Portable Armored Bunker Signals Shift in Mobile Shelter Design
There is an interesting portable shelter developed by Parabella and showcased by it at Eurosatory exhibition in Paris that highlights one of the possible paths of development of compact fortified positions that of increased transportability, armored construction and visual awareness. Unlike traditional compact pillbox, which is an unmovable fortified position, this device is promoted as a movable bunker that should enable easy positioning in proximity to frontlines.
One of the key technical aspects of the design is the actual physical construction of the bunker: 16 mm thick three-layered armored steel case that is equipped with metal screens covering its openings. The bunker is said to accommodate up to 10 armored soldiers with providing them with a 360 degree view of surroundings. This combination is significant because, traditionally, small protective constructions require one to make a choice between providing good protection and enabling good vision.
This leads us to the discussion of a difference between design priorities of the modern armored bunkers and their predecessors. Traditional pillboxes used in the First and Second World War were concrete constructions that featured low profile, fixed location and heavy nature. Their key advantage is obvious: once established, they had no intention to move. Modern bunkers take a different approach.
Namely, the Parabella bunker features more modular design based on using steel construction. This brings two benefits: ability to be fabricated in factories and possibility to relocate it to another place once required. This does not automatically mean improved level of real protection, but it does show that designers of this type of constructions moved away from fixed fortifications towards deployable equipment.
However, the history of similar constructions is also important to understand. Back in 2015, Ukraine introduced its MOS-2 bunker, a hexagonal metal construction capable of withstanding small arms fire and providing a protected firing position for a shooter. In early 2020s, Metinvest Group created number of mobile steel shelters for Ukrainian forces. These shelters were described as tubular constructions buried underground and covered with wooden beams, containing beds, stoves and other equipment necessary for functioning as a living space.
Thus, mechanically, this is a different but related type of the shelter: its priority is not all-around vision, but fast installation of protected steel construction that has minimal set of equipment necessary for its inhabitants. Thus, we see what place the proposed by Parabella bunker occupies in the evolutionary chain of similar shelters. Pillboxes were emphasizing permanence of a position. MOS-2 emphasized provision of protected firing position. Metinvest shelters were emphasizing mobility, ability to install them in place and providing some support facilities for people occupying them. Thus, proposed Parabella bunker seems to be a fusion of these elements into more compact armored construction with focus on mobility and protection.
The use of metal screens over openings of the shelter is an interesting element of its design. It shows one of the common problems that arise when constructing armored shelters: every opening reduces the protection of its construction. Firing holes, vision slits, entrance/exit are essential elements, but they create gaps in the armor. Metal screen seems to be an attempt to add some additional distance between openings and the steel shell, but this assessment requires more information.
This is the key limitation of this kind of analysis of the system publicly available information can tell a lot about its design priorities, but nothing about its survivability, durability under prolonged load, reparability and ease of deployment in complicated terrain. All these parameters determine the actual applicability of such shelters. Even so, the evolution is clear enough. Small battlefield shelters evolve from immobile concrete shelters to movable steel shelters that provide balance between protection, manufacturability and faster deployment capabilities.
By Edward Collins — Senior editor for AMI’s performance systems and mechanical design coverage, focused on powertrains, drivetrain systems, manufacturing precision, materials and high-performance engineering.
