Operational Technology; OT Network Engineer

Overview

As an Operational Technology (OT) Network Engineer, you will be responsible for managing, supporting, and securing Thames Water's OT network infrastructure. These network systems are vital for enabling remote control, monitoring, and data acquisition across Water and, Wastewater and Electronic Security System Assets, helping to deliver essential services to our customers, communities, and the environment.

This role involves ensuring that OT network assets and systems remain highly available, secure, and aligned with business and industry best practices. You will contribute to both day-to-day operations and long-term strategic improvements, including digital transformation initiatives across the OT estate.

• Act as a Subject Matter Expert (SME) on network routing, switching, and associated OT network infrastructure.
• Support the operational reliability of OT network systems to ensure 99.98% availability of critical assets.
• Lead and support the delivery of network changes in line with change management and risk assessment procedures to minimise operational impact.
• Maintain OT network standards, configurations, and firmware in accordance with defined policies and procedures.
• Provide technical support across the design, build, and delivery of both high-level and low-level network solutions.
• Deliver updates and upgrades to routers, switches, firewalls, and other network components at agreed intervals.
• Manage and monitor OT network system security, including compliance audits, licence reviews, and obsolescence tracking.
• Configure and support a wide range of technologies including Fortinet, CheckPoint, Cisco security appliances, Hirschmann HiVision, VPNs, Radius, Active Directory, Solar Winds, and Pulse Secure.
• Manage routing and switching protocols including OSPF, RIP, BGP, MPLS, NAT, VLAN, STP, and policy-based routing.
• Apply principles of cloud IaaS networking and assist in secure connectivity between cloud and on‑prem systems.
• Identify, assess, and implement security improvements in line with cyber and operational risk requirements.
• Respond to incidents and provide 24/7 out-of-hours support for the OT network, as part of a shared on‑call rota.
• Collaborate with internal stakeholders across OT and operational teams to deliver network improvements and project support.
• Support internal and capital delivery projects by providing network design, implementation, and technical oversight.
• Engage in continuous improvement initiatives through lessons learned, internal feedback, and proactive issue resolution.
• Maintain accurate records of preventative and reactive maintenance, and complete relevant documentation as required.
• Identify skill gaps and contribute to personal development planning (PDP) to ensure continuous growth and learning.

• Higher education qualification (HNC or equivalent experience) in an engineering or IT discipline.
• Security clearance to SC level or the ability to obtain it.
• Proven experience in maintaining and supporting enterprise network infrastructure within a large organisation.
• Industry-recognised networking certifications (e.g. CCNP, CCNA minimum, CheckPoint CCSE/CCSA).
• Strong understanding of IP networking, including LAN, WAN, and routing protocols (OSPF, BGP, RIP, MPLS).
• Experience managing network security technologies (e.g., firewalls, VPNs, anomaly detection).
• Proficiency in network monitoring and management tools such as Solar Winds, Tufin, and Hirschmann HiVision.
• Confident decision-making skills with the ability to balance operational, technical, and customer priorities.
• Excellent communication and interpersonal skills, capable of working with technical and non-technical stakeholders.
• Valid UK driving licence and ability to participate in an on‑call support rota.
• Strong documentation, report writing, and root cause analysis skills.
• Proficient in MS Office, including Visio for network diagramming.
• Understanding of IT and OT service delivery approaches (ITIL, Agile, Lean).
• Experience working in the utilities or water industry.
• Familiarity with SCADA and telemetry systems or willingness to learn.
• Knowledge of mobile communications, remote access technologies, and cloud…