt;Medieval Belgian 2-wheel crane &lt;ins class=&quot;diffchange diffchange-inline&quot;&gt;{{By&lt;/ins&gt;|&lt;ins class=&quot;diffchange diffchange-inline&quot;&gt;BJB}}&lt;/ins&gt;]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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 use of two stoppers per wheel would either be simply for more strength, to prevent just this from happening, or alternately having each of the two per wheel engage in an alternating fashion so that the wheel won't have as far to turn and won't build up as much momentum if it does start to turn backwards, also to keep it from failing. With these large loads and a crane built, I assume, out of wood, the working parts would have to be large for strength. This means using larger teeth on the ratchet wheel, and therefore possibly requiring the latter of these two configurations. Either way, when Riddley tripped and knocked over the others working his wheel the stoppers had to take the strain, which they failed to do, causing all the force to be held by the other wheel, and then it too failed. It is a small point, but might be significant because it permits Riddley to be absolved of any blame in the accident, at least by Fister and Straiter Empy. Chalker Marchman's reply puts the blame on the men ... though of course the management would want to avoid blame.&amp;quot;&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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 use of two stoppers per wheel would either be simply for more strength, to prevent just this from happening, or alternately having each of the two per wheel engage in an alternating fashion so that the wheel won't have as far to turn and won't build up as much momentum if it does start to turn backwards, also to keep it from failing. With these large loads and a crane built, I assume, out of wood, the working parts would have to be large for strength. This means using larger teeth on the ratchet wheel, and therefore possibly requiring the latter of these two configurations. Either way, when Riddley tripped and knocked over the others working his wheel the stoppers had to take the strain, which they failed to do, causing all the force to be held by the other wheel, and then it too failed. It is a small point, but might be significant because it permits Riddley to be absolved of any blame in the accident, at least by Fister and Straiter Empy. Chalker Marchman's reply puts the blame on the men ... though of course the management would want to avoid blame.&amp;quot;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;/td&gt;&lt;td class='diff-marker'&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;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;[[Category:Chapter 2]]&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;[[Category:Chapter 2]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Eli Bishop</name></author>
	</entry>
	<entry>
		<id>http://www.errorbar.net/rw/w/index.php?title=A_9_8&amp;diff=163&amp;oldid=prev</id>
		<title>Eli Bishop: moved A 2 9 8 to A 9 8</title>
		<link rel="alternate" type="text/html" href="http://www.errorbar.net/rw/w/index.php?title=A_9_8&amp;diff=163&amp;oldid=prev"/>
		<updated>2013-07-28T22:25:46Z</updated>

		<summary type="html">&lt;p&gt;moved &lt;a href=&quot;/rw/w/index.php?title=A_2_9_8&amp;amp;action=edit&amp;amp;redlink=1&quot; class=&quot;new&quot; title=&quot;A 2 9 8 (page does not exist)&quot;&gt;A 2 9 8&lt;/a&gt; to &lt;a href=&quot;/rw/A_9_8&quot; title=&quot;A 9 8&quot;&gt;A 9 8&lt;/a&gt;&lt;/p&gt;
&lt;table class=&quot;diff diff-contentalign-left diff-editfont-monospace&quot; data-mw=&quot;interface&quot;&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;1&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;1&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 22:25, 28 July 2013&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-notice&quot; lang=&quot;en&quot;&gt;&lt;div class=&quot;mw-diff-empty&quot;&gt;(No difference)&lt;/div&gt;
&lt;/td&gt;&lt;/tr&gt;&lt;/table&gt;</summary>
		<author><name>Eli Bishop</name></author>
	</entry>
	<entry>
		<id>http://www.errorbar.net/rw/w/index.php?title=A_9_8&amp;diff=162&amp;oldid=prev</id>
		<title>Eli Bishop at 22:25, 28 July 2013</title>
		<link rel="alternate" type="text/html" href="http://www.errorbar.net/rw/w/index.php?title=A_9_8&amp;diff=162&amp;oldid=prev"/>
		<updated>2013-07-28T22:25:36Z</updated>

		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table class=&quot;diff diff-contentalign-left diff-editfont-monospace&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;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&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 22:25, 28 July 2013&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-l1&quot; &gt;Line 1:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 1:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;* {{PP&lt;del class=&quot;diffchange diffchange-inline&quot;&gt;|2&lt;/del&gt;|9|8}} &amp;quot;a 16 man treadl crane with 2 weals&amp;quot;&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;* {{PP|9|8}} &amp;quot;a 16 man treadl crane with 2 weals&amp;quot;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;[[File:crane-rome-small.jpg|frame|left|link=First-century Roman crane|1st-century Roman crane with a single wheel]]&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;[[File:crane-rome-small.jpg|frame|left|link=First-century Roman crane|1st-century Roman crane with a single wheel]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;In a treadwheel crane, people walk on the inside of a large wheel (think of a hamster wheel) and the weight of their bodies provides the lifting force. Treadwheel cranes have been used in England since Roman times.&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;In a treadwheel crane, people walk on the inside of a large wheel (think of a hamster wheel) and the weight of their bodies provides the lifting force. Treadwheel cranes have been used in England since Roman times.&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-l7&quot; &gt;Line 7:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 7:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;[[File:crane-bruges-small.jpg|frame|right|link=Medieval Belgian 2-wheel crane|Medieval Belgian 2-wheel crane]]&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;[[File:crane-bruges-small.jpg|frame|right|link=Medieval Belgian 2-wheel crane|Medieval Belgian 2-wheel crane]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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 use of two stoppers per wheel would either be simply for more strength, to prevent just this from happening, or alternately having each of the two per wheel engage in an alternating fashion so that the wheel won't have as far to turn and won't build up as much momentum if it does start to turn backwards, also to keep it from failing. With these large loads and a crane built, I assume, out of wood, the working parts would have to be large for strength. This means using larger teeth on the ratchet wheel, and therefore possibly requiring the latter of these two configurations. Either way, when Riddley tripped and knocked over the others working his wheel the stoppers had to take the strain, which they failed to do, causing all the force to be held by the other wheel, and then it too failed. It is a small point, but might be significant because it permits Riddley to be absolved of any blame in the accident, at least by Fister and Straiter Empy. Chalker Marchman's reply puts the blame on the men ... though of course the management would want to avoid blame.&amp;quot;&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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 use of two stoppers per wheel would either be simply for more strength, to prevent just this from happening, or alternately having each of the two per wheel engage in an alternating fashion so that the wheel won't have as far to turn and won't build up as much momentum if it does start to turn backwards, also to keep it from failing. With these large loads and a crane built, I assume, out of wood, the working parts would have to be large for strength. This means using larger teeth on the ratchet wheel, and therefore possibly requiring the latter of these two configurations. Either way, when Riddley tripped and knocked over the others working his wheel the stoppers had to take the strain, which they failed to do, causing all the force to be held by the other wheel, and then it too failed. It is a small point, but might be significant because it permits Riddley to be absolved of any blame in the accident, at least by Fister and Straiter Empy. Chalker Marchman's reply puts the blame on the men ... though of course the management would want to avoid blame.&amp;quot;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot;&gt; &lt;/td&gt;&lt;td class='diff-marker'&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;&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot;&gt; &lt;/td&gt;&lt;td class='diff-marker'&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;[[Category:Chapter 2]]&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Eli Bishop</name></author>
	</entry>
	<entry>
		<id>http://www.errorbar.net/rw/w/index.php?title=A_9_8&amp;diff=99&amp;oldid=prev</id>
		<title>Eli Bishop at 21:46, 28 July 2013</title>
		<link rel="alternate" type="text/html" href="http://www.errorbar.net/rw/w/index.php?title=A_9_8&amp;diff=99&amp;oldid=prev"/>
		<updated>2013-07-28T21:46:20Z</updated>

		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table class=&quot;diff diff-contentalign-left diff-editfont-monospace&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;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&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 21:46, 28 July 2013&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-l1&quot; &gt;Line 1:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 1:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;* {{PP|2|9|8}} &amp;quot;a 16 man treadl crane with 2 weals&amp;quot;&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;* {{PP|2|9|8}} &amp;quot;a 16 man treadl crane with 2 weals&amp;quot;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;[[File:crane-rome-small.jpg|frame|left|link=First-century Roman crane|1st-century Roman crane with a single wheel]]&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;[[File:crane-rome-small.jpg|frame|left|link=First-century Roman crane|1st-century Roman crane with a single wheel]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;[[File:crane-bruges-small.jpg|frame|right|link=Medieval Belgian 2-wheel crane|Medieval Belgian 2-wheel crane]]&lt;/del&gt;&lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot;&gt; &lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;In a treadwheel crane, people walk on the inside of a large wheel (think of a hamster wheel) and the weight of their bodies provides the lifting force. Treadwheel cranes have been used in England since Roman times.&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;In a treadwheel crane, people walk on the inside of a large wheel (think of a hamster wheel) and the weight of their bodies provides the lifting force. Treadwheel cranes have been used in England since Roman times.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;/td&gt;&lt;td class='diff-marker'&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;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;An earlier version of this note suggested that the crane had no brake and relied on the walkers' weight to keep the load from falling. {{By|H}} replies: &amp;quot;I believe this is not quite right, that it actually does have brakes on the wheels but that they failed because the load was too heavy and the mechanism broke. The brakes are referred to as &amp;quot;stoppers&amp;quot; and are probably like the [http://www.technologystudent.com/cams/ratch1.htm ratchet mechanism] in a clock, with the stopper being the pawl. On page 11 [after the accident], Fister says 'That load wer too much for that weal ... it wer the stoppers coming luce and the weal took charge.'&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;An earlier version of this note suggested that the crane had no brake and relied on the walkers' weight to keep the load from falling. {{By|H}} replies: &amp;quot;I believe this is not quite right, that it actually does have brakes on the wheels but that they failed because the load was too heavy and the mechanism broke. The brakes are referred to as &amp;quot;stoppers&amp;quot; and are probably like the [http://www.technologystudent.com/cams/ratch1.htm ratchet mechanism] in a clock, with the stopper being the pawl. On page 11 [after the accident], Fister says 'That load wer too much for that weal ... it wer the stoppers coming luce and the weal took charge.'&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;/td&gt;&lt;td class='diff-marker'&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;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot;&gt; &lt;/td&gt;&lt;td class='diff-marker'&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:crane-bruges-small.jpg|frame|right|link=Medieval Belgian 2-wheel crane|Medieval Belgian 2-wheel crane]]&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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 use of two stoppers per wheel would either be simply for more strength, to prevent just this from happening, or alternately having each of the two per wheel engage in an alternating fashion so that the wheel won't have as far to turn and won't build up as much momentum if it does start to turn backwards, also to keep it from failing. With these large loads and a crane built, I assume, out of wood, the working parts would have to be large for strength. This means using larger teeth on the ratchet wheel, and therefore possibly requiring the latter of these two configurations. Either way, when Riddley tripped and knocked over the others working his wheel the stoppers had to take the strain, which they failed to do, causing all the force to be held by the other wheel, and then it too failed. It is a small point, but might be significant because it permits Riddley to be absolved of any blame in the accident, at least by Fister and Straiter Empy. Chalker Marchman's reply puts the blame on the men ... though of course the management would want to avoid blame.&amp;quot;&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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 use of two stoppers per wheel would either be simply for more strength, to prevent just this from happening, or alternately having each of the two per wheel engage in an alternating fashion so that the wheel won't have as far to turn and won't build up as much momentum if it does start to turn backwards, also to keep it from failing. With these large loads and a crane built, I assume, out of wood, the working parts would have to be large for strength. This means using larger teeth on the ratchet wheel, and therefore possibly requiring the latter of these two configurations. Either way, when Riddley tripped and knocked over the others working his wheel the stoppers had to take the strain, which they failed to do, causing all the force to be held by the other wheel, and then it too failed. It is a small point, but might be significant because it permits Riddley to be absolved of any blame in the accident, at least by Fister and Straiter Empy. Chalker Marchman's reply puts the blame on the men ... though of course the management would want to avoid blame.&amp;quot;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Eli Bishop</name></author>
	</entry>
	<entry>
		<id>http://www.errorbar.net/rw/w/index.php?title=A_9_8&amp;diff=98&amp;oldid=prev</id>
		<title>Eli Bishop at 21:44, 28 July 2013</title>
		<link rel="alternate" type="text/html" href="http://www.errorbar.net/rw/w/index.php?title=A_9_8&amp;diff=98&amp;oldid=prev"/>
		<updated>2013-07-28T21:44:38Z</updated>

		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table class=&quot;diff diff-contentalign-left diff-editfont-monospace&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;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&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 21:44, 28 July 2013&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-l1&quot; &gt;Line 1:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 1:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;* {{PP|2|9|8}} &amp;quot;a 16 man treadl crane with 2 weals&amp;quot;&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;* {{PP|2|9|8}} &amp;quot;a 16 man treadl crane with 2 weals&amp;quot;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;	&lt;/del&gt;&lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot;&gt; &lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;1st-century Roman crane with a single wheel.&lt;/del&gt;&lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot;&gt; &lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;	&lt;/del&gt;&lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot;&gt; &lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;	&lt;/del&gt;&lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot;&gt; &lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;Medieval 2-wheel Belgian crane.&lt;/del&gt;&lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot;&gt; &lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;[[File:crane-rome-small.jpg|frame|left|link=First-century Roman crane|1st-century Roman crane with a single wheel]]&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;[[File:crane-rome-small.jpg|frame|left|link=First-century Roman crane|1st-century Roman crane with a single wheel]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&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;[[File:crane-bruges-small.jpg|frame|right|link=Medieval Belgian 2-wheel crane|Medieval Belgian 2-wheel crane]]&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&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;[[File:crane-bruges-small.jpg|frame|right|link=Medieval Belgian 2-wheel crane|Medieval Belgian 2-wheel crane]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Eli Bishop</name></author>
	</entry>
	<entry>
		<id>http://www.errorbar.net/rw/w/index.php?title=A_9_8&amp;diff=97&amp;oldid=prev</id>
		<title>Eli Bishop: Created page with &quot;* {{PP|2|9|8}} &quot;a 16 man treadl crane with 2 weals&quot; 	 1st-century Roman crane with a single wheel. 	 	 Medieval 2-wheel Belgian crane. [[File:crane-rome-small.jpg|frame|left|l...&quot;</title>
		<link rel="alternate" type="text/html" href="http://www.errorbar.net/rw/w/index.php?title=A_9_8&amp;diff=97&amp;oldid=prev"/>
		<updated>2013-07-28T21:43:45Z</updated>

		<summary type="html">&lt;p&gt;Created page with &amp;quot;* {{PP|2|9|8}} &amp;quot;a 16 man treadl crane with 2 weals&amp;quot; 	 1st-century Roman crane with a single wheel. 	 	 Medieval 2-wheel Belgian crane. [[File:crane-rome-small.jpg|frame|left|l...&amp;quot;&lt;/p&gt;
&lt;p&gt;&lt;b&gt;New page&lt;/b&gt;&lt;/p&gt;&lt;div&gt;* {{PP|2|9|8}} &amp;quot;a 16 man treadl crane with 2 weals&amp;quot;&lt;br /&gt;
	&lt;br /&gt;
1st-century Roman crane with a single wheel.&lt;br /&gt;
	&lt;br /&gt;
	&lt;br /&gt;
Medieval 2-wheel Belgian crane.&lt;br /&gt;
[[File:crane-rome-small.jpg|frame|left|link=First-century Roman crane|1st-century Roman crane with a single wheel]]&lt;br /&gt;
[[File:crane-bruges-small.jpg|frame|right|link=Medieval Belgian 2-wheel crane|Medieval Belgian 2-wheel crane]]&lt;br /&gt;
In a treadwheel crane, people walk on the inside of a large wheel (think of a hamster wheel) and the weight of their bodies provides the lifting force. Treadwheel cranes have been used in England since Roman times.&lt;br /&gt;
&lt;br /&gt;
An earlier version of this note suggested that the crane had no brake and relied on the walkers' weight to keep the load from falling. {{By|H}} replies: &amp;quot;I believe this is not quite right, that it actually does have brakes on the wheels but that they failed because the load was too heavy and the mechanism broke. The brakes are referred to as &amp;quot;stoppers&amp;quot; and are probably like the [http://www.technologystudent.com/cams/ratch1.htm ratchet mechanism] in a clock, with the stopper being the pawl. On page 11 [after the accident], Fister says 'That load wer too much for that weal ... it wer the stoppers coming luce and the weal took charge.'&lt;br /&gt;
&lt;br /&gt;
The use of two stoppers per wheel would either be simply for more strength, to prevent just this from happening, or alternately having each of the two per wheel engage in an alternating fashion so that the wheel won't have as far to turn and won't build up as much momentum if it does start to turn backwards, also to keep it from failing. With these large loads and a crane built, I assume, out of wood, the working parts would have to be large for strength. This means using larger teeth on the ratchet wheel, and therefore possibly requiring the latter of these two configurations. Either way, when Riddley tripped and knocked over the others working his wheel the stoppers had to take the strain, which they failed to do, causing all the force to be held by the other wheel, and then it too failed. It is a small point, but might be significant because it permits Riddley to be absolved of any blame in the accident, at least by Fister and Straiter Empy. Chalker Marchman's reply puts the blame on the men ... though of course the management would want to avoid blame.&amp;quot;&lt;/div&gt;</summary>
		<author><name>Eli Bishop</name></author>
	</entry>
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