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【Sweden News】Sustainability Strategy in CRTG Engineering Sweden AB - Stockholm Metro Blue Line 87131/87132/87133 Project

Created on:2021-09-28

1.Aim and Purpose of CRTG Engineering Sweden AB

Identifying measures to reduce climate impact based on our tunnel working procedure. The sequential operations performed at the face in tunneling by CRTG:

 •  Drilling and Grouting

 •  Charging

 •  Blasting

 •  Ventilation

 •  Mucking

 •  Scaling

 •  Concrete spraying

 •  Bolting



To optimize the above workflow, CRTG chose the most safety, productivity, reliability and most environmentally friendly machinery.

Create a Resource Efficiency Plan in accordance with FUT requirements – detailing activities and responsibilities.

•  Products and materials used do not pose unacceptable risks to people and the environment

•  Sustainability is an integrated part of the construction phase. 

•  Resources are managed in a sustainable way and climate emissions are minimized.

• Products and materials used have been produced and handled under sustainable, fair and responsible conditions.

•  The contract is fulfilled in a socially and environmentally sustainable way.


2.Client Requirements for Increased Resource Efficiency and Limited Climate Impact - 1312-P11-47-00048

The project must have a systematic approach/method for preventing and reducing unnecessary resource consumption and reducing climate impact.

In collaboration with the Client, a goal for reducing climate impact throughout the project should be set.  The goal should be based on the contract's estimated climate impact and the calculated effect of planned improvement measures/actions.

The contractor shall identify and prioritize improvement measures for increased resource efficiency, waste prevention and reduced climate impact. The starting point should be relevant issues in Chapter 8, Physical resources - use and management, in Ceequal. Any activities or measures that lead to increased resource efficiency and reduced climate impact shall clearly documented in a Resource Efficiency Plan.

A climate calculation must be undertaken to quantify the project’s carbon dioxide emissions from working methods and material use. To reduce carbon dioxide emissions from the start to the finish of the project Goal.


3.Climate Calculation and Climate Impact – Basic Definitions

•  The Greenhouse Effect

The natural process that warms the Earth’s surface. When the Sun’s energy reaches the Earth’s atmosphere, some of it is reflected back to space and the rest is absorbed and re-radiated by greenhouse gases which makes the earth livabl e.

•  Greenhouse gases (GHs)

Greenhouse gases include water vapour, carbon dioxide, nitrous oxide, ozone and some artificial chemicals such as chlorofluorocarbons (CFCs).

Global warming - Due to the unnatural increase in concentrations of GHGs from human activity, particularly from the burning of fossil fuels, the   Earths*s temperature is rising at an unprecedented speed.

•  Climate Change

A change in global or regional climate patterns, in particular a change apparent from the mid to late 20th century onwards and attributed largely to the increased levels of atmospheric carbon dioxide produced by the use of fossil fuels.

•  CO2 equivalents (CO2e)

The unit of measurement used in the Climate Calculation. A metric measure used to compare the emissions from various greenhouse gases on the basis of their global-warming potential (GWP).



4.Analysis of Climate Impact From 87131/87132/87133 project activities by CRTG Engineering Sweden AB

The greatest climate impact from the construction of 87131/87132/87133 projects come from material-use, the construction processes in themselves and transports.



The Swedish Transport Agency's model:

The Climate Calculation model version 3.0 is limited to include emissions from:

•  Extraction of raw materials

•  Processing of raw materials into products

•  Transports in the value-chain, the construction-phase and transports from construction.

The tool is limited to calculating climate impact and energy use based on current technology and material choices.

The climate calculation model is based on Life Cycle Assessment (LCA) methodology and uses emission factors together with project-specific resource-use to calculate energy use and GHG-emissions (CO2 equivalents).

The climate calculation should take into account the entire project/contract and emissions shall be calculated based on:

•  Quantities of materials from the execution of the project, based on functions and methods prescribed in the contract documents, and

•  Emission factors for the specific materials used, obtained from product-specific Environmental Product Declarations (EPDs), certified in accordance with ISO 14025, or equivalent third party certification for environmental product declarations of type III.

5.Approach and Working Method for reducing Climate Impact

Climate Calculation:

•  Accept the baseline calculation

•  Update calculation based on tender

Efficiency Improvement Measures:

•  Workshop based on the climate calculation

•  Prioritize proposed actions

•  The decision to implement the proposed measures (some by FUT)

Plan of action:

•  Goal

•  Priority actions

•  Identify the starting position for priority actions

•  Potential reduction

•  Timeline

•  Responsibility


•  Calculation of measures carried out in CO2 eq, energy (and tonnes of material)

•  Documentation

•  Update in the climate calculation based on measures taken

•  New identified measures and reductions are notified to FUT

•  Final calculation made on final volumes and the effect of reductions made

•  Final follow-up of targets

6.Climate Calculation at Various Stages Throughout the Project

Climate impact is calculated at the start and at the end of each stage. The degree of detail increases as the project progresses - climate impact increases. It is important to document measures that are carried out and compare with the outcome for each stage.

Climate Calculation 87131/87132/87133


87131-Total CO2-e: 1846 ton CO2-e

Tunnel: Blasting, extraction of rock and transported to

other site – 936 tons

Shotcrete -544 tons

Cement – 157 tons

Bolts,steel – 92 tons

Concrete – 38 tons


87132-Total CO2-e: 1967 ton CO2-e

Tunnel: Blasting, extraction of rock and transported to

other site – 819 tons

Shotcrete -693 tons

Cement – 222 tons

Bolts,steel – 86 tons

Concrete – 35 tons


87133-Total CO2-e: 1337 ton CO2-e

Tunnel: Blasting, extraction of rock and transported to

other site – 936 tons

Shotcrete -544 tons

Cement – 157 tons

Bolts,steel – 92 tons

Concrete – 38 tons


7.Materials requiring EPDs

The Environmental Product Declarations shall include the life-cycle phases (in accordance with SS-EN 15804, product-specific rules for environmental declarations, type III, for construction products):

• A1 - A3, from raw material extraction to factory delivery

• A4, transport from factory to construction site in Stockholm

EPDs needs to be collected from the supplier.

For example (major materials for tunneling works):


•  Steel

•  Concret

•  Cement

•  Asphalt



8.Identifying actions and improvement measures:

Starting-point is the baseline climate calculation for each production tunnel. Consider measures relating to:

•  Material use from a life cycle perspective;

• The life cycle of materials includes raw material extraction, processing, production, transport, use and recycling / reuse

•  Optimization of alternative design solutions to reduce material use

•  Alternative materials (eg. in slag in concrete)

•  Waste prevention,

•  Use of electricity and fuel,

•  Use of work machines,

•  Transport by mass handling,

•  Other sources of CO2 emissions that we consider relevant.


Some good examples:

•  Quantity optimization - can reduce emissions by up to 60%.

•  Minimizing waste can reduce emissions by about 5%

•  Circular mass management - overview of the mass balance in a region - 30% reduced CO2 emissions from transport

•  Training of rock workers - reduces the need for shotcrete. Example: in the project Norra länken, an overuse of 89% occurred, the requirement was 75 mm spray concrete but the actual result was 141 mm.

•  Combination of concrete measures - combining choice of cement supplier, choice of concrete quality and type and maximum admixture of additives can reduce emissions by about 25%


Eample - Choosing Materials

•  Reinforcement steel

The choice of supplier plays a big part

Origin (and energy in manufacturing)

Percentage of recycled steel

Results for finished concrete construction can vary between + 46% and -27%


•  Concrete

Concrete with admixture (eg fly ash, GGBS) can reduce emissions for concrete construction by up to 21%

Concrete with other quality - as high as possible (can reduce emissions by up to 9%)


•  Steel

Different types of steel have different high climatic loads

By comparison other metals are also presented


9.Template for Documentation of Identified Measures - Resource Efficiency Plan

10.Next step taken by CRTG Engineering Sweden AB

A goal will be set for the percentage of our project to reduce climate impact

Establish resource efficiency plan:

•  All identified measures

•  Priority measures are provided with a responsible person and, if possible, with a forum for management

•  Updated regularly with new identified measures

•  Follow-up of priority measures is done regularly - Status, savings of CO2, energy and quantities

Issues that need to be addressed should be a standing point at the production meetings and will be followed up at sustainability meetings.The compilation and update of the climate calculation is done every quarterly period and is reported to FUT.