<ARTICLE>            5
<LEGEND>             THIS SCHEDULE CONTAINS SUMMARY FINANCIAL
                     INFORMATION EXTRACTED FROM THE 
                     COMPANY'S UNAUDITED FINANCIAL STATEMENTS
                     AS OF AND FOR THE PERIOD ENDING JUNE 30,
                     1998, AND IS QUALIFIED IN ITS ENTIRETY BY 
                     REFERENCE TO SUCH FINANCIAL STATEMENTS 
<MULTIPLIER>         1,000
<FISCAL-YEAR-END>    DEC-31-1998
<PERIOD-END>         JUN-30-1998
<PERIOD-TYPE>        6-MOS

<CASH>                                 3,553
<SECURITIES>                               0
<RECEIVABLES>                         73,257
<ALLOWANCES>                               0
<INVENTORY>                           20,894
<CURRENT-ASSETS>                     113,145
<PP&E>                               321,374
<DEPRECIATION>                       149,258
<TOTAL-ASSETS>                       341,450
<CURRENT-LIABILITIES>                 68,776
<BONDS>                                    0
<PREFERRED-MANDATORY>                      0
<PREFERRED>                                0
<COMMON>                              18,356
<OTHER-SE>                           107,646
<TOTAL-LIABILITY-AND-EQUITY>         341,450
<SALES>                              254,260
<TOTAL-REVENUES>                     253,935
<CGS>                                225,781
<TOTAL-COSTS>                          7,402
<OTHER-EXPENSES>                           0
<LOSS-PROVISION>                           0
<INTEREST-EXPENSE>                     4,945
<INCOME-PRETAX>                       15,807
<INCOME-TAX>                           5,216
<INCOME-CONTINUING>                   10,591
<DISCONTINUED>                             0
<EXTRAORDINARY>                            0
<CHANGES>                                  0
<NET-INCOME>                          10,591
<EPS-PRIMARY>                           0.58
<EPS-DILUTED>                           0.58