SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person* Blue Harbour Group, L.P. (Last) (First) (Middle) 646 STEAMBOAT RD. (Street) GREENWICH CT 06830 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 07/01/2015	3. Issuer Name and Ticker or Trading Symbol BWX Technologies, Inc. [ BWTX ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director 10% Owner Officer (give title below) X Other (specify below) See Remarks	5. If Amendment, Date of Original Filed (Month/Day/Year)
			6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock, par value $0.01 per share ("Common Stock")	10,561,086	I	See footnotes(1)(2)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

1. Name and Address of Reporting Person* Blue Harbour Group, L.P. (Last) (First) (Middle) 646 STEAMBOAT RD. (Street) GREENWICH CT 06830 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director 10% Owner Officer (give title below) X Other (specify below) See Remarks

1. Name and Address of Reporting Person* Blue Harbour Holdings, LLC (Last) (First) (Middle) 646 STEAMBOAT RD. (Street) GREENWICH CT 06830 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director 10% Owner Officer (give title below) X Other (specify below) See Remarks

1. Name and Address of Reporting Person* ROBBINS CLIFTON S (Last) (First) (Middle) C/O BLUE HARBOUR GROUP, LP 646 STEAMBOAT RD. (Street) GREENWICH CT 06830 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director 10% Owner Officer (give title below) X Other (specify below) See Remarks

Explanation of Responses:

1. This Form 3 is filed by Blue Harbour Group, LP (the "Manager"), Blue Harbour Holdings, LLC ("Manager GP") and Clifton S. Robbins. Manager GP is the general partner of Manager. Mr. Robbins directly and indirectly through trusts or other entities controlled by Mr. Robbins is the controlling shareholder of Manager GP.

2. Pursuant to Rule 16a-1 under the Securities Exchange Act of 1934, as amended (the "Act"), each of the Reporting Persons may be deemed to be the beneficial owner of the securities reported herein to the extent of his or its pecuniary interest therein, but disclaims beneficial ownership in excess of such amount; and pursuant to Rule 16a-1(a)(4) under the Act, this filing shall not be deemed an admission that any of the Reporting Persons is, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any securities reported herein in excess of such amount.

Remarks:

Because Robb A. LeMasters, an employee of the Manager, serves as a member of the board of directors of the Issuer, each of the Reporting Persons may be deemed to be a director by deputization.

	BLUE HARBOUR GROUP, LP, By: Blue Harbour Holdings, LLC, its general partner, /s/ Clifton S. Robbins, Managing Member	07/13/2015
	BLUE HARBOUR HOLDINGS, LLC, /s/ Clifton S. Robbins, Managing Member	07/13/2015
	/s/ Clifton S. Robbins	07/13/2015
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
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