FORM 4
[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).         
 UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES
                                                                                  
 OMB APPROVAL
OMB Number: 3235-0287
Estimated average burden
hours per response... 0.5
                      
Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940
                      

1. Name and Address of Reporting Person *

ECP ControlCo, LLC		 2. Issuer Name and Ticker or Trading Symbol

Custom Truck One Source, Inc. [ CTOS ] 		5. Relationship of Reporting Person(s) to Issuer (Check all applicable)

__X__ Director                    __X__ 10% Owner
_____ Officer (give title below)    _____ Other (specify below)
(Last)          (First)          (Middle)

40 BEECHWOOD ROAD		 3. Date of Earliest Transaction (MM/DD/YYYY)

4/29/2022
(Street)

SUMMIT,, NJ 07901
(City)        (State)        (Zip)
4. If Amendment, Date Original Filed (MM/DD/YYYY)

 
 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 Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3) 		2. Trans. Date 2A. Deemed Execution Date, if any 3. Trans. Code
(Instr. 8) 		4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5) 		5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4) 		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4)
Code V Amount (A) or (D) Price

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivate Security
(Instr. 3)		2. Conversion or Exercise Price of Derivative Security3. Trans. Date3A. Deemed Execution Date, if any4. Trans. Code
(Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date7. Title and Amount of Securities Underlying Derivative Security
(Instr. 3 and 4)		8. Price of Derivative Security
(Instr. 5)		9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)11. Nature of Indirect Beneficial Ownership (Instr. 4)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
Restricted Stock Unit  (1)4/29/2022  A   14315     (2) (2)Common Stock 14315 $0 14315 I See footnote (3)
Explanation of Responses:
(1) Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock.
(2) The restricted stock units will vest on March 31, 2023 and have no expiration date.
(3) Represents securities held directly by Energy Capital Partners Management, LP ("ECP Management"). ECP Management GP, LLC is the general partner of ECP Management and may be deemed to share beneficial ownership of the securities held by ECP Management. ECP ControlCo, LLC ("ECP ControlCo") is the sole member of ECP Management GP, LLC. As a result, ECP ControlCo may be deemed to share beneficial ownership of the securities beneficially owned by ECP Management GP, LLC. The managing members of ECP ControlCo are Douglas Kimmelman, Andrew Singer, Peter Labbat, Tyler Reeder and Rahman D'Argenio all of whom collectively share the power to vote and dispose of the securities beneficially owned by ECP ControlCo. Each such individual disclaims beneficial ownership of such shares except to the extent of his pecuniary interest therein.

Reporting Owners
Reporting Owner Name / Address
Relationships
Director10% OwnerOfficerOther
ECP ControlCo, LLC
40 BEECHWOOD ROAD
SUMMIT,, NJ 07901		XX

ECP Management GP, LLC
40 BEECHWOOD ROAD,
SUMMIT,, NJ 07901		XX

Energy Capital Partners Management, LP
40 BEECHWOOD ROAD,
SUMMIT,, NJ 07901		XX
Signatures
ECP ControlCo, LLC By: /s/ Rahman D'Argenio, Managing Member5/3/2022
**Signature of Reporting PersonDate

ECP Management GP, LLC By: ECP ControlCo, LLC, its sole member By: /s/ Rahman D'Argenio, Managing Member5/3/2022
**Signature of Reporting PersonDate

ECP ControlCo, LLC By: ECP Management GP, LLC, its general partner By: ECP ControlCo, LLC, its sole member By: /s/ Rahman D'Argenio, Managing Member5/3/2022
**Signature of Reporting PersonDate
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 4(b)(v).
**Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note:File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.
Nesco (NYSE:NSCO)
Historical Stock Chart
From Mar 2025 to Apr 2025 Click Here for more Nesco Charts.
Nesco (NYSE:NSCO)
Historical Stock Chart
From Apr 2024 to Apr 2025 Click Here for more Nesco Charts.