<ARTICLE> 5
<LEGEND>
(THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM CONDENSED
CONSOLIDATED BALANCE SHEETS AND FROM CONSOLIDATED STATEMENTS OF EARNINGS AND IS
QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS)
</LEGEND>
       
                             
<PERIOD-TYPE>                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-1997
<PERIOD-END>                               JUN-30-1998
<CASH>                                           1,203
<SECURITIES>                                         0
<RECEIVABLES>                                  500,047
<ALLOWANCES>                                         0
<INVENTORY>                                    280,398
<CURRENT-ASSETS>                               823,356
<PP&E>                                       3,552,936
<DEPRECIATION>                             (1,678,288)
<TOTAL-ASSETS>                               2,880,410
<CURRENT-LIABILITIES>                          734,111
<BONDS>                                        544,195
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                        15,624
<OTHER-SE>                                   1,271,155
<TOTAL-LIABILITY-AND-EQUITY>                 2,880,410
<SALES>                                      2,037,357
<TOTAL-REVENUES>                             2,066,892
<CGS>                                        1,625,995
<TOTAL-COSTS>                                  179,157
<OTHER-EXPENSES>                               177,677
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                              17,603
<INCOME-PRETAX>                                 66,460
<INCOME-TAX>                                    23,323
<INCOME-CONTINUING>                             43,137
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    43,137
<EPS-PRIMARY>                                     1.38
<EPS-DILUTED>                                        0