Exhibit 3.15

                            ARTICLES OF INCORPORATION

                                       OF

                                    NTI, INC.



                                    ARTICLE I

                                      Name

          The name of this Corporation is NTI, Inc.

                                   ARTICLE II

                                  Capital Stock

          The total number of shares which this Corporation is authorized to
issue is one million (1,000,000) shares of Common Stock, no par value, which
shall be the only class of shares of this Corporation.

                                   ARTICLE III

                              No Preemptive Rights

          Except as may otherwise be provided by the Board of Directors, no
holder of any shares of this Corporation shall have any preemptive right to
purchase, subscribe for or otherwise acquire any securities of this Corporation
of any class or kind now or hereafter authorized.

                                   ARTICLE IV

                               Number of Directors

          A. This Corporation shall have at least one director, the actual
number to be fixed in accordance with the Bylaws. The initial Board of Directors
shall consist of two (2) directors.

                                       -1-

          B. The names and addresses of the first Board of Directors of the
Corporation are as follows:

             Donald A. Wright
             434 Olds Station Road
             Wenatchee, WA 98801

             Nick A. Gerde
             434 Olds Station Road
             Wenatchee, WA 98801

                                    ARTICLE V

                                Cumulative Voting

          There shall be no cumulative voting of shares in this Corporation.

                                   ARTICLE VI

               Shareholder Voting on Significant Corporate Action

          Any corporate action for which the Washington Business Corporation
Act, as then in effect, would otherwise require approval by either a two-thirds
vote of the shareholders of the Corporation or by a two-thirds vote of one or
more voting groups shall be deemed approved by the shareholders or the voting
group(s) if it is approved by the affirmative vote of the holders of a majority
of shares entitled to vote or, if approval by voting groups is required, by the
holders of a majority of shares within each voting group entitled to vote
separately. Notwithstanding this Article, effect shall be given to any other
provision of these Articles that specifically requires a greater vote for
approval of any particular corporate action.

                                   ARTICLE VII

                        Limitation on Director Liability

          To the fullest extent permitted by Washington law and subject to the
Bylaws of this Corporation, a director of this Corporation shall not be liable
to the Corporation or its shareholders for monetary damages for his or her
conduct as a director. Any amendment to or repeal of this Article shall not
adversely affect any right of a director of this Corporation hereunder with
respect to any acts or omissions of the director occurring prior to amendment or
repeal.

                                      -2-

                                  ARTICLE VIII

                          Indemnification of Directors

          To the fullest extent permitted by its Bylaws and Washington law, this
Corporation is authorized to indemnify any of its directors. The Board of
Directors shall be entitled to determine the terms of indemnification, including
advance of expenses, and to give effect thereto through the adoption of Bylaws,
approval of agreements, or by any other manner approved by the Board of
Directors. Any amendment to or repeal of this Article shall not adversely affect
any right of an individual with respect to any right to indemnification arising
prior to such amendment or repeal.

                                   ARTICLE IX

                     Registered Office and Registered Agent

          The name of the registered agent of this Corporation and the street
address of its registered office are as follows:


                             JGB SERVICE CORPORATION
                             3600 One Union Square
                             600 University Street
                             Seattle, WA 98101-3197

                                    ARTICLE X

                                  Incorporator

          The name and address of the incorporator are as follows:

                           Eugenie D. Mansfield, Esq.
                           3600 One Union Square
                           600 University Street
                           Seattle, WA 98101-3197


DATED: February 18, 1997              /s/ EUGENIE D. MANSFIELD
                                     -----------------------------------------
                                       Eugenie D. Mansfield, Esq.
                                       Incorporator

                                       -3-

                   CONSENT TO APPOINTMENT AS REGISTERED AGENT


          The undersigned hereby consents to serve as registered agent for NTI,
Inc. in the State of Washington.


          DATED this 18th day of February, 1997.


                                       JGB SERVICE CORPORATION


                                       /s/ CONNIE CHAPMAN
                                       -----------------------------------------
                                       By:   Connie Chapman
                                       Its:  Assistant Secretary

                                             3600 One Union Square
                                             600 University Street
                                             Seattle, WA 98101-3197


                                       -4-

                              ARTICLES OF AMENDMENT
                         OF ARTICLES OF INCORPORATION OF
                                    NTI, INC.


     Articles of Amendment of Articles of Incorporation of NTI, Inc., a
Washington corporation, are herein executed by said corporation, pursuant to the
provisions of RCW 23B.01.200 and RCW 23B.10.060, as follows:

     1. The name of the corporation is NTI, Inc.

     2. The amendment to the Articles of Incorporation of this corporation
deletes the language of Article I in its entirety and replaces such Article with
the following language:

                                    ARTICLE I

                                      Name

     The name of this corporation is Northwest Technical Industries, Inc.

     3. No exchange, reclassification or cancellation of issued shares shall be
effected by this amendment.

     4. The date of the adoption of said amendment by the Board of Directors of
said corporation was April 30, 1997.

     5. The amendment to the Articles of Incorporation was duly approved by the
Board of Directors in accordance with the provisions of RCW 23B.10.020, and
shareholder action was not required.

     IN WITNESS WHEREOF, the undersigned has executed these Articles of
Amendment in an official and authorized capacity under penalty of perjury this
30th day of April, 1997.

                                       NTI, Inc.


                                       By: /s/ DONALD A. WRIGHT
                                           -------------------------------------
                                           Donald A. Wright
                                           Its: Executive Vice President