Completed in 2024, Savilahden Luola in Kuopio is a large civil defense shelter built into the bedrock, with capacity for approximately 7,000 people. In normal conditions, the facility serves as a sports and event centre with capacity for around 2,500 people.

JTK Power supplied the shelter with custom-made double and single civil defense shelter doors, hatches and more than 500 other civil defense shelter components, including wall sleeves and covers. The total amount of steel used for the deliveries was estimated at nearly 100,000 kilograms.

Large Civil Defense Shelters Require Careful Planning

Savilahden Luola is a major civil defense shelter built into bedrock, a relatively rare project in Finland.

The project spanned several years. The first requests for quotation were received in 2021, the contract was signed in 2022, and deliveries began later that year. The final main deliveries were completed in late 2023, and Savilahden Luola opened in 2024.

“When dealing with a civil defense shelter of this scale, the overall solution and the design and manufacture of the products require time. This project involved heavy pressure-resistant doors for a rock shelter. Manufacturing doors of this type is always more demanding, and every solution goes through engineering and an approval process before entering production. This needs to be considered when setting realistic project schedules,” says Jarmo Latvala, Quality Manager at JTK Power.

Custom-Made Doors for Demanding Civil Defense Shelters

Almost all the products used in the project were manufactured specifically for the site. Pressure requirements affected the construction and thickness of the doors, and the shelter required both gas-tight and pressure-resistant doors.

“Because this was not a delivery based on our standard product range, the required components were not available from stock and had to be ordered specifically for the project. Standard components could hardly be used at all, as details such as frame dimensions and locking mechanisms differ. With wall thicknesses of up to 800 mm, the structures are also affected considerably, resulting in extremely heavy doors,” explains Jenni-Sofia Viitala-Talso, Sales and Product Manager at JTK Power.

“A civil defense shelter door and all its components must withstand loads from both directions. Every part and mechanism are carefully calculated to ensure that the door stays closed and does not fail under external pressure. Each door is designed to withstand the specific loads required for that particular site. This ensures that the finished door meets all required performance and approval criteria,” Latvala adds.

The Massive Doors Shaped the Delivery Process

The delivery sequence was coordinated according to the needs of the construction site and JTK Power’s production resources. Installing all the doors immediately upon delivery would not have been possible, as both installation and reinforcement work required time.

The delivery batches were planned around the installation sequence to make the work on site as smooth as possible. Some of the lifting points on the doors were modified according to the customer’s requirements.

The doors were too heavy to be handled manually, so their movement, rotation and final positioning inside the facility also had to be considered when planning the deliveries.

Rock Shelter Expertise Supported the Project

The project also involved a consultant with extensive experience in S2-class shelters and rock shelters, as well as in JTK Power’s civil defense shelter products. Together, the parties addressed practical questions relating to deliveries, installation and scheduling.

Products Supplied to Savilahden Luola

Double-leaf civil defense shelter doors

Types: Pressure-resistant and gas-tight double doors (SO-3 & VO-3)
Dimensions                                 2.7 m × 2.5 m
Weight                                         2,462–5,154 kg / double door
Wall thickness                             0.8 m & 0.4 m
Pressure load                               600 kN/m² and 100 kN/m²

Single-leaf civil defense shelter doors

Types: Pressure-resistant and gas-tight doors (SO-3 & VO-3)
Dimensions                              0.9 m × 2.0 m, 1.5 m × 2.1 m & 1.8 m × 2.0 m
Weight                                      1,554–2,372 kg / door
Wall thickness                           0.8 m & 0.4 m
Pressure load                             600 kN/m² and 100 kN/m²

Civil defense shelter hatches

Types: Pressure-resistant and gas-tight hatches (SL-3 & VL-3)
Dimensions                              0.7 m × 0.7 m & 0.7 m × 1.2 m
Weight                                         213–465 kg / hatch
Wall thickness                      0.8 m & 0.4 m
Pressure load                        600 kN/m² and 100 kN/m²

Finnish Specialist Expertise in Civil Defense Shelter Doors

JTK Power’s engineering and production teams operate under the same roof, making it easier to take specialised solutions from the drawing board into manufacturing. Decades of experience also help the company realistically assess the time required for engineering, manufacturing, deliveries, reinforcement and installation.

At the initial design stage, comprehensive project information is essential. This includes the door dimensions, pressure requirements, wall thickness and whether a pressure-resistant or gas-tight door is required. Ideally, the civil defence shelter door manufacturer should be involved at an early stage of the project.

“Architects now ask for product information more frequently than before. That is a positive development, because it reduces the need to revise drawings later in the project,” Latvala says.

In large S2-class shelters, doors are generally designed specifically for each project. Unlike standard S1 shelters, door dimensions, frames and structural requirements vary, meaning that these doors cannot simply be manufactured for stock.

At JTK Power, each customer’s specific requirements are reviewed by the company’s own engineering team to determine how the solution can be implemented in practice.

“This is exactly where our specialist expertise lies. We can draw on decades of experience, strong technical know-how and an in-depth understanding of the legislation and requirements governing civil defense shelters,” Latvala and Viitala-Talso conclude.