<?xml version="1.0" encoding="us-ascii"?><InstanceReport xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"><Version>2.2.0.25</Version><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios><ReportLongName>006070 - Disclosure - Property, Plant &amp; Equipment</ReportLongName><DisplayLabelColumn>true</DisplayLabelColumn><ShowElementNames>false</ShowElementNames><RoundingOption /><HasEmbeddedReports>false</HasEmbeddedReports><Columns><Column><Id>1</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><LabelColumn>false</LabelColumn><CurrencyCode>USD</CurrencyCode><FootnoteIndexer /><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios><MCU><KeyName>1/1/2011 - 3/31/2011
USD ($)

USD ($) / shares
</KeyName><CurrencySymbol>$</CurrencySymbol><contextRef><ContextID>c00004</ContextID><EntitySchema>http://www.sec.gov/CIK</EntitySchema><EntityValue>0000060849</EntityValue><PeriodDisplayName /><PeriodType>duration</PeriodType><PeriodStartDate>2011-01-01T00:00:00</PeriodStartDate><PeriodEndDate>2011-03-31T00:00:00</PeriodEndDate><Segments /><Scenarios /></contextRef><UPS><UnitProperty><UnitID>u000</UnitID><UnitType>Standard</UnitType><StandardMeasure><MeasureSchema>http://www.xbrl.org/2003/iso4217</MeasureSchema><MeasureValue>USD</MeasureValue><MeasureNamespace>iso4217</MeasureNamespace></StandardMeasure><Scale>0</Scale></UnitProperty><UnitProperty><UnitID>u002</UnitID><UnitType>Divide</UnitType><NumeratorMeasure><MeasureSchema>http://www.xbrl.org/2003/iso4217</MeasureSchema><MeasureValue>USD</MeasureValue><MeasureNamespace>iso4217</MeasureNamespace></NumeratorMeasure><DenominatorMeasure><MeasureSchema>http://www.xbrl.org/2003/instance</MeasureSchema><MeasureValue>shares</MeasureValue><MeasureNamespace>xbrli</MeasureNamespace></DenominatorMeasure><Scale>0</Scale></UnitProperty></UPS><CurrencyCode>USD</CurrencyCode><OriginalCurrencyCode>USD</OriginalCurrencyCode></MCU><CurrencySymbol>$</CurrencySymbol><Labels><Label Id="1" Label="3 Months Ended" /><Label Id="2" Label="Mar. 31, 2011" /></Labels></Column></Columns><Rows><Row><Id>2</Id><IsAbstractGroupTitle>true</IsAbstractGroupTitle><Level>0</Level><ElementName>lufk_NotesToFinancialStatementsAbstract</ElementName><ElementPrefix>lufk</ElementPrefix><IsBaseElement>false</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><ShortDefinition>No definition available.</ShortDefinition><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsSubReportEnd>false</IsSubReportEnd><IsCalendarTitle>false</IsCalendarTitle><IsTuple>false</IsTuple><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><PreferredLabelRole /><FootnoteIndexer /><Cells><Cell><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText /><NonNumericTextHeader /><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios></Cell></Cells><OriginalInstanceReportColumns /><Unit>Other</Unit><ElementDataType>xbrli:stringItemType</ElementDataType><SimpleDataType>string</SimpleDataType><ElementDefenition>No definition available.</ElementDefenition><IsTotalLabel>false</IsTotalLabel><IsEPS>false</IsEPS><Label>Notes To Financial Statements [Abstract]</Label></Row><Row><Id>3</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><Level>0</Level><ElementName>us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock</ElementName><ElementPrefix>us-gaap</ElementPrefix><IsBaseElement>true</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><ShortDefinition>No definition available.</ShortDefinition><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsSubReportEnd>false</IsSubReportEnd><IsCalendarTitle>false</IsCalendarTitle><IsTuple>false</IsTuple><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><PreferredLabelRole /><FootnoteIndexer /><Cells><Cell><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText>&lt;div style="TEXT-INDENT: 0pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 19.3pt" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: Times New Roman; FONT-SIZE: 10pt; FONT-WEIGHT: bold"&gt;7. Property, Plant &amp;amp; Equipment&lt;/font&gt;&lt;/div&gt;&lt;div style="TEXT-INDENT: 0pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 19.3pt" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: Times New Roman; FONT-SIZE: 10pt"&gt;The following is a summary of the Company's property, plant and equipment balances (in thousands of dollars):&lt;/font&gt;&lt;br /&gt;&lt;/div&gt;&lt;div align="left"&gt;&lt;table style="FONT-FAMILY: times new roman; FONT-SIZE: 10pt" cellspacing="0" cellpadding="0" width="100%"&gt;&lt;tr&gt;&lt;td valign="bottom"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160; &lt;/font&gt;&lt;/td&gt;&lt;td valign="bottom"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td valign="bottom" colspan="2"&gt;&lt;div style="TEXT-INDENT: 0pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt" align="center"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;March 31,&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td valign="bottom"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td valign="bottom" colspan="2"&gt;&lt;div style="TEXT-INDENT: 0pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt" align="center"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;December 31,&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr&gt;&lt;td style="PADDING-BOTTOM: 2px" valign="bottom"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160; &lt;/font&gt;&lt;/td&gt;&lt;td style="PADDING-BOTTOM: 2px" valign="bottom"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="BORDER-BOTTOM: black 2px solid" valign="bottom" colspan="2"&gt;&lt;div style="TEXT-INDENT: 0pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt" align="center"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;2011&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left; PADDING-BOTTOM: 2px" valign="bottom" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="PADDING-BOTTOM: 2px" valign="bottom"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="BORDER-BOTTOM: black 2px solid" valign="bottom" colspan="2"&gt;&lt;div style="TEXT-INDENT: 0pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt" align="center"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;2010&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left; PADDING-BOTTOM: 2px" valign="bottom" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr&gt;&lt;td valign="bottom"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160; &lt;/font&gt;&lt;/td&gt;&lt;td valign="bottom"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td valign="bottom" colspan="2"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td valign="bottom"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td valign="bottom" colspan="2"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr bgcolor="#cceeff"&gt;&lt;td valign="bottom" width="76%" align="left"&gt;&lt;div style="TEXT-INDENT: 0pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;Land&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td valign="bottom" width="1%" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;$&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: right" valign="bottom" width="9%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;19,961&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td valign="bottom" width="1%" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;$&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: right" valign="bottom" width="9%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;19,775&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr bgcolor="white"&gt;&lt;td valign="bottom" width="76%" align="left"&gt;&lt;div style="TEXT-INDENT: 0pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;Land improvements&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td valign="bottom" width="1%" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: right" valign="bottom" width="9%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;10,491&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td valign="bottom" width="1%" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: right" valign="bottom" width="9%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;10,449&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr bgcolor="#cceeff"&gt;&lt;td valign="bottom" width="76%" align="left"&gt;&lt;div style="TEXT-INDENT: 0pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;Buildings&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td valign="bottom" width="1%" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: right" valign="bottom" width="9%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;120,486&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td valign="bottom" width="1%" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: right" valign="bottom" width="9%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;106,199&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr bgcolor="white"&gt;&lt;td valign="bottom" width="76%" align="left"&gt;&lt;div style="TEXT-INDENT: 0pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;Machinery and equipment&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td valign="bottom" width="1%" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: right" valign="bottom" width="9%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;296,963&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td valign="bottom" width="1%" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: right" valign="bottom" width="9%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;289,579&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr bgcolor="#cceeff"&gt;&lt;td valign="bottom" width="76%" align="left"&gt;&lt;div style="TEXT-INDENT: 0pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;Furniture and fixtures&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td valign="bottom" width="1%" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: right" valign="bottom" width="9%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;6,809&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td valign="bottom" width="1%" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: right" valign="bottom" width="9%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;6,839&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr bgcolor="white"&gt;&lt;td style="PADDING-BOTTOM: 2px" valign="bottom" width="76%" align="left"&gt;&lt;div style="TEXT-INDENT: 0pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;Computer equipment and software&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td style="PADDING-BOTTOM: 2px" valign="bottom" width="1%" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="BORDER-BOTTOM: black 2px solid; TEXT-ALIGN: left" valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="BORDER-BOTTOM: black 2px solid; TEXT-ALIGN: right" valign="bottom" width="9%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;27,292&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left; PADDING-BOTTOM: 2px" valign="bottom" width="1%" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="PADDING-BOTTOM: 2px" valign="bottom" width="1%" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="BORDER-BOTTOM: black 2px solid; TEXT-ALIGN: left" valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="BORDER-BOTTOM: black 2px solid; TEXT-ALIGN: right" valign="bottom" width="9%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;23,407&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left; PADDING-BOTTOM: 2px" valign="bottom" width="1%" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr bgcolor="#cceeff"&gt;&lt;td style="PADDING-LEFT: 3%" valign="bottom" width="76%" align="left"&gt;&lt;div style="TEXT-INDENT: 0pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;Total property, plant and equipment&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td valign="bottom" width="1%" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: right" valign="bottom" width="9%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;482,002&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td valign="bottom" width="1%" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: right" valign="bottom" width="9%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;456,248&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr bgcolor="white"&gt;&lt;td style="PADDING-BOTTOM: 2px" valign="bottom" width="76%" align="left"&gt;&lt;div style="TEXT-INDENT: 0pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;Less accumulated depreciation&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td style="PADDING-BOTTOM: 2px" valign="bottom" width="1%" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="BORDER-BOTTOM: black 2px solid; TEXT-ALIGN: left" valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="BORDER-BOTTOM: black 2px solid; TEXT-ALIGN: right" valign="bottom" width="9%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;(256,489&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left; PADDING-BOTTOM: 2px" valign="bottom" width="1%" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;)&lt;/font&gt;&lt;/td&gt;&lt;td style="PADDING-BOTTOM: 2px" valign="bottom" width="1%" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="BORDER-BOTTOM: black 2px solid; TEXT-ALIGN: left" valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="BORDER-BOTTOM: black 2px solid; TEXT-ALIGN: right" valign="bottom" width="9%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;(252,531&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left; PADDING-BOTTOM: 2px" valign="bottom" width="1%" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;)&lt;/font&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr bgcolor="#cceeff"&gt;&lt;td style="PADDING-BOTTOM: 4px; PADDING-LEFT: 3%" valign="bottom" width="76%" align="left"&gt;&lt;div style="TEXT-INDENT: 0pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;Total property, plant and equipment, net&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td style="PADDING-BOTTOM: 4px" valign="bottom" width="1%" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="BORDER-BOTTOM: black 4px double; TEXT-ALIGN: left" valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;$&lt;/font&gt;&lt;/td&gt;&lt;td style="BORDER-BOTTOM: black 4px double; TEXT-ALIGN: right" valign="bottom" width="9%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;225,513&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left; PADDING-BOTTOM: 4px" valign="bottom" width="1%" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="PADDING-BOTTOM: 4px" valign="bottom" width="1%" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="BORDER-BOTTOM: black 4px double; TEXT-ALIGN: left" valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;$&lt;/font&gt;&lt;/td&gt;&lt;td style="BORDER-BOTTOM: black 4px double; TEXT-ALIGN: right" valign="bottom" width="9%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;203,717&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left; PADDING-BOTTOM: 4px" valign="bottom" width="1%" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr bgcolor="white"&gt;&lt;td valign="bottom" width="76%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160; &lt;/font&gt;&lt;/td&gt;&lt;td valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: right" valign="bottom" width="9%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: right" valign="bottom" width="9%"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;td style="TEXT-ALIGN: left" valign="bottom" width="1%" nowrap="nowrap"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: times new roman; FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/td&gt;&lt;/tr&gt;&lt;/table&gt;&lt;/div&gt;&lt;div style="TEXT-INDENT: 0pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 19.3pt" align="justify"&gt;&lt;font style="DISPLAY: inline; FONT-FAMILY: Times New Roman; FONT-SIZE: 10pt"&gt;Depreciation expense related to property, plant and equipment was $5.1 million and $4.6 million for the&amp;#160;three months ended March 31, 2011 and 2010, respectively.&lt;/font&gt;&lt;/div&gt;&lt;br /&gt;</NonNumbericText><NonNumericTextHeader>7. Property, Plant &amp;amp; EquipmentThe following is a summary of the Company's property, plant and equipment balances (in thousands of dollars):&amp;#160;</NonNumericTextHeader><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios></Cell></Cells><OriginalInstanceReportColumns /><Unit>Other</Unit><ElementDataType>us-types:textBlockItemType</ElementDataType><SimpleDataType>string</SimpleDataType><ElementDefenition>Disclosure of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale. Examples include land, building and production equipment. This disclosure may include property plant and equipment accounting policies and methodology, a schedule of property, plant and equipment gross, additions, deletions, transfers and other changes, depreciation, depletion and amortization expense, net, accumulated depreciation, depletion and amortization expense and useful lives, income statement disclosures, assets held for sale and public utility disclosures. This element may be used as a single block of text to include the entire PPE disclosure, including data and tables.</ElementDefenition><ElementReferences>Reference 1: http://www.xbrl.org/2003/role/presentationRef
 -Publisher AICPA
 -Name Accounting Principles Board Opinion (APB)
 -Number 12
 -Paragraph 5

</ElementReferences><IsTotalLabel>false</IsTotalLabel><IsEPS>false</IsEPS><Label>Property, Plant &amp; Equipment</Label></Row></Rows><Footnotes /><NumberOfCols>1</NumberOfCols><NumberOfRows>2</NumberOfRows><ReportName>Property, Plant &amp; Equipment</ReportName><MonetaryRoundingLevel>UnKnown</MonetaryRoundingLevel><SharesRoundingLevel>UnKnown</SharesRoundingLevel><PerShareRoundingLevel>UnKnown</PerShareRoundingLevel><ExchangeRateRoundingLevel>UnKnown</ExchangeRateRoundingLevel><HasCustomUnits>false</HasCustomUnits><SharesShouldBeRounded>true</SharesShouldBeRounded></InstanceReport>
