In order to be able to treat the City of Stockholm’s wastewater in the future, the municipal
company Stockholm Vatten och Avfall is making a significant investment. Henriksdal
wastewater treatment plant is being developed into one of the most modern in the world,
the Sickla plant is being expanded and a new 14 km long wastewater tunnel is being
constructed from Bromma. This is an extensive project that will run until 2029. In order for
the underground work to be safe, Stockholm Vatten has invested in the latest generation
of Jama’s rescue chamber, the MRC 2, which will be involved throughout the project.
Stockholm is growing and the city’s wastewater treatment plants must be adapted,
modernised and dimensioned in order to meet the population growth and new, tougher
environmental requirements in a sustainable manner. As a result, the wastewater treatment
system is being expanded.
The investment also means that the water in Lake Mälaren will become cleaner, that
discharges into the Baltic Sea will be reduced and that the transport of wastewater sludge
through residential areas will be eliminated.
Safety and the working environment are important factors in the project. The work involves
a large number of people, and a significant proportion of the work is taking place
underground in the form of rock work and blasting. In the project in Henriksdal, 250,000 m3
of rock is expected to be removed.
At a depth of 60 metres
Jama’s MRC 2 rescue chamber was delivered in spring 2021 and is being used at the lowest
level in Henriksdalsberget, Level D, at a depth of around 60 metres. The chamber is situated
just over 300 metres into the almost 400 metre-long work tunnel. The tunnel will be used,
for example, when the wastewater basins located on the level above are to be blasted and
the rock is to be transported out.
“As the work tunnel is more than 300 metres long and it is only possible to get in and out of
the tunnel at one end, we have to have a rescue chamber,” says Joacim Andersson, Health
and Safety Coordinator for Execution in the ‘Stockholm’s future wastewater treatment’
project and responsible for construction and environmental coordination in relation to
Stockholm Vatten och Avfall has chosen to invest in a new rescue chamber due to the design
of the tunnel, current regulations and the fact that their previous chamber does not meet
“We already had an older chamber, but it was necessary for us to procure a new chamber
that satisfies today’s modern requirements in full, is mask-free and has a high capacity,”
Requirement for an air system without breathing masks
The new regulations that Stockholm Vatten och Avfall needs to comply with state, for
example, that the rescue chamber must be equipped with an air purification system that
allows ordinary breathing, i.e. that the chamber must not be equipped with a system of
breathing masks. Eliminating the need to use masks makes a big difference, not least for the
users’ sense of security, considers Joacim Andersson.
“Imagine there is an emergency and you need to get to the rescue chamber quickly. You will
probably be fairly stressed and be feeling a sense of unease. At this point, there is a big
difference between putting on a tight, uncomfortable face mask that you have to wear for
several hours, compared to sitting down without a mask and breathing fresh air in a
“Jama’s chamber has a modern, intuitive air system that is easy to adjust and that
contributes directly to increasing comfort for its users,” he says.
External assistance with setting requirements
During the requirement setting stage, Stockholm Vatten och Avfall received assistance from
an external fire safety consultant, who helped Joacim and his group to lay down the
“There is a lot to consider when making procurements, which is why we often bring in
experts. We have been collaborating closely with a fire safety consultant for a long time, and
as he was very familiar with the regulations, we worked together to draw up the correct
requirements from a business, working environment and safety perspective. After that, we
took the requirement specification to the project’s construction management, obtained
their approval and then continued with the procurement as normal,” says Andersson.
Full operation when the basins are blasted
The decision to use Jama’s MRC 2 rescue chamber resulted from the fact that the chamber
met the stipulated requirements as regards function. The chamber was delivered in the
spring of 2021 and has had a smooth start since then. The activities carried out in the work
tunnel have tended to be sporadic to date, but from the end of the year it will be fully
“When we start working with biolines 6 and 7 around the end of the year, we will be
operating at fully capacity. At the moment, the tunnel is primarily being used for operation
and maintenance activities. For example, we may have electricians in there adjusting certain
installations, and we may need to pump out sumps with a pump truck. The main job will be
when we blast the basins on Level C down to Level D and have to transport all the rock out
using excavators and trucks. At that point, the activity will be non-stop, 24 hours a day,” says
A role model
Health and safety issues are extremely important in this project. Many other players are
glancing in the direction of Stockholm Vatten och Avfall, and the entire project has an
environmental profile. As a result, every stage is being carefully planned and all the
equipment involved has to be of the highest quality, particularly when it comes to safety and
the working environment.
Joacim Andersson explains that he appreciated Jama’s chamber right from the very
“The demonstration that Jama gave when they delivered the chamber was serious,
professional and easy to understand. They provided clear instructions, good explanations
and presented it in both Swedish and English.”
Easy to use
He continues by describing his impressions of the MRC 2 rescue chamber:
“It’s very pleasant, and there’s an enormous difference compared to our old one. Jama’s
MRC 2 is modern, easy to start up, user-friendly and stable. It also has a toilet, which is vital.
In addition, it comes with various supplies, such as basic food items as well as board games,
wifi and power outlets.
“The chamber offers a high level of comfort and has good capacity for a number of people,
and it can also be powered by battery for an extended period.”
Underground safety is important. As a result, training is provided for everyone involved.
“We conduct a number of fire drills every year within the project. We also run special
training initiatives aimed at those who are going to be working on Level D, the lowest level
of the work tunnel. This is a requirement that we impose on ourselves. Everyone has to
attend that training,” says Andersson.
The chamber is also subject to regular maintenance.
“We carry out a safety round in the chamber every month, and we affix safety stripes to
show that no one has damaged the chamber or been into it. We take great care with
maintenance and inspections. In the event of an accident, it must be in absolutely perfect
condition and fully functional in order to provide optimum protection for our employees and
contractors,” emphasises Joacim Andersson.
“We feel that we have made a good choice with Jama’s rescue chamber. It feels extremely
safe and modern, and clearly lives up to our expectations.”
“We are pleased to have been entrusted to supply our first new rescue chamber to
Stockholm Vatten och Avfall. At present, we are the only supplier on the market to offer our
technology, which fully satisfies all the requirements and guidelines that exist for rescue
chambers, such as constant monitoring of the air quality in the chamber,” says Rolf
Schönfeldt, Sales Manager at Jama.
Our origins can be traced back 70 years. Our collaboration with northern Sweden’s mining industry
has been almost as long and close, and has now made us a world-leading manufacturer of vehicles
and special products for the international mining sector. We are passionate about innovations and
have been awarded quality certification according to ISO 9001:2008. Our manufacturing plant is
located in Skelleftehamn, just outside Skellefteå, and has close, high-quality transport links by road,
rail, an international port and an airport. This enables fast and secure deliveries, whatever the
destination around the world.