The «heart» of pumped hydroelectric energy storage is located deep inside a mountain: In a cavern, pumps and turbines are installed in huge halls. The access tunnels are usually several hundred meters long. Individual company fire services have recognized the similarities between their facilities and other underground transport systems such as tunnels. They use the training infrastructure of the International Fire Academy in Lungern and their teachings for their preparation.
Great penetration depths as a central commonality
In the event of a fire, long distances to the site are incredibly strenuous and particularly dangerous for firefighters. Because the aim is to penetrate smoke-filled areas, the International Fire Academy has defined the term «penetration depth». It refers to the distance from the safe area of a building to the working area of the fire service. The penetration depth is rated as «great» if this route is more than 80 m long.
In pumped hydroelectric energy storages, such penetration depths can arise, for example, with a lorry fire in an access tunnel or with a fire in a cavern of more than 80 m in length, as long as there are no lateral accesses. The Tunnel Firefighting Procedure of the International Fire Academy shows how such great penetration depths can be mastered.
Training during continuous power plant operation
Pumped hydroelectric energy storage play an essential role for a stable power supply. For example, they compensate for fluctuations in electricity production of renewable energies from wind and solar radiation. In order to ensure a secure power supply, the power plants are on the grid without interruption.
For firefighters, this means limited training opportunities, as the operation of the plant must not be disturbed or interrupted. Basically, all necessary practical tasks can be trained in the power plant, as well as communication and orientation. A smoke test was also possible in a power station belonging to the Schluchseewerk AG, with the International Fire Academy providing counsel.
However, a firefighting attack and the heat load in the event of a fire cannot be displayed in a pumped hydroelectric energy storage. Special training tunnel systems are suitable for this purpose, which offer realistic operating conditions.
Smoke test in an underground power station of the Schluchseewerk AG: Observation of smoke propagation in the access tunnel
Smoke propagation in the machine hall
«It feels like our location»
Similar to an underground power station, the International Fire Academy's training tunnel facility in Lungern is deep in the mountain. The atmosphere is immediately familiar to members of the plant's fire service. Nevertheless, other aspects are deciding for its suitability as a training tunnel. At its core, it is a matter of making the relevant operational conditions experienceable during practical training. First and foremost is the great penetration depth. It can be experienced in Lungern in different ways realistically. The facility also includes uneven, raw surfaces in a tunnel with incline. Such access also increases the effort for the firefighters.
Another operational requirement is working in smoke-filled areas, which can only be represented to a limited extent and with great effort in an underground power station. In the training tunnel facility, filling the attack routs with artificial smoke is standard. In the smoke, participants must reconnoitre and search and rescue people. The detailed lessons and the drills also include extinguishing the fire, whereby the heat load from gas-powered fire mock-ups is made tangible.
Practising precisely what has to be done during deployment
In the courses at the International Fire Academy, participants should be able to train everything they are supposed to do during deployment. This requires training with precisely the equipment that is available to the firefighters in their facility. For this reason, the company fire service of Kraftwerke Oberhasli AG (KWO) brought its closed-circuit breathing apparatus (BA) to the training tunnels of the International Fire Academy in the first few years. In the meantime, this fire service has switched to two-bottle BAs and the quick-fill system. The quick-fill system consists of large compressed air storage systems, where the bottles of the BA can be filled directly and very quickly without having to take the apparatus off the back. It ensures that sufficient breathing air is always available for the way back. A permanently installed and two mobile quick-fill stations are available at the Oberhasli Power Plant. One of these mobile devices was used during the course in Lungern to practice the rapid filling of the bottles under operational conditions.
Fire services benefit from the exchange of experience
If a safety officer of a pumped hydroelectric energy storage or the fire chief of the company fire service contacts the International Fire Academy, a visit date is usually arranged first. Getting to know each other is either connected with a visit to the power plant – as was the case recently in Vianden. Alternatively, the training tunnel facility in Lungern is agreed as a meeting point, as it was with the KWO's company fire service.
The training can be carried out for the ongoing operation of the plant, as well as for the construction or expansion phase of a plant because there are also many parallels to the construction of road or rail tunnels in the construction phase. The fire services benefit from the regular exchange of experience on various underground transport systems at the International Fire Academy. As a result, a wide range of challenges and solutions are known. Also, there is the knowledge and experience of the part-time instructors, including, for example, an instructor and officer of the KWO company fire service.
View of the large machine hall in the Vianden Pumped Hydroelectric Energy Storage.
Machine hall in the Limmern Pumped Hydroelectric Energy Storage