FORORAK modular shelters are a scalable underground protection system based on prefabricated steel modules. Individual segments can be combined into larger complexes — from a single family shelter to expanded layouts with corridors, technical rooms, and storage areas.
Each module is designed with a focus on:
- high load-bearing capacity and resistance to soil loads,
- the ability to perform under dynamic impacts (explosions, shocks),
- easy connection into larger configurations,
- full integration with ventilation, power, and telecommunications systems.
Scalable Underground Protection System
The FORORAK system enables the construction of complete underground shelter complexes by connecting additional modules. The modules can be arranged in:
- linear layouts,
- branched layouts,
- ring layouts.
This makes it possible to design a configuration tailored to the facility’s function and intended use – from simple, compact solutions to larger sets of rooms.
Steel Modules - the Core of the System
We present a steel modular shelter that can be used to build complete underground shelter complexes by connecting subsequent modules into larger systems. The structure is made of high-grade steel, with full ribbing and reinforcements.
This solution provides:
- high stiffness and load-bearing capacity when backfilled with soil,
- resistance to loads generated by a blast wave,
- long-term operation in an underground environment.
Dimensional Range of Steel Modules
- length: from 5.8 m to 15 m,
- width: from 2.5 m to 3.0 m,
- height: 2.5 m (internal clear height adjusted to the intended purpose).
Foundation and Anchoring
The steel module is installed on a reinforced concrete slab (C30/37), reinforced and designed as a foundation. As standard, we provide full anchoring of the module to the foundation slab, which:
- stabilizes the shelter in the ground,
- protects it against displacement,
- enables the transfer of horizontal loads (e.g., from shocks or ground movement).
Optional Protective Concrete Shell
At the investor’s request, the steel modules can additionally be:
- fitted with reinforcement (meshes, anchoring bars),
- encased in C30/37 concrete as an external protective shell.
This creates a system consisting of a steel load-bearing core + external reinforced concrete armor, which significantly increases:
- blast resistance,
- resistance to fragments and projectiles,
- long-term durability of the structure.
After the concrete shell is completed, the entire structure is backfilled and the site can be restored to its original condition – the shelter remains invisible from the outside.
Ventilation, Entrances, and Exits
FORORAK modular shelters are designed as complete functional facilities.
The equipment includes:
- a ventilation installation network — supply and exhaust ducts routed within the modules,
- the option to integrate filtration systems (including filter-absorbers, shut-off valves, dampers),
- distributed entrances and exits (main entrances, emergency exits, technical hatches).
The number and location of entrances, exits, and hatches:
- are individually adjusted to the size and layout of the complex,
- take into account the expected number of users and the intended purpose (family shelter, facility for an industrial site, critical infrastructure, part of a military facility).
Backfilling and Integration with the Surroundings
After installation is completed, the modules (steel or reinforced concrete) are backfilled. If necessary, additional drainage and filtration layers are installed.
The area is then reclaimed — a lawn can be restored, vegetation planted, or a maneuvering yard or parking area created. The result is a fully concealed underground facility, invisible to outsiders, providing users with a high level of safety and comfort while inside.