BAE Systems Bofors officially introduced its Sea Tridon modular 40mm naval gun system family at the EURONAVAL 2026 defense exhibition.
Developed as a maritime evolution of the land-based Tridon 40mm air defense solution, the scalable modular product family is built around the Bofors 40mm gun architecture and 3P (Pre-fragmented, Programmable, Proximity-fuzed) multi-role ammunition. The product line includes four configurations—Sea Tridon, Sea Tridon C (containerized), Sea Trinity (CIWS), and the baseline Bofors 40 Mk4—offering scalable options for merchant vessels, auxiliary fleets, and naval surface combatants.
TECHNICAL SPECIFICATIONS: BAE SYSTEMS SEA TRIDON 40mm NAVAL GUN FAMILY
System Architecture, Commonality & Ammunition Baseline
⚡ OEM & Prime Systems Integrator: BAE Systems Bofors (Karlskoga, Sweden)
⚡ Core Effector Ordnance: Bofors 40mm L/70 automatic cannon
⚡ Primary Ammunition Type: Bofors 40mm 3P (Pre-fragmented, Programmable, Proximity-fuzed) all-target ammunition
⚡ Ammunition Fuzing Modes: 6× field-selectable electronic fuze modes (Gated Proximity / Impact, Proximity with Altitude Limit, Gated Proximity, Time, Impact, and Delayed Impact)
⚡ Rate of Fire & Magazine Capacity: Up to 300 rounds per minute; 100-round operational magazine feed with rapid multi-type ammunition switching
⚡ Effective Engagement Envelope: Slant Intercept Range: Up to 12.5 km (6.7 nautical miles); Vertical Ceiling: Up to 7,500 m (24,600 ft) 
Configuration Lineup & Sensor Integration Options
💥 Configuration 1 — Sea Tridon:
• Maritime baseline adapting the Tridon concept; incorporates an on-mount high-resolution Electro-Optical/Infrared (EO/IR) tracking pod and laser rangefinder for autonomous fire control
💥 Configuration 2 — Sea Tridon C (Containerized):
• Fully containerized, autonomous ISO-module variant designed for rapid “plug-and-play” deployment on commercial cargo ships, oil tankers, auxiliary naval vessels, or austere forward bases without structural deck penetrations
💥 Configuration 3 — Sea Trinity (CIWS):
• High-end Close-In Weapon System variant integrating an on-mount Ku-band or 3D target acquisition/tracking radar alongside EO sensors for all-weather, autonomous engagement of anti-ship missiles, fast attack craft, and drone swarms
💥 Configuration 4 — Bofors 40 Mk4 Naval Gun:
• Compact, low-weight (2,300 kg empty) fully remote-controlled turret integrated directly into a host ship’s Combat Management System (CMS) for permanently armed surface combatants
TIMES OF DEFENCE ASSESSMENT
The debut of the Sea Tridon family by BAE Systems at EURONAVAL 2026 highlights the demand for modular, high-rate-of-fire 40mm air defense systems across naval forces.
From an aerospace engineering and naval warfare perspective, the product line delivers three primary strategic advantages:
1. **Containerized Defense for Commercial and Auxiliary Fleets**: The Sea Tridon C module provides a rapidly deployable self-defense system for un-armed commercial ships or auxiliary logistics vessels operating through high-threat choke points. A self-contained ISO module allows operators to install hard-kill air defense onto flat decks within hours, bypassing complex drydock overhauls.
2. **Mitigating Swarm Threats with 3P Ammunition**: The Bofors 3P programmable round enables a single 40mm gun to engage diverse threat profiles. Programming 3P rounds to detonate in gated proximity mode creates high-density tungsten fragment clouds that destroy incoming low-RCS loitering munitions, sea-skimming cruise missiles, and uncrewed surface vessels (USVs) before impact.
3. **Commonality Across Logistics and Training**: Offering four distinct configurations based on a shared 40mm barrel and 3P ammunition framework simplifies lifecycle support, spare parts management, and crew qualification for navies operating both surface combatants and auxiliary fleets.
