The T4 robotic system is a mobile unmanned ground vehicle engineered to fulfil the requirements of both commercial and military operations. Credit: L3Harris Technologies, Inc.
The T4 robot is suitable for explosive ordnance disposal and detecting chemical, biological, radiological, nuclear, and explosive threats. Credit: L3Harris Technologies, Inc.
The T4 robot is part of L3Harris Technologies’ family of robots, which includes the T7 robot. Credit: L3Harris Technologies, Inc.

The T4 robotic system is a mobile unmanned ground vehicle (UGV) developed by L3Harris Technologies, an aerospace and defence company based in the US, to meet the rigorous demands of commercial and military missions.

The ruggedised robot is ideal for handling explosive ordnance disposal (EOD), detecting chemical, biological, radiological, nuclear, and explosives and clearing hazardous materials. It is also well-suited for special weapons and tactics missions.

The UK Ministry of Defence (MOD) awarded an $18m contract to L3Harris to provide up to 50 medium-sized T4 EOD robots in May 2024.

The contract involves supplying robots and offering local support, maintenance, and training. It follows L3Harris’ previous success with the UK MOD’s Project STARTER, which involved the replacement of the old EOD robot fleet with 122 T7 systems.

The first T4 units are expected to be delivered by the end of 2024.

T4 EOD robot design and features

The T4 robotic system measures 36.2in x 17.5in x 46.8in, with the arm stowed and the pan tilt zoom camera raised. The chassis alone measures 36.2in x 17.5in x 13.5in.

The system weighs 154lbs (70kg) with the chassis and batteries installed and 72lbs (33kg) with the quick-release manipulator arm.

The T4 robot offers a runtime of more than seven hours (task-dependent) powered by six BB-2590 batteries and can travel at speeds exceeding 5mph (8kmph).

The robotic system features a skid steer track system, allowing it to ascend stairs and slopes exceeding 45°. It can also navigate lateral slopes surpassing 30° and has a maximum fording depth of 12in.

The T4 robot can operate in temperatures ranging between -4°F and +140°F (-20°C to +60°C). It is equipped with advanced electromagnetic interference protection, allowing concurrent operation with electronic countermeasures.

T4 EOD robot manipulator specifications

The T4 EOD robot’s manipulator arm has a reach of 80in (2m) horizontally and 98in (2.5m) vertically. It has a lift capacity of 121lbs (55kg) near the chassis and 44lbs (20kg) when fully extended.

The arm has a self-righting capability and features stabilisers that offer omnidirectional stability. In addition, it is equipped with a force-sensing gripper with a non-conductive wire cutter.

The manipulator arm can support up to three disruptors, including up to two large disruptors, such as percussion-actuated non-electric, pigstick and hotrod. The disruptors enable the destruction of large targets.

T4 EOD robot operation and control

The T4 robot utilises haptic feedback technology, enabling operators to feel what the robotic arm touches or holds through the haptic controller.

The robot arm copies the user’s hand movements through its special interface, reducing training needs and boosting mission efficiency. The intuitive haptic control simplifies complex tasks such as unzipping bags and opening glove boxes, making them quick and effortless.

The haptic controller weighs 35lbs (16kg) and measures 18.7in x 16.2in x 9.2in. It has a daylight-visible display and a run time of more than six hours.

Cameras and radio

The T4 robotic system features two driving cameras (front and rear), a PTZ mast camera with 120x zoom and a zoomable gripper camera.

The system’s radio has a line-of-sight (LOS) range exceeding 3,300ft (1000m) and a non-line-of-sight (NLOS) range surpassing 660ft (200m).

T4 robot mission capabilities

The T4 robot supports various attachments for standard sensors, disruptors and tools, enabling a wide range of missions, including the disabling of improvised explosive devices in tight urban spaces such as vehicles, buses, trains and aircraft.

It can be easily reconfigured to carry different payloads for various mission requirements.

The robot benefits from a common controller shared with the T7 robotic system, enabling integrated missions, reducing training and equipment expenses, and facilitating simple deployment.

T4 robot orders

In May 2023, L3Harris secured a $30m contract from the Australian Defence Force to supply up to 80 robotic EOD systems including medium-sized T4 and large-sized T7 robots, as part of the Land-154 programme.

The Land-154 programme aims to enhance EOD unit capabilities in neutralising improvised explosive devices and route clearance operations.