bulletproof doors

Bulletproof steel doors seal off rooms by protecting them against the effects of discharge from various firearms. Many construction projects, particularly in the areas of public, military and industrial buildings, place strong emphasis on a high level of security of construction joinery. One of several security-related features of joinery is its ballistic resistance. Bulletproof doors are manufactured in different classes of bullet penetration resistance and are applied accordingly to the characteristics, threat level and type of the buildings to be secured.

Bulletproof steel doors

are installed in buildings requiring special protection. These are various types of buildings at risk of robbery, terrorist attacks or accidental firearm discharge. Doors with enhanced bullet penetration resistance protect people and property against the effects of discharge from small arms and – if selected appropriately – ensure the highest safety standards in this scope. Selection of doors in regard to their ballistic resistance class is based on special instructions, such as a security standard, in the case of military facilities. In other facilities, the selection of bulletproof doors is based on projects opined on by anti-terrorism and ballistics specialists, who analyze the potential use of specific types of weapons and ammunition and predict the threat level. Doors with enhanced bullet penetration resistance are characterized by different ballistic resistance classes and should be optimally adapted for use under various threat conditions involving projectiles discharged from firearms.

Classification of bulletproof doors.

Steel doors with enhanced bullet penetration resistance are applied in construction projects requiring enhanced specifications for the purposes of protecting people and property. The level of a door’s protection against bullet penetration is determined by classification standard PN-EN 1522. Doors of this type are classified, in terms of their resistance to penetration by bullets discharged from firearms, into eight ballistic resistance classes; seven base classes for pistols, revolvers and rifles, and an additional class for hunting rifles. The base ballistic resistance classes are designated by symbols from FB1 to FB7, where FB1 signifies the weakest protection and FB7 the highest level of protection against perforation of the door’s construction by a bullet. The additional class, assigned to hunting rifles, is designated by the symbol FSG.
Classification standard PN-EN 1522 “Windows, doors, shutters and blinds. Bullet resistance. Requirements and classification” characterizes data making it possible to classify doors into the appropriate ballistic resistance class. To determine a door’s bullet resistance, not only the type and caliber of the firearm are taken into account, but also the type of bullet being discharged: its mass, velocity, as well as the material from which it is made, its design and shape. The firing distance is also taken into consideration, and in the case of the highest bullet resistance class, also the minimum length of the rifled part of the barrel. All of these characteristics have a substantial influence on the kinetic energy of a bullet fired from a firearm and on its ability to perforate a bulletproof door. The firing distance, bullet velocity and mass translate to the kinetic energy that must be resisted by the door’s construction. The material, shape and design of a bullet are equally important characteristics that have an impact on its potential to penetrate a door. Bullets made of lead, copper and steel, with shapes ranging from flat-nosed, through round-nosed, conical, all the way to pointed, and with varying designs: simple uniform or with inner core, have differing door perforation threat levels at the same energy. All of these factors make it possible to categorize doors as bulletproof partitions in the appropriate classes, from the lowest FB1 to the highest FB7. Partitions of class FB1 are the basic, weakest barrier ensuring protection against lead bullets discharged from a sporting weapon. The popular FB4 class provides doors with resistance to discharge from 9 mm caliber handguns, and doors with bullet resistance class FB7 provide protection against 7.62 mm caliber bullets with a hardened steel core discharged from rifles.

The design of bulletproof doors

is based on tried and tested structural matrices applied in steel anti-burglary doors. However bulletproof doors have many additional solutions specially designed from the perspective of ensuring bullet penetration resistance of all components and fulfilling rigorous safety requirements.

Bulletproof steel doors

are therefore distinguished by well-thought-out, smart design and materials solutions calculated to absorb bullets’ kinetic energy and protect doors against penetration. The basis of such solutions is the application of materials that provide the highest resistance to impact and penetration by bullets discharged from firearms. The sheathing of bulletproof door leafs is made of galvanized steel sheet 2.0 mm thick, and the thickness of linings can be increased by adding additional sheets at the stage of forming the door leaf’s plate. The leaf’s internal construction consists of a reinforcement made of steel sections as well as of a mineral wool filling and bulletproof insert in the form of reinforced, joined steel sheets or special, removable sheets. Doors are equipped with a high-class, multi-point lock of the leaf, a stainless steel handle with a rosette, and an additional plate protecting the lock insert. Doors have hinges with solid bearings, welded to the leaf and fastened to the exterior side of the door frame. The door frame is made of galvanized steel sheet 3.0 mm thick or from 6.0 mm steel sections welded into the shape of the frame. On the side of the hinges, bulletproof doors have an additional safeguard in the form of pins locking the edge of the leaf into the door frame.  
Steel doors achieve resistance to bullet penetration through the application of special design and materials solutions that fulfill the appropriate penetration resistance standards. It is also important to maintain this protection throughout the door’s entire surface, including the frame and fittings. A door's resistance to bullet penetration is tested under laboratory conditions according to the procedure defined in testing standard PN-EN 1523. Door tests are conducted using firearms of the type appropriate to the desired bullet resistance class. Based on analysis of the door’s construction, targeting areas are defined, aimed towards sites where the bullet will encounter the least resistance and is most likely to perforate or open the door. During the test, bullets are fired at the tested door perpendicularly and at selected angles, with the use of the appropriate ammunition and maintaining the defined firing distance, with controlled bullet velocity. Positive results of tests conducted according to standard PN-EN 1523 allow for the classification of doors in terms of their bullet resistance.

Manufacturing of bulletproof doors.

Bulletproof steel doors are manufactured in single-leaf and double-leaf variants, in both typical and non-standard dimensions. If they have no defined side of attack, they can open to the outside or inside of the protected room. Bulletproof doors are made as solid or glazed. It is possible to apply a glazing to the door leaf as well as glazings above or to the sides of the leaf. Glazings of bulletproof doors are made with special glass, classified as bullet-resistance in accordance with standard PN-EN 1063. According to this standard, glass is classified – analogously to the classification of doors – into seven base classes: from the lowest BR1 to the highest BR7, and a separate class for hunting rifles SG2. The rule is that the minimum bullet resistance class of a glazing compliant with PN-EN 1063, applied in a door, should correspond to the door’s bullet resistance class according to standard PN-EN 1522. This means that a door of class FB6 can be glazed with glass of a class no lower than BR6. In doors of class FSG, class SG2 glass is applied in glazings. 
Thanks to its solid design and the materials used in its production, such a door has very high mechanical resistance - of class 4 according to standard PN-EN 1192: 2001, corrosion resistance of category C3 or C4 according to PN-EN ISO 12944-2: 2001, and anti-burglary resistance of class RC4 – RC5 according to PN- EN 1627: 2012 - and so it not only provides effective protection against firearm discharge but also against burglary attempts, and what is more, it is also weatherproof and resistant to mechanical damage.

Application of bulletproof doors.

The large number of construction projects executed with the application of bulletproof steel doors is the result of a growing demand for ensuring security in public buildings, the growing number of terrorist attacks and robberies, as well as the progressing modernization of military infrastructure. Bulletproof steel doors find applications in diplomatic facilities, government buildings and facilities at particular risk of attempted attacks with the use of firearms, such as penitentiaries and jails. Doors with enhanced resistance to bullet penetration are commonly used in military facilities, often in guardhouses and weapons depots. They are also installed in places at risk of accidental firearm discharge: in recreational, Police and military shooting ranges. Doors of this type are ordered by security companies, the State Treasury, railway security services and other units requiring special protection. Bulletproof steel doors simultaneously characterized by enhanced resistance to burglary are perfectly suited for facilities at elevated risk of assault and robbery, such as banks, currency exchanges, jewelry shops, mints, post offices, securities printing houses and others where there is a high risk of attack with the use of firearms.