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  <xsd:element name="OtherLongTermLiabilitiesAbstract" id="orn_OtherLongTermLiabilitiesAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="FailedSaleLeasebackLiabilityNoncurrent" id="orn_FailedSaleLeasebackLiabilityNoncurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element name="FailedSaleLeasebackMember" id="orn_FailedSaleLeasebackMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="FailedSaleLeasebackTransactionGrossProceedsFinancingActivities" id="orn_FailedSaleLeasebackTransactionGrossProceedsFinancingActivities" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element name="FailedSaleLeasebackArrangementLeaseTermOfContract" id="orn_FailedSaleLeasebackArrangementLeaseTermOfContract" type="xbrli:durationItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="FailedSaleLeasebackArrangementAnnualRentalPayments" id="orn_FailedSaleLeasebackArrangementAnnualRentalPayments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element name="FailedSaleLeasebackArrangementAnnualRentIncreasePercent" id="orn_FailedSaleLeasebackArrangementAnnualRentIncreasePercent" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="FailedSaleLeasebackArrangementNumberOfExtensionOptions" id="orn_FailedSaleLeasebackArrangementNumberOfExtensionOptions" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="FailedSaleLeasebackArrangementLeaseTermOfOptions" id="orn_FailedSaleLeasebackArrangementLeaseTermOfOptions" type="xbrli:durationItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="IndependentDirectorsAndCertainOfficersAndExecutivesMember" id="orn_IndependentDirectorsAndCertainOfficersAndExecutivesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="CertainExecutivesMember" id="orn_CertainExecutivesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardPerformanceBasedSharesEarnedPercentage" id="orn_ShareBasedCompensationArrangementByShareBasedPaymentAwardPerformanceBasedSharesEarnedPercentage" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="RightOfUseAsset" id="orn_RightOfUseAsset" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element name="OperatingAndFinanceLeaseLiabilityCurrent" id="orn_OperatingAndFinanceLeaseLiabilityCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element name="OperatingAndFinanceLeaseLiabilityNoncurrent" id="orn_OperatingAndFinanceLeaseLiabilityNoncurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element name="OperatingAndFinanceLeaseLiabilities" id="orn_OperatingAndFinanceLeaseLiabilities" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element name="OperatingLeaseRightOfUseAssetAccumulatedDepreciation" id="orn_OperatingLeaseRightOfUseAssetAccumulatedDepreciation" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element name="PropertyPlantAndEquipmentNetBookValueOfDepreciableAssets" id="orn_PropertyPlantAndEquipmentNetBookValueOfDepreciableAssets" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element name="DebtInstrumentCovenantComplianceLeverageRatioMaximum" id="orn_DebtInstrumentCovenantComplianceLeverageRatioMaximum" type="xbrli:pureItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="TermLoanMember" id="orn_TermLoanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="OfficersAndExecutivesMember" id="orn_OfficersAndExecutivesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="RevenueRemainingPerformanceObligationExpectedTimingPercentage" id="orn_RevenueRemainingPerformanceObligationExpectedTimingPercentage" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="TradeAccountsReceivableAndContractReceivableRetainageGross" id="orn_TradeAccountsReceivableAndContractReceivableRetainageGross" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element name="NumberOfCustomersExceedingBenchmarkPercentage" id="orn_NumberOfCustomersExceedingBenchmarkPercentage" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="LesseeOperatingLeaseLiabilityToBePaidAfterYearFour" id="orn_LesseeOperatingLeaseLiabilityToBePaidAfterYearFour" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element name="FinanceLeaseLiabilityToBePaidAfterYearFour" id="orn_FinanceLeaseLiabilityToBePaidAfterYearFour" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element name="ContractWithCustomerAssetAfterAllowanceForCreditLossAndContractWithCustomerLiabilitiesCurrentTotal" id="orn_ContractWithCustomerAssetAfterAllowanceForCreditLossAndContractWithCustomerLiabilitiesCurrentTotal" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element name="TotalBillingsOnUncompletedContracts" id="orn_TotalBillingsOnUncompletedContracts" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element name="CovenantComplianceFixedChargeCoverageRatio" id="orn_CovenantComplianceFixedChargeCoverageRatio" type="xbrli:pureItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="SeniorCreditFacilityMember" id="orn_SeniorCreditFacilityMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="UnitedStatesNavyMember" id="orn_UnitedStatesNavyMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="ContractWithCustomerContractAwarded" id="orn_ContractWithCustomerContractAwarded" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="credit" />
  <xsd:element name="AssetBasedRevolvingCreditFacilityMember" id="orn_AssetBasedRevolvingCreditFacilityMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="PortLavacaSouthYardPropertySaleLeasebackMember" id="orn_PortLavacaSouthYardPropertySaleLeasebackMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="ChannelviewTexas17300And17140MarketStreetPropertySaleLeasebackMember" id="orn_ChannelviewTexas17300And17140MarketStreetPropertySaleLeasebackMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="DebtInstrumentInterestRateFloor" id="orn_DebtInstrumentInterestRateFloor" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="EquipmentSaleLeasebackMember" id="orn_EquipmentSaleLeasebackMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="EquipmentFinancingArrangementMember" id="orn_EquipmentFinancingArrangementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="LandSaleLeasebackContractMember" id="orn_LandSaleLeasebackContractMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="LandSaleLeasebackMember" id="orn_LandSaleLeasebackMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="DebtInstrumentLiquidityPeriodAxis" id="orn_DebtInstrumentLiquidityPeriodAxis" type="xbrli:stringItemType" substitutionGroup="xbrldt:dimensionItem" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="DebtInstrumentLiquidityPeriodDomain" id="orn_DebtInstrumentLiquidityPeriodDomain" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="DepreciablePropertyPlantAndEquipmentGross" id="orn_DepreciablePropertyPlantAndEquipmentGross" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="debit" />
  <xsd:element name="DepreciationAndAmortizationIncludingAmortizationOfRouAssetsFromFinanceLeases" id="orn_DepreciationAndAmortizationIncludingAmortizationOfRouAssetsFromFinanceLeases" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="ShareBasedPaymentArrangementTrancheFiveMember" id="orn_ShareBasedPaymentArrangementTrancheFiveMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="ScheduleOfShareBasedPaymentAwardPerformanceShareUnitsValuationAssumptionsTableTextBlock" id="orn_ScheduleOfShareBasedPaymentAwardPerformanceShareUnitsValuationAssumptionsTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="ShareBasedPaymentArrangementCompensationCostNotYetRecognizedTableTextBlock" id="orn_ShareBasedPaymentArrangementCompensationCostNotYetRecognizedTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="ProceedsFromIssuanceOfCommonStockEmployeeStockPurchasePlan" id="orn_ProceedsFromIssuanceOfCommonStockEmployeeStockPurchasePlan" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="SalesTaxAssessment" id="orn_SalesTaxAssessment" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="J.e.McamisIncAndJemMarineLeasingLlcMember" id="orn_J.e.McamisIncAndJemMarineLeasingLlcMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="DebtInstrumentNumberOfInstallments" id="orn_DebtInstrumentNumberOfInstallments" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="ConstructionFinancingObligationMember" id="orn_ConstructionFinancingObligationMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="OtherBorrowingsMember" id="orn_OtherBorrowingsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="InitialValueMember" id="orn_InitialValueMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="BeginningMarch12027Member" id="orn_BeginningMarch12027Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="BeginningMarch12028Member" id="orn_BeginningMarch12028Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="BeginningMarch12029Member" id="orn_BeginningMarch12029Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="BusinessCombinationConsiderationTransferredContingentConsideration" id="orn_BusinessCombinationConsiderationTransferredContingentConsideration" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="credit" />
  <xsd:element name="BusinessCombinationRecognizedAssetAcquiredPropertyPlantAndEquipmentBuildingAndEquipment" id="orn_BusinessCombinationRecognizedAssetAcquiredPropertyPlantAndEquipmentBuildingAndEquipment" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="debit" />
  <xsd:element name="StatementOfFinancialPositionLocationBalance1Axis" id="orn_StatementOfFinancialPositionLocationBalance1Axis" type="xbrli:stringItemType" substitutionGroup="xbrldt:dimensionItem" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="BusinessCombinationContractAssets" id="orn_BusinessCombinationContractAssets" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="debit" />
  <xsd:element name="BusinessCombinationContractLiabilities" id="orn_BusinessCombinationContractLiabilities" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="credit" />
  <xsd:element name="NumberOfNonOperatingSegments" id="orn_NumberOfNonOperatingSegments" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="IncrementalCommonSharesAttributableToPerformanceShareUnits" id="orn_IncrementalCommonSharesAttributableToPerformanceShareUnits" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentWorkingCapitalAdjustment" id="orn_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentWorkingCapitalAdjustment" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="credit" />
  <xsd:element name="BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentFairValueOfContingentConsideration" id="orn_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentFairValueOfContingentConsideration" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="credit" />
  <xsd:element name="BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentDeferredTaxLiability" id="orn_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentDeferredTaxLiability" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
</xsd:schema>
