UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE
DEPOSITORY TRUST COMPANY (55 WATER STREET, NEW YORK, NEW YORK) TO THE ISSUER OR
ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE
ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR SUCH OTHER NAME AS REQUESTED
BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY AND ANY PAYMENT
IS MADE TO CEDE & CO., ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR
OTHERWISE BY OR TO ANY PERSON IS WRONGFUL SINCE THE REGISTERED OWNER HEREOF,
CEDE & CO., HAS AN INTEREST HEREIN.


                            ======================= 

                                CSX CORPORATION

                            ======================= 

                                    FORM OF
                                  $___________
                            7.95% DEBENTURE DUE 2027



No. ___                                                     CUSIP ___________


          This security (the "Security") is one of a duly authorized issue of
securities (herein called the "Securities") of CSX Corporation, a Virginia
corporation (hereinafter called the "Company," which term includes any successor
corporation under the Indenture hereinafter referred to), issued and to be
issued in one or more series under an indenture, unlimited as to aggregate
principal amount, dated as of August 1, 1990 between the Company and The Chase
Manhattan Bank, Trustee (herein called the "Trustee," which term includes any
successor trustee under the Indenture (as hereinafter defined)), as supplemented
by a First Supplemental Indenture dated as of June 15, 1991 and a Second
Supplemental Indenture dated as of May 6, 1997, to which indenture and all
indentures supplemental thereto (the indenture, as supplemented being herein
called the "Indenture") reference is hereby made for a statement of the
respective rights thereunder of the Company, the Trustee and the Holders of the
Securities and of the terms upon which the Securities are, and are to be,
authenticated and delivered.  This Security is one of the series designated on
the face hereof, which series has been issued in an aggregate initial principal
amount of $___________ (___________________ DOLLARS).  This Security represents
an aggregate initial principal amount of $___________ (___________________
DOLLARS) (as adjusted from time to time in accordance with the terms and
provisions hereof and as set forth on Exhibit A hereto, the "Principal Amount")
of the Securities of such series, with the Interest      

 
     
                                       2

Payment Dates, date of original issuance, and date of Maturity specified herein
and bearing interest on said Principal Amount at the interest rate specified
herein.

          The Company, for value received, hereby promises to pay _____________,
or its registered assigns, the principal sum of $___________ (__________________
DOLLARS) on May 1, 2027, and to pay interest (computed on the basis of a 360-day
year of twelve 30-day months) thereon from May 1, 1997 or from the most recent
Interest Payment Date to which interest has been paid or duly provided for, or,
if the date of this Security is an Interest Payment Date to which interest has
been paid or duly provided for, then from the date hereof, semiannually in
arrears on May 1 and November 1 in each year, commencing November 1, 1997, and
at Maturity at the rate of 7.95% per annum, until the principal hereof is paid
or duly made available for payment. The Company shall pay interest on overdue
principal and premium, if any, and (to the extent lawful) interest on overdue
installments of interest at the rate per annum borne by the Security. The
interest so payable, and punctually paid or duly provided for, on any Interest
Payment Date will, as provided in such Indenture, be paid to the Person in whose
name this Security (or one or more Predecessor Securities) is registered at the
close of business on the Regular Record Date for such interest, which shall be
the April 15 or October 15 (whether or not a Business Day), as the case may be,
next preceding such Interest Payment Date. Except as otherwise provided in the
Indenture, any such interest not so punctually paid or duly provided for shall
forthwith cease to be payable to the Holder on such Regular Record Date and may
be paid to the Person in whose name this Security (or one or more Predecessor
Securities) is registered at the close of business on a Special Record Date to
be fixed by the Trustee for the payment of such Defaulted Interest, notice
whereof shall be given to the Holder of this Security not less than 10 days
prior to such Special Record Date, or may be paid at any time in any other
lawful manner not inconsistent with the requirements of any securities exchange
on which the Security of this series may be listed, and upon such notice as may
be required by such exchange, all as more fully provided in such Indenture.
Notwithstanding the foregoing, interest payable on this Security at Maturity
will be payable to the person to whom principal is payable.

          This Security is exchangeable in whole or from time to time in part
for definitive Registered Securities of this series only as provided in this
paragraph.  If (x) the U.S. Depository with respect to the Securities of this
series (the "U.S. Depository") notifies the Company that it is unwilling, unable
or ineligible to continue as U.S. Depository for this Security or if at any time
the U.S. Depository ceases to be a clearing agency registered under the
Securities Exchange Act of 1934, as amended, (y) the Company in its sole
discretion determines that this Security shall be exchangeable for definitive
Registered Securities and executes and delivers to the Trustee a Company Order
providing that this Security shall be so exchangeable or (z) there shall have
happened and be continuing an Event of Default or any event which, after notice
or lapse of time, or both, would become an Event of Default with respect to the
Securities of the series of which this Security is a part, this Security or any
     

 
    
                                       3


portion hereof shall, in the case of clause (x) above, be exchanged for
definitive Registered Securities of this series, and in the case of clauses (y)
and (z) above, be exchangeable for definitive Registered Securities of this
series, provided that the definitive Security so issued in exchange for this
Security shall be in authorized denominations and be of like tenor and of an
equal aggregate principal amount as the portion of the Security to be exchanged,
and provided further that, in the case of clauses (y) and (z) above, definitive
Registered Securities of this series will be issued in exchange for this
Security, or any portion hereof, only if such definitive Registered Securities
were requested by written notice to the Security Registrar by or on behalf of a
Person who is a beneficial owner of an interest herein given through the Holder
hereof.  Any definitive Registered Security of this series issued in exchange
for this Security, or any portion hereof, shall be registered in the name or
names of such Person or Persons as the Holder hereof shall instruct the Security
Registrar.  Except as provided above, owners of beneficial interests in this
Security will not be entitled to receive physical delivery of Security in
definitive form and will not be considered the Holders thereof for any purpose
under the Indenture.

          Any exchange of this Security or portion hereof for one or more
definitive Registered Securities of this series will be made at the New York
office of the Security Registrar.  Upon exchange of any portion of this Security
for one or more definitive Registered Securities of this series, the Trustee
shall endorse Exhibit A of this Security to reflect the reduction of its
Principal Amount by an amount equal to the aggregate principal amount of the
definitive Registered Securities of this series so issued in exchange, whereupon
the Principal Amount hereof shall be reduced for all purposes by the amount so
exchanged and noted.  Except as otherwise provided herein or in the Indenture,
until exchanged in full for one or more definitive Registered Securities of this
series, this Security shall in all respects be subject to and entitled to the
same benefits and conditions under the Indenture as a duly authenticated and
delivered definitive Registered Security of this series.

          The principal and any interest in respect of any portion of this
Security payable in respect of an Interest Payment Date or at the Stated
Maturity thereof, in each case occurring prior to the exchange of such portion
for a definitive Registered Security or Securities of this series, will be paid,
as provided herein, to the Holder hereof which will undertake in such
circumstances to credit any such principal and interest received by it in
respect of this Security to the respective accounts of the Persons who are the
beneficial owners of such interests on such Interest Payment Date or at Stated
Maturity.  If a definitive Registered Security or Registered Securities of this
series are issued in exchange for any portion of this Security after the close
of business at the office or agency where such exchange occurs on (i) any
Regular Record Date and before the opening of business at such office or agency
on the relevant Interest Payment Date, or (ii) any Special Record Date and
before the opening of business at such office or agency on the related proposed
date for payment of Defaulted Interest, then interest or Defaulted Interest, as
the case may be, will not be payable on such Interest Payment Date or proposed
date for payment, as the case may      

 
    
                                       4

be, in respect of such Registered Security, but will be payable on such Interest
Payment Date or proposed date for payment, as the case may be, only to the
Holder hereof, and the Holder hereof will undertake in such circumstances to
credit such interest to the account or accounts of the Persons who were the
beneficial owners of such portion of this Security on such Regular Record Date
or Special Record Date, as the case may be.

          Payment of the principal of and any such interest on this Security
will be made at the offices of The Chase Manhattan Bank, as Paying Agent, in the
Borough of Manhattan, The City of New York, or at such other office or agency of
the Company as may be designated by it for such purpose in the Borough of
Manhattan, The City of New York, in such coin or currency of the United States
of America as at the time of payment shall be legal tender for the payment of
public and private debts by check mailed to the registered Holders thereof;
provided, however, that at the option of the Holder, payment of interest may be
- --------  -------                                                              
made by wire transfer of immediately funds to an account of the Person entitled
hereto as such account shall be provided to the Security Registrar and shall
appear in the Security Register.

          If an Event of Default with respect to Securities of this series shall
occur and be continuing, the principal of the Securities of this series
(including this Security and the interests represented hereby) may be declared
due and payable in the manner and with the effect provided in the Indenture.
Upon payment (i) of the amount of principal so declared due and payable and (ii)
of interest on any overdue principal and overdue interest (in each case to the
extent that the payment of such interest shall be legally enforceable), all of
the Company's obligations in respect of the payment of the principal of and any
interest on the Securities of this series (including this Security and the
interests represented hereby) shall terminate.

          The Indenture contains provisions for defeasance at any time of (a)
the entire indebtedness of the Company on this Security and (b) certain
restrictive covenants and the related defaults and Events of Default, upon
compliance with certain conditions set forth therein, which provisions shall
apply to this Security.

          The provisions of Article Fourteen of the Indenture apply to
Securities of this series.

          The Indenture permits, with certain exceptions as therein provided,
the amendment thereof and the modification of the rights and obligations of the
Company and the rights of the Holders of the Securities of each series to be
affected under the Indenture at any time by the Company and the Trustee with the
consent of the Holders of a majority in aggregate principal amount of the
Securities at the time Outstanding of each series affected thereby.  The
Indenture also contains provisions permitting the Holders of specified
percentages in aggregate principal amount of the Securities of each series at
the time      

 
    
                                       5

Outstanding on behalf of the Holders of all Securities of such series to waive
compliance by the Company with certain provisions of the Indenture and certain
past defaults under the Indenture and their consequences.  Any such consent or
waiver by the Holder of this Security shall be conclusive and binding upon such
Holder and upon all future Holders of this Security  and the Persons who are
beneficial owners of interests represented hereby, and of any Security issued in
exchange herefor or in lieu hereof whether or not notation of such consent or
waiver is made upon this Security.

          As set forth in, and subject to, the provisions of the Indenture, no
Holder of any Security of this series will have any right to institute any
proceeding with respect to the Indenture or for any remedy thereunder, unless
such Holder shall have previously given to the Trustee written notice of a
continuing Event of Default with respect to the Securities of this series, the
Holders of not less than 25% in aggregate principal amount of the Outstanding
Securities of this series shall have made written request, and offered
reasonable indemnity, to the Trustee to institute such proceeding as trustee,
and the Trustee shall not have received from the Holders of a majority in
aggregate principal amount of the Outstanding Securities of this series a
direction inconsistent with such request and shall have failed to institute such
proceeding within 60 days; provided, however, that such limitations do not apply
to a suit instituted by the Holder hereof for the enforcement of payment of the
principal of (and premium, if any) or interest on this Security on or after the
respective due dates expressed herein.

          No reference herein to the Indenture and no provision of this Security
or of the Indenture shall alter or impair the obligation of the Company, which
is absolute and unconditional to pay the principal of (and premium, if any) and
interest on this Security at the time, place and rate, and in the coin or
currency, herein prescribed.

          As provided in the Indenture and subject to certain limitations
therein and herein set forth, the transfer of Registered Securities of the
series of which this Security is a part may be registered on the Security
Register of the Company, upon surrender of such Securities for registration of
transfer at the office of the Security Registrar, duly endorsed by, or
accompanied by a written instrument of transfer in form satisfactory to the
Company and the Security Registrar duly executed by the Holder thereof or his
attorney duly authorized in writing, and thereupon one or two more new
Securities of this Series and of like tenor, of authorized denominations and for
the same aggregate principal amount, will be issued to the designated transferee
or transferees.

          No service charge shall be made for any such registration of transfer
or exchange of Securities as provided above, but the Company may require payment
of a sum sufficient to cover any tax or other governmental charge payable in
connection therewith.      

 
    
                                       6

          Prior to due presentment of this Security for registration of
transfer, the Company, the Trustee and any agent of the Company or the Trustee
may treat the Person in whose name this Security is registered as the owner
hereof for all purposes, whether or not this Security be overdue, and neither
the Company, the Trustee nor any such agent shall be affected by notice to the
contrary.

          The Securities of this series of which this Security is a part are
issuable only in registered form without coupons, in denominations of $1,000.00
and any integral multiple thereof.  As provided in the Indenture and subject to
certain limitations therein set forth, the Securities of this series are
exchangeable for a like aggregate principal amount of Securities of this series
and of like tenor of a different authorized denomination, as requested by the
Holder surrendering the same.

          The Securities of this series shall be dated the date of their
authentication.

          All terms used in this Security which are defined in the Indenture
shall have the meanings assigned to them in the Indenture.

          Unless the certificate of authentication hereon has been executed by
or on behalf of The Chase Manhattan Bank, the Trustee under the Indenture, or
its successor thereunder, by the manual signature of one of its authorized
officers, this Security shall not be entitled to any benefit under the Indenture
or be valid or obligatory for any purpose.      

 
    
                                       7

          IN WITNESS WHEREOF, the Company has caused this instrument to be duly
executed under its corporate seal.


Dated: _____, 1997



                                       CSX CORPORATION
                                  
                                  
                                  
[Seal]                              By:
                                       ----------------------------------------
                                          Name:    David D. Owen
                                          Title:   Managing Director--Corporate 
                                                   Finance


Attest:


- -------------------------------------------------- 
              Corporate Secretary



                    TRUSTEE'S CERTIFICATE OF AUTHENTICATION

          This is one of the Securities of a series issued under the Indenture
described herein.


                                    THE CHASE MANHATTAN BANK, as Trustee



 
                                  By:
                                     -------------------------------------------
                                                  Authorized Officer
     

 
    
                                       8

                            FORM OF TRANSFER NOTICE


     FOR VALUE RECEIVED the undersigned registered holder hereby sell(s),
assign(s) and transfer(s) unto

Insert Taxpayer Identification No.
- ----------------------------------


- --------------------------------------------------------------------------------
Please print or typewrite name and address including zip code of assignee

- --------------------------------------------------------------------------------
the within Debenture and all rights thereunder, hereby irrevocably constituting
and appointing ___________________________________ attorney to transfer said
Debenture the books of the Security Registrar with full power of substitution in
the premises.


Date:
     -------------------        ------------------------------------------------
                                NOTICE: The signature to this assignment must
                                correspond with the name as written upon the
                                face of the within-mentioned instrument in every
                                particular, without alteration or any change
                                whatsoever.
     

 
    
                                                                       EXHIBIT A
                                                                       ------- -


                             Schedule of Exchanges
                             ---------------------