<ARTICLE> 5 <LEGEND> THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THERMO TERRATECH INC.'S QUARTERLY REPORT ON FORM 10-Q FOR THE PERIOD ENDED OCTOBER 2, 1999 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS. </LEGEND> <MULTIPLIER> 1,000 <PERIOD-TYPE> 6-MOS <FISCAL-YEAR-END> APR-01-2000 <PERIOD-END> OCT-02-1999 <CASH> 3,888 <SECURITIES> 0 <RECEIVABLES> 57,999 <ALLOWANCES> 3,327 <INVENTORY> 2,359 <CURRENT-ASSETS> 144,471 <PP&E> 135,248 <DEPRECIATION> 62,850 <TOTAL-ASSETS> 319,166 <CURRENT-LIABILITIES> 120,425 <BONDS> 120,036 <PREFERRED-MANDATORY> 0 <PREFERRED> 0 <COMMON> 1,958 <OTHER-SE> 47,715 <TOTAL-LIABILITY-AND-EQUITY> 319,166 <SALES> 0 <TOTAL-REVENUES> 153,944 <CGS> 0 <TOTAL-COSTS> 121,830 <OTHER-EXPENSES> 54,317 <LOSS-PROVISION> 217 <INTEREST-EXPENSE> 4,465 <INCOME-PRETAX> (47,332) <INCOME-TAX> 241 <INCOME-CONTINUING> (43,887) <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> (43,887) <EPS-BASIC> (2.30) <EPS-DILUTED> (2.30)