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For quick cover

Extra bunkers – mobile reinforced concrete shelters delivered fully assembled

An Extra bunker is a compact, mobile reinforced concrete shelter that is assembled at the factory and delivered to your site ready to use. It is designed to give people somewhere to take cover quickly once an air-raid alert is announced, and is placed next to business premises, public transport stops, checkpoints and critical infrastructure sites. It does not need to be buried: the shelter can stand on the ground surface and, if required, be easily moved to another location.

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Price on request. Consultations Mon–Fri 8:00–20:00.

Mobile reinforced concrete EXTRA-6S shelter with a dark polymer coating on a site
EXTRA-6S with a dark polymer coating
Up to 6 people*for short-term cover (manufacturer’s data)
300 mmreinforced concrete walls and a sealed, reinforced metal door
Factory-assembled– on site it only needs to be placed and connected
Ready to use– the interior can be fitted out at the factory

* Extra is a shelter for taking cover quickly during an air-raid alert. The number of people given is the short-term capacity according to the manufacturer’s data, not the official shelter capacity, which is calculated at 1.5 m² of floor area per person under the standard set by the Government of Lithuania for shelters. For institutions that need an official shelter, and for longer stays, we design block bunkers.

What is an Extra bunker

An Extra bunker is a modular, mobile reinforced concrete shelter made up of standard factory-made sections. The sections are joined by welding through cast-in steel plates, and the joints can be taken apart and re-joined if required. This means the shelter can not only be put up quickly but also later dismantled, moved and installed somewhere else.

A standard Extra shelter consists of two sections. Its ends are closed with end walls, one of which has a sealed metal door. The shelter is assembled at the factory and delivered to the site fully assembled. If local conditions make it impossible to unload the assembled shelter, it is assembled at the delivery location.

The interior can be fitted out at the factory, so the client receives a shelter that can be used as soon as it has been placed and connected.

The Extra bunker’s strength is speed

This is not a permanent blast shelter but a quick-cover shelter: it is placed where people are outdoors when an air-raid alert sounds, and it protects them as soon as it is in position – with no excavation, no foundations and no lengthy construction work. Where a larger group needs a shelter for a longer stay, we offer block bunkers.

Extra shelter – concrete bunker visualisation
Extra shelter – blank wall and front with door (visualisation)
Extra shelter with its sealed door open, showing a bench and equipment inside
Open door, bench and equipment inside

Advantages of Extra bunkers

Inside an Extra shelter with lighting, an electrical panel and sockets
Interior – lighting and electrical installation

Factory-built

The shelter is assembled under factory conditions and delivered to the site in one piece. There is no concreting or lengthy installation on site – work on site is cut to a few hours.

No digging

An Extra shelter stands on the surface and, if required, can be partly or fully sunk into the ground. No pit, foundations or lengthy earthworks are needed.

Mobility

The joints between sections can be taken apart and re-joined. If your needs change, the shelter can be moved, transported and installed somewhere else.

Solid reinforced concrete structure

300 mm thick reinforced concrete walls with steel fibre – read more about protection in the ‘Structure and protection’ section.

Reinforced sealed door

A special sealed metal door protects the entrance – the weakest point of any shelter.

Ready to use straight away

You can order the shelter already fitted out at the factory – with furniture, electrics, ventilation and safety equipment. It can be used as soon as it has been placed and connected. Full specification – in the ‘Equipment and fit-out’ section.

Can be combined into larger shelters

The sections are compatible with one another, so a larger shelter for more people can be formed to a bespoke design.

Where Extra bunkers are used

An Extra shelter is placed where people have to take cover within a few minutes during an air-raid alert and the nearest blast shelter is too far away or there is none at all.

On business premises

For employees at production sites, warehouses, logistics centres and construction sites.

Next to public transport stops and busy public places

For waiting passengers and passers-by.

At checkpoints and security posts

At entrances to secured areas and at inspection points.

At military, national defence and critical infrastructure sites

For personnel, where a shelter is needed quickly and must be movable if required.

Next to schools, kindergartens, municipal buildings and other institutions

As an additional quick-cover shelter for people who are outdoors.

On private property

For a family or the staff of a small business.

In peacetime, an Extra shelter can be used as a secure room for storing equipment or supplies, and in an emergency it immediately becomes a shelter.

Extra bunker models and technical data

We offer two versions of the same design: the basic EXTRA-6 and the reinforced EXTRA-6S with an additional polymer coating. External dimensions, wall thickness and internal floor area are the same for both models – the difference lies in the level of protection and the equipment.

White Extra shelter with a sealed door and a ventilation cowl
Shelter with a sealed door
For quick cover2 sections · basic

EXTRA-6 – basic shelter

A two-section reinforced concrete shelter that stands on the ground surface. Supplied with a sealed reinforced door, fold-down benches, electrical installation and ventilation with a blast valve.

Capacity
up to 6 people for short-term cover*
Number of sections
2
External dimensions
2660 × 2000 × 2660 mm
Wall thickness
300 mm
Internal dimensions
2000 × 1400 mm
Internal floor area
2.8 m²
Internal height
as per model specification
Weight
approx. 18 t
Number of entrances
1
Material
reinforced concrete
Installation
on the ground surface
Price
on request

* Manufacturer’s data. Extra is a shelter for taking cover quickly during an air-raid alert, not a long-stay shelter.

Get a quote
Mobile reinforced concrete EXTRA-6S shelter with a dark polymer coating (visualisation)
EXTRA-6S with a dark polymer coating
For quick cover2 sections · reinforced

EXTRA-6S – reinforced shelter with polymer coating

The same two-section structure with an additional special polymer coating that increases resistance to blast effects. Supplied with a reinforced sealed door, forced ventilation and a fan heater.

Capacity
up to 6 people for short-term cover*
Number of sections
2
External dimensions
2660 × 2000 × 2660 mm
Wall thickness
300 mm
Internal dimensions
2000 × 1400 mm
Internal floor area
2.8 m²
Internal height
as per model specification
Weight
approx. 18 t
Number of entrances
1
Material
reinforced concrete + blast-resistant polymer coating
Door
reinforced, sealed; withstands a pressure of 440 kPa according to the manufacturer’s data
Price
on request

* Manufacturer’s data. Extra is a shelter for taking cover quickly during an air-raid alert, not a long-stay shelter.

Get a quote

EXTRA-6 and EXTRA-6S compared

EXTRA-6EXTRA-6S
Capacity (short-term cover)up to 6 people*up to 6 people*
External dimensions2660 × 2000 × 2660 mm2660 × 2000 × 2660 mm
Wall thickness300 mm300 mm
Internal floor area2.8 m²2.8 m²
Weightapprox. 18 tapprox. 18 t
Polymer coatingnoyes
Doorreinforced, sealedreinforced, sealed, 440 kPa (manufacturer’s data)
Ventilationduct fan with blast valveforced ventilation
Fan heaternoyes
Benchesfold-downyes
Fire extinguisher and first aid kityesyes

* Manufacturer’s data. This is the short-term capacity, not the official shelter capacity calculated at 1.5 m² of floor area per person.

Dimension drawing

EXTRA-6 front, rear and side elevations; two sections. Drawing in preparation.

Larger configurations

Extra shelter sections are compatible with one another: a module can have more sections, with partition walls with door openings installed along its length. We design higher-capacity shelters to suit the needs of the specific site.

Not sure which model to choose?

We will help you choose based on the site’s risk profile and how the shelter will be used.

Get a quote

Equipment and fit-out

An Extra bunker can be ordered as a bare reinforced concrete shelter or fully ready to use. We select the equipment according to the conditions in which the shelter will be used.

Inside an Extra shelter with benches, a fire extinguisher and ventilation grilles
Interior – benches, fire extinguisher, ventilation

Protection and entrance

Special reinforced sealed metal door; additional blast-resistant polymer coating (EXTRA-6S).

Ventilation

Ventilation inlets in the walls; duct fan with blast valve (EXTRA-6) or forced ventilation (EXTRA-6S).

Electrics and heating

Electrical installation and power inlets; fan heater (EXTRA-6S).

Interior fit-out

Painted interior walls; benches or fold-down benches.

Safety equipment

Fire extinguisher; first aid kit.

On request

Preparation of the base for the shelter; delivery and unloading.

To a bespoke design

  • standalone power source (generator);
  • outdoor floodlight and additional lighting;
  • other additional equipment to suit the site’s needs.

Structure and protection

Steel-fibre reinforced concrete

Extra shelter sections are made from C35/45 class concrete. Wall thickness is 300 mm. The structure is reinforced with bars up to 18 mm in diameter, and the reinforcement meshes are offset – the crossing point of one mesh sits opposite the opening of the other. Steel fibre is also added to the concrete. This reinforcement helps keep the structure intact and contain debris.

Rigidity and joints

The spatial rigidity of the structure is provided by the shape of the standard sections, the way they work together and the stiffening partitions. The sections are joined by welding through cast-in steel plates; the joints can be separated and re-joined, so the shelter is suitable for repeated installation and relocation.

What it protects against

An Extra shelter protects against shrapnel, debris and blast waves, as well as the effects of drone attacks. The solid reinforced concrete walls also protect against bullets and parts of collapsed buildings.

Test data

According to the manufacturer’s test data, with a wall thickness of 300 mm the structure withstands an air blast wave overpressure of approximately 850 kPa. The structure has been tested in the laboratory and on a test range, and its load-bearing capacity has been verified by numerical modelling. Structures of this type have been tested in real wartime conditions in Ukraine.

For each site, our design engineers determine the location, number and fit-out of the shelters.

Load testing of an Extra shelter reinforced concrete section in a laboratory
Section load testing in a laboratory
Concrete class
C35/45
Wall thickness
300 mm
Reinforcement
up to 18 mm in diameter
In addition
steel fibre
Section joints
welded, detachable
Air blast wave overpressure
approx. 850 kPa*

* Manufacturer’s test data.

Delivery and installation

An Extra shelter can be placed on the ground surface or partly or fully sunk into the ground.

On the ground surface

The quickest option – no digging needed.

Partly sunk

The shelter is partly sunk into the ground.

Fully sunk

When extra protection is needed or the shelter should be less visible.

What you need to know in advance

The shelter weighs about 18 t, so heavy transport and lifting equipment are needed to deliver and place it; the lifting equipment is chosen to suit site conditions. There must be suitable vehicle access to the installation point. We assess all of this before we submit a quote.

Relocation

If your needs change, an Extra shelter can be lifted, transported and placed somewhere else. The joints between sections can be separated and re-joined.

How the work is carried out

  1. Stage 1

    Consultation and site assessment

    We find out how many people need to take cover and how quickly, and assess the site, vehicle access and the ground.

  2. Stage 2

    Design

    Our design engineers select the model and the number of shelters, and plan their location and equipment.

  3. Stage 3

    Manufacturing

    The shelter is manufactured and assembled at the factory, and the ordered equipment is installed.

  4. Stage 4

    Site preparation

    We prepare a level, firm base for the shelter; the base is chosen according to geological surveys and the design.

  5. Stage 5

    Delivery and placement

    The assembled shelter is delivered from 3 weeks after the order and placed in the planned location within 1 day. If the assembled shelter cannot be unloaded on site, the sections are assembled on site – this takes 6 to 10 hours.

  6. Stage 6

    Connection and handover

    We connect the electricity, check the equipment and hand over the shelter with the declarations of conformity and operating instructions.

The exact timeline is given in the quote.

Get a quote

Project examples

Full gallery
Extra shelter with its sealed door open, showing a bench and equipment inside Open door, bench and equipment inside Mobile reinforced concrete shelter in the street next to a retail building Shelter next to a retail building Mobile reinforced concrete EXTRA-6S shelter with a dark polymer coating on a site EXTRA-6S with a dark polymer coating Mobile reinforced concrete shelter with its door open, a bench and a fire extinguisher inside Open door and bench 3D visualisation of a mobile reinforced concrete Extra shelter Extra shelter (visualisation) Fold-down wooden benches inside an Extra shelter Fold-down benches White Extra shelter with a sealed door and a ventilation cowl White shelter Handle and lock of the Extra shelter’s sealed door Sealed door locking mechanism Inside an Extra shelter with benches, a fire extinguisher and ventilation grilles Interior – benches, fire extinguisher, ventilation

Frequently asked questions about Extra bunkers

How is an Extra bunker different from other shelters?

An Extra bunker is assembled at the factory and delivered to the site fully assembled, so there is very little work on site. It is a compact, mobile reinforced concrete shelter designed for taking cover quickly once an air-raid alert is announced. It does not need to be buried and can be moved to another location if required. For a larger group and longer stays, we offer block bunkers.

How many people does an Extra shelter hold?

According to the manufacturer’s data, the two-section EXTRA-6 and EXTRA-6S shelters can hold up to 6 people for short-term cover. The internal floor area is 2.8 m². This is a shelter for taking cover quickly during an air-raid alert, so the figure given is its short-term capacity. The official shelter capacity assessed by municipalities is calculated at 1.5 m² of floor area per person under the standard set by the Government of Lithuania for shelters, so for those needs we design block bunkers. Our design engineers calculate the number of shelters needed for a specific site.

Does an Extra bunker need to be buried?

No. An Extra shelter can simply stand on the ground surface. If required, it can be partly or fully sunk into the ground. We choose the most suitable installation method after assessing the site and the level of protection needed.

How long does installation take?

The shelter is assembled at the factory and delivered in one piece, so on site it only needs to be placed in the prepared location and connected. If the assembled shelter cannot be unloaded on site, the sections are assembled on site – this takes 6 to 10 hours. We deliver the shelter from 3 weeks after the order and place it within 1 day. The exact timeline from order to handover is given in the quote.

What does an Extra shelter protect against?

An Extra shelter protects against shrapnel, debris and blast waves, as well as the effects of drone attacks. The walls are 300 mm thick steel-fibre reinforced concrete, and the entrance is protected by a reinforced sealed metal door. According to the manufacturer’s test data, the structure withstands an air blast wave overpressure of approximately 850 kPa.

What is the difference between EXTRA-6 and EXTRA-6S?

Both models have the same dimensions, wall thickness and internal floor area. The EXTRA-6S has an additional polymer coating that increases blast resistance, and its door withstands a pressure of 440 kPa according to the manufacturer’s data. The EXTRA-6S also has forced ventilation and a fan heater. The EXTRA-6 is the basic version with a duct fan and a blast valve. We will help you choose based on the site’s risk profile and how the shelter will be used.

What is installed inside the shelter?

The shelter can be delivered ready to use: painted interior walls, benches, electrical installation, ventilation, a fire extinguisher and a first aid kit; the EXTRA-6S also has a fan heater. A generator or an outdoor floodlight can be added to a bespoke design. You can also order the shelter without equipment and fit it out yourself.

Can an Extra bunker be moved to another location?

Yes. This is one of the key features of Extra shelters. The sections are joined by welding through cast-in steel plates, and the joints can be separated and re-joined. The shelter can be lifted, transported and placed in a new location – for example, if the site layout or the needs of the facility change.

What is needed to deliver and place the shelter?

The shelter weighs about 18 t, so heavy transport and lifting equipment are needed to deliver and place it. There must be suitable vehicle access to the planned location, and the location itself must be prepared and level. We can carry out site preparation, delivery and unloading – this is included in the quote.

How much does an Extra bunker cost?

Price on request. It depends on the model, equipment, number of shelters, delivery distance and site preparation work. Fill in the enquiry form or call +370 685 09501 – we will prepare a quote for your site.

Does an Extra shelter meet Lithuanian requirements?

Extra is a quick-cover shelter, and we do not declare its compliance with STR 2.07.02:2024 ‘Requirements for the design and installation of blast shelters, collective protection structures and shelters’ (a Lithuanian construction technical regulation). For institutions that need an official shelter included in the municipality’s list of shelters, we design block bunkers. In each case, we assess what the shelter will be used for and how many people it must hold. Extra shelters are supplied with declarations of conformity. The solutions for a specific project are discussed during the consultation. More about shelter requirements.

Can an Extra shelter be used in peacetime?

Yes. In peacetime, an Extra shelter can be used as a secure room for storing equipment or supplies. What matters is that once an air-raid alert is announced, it is freely accessible and can be cleared for people quickly.

Why order Extra shelters from bunker24.lt

bunker24.lt is a full-cycle partner for shelter design, supply, installation and fit-out. One team works with you from the first consultation to the handover of the shelter.

Our own design engineers

We calculate how many shelters you need and of what capacity, and plan where they go on your site.

Four types of solution

If the Extra model is not right for you, we will offer another solution – block, underground or metal bunkers.

Manufactured at trusted partner factories

The shelters are made by factories we have contracts with.

Delivery, installation and fit-out

We take care of transport, placement, doors, ventilation, electrics and furniture.

Documentation

We hand over the shelter with declarations of conformity and operating instructions.

Clients

We work with state institutions, municipalities, educational institutions, businesses, critical infrastructure operators, the armed forces and national defence organisations.

Get a quote for an Extra shelter

Price on request. It depends on the model, equipment, number of shelters, delivery distance and site preparation work. Fill in the enquiry form or give us a call – we will prepare a quote for your site.

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  • We will prepare a quote within 3–5 working days
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