Named ROBOGAT, the robot moves along a lightweight monorail, that also includes mains for water (and optionally foam). It is equipped with both visible and infrared cameras. When a fire alert is triggered in the tunnel, two robots will start, one from each end of the tunnel, and traveling at up to 60 km/h they will reach the site of the fire. Once there, they will autonomously attach to the closest water/foam plug and aim to the fire with their multiple rotating nozzles. The external body is made of a ceramic/titanium composite, also once the robot is attached to the water plug, water is used to cool the "skin" of the robot before feeding the nozzles.
While the robot is fully autonomous, an operator from a control room may take over as needed. The robot runs on batteries; optionally, water from the mains can operate a small turbine recharging the batteries and extending the operating time. The whole thing is quite small, and can be easily retrofitted in existing galleries.
Company website (in English): http://www.robogat.com/home_Eng.htm
(Notice: I am not related in any way with the manufacturing company, I just found a featured article in the magazine of the Italian National Council of Engineers — only in dead tree form, sorry.)"