# EDGAR Filing Document

**Accession Number:** 0000352825
**File Stem:** 0000921895-25-003328
**Filing Date:** 2025-12
**Character Count:** 25938
**Document Hash:** 489cfea443d47ac7126892b0af77c9d3
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000921895-25-003328.hdr.sgml**: 20251212

**ACCESSION NUMBER**: 0000921895-25-003328

**CONFORMED SUBMISSION TYPE**: SCHEDULE 13D/A

**PUBLIC DOCUMENT COUNT**: 3

**FILED AS OF DATE**: 20251212

**DATE AS OF CHANGE**: 20251212

**SUBJECT COMPANY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** FOSTER L B CO
- **CENTRAL INDEX KEY:** 0000352825
- **STANDARD INDUSTRIAL CLASSIFICATION:** WHOLESALE-METALS SERVICE CENTERS & OFFICES [5051]
- **ORGANIZATION NAME:** 07 Trade & Services
- **EIN:** 251324733
- **STATE OF INCORPORATION:** PA
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13D/A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-34076
- **FILM NUMBER:** 251569423

**BUSINESS ADDRESS:**
- **STREET 1:** 415 HOLIDAY DR
- **CITY:** PITTSBURGH
- **STATE:** PA
- **ZIP:** 15220
- **BUSINESS PHONE:** 4129283431

**MAIL ADDRESS:**
- **STREET 1:** 415 HOLIDAY DR
- **CITY:** PITTSBURGH
- **STATE:** PA
- **ZIP:** 15220
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** 22NW Fund, LP
- **CENTRAL INDEX KEY:** 0001640809

**ORGANIZATION NAME:**
- **EIN:** 473303449
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13D/A

**BUSINESS ADDRESS:**
- **STREET 1:** 1455 NW LEARY WAY
- **STREET 2:** SUITE 400
- **CITY:** SEATTLE
- **STATE:** WA
- **ZIP:** 98107
- **BUSINESS PHONE:** 206-227-3078

**MAIL ADDRESS:**
- **STREET 1:** 1455 NW LEARY WAY
- **STREET 2:** SUITE 400
- **CITY:** SEATTLE
- **STATE:** WA
- **ZIP:** 98107

## Ex-1

Exhibit 1

**<u>Transactions in the Securities of the Issuer During the Past Sixty (60) Days</u>**

---

| | | | | |
|:---|:---|:---|:---|:---|
| &nbsp;&nbsp;<u>Nature of the Transaction</u> | &nbsp;&nbsp; Securities<br> <u>Purchased/(Sold)</u> | &nbsp;&nbsp; Price Per<br> <u>Security($)<sup>\*</sup></u> | &nbsp;&nbsp;<u>Price Range ($)</u> | &nbsp;&nbsp; Date of<br> <u>Purchase/Sale</u> |

---

**<u>22NW FUND, LP</u>**

---

| | | | | |
|:---|:---|:---|:---|:---|
| &nbsp;&nbsp;Sale of Common Stock | &nbsp;&nbsp;(4813) | &nbsp;&nbsp;28.1749 | &nbsp;&nbsp;28.1600 - 28.1750 | &nbsp;&nbsp;11/11/2025 |
| &nbsp;&nbsp;Sale of Common Stock | &nbsp;&nbsp;(2749) | &nbsp;&nbsp;27.5187 | &nbsp;&nbsp;27.1000 - 28.0200 | &nbsp;&nbsp;11/11/2025 |
| &nbsp;&nbsp;Sale of Common Stock | &nbsp;&nbsp;(3368) | &nbsp;&nbsp;27.0643 | &nbsp;&nbsp;27.0000 - 27.2400 | &nbsp;&nbsp;11/12/2025 |
| &nbsp;&nbsp;Sale of Common Stock | &nbsp;&nbsp;(1600) | &nbsp;&nbsp;27.0019 | &nbsp;&nbsp;27.0000 - 27.0300 | &nbsp;&nbsp;11/13/2025 |
| &nbsp;&nbsp;Sale of Common Stock | &nbsp;&nbsp;(2247) | &nbsp;&nbsp;27.0000 | &nbsp;&nbsp;- | &nbsp;&nbsp;11/14/2025 |
| &nbsp;&nbsp;Sale of Common Stock | &nbsp;&nbsp;(400) | &nbsp;&nbsp;27.0000 | &nbsp;&nbsp;- | &nbsp;&nbsp;11/17/2025 |
| &nbsp;&nbsp;Sale of Common Stock | &nbsp;&nbsp;(3412) | &nbsp;&nbsp;27.0288 | &nbsp;&nbsp;27.0000 - 27.0500 | &nbsp;&nbsp;11/21/2025 |
| &nbsp;&nbsp;Sale of Common Stock | &nbsp;&nbsp;(27003) | &nbsp;&nbsp;26.8357 | &nbsp;&nbsp;26.8300 - 27.0000 | &nbsp;&nbsp;11/24/2025 |
| &nbsp;&nbsp;Sale of Common Stock | &nbsp;&nbsp;(1725) | &nbsp;&nbsp;26.9375 | &nbsp;&nbsp;26.9100 - 26.9900 | &nbsp;&nbsp;11/25/2025 |
| &nbsp;&nbsp;Sale of Common Stock | &nbsp;&nbsp;(1307) | &nbsp;&nbsp;27.0855 | &nbsp;&nbsp;27.0000 - 27.3650 | &nbsp;&nbsp;11/28/2025 |
| &nbsp;&nbsp;Sale of Common Stock | &nbsp;&nbsp;(101) | &nbsp;&nbsp;26.8168 | &nbsp;&nbsp;26.8000 - 27.0000 | &nbsp;&nbsp;12/01/2025 |
| &nbsp;&nbsp;Sale of Common Stock | &nbsp;&nbsp;(9765) | &nbsp;&nbsp;27.2773 | &nbsp;&nbsp;26.9800 - 27.5200 | &nbsp;&nbsp;12/08/2025 |
| &nbsp;&nbsp;Sale of Common Stock | &nbsp;&nbsp;(4800) | &nbsp;&nbsp;26.9251 | &nbsp;&nbsp;26.7500 - 27.0800 | &nbsp;&nbsp;12/09/2025 |
| &nbsp;&nbsp;Sale of Common Stock | &nbsp;&nbsp;(11248) | &nbsp;&nbsp;26.8335 | &nbsp;&nbsp;26.7500 - 27.0150 | &nbsp;&nbsp;12/10/2025 |
| &nbsp;&nbsp;Sale of Common Stock | &nbsp;&nbsp;(34025) | &nbsp;&nbsp;26.7941 | &nbsp;&nbsp;26.7500 - 27.1500 | &nbsp;&nbsp;12/11/2025 |
| &nbsp;&nbsp;Sale of Common Stock | &nbsp;&nbsp;(13512) | &nbsp;&nbsp;26.7855 | &nbsp;&nbsp;26.7500 - 26.9800 | &nbsp;&nbsp;12/12/2025 |

---

 

_______________________________

<sup>\*</sup> The price reported in column <u>Price Per Security ($)</u> is a weighted average price if a price range is indicated in column <u>Price Range ($)</u>. These securities were sold in multiple transactions at prices between the corresponding price ranges in the applicable row. The Reporting Persons undertake to provide the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of securities sold at each separate price.

## Exhibit 99.1

Exhibit 99.1

**<u>JOINT FILING AGREEMENT</u>**

In accordance with Rule 13d-1(k)(1)(iii) under the Securities Exchange Act of 1934, as amended, the persons named below agree to the joint filing on behalf of each of them of a Statement on Schedule 13D (including additional amendments thereto) with respect to the shares of Common Stock, par value $0.01 per share, of L.B. Foster Company, a Pennsylvania corporation. This Joint Filing Agreement shall be filed as an Exhibit to such Statement.

---

| | |
|:---|:---|
| 22NW Fund, LP | 22NW Fund, LP |
| By: | /s/ Aron R. English |
|  | Aron R. English, Manager of 22NW Fund GP, LLC, its General Partner |
| Date: | 12/12/2025 |

---

---

| | |
|:---|:---|
| 22NW, LP | 22NW, LP |
| By: | /s/ Aron R. English |
|  | Aron R. English, President and Sole Shareholder of 22NW GP, Inc., its General Partner |
| Date: | 12/12/2025 |

---

---

| | |
|:---|:---|
| 22NW Fund GP, LLC | 22NW Fund GP, LLC |
| By: | /s/ Aron R. English |
|  | Aron R. English, Manager |
| Date: | 12/12/2025 |

---

---

| | |
|:---|:---|
| 22NW GP, Inc. | 22NW GP, Inc. |
| By: | /s/ Aron R. English |
|  | Aron R. English, President and Sole Shareholder |
| Date: | 12/12/2025 |

---

---

| | |
|:---|:---|
| English Aron R. | English Aron R. |
| By: | /s/ Aron R. English |
|  | ARON R. ENGLISH |
| Date: | 12/12/2025 |

---

---

| | |
|:---|:---|
| Hirai-Hadley Bryson | Hirai-Hadley Bryson |
| By: | /s/ Bryson O. Hirai-Hadley |
|  | BRYSON O. HIRAI-HADLEY |
| Date: | 12/12/2025 |

---

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## SCHEDULE 13D

### Under the Securities Exchange Act of 1934

**(Amendment No. 4)**

**FOSTER L B CO**

*(Name of Issuer)*

**Common Stock, par value $0.01 per share**

*(Title of Class of Securities)*

**350060109**

*(CUSIP Number)*

**ARON R. ENGLISH**<br>22NW, LP<br>590 1st Ave. S, Unit C1<br>Seattle WA 98104<br>206-227-3078

*(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)*

**12/10/2025**

*(Date of Event Which Requires Filing of this Statement)*

| **CUSIP No.** | **350060109** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**22NW Fund, LP** | Name of reporting person<br>**22NW Fund, LP** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**WC** | Source of funds (See Instructions)<br>**WC** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**1191046.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**1191046.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**0.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**1191046.00** | Aggregate amount beneficially owned by each reporting person<br>**1191046.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**11.5%** | Percent of class represented by amount in Row (11)<br>**11.5%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**PN** | Type of Reporting Person (See Instructions)<br>**PN** | |

---

| **CUSIP No.** | **350060109** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**22NW, LP** | Name of reporting person<br>**22NW, LP** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**OO** | Source of funds (See Instructions)<br>**OO** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**1191046.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**1191046.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**0.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**1191046.00** | Aggregate amount beneficially owned by each reporting person<br>**1191046.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**11.5%** | Percent of class represented by amount in Row (11)<br>**11.5%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**PN** | Type of Reporting Person (See Instructions)<br>**PN** | |

---

| **CUSIP No.** | **350060109** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**22NW Fund GP, LLC** | Name of reporting person<br>**22NW Fund GP, LLC** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**OO** | Source of funds (See Instructions)<br>**OO** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**1191046.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**1191046.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**0.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**1191046.00** | Aggregate amount beneficially owned by each reporting person<br>**1191046.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**11.5%** | Percent of class represented by amount in Row (11)<br>**11.5%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**OO** | Type of Reporting Person (See Instructions)<br>**OO** | |

---

| **CUSIP No.** | **350060109** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**22NW GP, Inc.** | Name of reporting person<br>**22NW GP, Inc.** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**OO** | Source of funds (See Instructions)<br>**OO** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**1191046.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**1191046.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**0.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**1191046.00** | Aggregate amount beneficially owned by each reporting person<br>**1191046.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**11.5%** | Percent of class represented by amount in Row (11)<br>**11.5%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**CO** | Type of Reporting Person (See Instructions)<br>**CO** | |

---

| **CUSIP No.** | **350060109** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**English Aron R.** | Name of reporting person<br>**English Aron R.** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**PF** | Source of funds (See Instructions)<br>**PF** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**X1** | Citizenship or place of organization<br>**X1** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**1191951.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**1191951.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**0.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**1191951.00** | Aggregate amount beneficially owned by each reporting person<br>**1191951.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**11.5%** | Percent of class represented by amount in Row (11)<br>**11.5%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**IN** | Type of Reporting Person (See Instructions)<br>**IN** | |

---

| **CUSIP No.** | **350060109** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Hirai-Hadley Bryson** | Name of reporting person<br>**Hirai-Hadley Bryson** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**PF** | Source of funds (See Instructions)<br>**PF** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**X1** | Citizenship or place of organization<br>**X1** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**991.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**991.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**0.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**991.00** | Aggregate amount beneficially owned by each reporting person<br>**991.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**0.01%** | Percent of class represented by amount in Row (11)<br>**0.01%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**IN** | Type of Reporting Person (See Instructions)<br>**IN** | |

---

| **CUSIP No.** | **350060109** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Jones Alexander B** | Name of reporting person<br>**Jones Alexander B** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[ ] (a)<br>[x] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[ ] (a)<br>[x] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**PF** | Source of funds (See Instructions)<br>**PF** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**X1** | Citizenship or place of organization<br>**X1** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**8312.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**8312.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**0.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**8312.00** | Aggregate amount beneficially owned by each reporting person<br>**8312.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**0.1%** | Percent of class represented by amount in Row (11)<br>**0.1%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**IN** | Type of Reporting Person (See Instructions)<br>**IN** | |

---

**Item 1. Security and Issuer**

**(a) Title of Class of Securities:**
Common Stock, par value $0.01 per share

**(b) Name of Issuer:**
FOSTER L B CO

**(c) Address of Issuer's Principal Executive Offices:**
415 HOLIDAY DR, PITTSBURGH, PA, 15220

**Item 5. Interest in Securities of the Issuer**

**(a)**
Item 5(a) is hereby amended and restated to read as follows:

The aggregate percentage of Shares reported owned by each person named herein is based upon 10,393,009 Shares outstanding as of October 28, 2025, which is the total number of Shares outstanding as reported in the Issuer's quarterly report on Form 10-Q filed with the Securities and Exchange Commission on November 3, 2025.

As of the date hereof, 22NW Fund directly beneficially owned 1,191,046 Shares, constituting approximately 11.5% of the Shares outstanding.

As of the date hereof, Mr. English directly beneficially owned 905 Shares, constituting approximately 0.01% of the Shares outstanding.

As of the date hereof, Mr. Hirai-Hadley directly beneficially owned 991 Shares, constituting approximately 0.01% of the Shares outstanding.

As of the date hereof, Mr. Jones directly beneficially owned 8,312 Shares, constituting approximately 0.1% of the Shares outstanding.

22NW, as the investment manager of 22NW Fund, may be deemed to beneficially own the 1,191,046 Shares owned by 22NW Fund, constituting approximately 11.5% of the Shares outstanding. 22NW GP, as the general partner of 22NW Fund, may be deemed to beneficially own the 1,191,046 Shares owned by 22NW Fund, constituting approximately 11.5% of the Shares outstanding. 22NW Inc., as the general partner of 22NW, may be deemed to beneficially own the 1,191,046 Shares owned by 22NW Fund, constituting approximately 11.5% of the Shares outstanding. Mr. English, as the Portfolio Manager of 22NW, Manager of 22NW GP and President and sole shareholder of 22NW Inc., may be deemed to beneficially own the 1,191,046 Shares owned by 22NW Fund, which, together with the Shares he directly beneficially owns, constitutes an aggregate of 1,191,951 Shares, constituting approximately 11.5% of the Shares outstanding.

**(b)**
—

**(c)**
Item 5(c) is hereby amended and restated to read as follows:

The transactions in the Shares by the Reporting Persons during the past 60 days are set forth in Exhibit 1 and are incorporated herein by reference. All of such transactions were effected in the open market unless otherwise noted therein.

**Item 6. Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer.**

Item 6 is hereby amended to add the following:

On May 22, 2025, Mr. Jones was awarded 4,826 Shares as his annual director equity award in connection with his service as a director of the Issuer, which vest on May 22, 2026.

On December 12, 2025, the Reporting Persons entered into a Joint Filing Agreement in which the Reporting Persons who will remain Reporting Persons subsequent to this Amendment No. 4 to the Schedule 13D agreed to the joint filing on behalf of each of them of statements on Schedule 13D with respect to the securities of the Issuer to the extent as required by applicable law. A copy of this agreement is attached hereto as Exhibit 99.1 and is incorporated herein by reference.

### SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

**Reporting Person:** 22NW Fund, LP

**Signature:** /s/ Aron R. English

**Name/Title:** Aron R. English, Manager of 22NW Fund GP, LLC, General Partner

**Date:** 12/12/2025

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

**Reporting Person:** 22NW, LP

**Signature:** /s/ Aron R. English

**Name/Title:** Aron R. English, President and Sole Shareholder of 22NW GP, Inc., General Partner

**Date:** 12/12/2025

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

**Reporting Person:** 22NW Fund GP, LLC

**Signature:** /s/ Aron R. English

**Name/Title:** Aron R. English, Manager

**Date:** 12/12/2025

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

**Reporting Person:** 22NW GP, Inc.

**Signature:** /s/ Aron R. English

**Name/Title:** Aron R. English, Manager

**Date:** 12/12/2025

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

**Reporting Person:** English Aron R.

**Signature:** /s/ Aron R. English

**Name/Title:** Aron R. English

**Date:** 12/12/2025

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

**Reporting Person:** Hirai-Hadley Bryson

**Signature:** /s/ Bryson O. Hirai-Hadley

**Name/Title:** Bryson O. Hirai-Hadley

**Date:** 12/12/2025

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

**Reporting Person:** Jones Alexander B

**Signature:** /s/ Alexander B. Jones

**Name/Title:** Alexander B. Jones

**Date:** 12/12/2025