Carbon footprint study

Background and goal

The study was based on two products, Global Gravity’s TubeLock and business-as-usual wire sling. Those wire slings are manufactured and sold by different companies; thus, a specific model has not been selected for this study. The assessment focuses on a full life cycle perspective from the cradle to the grave, which includes the extraction of materials, production of the two compared products, transportation along the value chain, the use phase, and final disposal of the products.

With the aim of transparency, the study focuses on a particular case, with the client Total and their rig in the North Sea, which is connected via the Port of Esbjerg. The reason for the study to be conducted is due to the assumption that TTRS causes less climate change impacts compared to the baseline. The functional unit (FU) for the system under study is defined as:

“Safely and securely transport, lift, and offload a total of 1.004 pipe joints, each 41 feet long, from the Port of Esbjerg to Total’s rig in the North Sea in the year 2022.”

Systems’ description

TTRS has various configurations to accommodate different joint sizes. The TTRS vary in the size of the arches (cut-outs) in the H-profiles (the bars securing the joints), the length and number of lifting pipes, and the number of bolts and slings needed to fixate the joints.

Slings are metal wires which, at each end, are secured around a ferrule with one or more wire clamps. Just one type of wire and one type of clamp are considered in this study. Slings are wrapped around the pipe joints, and the diameter of the joints determines how many joints can be carried at a time. Two slings are needed for stability and balance for each joint bundle, one at each end. Slings are only used once and then discarded. In total, 422 slings are needed to fulfil the functional unit

TTRS is assumed to be reused 13 times per year in a lifetime of 10 years. This lifetime is equal to the warranty period of TTRS. This assumption is relatively conservative, as TTRS is expected to live significantly longer than its warranty period.

Slings are typically expected to be reused 4 times before disposal. However, for this given case, Total (the user) follows a safety protocol that dictates only 1-time use for the slings. This limitation is considerable for the results; thus, a sensitivity analysis has also investigated a 4 times reuse case.

Research parameters

The climate impact calculations consist of 5 parameters that add up to the total life cycle results in this comparative CFP study. The 5 parameters are:

  1. Material flow
  2. Forklifting
  3. Crane lifting
  4. Supply vessel operation
  5. EoL (recycling, credited in material flow)
Important findings

Figure 1 shows the overall results of the CFP study. The trends that are shown in the results are:

  • Due to the reusable design of TTRS, there is a relatively minor climate change impact in the material flow phase.
  • Forklifting, crane lifting, and supply vessel operation have a relatively lower impact on TTRS compared to slings. This is due to more efficient processes and a reduced number of lifts.
  • For slings, material flow is relatively high. This is due to the end users’ single-use safety protocol of wire slings. However, EoL crediting is also high due to the greater mass of metals for recycling.

The total GHG emissions for the system under study are (a sum of the five phases):

  • TTRS: 16.60 tons CO2 eq
  • Slings: 51.81 tons CO2 eq 
Figure 1: Results of the CFP study divided in the 5 stages
Figure 1: Results of the CFP study divided in the 5 stages

This study has shown that TTRS reduces GHG emissions by 35.21 tons of CO2 eq for the given use case. To put this into perspective, the GHG emissions are converted into the unit “trips around the world in a car.” It is assumed that an average European car emits 122 grams of CO2eq per km and that the earth’s circumference is 40075 km.


The 35.21 tons CO2 eq savings correspond to 7.2 trips around the world.

Read full Carbon Footprint Study – Comparing TTRS ® and business-as-usual wire slings

Read on

Previous slide
Next slide