<TABLE> <S> <C>

<ARTICLE> 5
       
<S>                             <C>                     <C>                     <C>
<PERIOD-TYPE>                   3-MOS                   6-MOS                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1996             DEC-31-1996             DEC-31-1996
<PERIOD-END>                               MAR-31-1996             JUN-30-1996             SEP-30-1996
<CASH>                                             937                   9,679                  24,968
<SECURITIES>                                         0                       0                       0
<RECEIVABLES>                                  194,628                 254,667                 200,347
<ALLOWANCES>                                         0                       0                       0
<INVENTORY>                                     10,484                  31,204                  60,929
<CURRENT-ASSETS>                               212,039                 316,465                 313,048
<PP&E>                                         799,817               1,547,738               1,558,803
<DEPRECIATION>                                 186,364                 196,119                 209,569
<TOTAL-ASSETS>                                 881,958               1,768,242               1,764,394
<CURRENT-LIABILITIES>                          223,764                 335,643                 334,008
<BONDS>                                        243,075               1,011,275                 896,755
<PREFERRED-MANDATORY>                           55,000                  53,246                  51,987
<PREFERRED>                                        460                     460                     460
<COMMON>                                         4,351                   4,351                   5,128
<OTHER-SE>                                     306,521                 312,542                 423,572
<TOTAL-LIABILITY-AND-EQUITY>                   881,958               1,768,242               1,764,394
<SALES>                                        432,401                 851,685               1,393,597
<TOTAL-REVENUES>                               432,401                 851,685               1,393,597
<CGS>                                          389,072                 761,865               1,228,825
<TOTAL-COSTS>                                  406,667                 801,499               1,301,093
<OTHER-EXPENSES>                                     0                       0                       0
<LOSS-PROVISION>                                     0                       0                       0
<INTEREST-EXPENSE>                               5,155                  12,539                  28,911
<INCOME-PRETAX>                                 17,645                  30,276                  44,613
<INCOME-TAX>                                     6,707                  11,323                  15,408
<INCOME-CONTINUING>                             10,938                  18,953                  29,205
<DISCONTINUED>                                       0                       0                       0
<EXTRAORDINARY>                                      0                       0                       0
<CHANGES>                                            0                       0                       0
<NET-INCOME>                                    10,938                  18,953                  29,205
<EPS-PRIMARY>                                     0.51                    0.85                    1.26
<EPS-DILUTED>                                        0                    0.85                    1.26
        

</TABLE>