Never Gray

What Never Gray does

Never Gray is a Toronto-based industrial engineering company founded in 2016 that provides training and software tools for tunnel ventilation analysis using the Subway Environment Simulation (SES) program. The company serves engineering consultancies (Hatch, SYSTRA, WSP), public transportation authorities (STM, Montréal), and academic institutions involved in subway, metro, and road tunnel design and fire life safety analysis. The firm is founder-led by Justin Edenbaum (the "SES Guru"), who was trained by the original SES developers at Parsons Brinckerhoff, giving the company direct technical lineage to the software's creators.

Never Gray's product portfolio centers on distributing the original SES 4.1 — a one-dimensional airflow and thermodynamic solver originally developed under US Government restrictions that have since been lifted — and surrounding it with complementary open-source tooling. Next-In is a free Excel-based input manager capable of reading or writing over 8,000 input lines per second; Next-Out converts SES outputs to structured Excel worksheets and Visio diagrams (with stencils for tunnel segments, fans, jet fans, and dampers). The company is also building OpenSES, an open-source fork of SES 4.1 with development tracked on GitHub and OpenSES.org, and has released a free Critical Velocity Calculator (MIT License) aligned with the 2026 NFPA 502 standard. The firm actively participates in the tunnel ventilation research community, with an abstract accepted for ISAVFT 21 (Melbourne, Nov 30 – Dec 2, 2026).

Never Gray generates revenue primarily through on-demand training courses (US$2,400–US$3,400 per seat) sold via Teachable, with a Road Tunnels course announced as coming soon. Free tools (Next-In, Next-Out, Critical Velocity Calculator) serve as top-of-funnel lead generators and ecosystem anchors, while Next-Vis — a commercial post-processor valued at US$1,200 per student — is bundled with training and offered with enterprise customization. Distribution is global via direct downloads from nevergray.biz, supplemented by community engagement at industry conferences (ISAVFT), GitHub repositories, and an email newsletter. The company appears privately held, bootstrapped, and operates with 1–10 employees.

Name

Never Gray

Legal name

Never Gray

Website

https://nevergray.biz

Company type

Private

Founded year

2016

Operating status

Operating

Headcount range

1–10 employees

Short description

Never Gray is a Toronto-based industrial engineering company that distributes the SES 4.1 tunnel ventilation simulation software and develops complementary open-source tools (Next-In, Next-Out) alongside paid training courses for engineering consultancies and transportation authorities.

Ownership category

akta.pro rank

Product category

Tunnel Ventilation Simulation Software

NAICS

Support Activities for Rail Transportation (48821), Support Activities for Rail Transportation (4882), Urban Transit Systems (4851)

SIC

Transportation Services (4700), Services-Computer Integrated Systems Design (7373)

akta.pro industry

PRIMARYTLAJAEAI

Rail Maintenance-of-Way & Possession/Work Window Coordination (Operational Control)

Transportation & Logistics/Transportation Infrastructure & Operations (Roads, Rail Networks, Traffic Management)/Rail Operations Control & Dispatch (Network Control Centers)

SECONDARYTLAKAIAG

Doors, HVAC & Auxiliary Systems Maintenance (Passenger & Cab Systems)

Transportation & Logistics/Vehicle & Equipment Maintenance, Repair & Services (MRO)/Rail Rolling Stock Maintenance & Repair

SECONDARYTLAJADAH

Rail Maintenance-of-Way (MOW) Equipment & Services (Tamping, Grinding, Renewal)

Transportation & Logistics/Transportation Infrastructure & Operations (Roads, Rail Networks, Traffic Management)/Rail Network Infrastructure Management (Track, Signaling, Electrification)

Keywords

• Tunnel ventilation analysis
• Airflow simulation software
• Fire safety engineering
• Tunnel design tools
• SES software distribution

Headquarters

HQ city

Toronto

HQ country

Canada

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Software

Cost components

Personnel, Technology or R&D, Marketing or Sales, Operations

Revenue model

1. SES Training Courses: On-demand video-based training courses with calculation templates, self-work exercises, and one-on-one support from the course creator. Courses include Emergency Analyses (US$3,400) and Normal Analyses (US$2,400), with Road Tunnels coming soon. Training provides access to Next-Vis post-processing tool for three months.
2. SES Software Distribution: Distribution of original SES 4.1 software for Windows. While the core program is distributed, the company provides free open-source tools (Next-In, Next-Out) to support the ecosystem.
3. Next-Vis Commercial License: Commercial access to Next-Vis post-processing tool, available as part of training packages with three months access (US$1,200 value per student), with customization services available for enterprise clients.

Pricing tiers

Go-to-market motion3 records

Distribution channels4 records

Marketing channels5 records

Core offering

Never Gray distributes the Subway Environment Simulation (SES) 4.1 program for Windows and develops free, open-source companion tools (Next-In input manager, Next-Out post-processor, and a Critical Velocity Calculator) for tunnel ventilation analysis. The company sells on-demand SES training courses covering emergency analyses, normal analyses with train movement, and road tunnel modeling, and participates in the OpenSES open-source fork of SES.

Product overview

Never Gray is a provider of training and software for tunnel ventilation analysis, centered on the Subway Environment Simulation (SES) Computer Program — a one-dimensional airflow and thermodynamic solver. Never Gray distributes the original SES 4.1 version for Windows, supplemented by two free, open-source companion tools: Next-In (an Excel-based input manager for creating and modifying SES files) and Next-Out (a post-processor that converts SES outputs to structured Excel worksheets and Visio diagrams). The company also participates in OpenSES, an open-source fork of SES 4.1, and offers a free Critical Velocity Calculator for NFPA 502 2026 compliance. Training services covering emergency analyses, normal analyses, and road tunnel modeling are available on-demand via a teachable platform. Free templates including a time-zone coordination spreadsheet are also offered.

Differentiator

Problem solved

Functional benefit

Brands

• Next-In: Free Excel-based input manager for creating and modifying SES input files
• Next-Out
• OpenSES
• Next-Vis

Products and services

• SES 4.1 Software The Subway Environment Simulation (SES) Computer Program is a one-dimensional airflow and thermodynamic solver that analyzes tunnel environments, distributed by Never Gray for Windows.
• Next-In Input Manager Free Excel-based input manager for SES that enables users to create, read, write, and post-process SES input files directly in Microsoft Excel. Version 4.2 and above can also perform simulations and initiate post-processing with Next-Out.
• Next-Out Post-Processor Free, open-source post-processor for SES that converts simulation text outputs into structured Microsoft Excel worksheets and populates Microsoft Visio diagrams with airflow, temperature, and fan data.
• OpenSES Open-source fork of the SES 4.1 codebase, initiated in the spirit of open-source community-driven development, with Never Gray as an active contributor.
• Critical Velocity Calculator (NFPA 502 2026) Open-source calculator (MIT License) that generates critical velocity estimates and plots for tunnels using equations from the 2026 NFPA 502 standard developed by Beyer, Stacey and Brenn, published in the Fire Technology journal.
• SES Training Courses On-demand training courses for tunnel ventilation analysis using the SES computer program, covering emergency analyses, normal analyses with train movement, and road tunnel modeling, including calculation templates, self-work samples, and one-on-one support from the course creator.
• Working Hours Coordination Template Free downloadable Microsoft Excel template that helps organize team working hours across different time zones, with an Offset sheet for tracking daylight saving time misalignment in Europe and North America.

Quantifiable outcome

• Over 250 hours of training content developed
• +3 more outcomes

Named customers4 records

Segments3 records

Ideal customer profiles3 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Integration5 records

Feature6 records

Partnerships

Four partnerships are on record, tiered core and minor.

• Stacey AgnewcoreStrategic or Co-development PartnerStacey Agnew supported the development and sharing of the critical velocity model (Beyer, Stacey and Brenn equations) adopted in NFPA 502. Special recognition given to Michael, Conrad, and Günter from Stacey Agnew for supporting the tunnelling industry.
• Technische Universität GrazcoreStrategic or Co-development PartnerTU Graz (Institute of Structural Engineering) co-developed the critical velocity model with Stacey Agnew. The equations developed by Beyer, Stacey and Brenn are published in Fire Technology journal and adopted in NFPA 502.
• OpenSES ContributorsminorStrategic or Co-development PartnerNever Gray is looking for engineers and programmers interested in contributing to OpenSES. Contributors will be acknowledged in publications and may be listed as co-authors depending on their level of involvement. Abstract accepted for ISAVFT 21 conference in Melbourne.
• Parsons BrinckerhoffminorStrategic or Co-development PartnerThe SES Guru (Never Gray founder) was trained by original SES developers at Parsons Brinckerhoff, providing direct lineage and expertise in the SES program.

Scale indicators3 records

Recent moves6 records

Expansion highlights6 records

Broad incumbents

• Arup: Arup is a global engineering consultancy with a renowned fire and ventilation practice that designs tunnel and underground station environments. They frequently engage in the same transit-authority RFPs as Never Gray's customer base.
• Mott MacDonald: Mott MacDonald is a global engineering consultancy with substantial tunnel and rail ventilation expertise, often working alongside or competing with Never Gray's customer base (WSP, Hatch, SYSTRA) on major transit projects worldwide.
• Jensen Hughes: Jensen Hughes is a global fire protection engineering and code consulting firm that performs tunnel fire and ventilation analyses for transit authorities and infrastructure owners. They compete for the same enterprise fire-safety consulting work as Never Gray's training alumni.
• Parsons Brinckerhoff (now part of WSP): The original developer of the SES program at Parsons Brinckerhoff; the firm that trained Never Gray's founder. Now merged into WSP, they remain the institutional origin of the SES ecosystem and the largest incumbent in subway/tunnel ventilation engineering worldwide.

Direct peers

• SYSTRA: SYSTRA is a global rail and tunnel engineering consultancy that uses SES/SVS for subway projects and is a verified user of Never Gray's Next-In. They operate in the same niche as a competitor for SES-driven tunnel ventilation engagements.
• WSP: WSP maintains a closed-source SI version of the SES program (tied to legacy US government restrictions) and is one of the largest global tunnel engineering consultancies. They are both a customer of Never Gray's Next-In/Next-Out and a direct competitor via their own SES distribution and training practice.
• Hatch: Hatch is a global engineering consultancy with a major tunnel ventilation practice and a documented SES user. They are a Never Gray training customer and an industry peer competing for the same engineering talent pool and transit-authority engagements.

Emerging players

• HBI Haerter: HBI Haerter is a Swiss engineering consultancy specializing in tunnel ventilation and safety, with deep expertise in SES/SVS-based analyses for European road and rail tunnels. They compete in the same niche engineering services market as Never Gray.
• Thunderhead Engineering: Thunderhead Engineering develops PyroSim and related fire simulation tools based on NIST's Fire Dynamics Simulator (FDS). They represent the next-generation CFD-based alternative to SES that could displace 1D solvers in tunnel fire analysis over time.
• Mosen Ltd: Mosen is an SES/SVS specialist consultancy that provides training and engineering services for tunnel ventilation analysis, operating as a direct niche competitor to Never Gray in the global SES training market.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat4 records

Key risks6 records

Key highlights6 records

Customer concentration

• GitHubgithub.com/NeverGray

Revenue estimate

Valuation estimate

Number of profiles

Profiles1 record

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Never Gray