<ARTICLE> 5
<MULTIPLIER> 1,000
       
                             
<PERIOD-TYPE>                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-1997
<PERIOD-END>                               JUN-30-1997
<CASH>                                           8,626
<SECURITIES>                                         0
<RECEIVABLES>                                   31,575
<ALLOWANCES>                                         0
<INVENTORY>                                     19,775
<CURRENT-ASSETS>                                62,649
<PP&E>                                         402,189
<DEPRECIATION>                                 223,737
<TOTAL-ASSETS>                                 258,642
<CURRENT-LIABILITIES>                           26,872
<BONDS>                                              0
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                        575
<COMMON>                                        13,789
<OTHER-SE>                                     154,019
<TOTAL-LIABILITY-AND-EQUITY>                   258,642
<SALES>                                         88,525
<TOTAL-REVENUES>                                91,746
<CGS>                                           68,160
<TOTAL-COSTS>                                   77,563
<OTHER-EXPENSES>                                 8,130
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                                 943
<INCOME-PRETAX>                                  4,333
<INCOME-TAX>                                       761
<INCOME-CONTINUING>                              3,572
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                     3,572
<EPS-PRIMARY>                                   (0.01)
<EPS-DILUTED>                                   (0.01)