“Merkur” Tunnel rescue vehicle, the world premiere with two heads
Published: 06 July, 2012
The world’s first electric drive tunnel rescue vehicle “Merkur” with two driver cabs has now been officially launched. Firefighter from all over the world experienced the “Merkur” live during a simulated fire rescue in the Croatian Ucka Tunnel on Friday the 29th of June.
German fire fighting vehicle manufacturer Ziegler explained the reasons for the development of the “Merkur” tunnel rescue vehicle. Due to the quick smoke development during a tunnel fire the visibility conditions become extremely bad within minutes. Moreover the tunnel is mostly blocked by cars and there is little room for manoeuvre for the rescue vehicles. Fire fighting vehicles with two driver cabs had been designed in the past before, and they had no requirement to turn around. However, these vehicles were not useful during a tunnel fire since they were driven by combustion engines which need oxygen to function. The engines stalled when the oxygen level dropped during a tunnel fire.
Ziegler took the problem head on and this has resulted in the world’s first rescue vehicle with two cabs allowing drive in both directions. A special highlight is that the vehicle is powered by two electric engines which require no oxygen. Thus, the “Merkur” vehicle is completely functional even when there is a lack of oxygen in the tunnel.
The “Merkur” vehicle has been in use by the motorway operator Bina Istra in the five kilometer long Ucka Tunnel in Croatia since the end of 2011. It has now officially been presented to the public on site. The participants were able to witness the extreme ease of operation of this new vehicle. The driver just moves the control lever to “forward” or “reverse” and then presses the throttle. A gearbox is not required. Additionally thermal image cameras are mounted in each driver cab and their images are transferred in real time to the driver. Thus, the “Merkur” vehicle can be operated trouble-free even under extremely bad visibility conditions.
During a simulated rescue action in the tunnel the participants also experienced the interaction of both driver cabs live. Only one driver cab can be in action at one time, this means that at activation of a chosen driver cab the other one is automatically deactivated. Hence, the driver can change cabs without worrying about additional operations, for example no worries about the position of the steering wheel. Once a cabin is activated, the steering wheel of the deactivated cabin is hydraulically moved to centre position and locked. Crossing from one cab to the other can be done directly through the mid-section rescue chamber. The driver gets oxygen through a personal compressed-air breathing apparatus. The vehicle’s rescue chamber has eight seats and standing room for four more persons, thus twelve persons can be evacuated at one time. Each seat is equipped with an oxygen mask, which is connected to the vehicle’s fresh air breathing unit. This unit consists of 14 cylinders, each with a volume of 50 liters of compressed air. The breathing air from the storage unit is distributed to the masks as well as the cabin’s overpressure nozzle. The overpressure nozzle in the rescue chamber helps prevent smoke from entering the cabin. The total air volume is sufficient for independent operation of up to five hours.
A fine water fog is produced all around the vehicle and at all wheels so that it can approach the source of the fire to a distance of up to one meter. On the way to the rescue, the electric engines with an output of 2 x 95 kW achieve an electronically limited maximum speed of 60 km/h. The “Merkur” can drive with one power load for four hours and cover a total distance of approx. 240 km.