M&D Construction Group and Efficient Trotech, two significant participants in the energy infrastructure market, are constructing two new double walled catch-pot tanks at Total South Africa’s state-of-the-art fuel depot in Alrode, Gauteng.
The joint venture is working alongside Kantey & Templer, which is the design engineer and is now overseeing the construction programme. Resident Engineer, Gabriel Russouw, is supervising the work with Total South Africa support.
Niekie Wagener is the joint venture’s Project Manager and Paul de Bruin Construction Manager for the tankage component of the works programme.
The joint venture harnesses M&D’s multi-disciplinary construction capabilities, including those of the Oil & Energy Division, which has extensive experience building and upgrading fuel depots, as well as specialised tanks. These extensive skills are augmented by Efficient Trotech’s proficiency in the engineering, design, manufacturing, and installation of various bulk-storage tanks.
Certainly, the two companies’ impressive safety track record working with other leading participants in the fuel sector also played a large part in them being appointed to construct the two double walled catch-pot tanks by Total South Africa.
Total is a broad energy group, which produces and markets fuels, natural gas and low-carbon electricity with the ambition to become the responsible energy major. It places safety as a core value and the basis of its strategy and its global operations. This includes in South Africa where the same exacting international standards, in terms of H&S protocols, have been implemented at its Alrode fuel depot.
“‘Being safe’ is one of M&D’s fundamental core values which, together with ‘doing it right’, ‘finding the best way’ and ‘doing what we say’, have enabled us to grow our presence in the extremely regulated fuels industry. We have demonstrated our commitment to all of these values on other demanding projects in the fuel infrastructure market and I am confident that our team will meet or even exceed expectations for Total South Africa on this contract,” Rukesh Raghubir, Chief Executive Officer of M&D Construction Group, says.
M&D and Efficient Trotech mobilised to site to commence working on this project in October 2019 and will complete the contract at the end of 2021. The joint venture was granted an extension of time to complete the work due to delays because of the Covid-19 lockdown that was implemented by national government to contain the spread of the virus.
It recommenced work at the end of June 2020 with the gradual opening of the economy, but in a cautious and staggered manner to ensure the health and safety of the about 160 people working on this project.
Preparing to resume operations during a pandemic was a very steep learning curve. It entailed extensive planning to also ensure that there were sufficient workers to supplement those on site who may have to be quarantined. This is in addition to planning the production programmes around the lengthier time it would take the many workers to enter the site while practicing social distancing and before being screened and sanitised.
Steady progress has since been made on the project which, in addition to constructing two new double walled catch-pot tanks, entails about 1,2km of piping to convey fuel and for the firefighting system.
The project has again provided M&D and Efficient Trotech ample opportunity to demonstrate their leadership in the African fuel infrastructure market through the innovative way that they are constructing the two large tanks that involves erecting more than 627t of steel. Each tank, which holds 11 200m³ of ULP95 petrol, is 18m high, with a catch pot diameter of 28,2m. It has an outer diameter of 32,2m and is 15,5m high.
This novel method of construction was refined by M&D and Efficient Trotech in 2009 while working on a project for the Airports Company of South Africa that entailed constructing similar-sized jet-fuel tanks at OR. Tambo International Airport.
Conventionally, fuel tanks are constructed from the foundation up and ending with the roof many metres above ground level. This is an extensive process that requires the installation of tons of scaffolding inside and outside of the tanks for the large team of welders to safely access the work face as the structures climb up from the ground.
On this project, however, the upper portion of the catch-pot tanks are being built first, starting with the second strake from the top and then the one above, before work commences on the roof only 5m above ground level. These sections of the two tanks are gradually jacked to their final height as additional strakes are added below in a repetitive process.
More than 40 jacks, each supporting about 12t, are used to lift a steel shell 100mm at a time. It takes up to 40 minutes to lift it 3m into the air, with the final portion of the tanks up to 19mm thick and weighing as much as 250t.
Notably, this is the first time that catch-pot tanks have been constructed in this manner for Total South Africa and the method has set the precedent for future such projects for the company. This is considering that it provides a more productive and safer means of building fuel-storage tanks. It mitigates the risk of potential welding spark flights in higher windier terrain, considering that the work is being undertaken in an operational area and directly adjacent to existing fuel tanks in the depot.
A critical component of the project are the tank’s ring-beam and layer works with their very intricate specifications.
To achieve the correct sand/bitumen layer thickness, the level of the top of the concrete ring-beam is critical. The finished level of the concrete is such that the difference in level does not exceed about 3mm in any 9m of the circumference and about 6mm in the total circumference.
Instead of tarpaulins on the scaffolding, the joint venture decided to use a heavy shrink-wrap material to adequately shield the welders from wind. It has also been extremely effective in containing the welding sparks and can be quickly repaired to keep construction on track.
The more than 50 qualified welders who are undertaking the fusion welding of the tanks are working to ambitious timelines as X-ray scanning can only be undertaken during the depot’s operational hours of between 7h00 and 17h00.
Productivity will receive an additional significant boost when the tank scaffolding has been modified to remove the piping that is obstructing the fusion welding machines to provide the welders with a clear run.
Certainly, one of the challenges has been working in an operational and highly congested area. Two tower cranes from M&D’s fleet of tower cranes had to be established on the confined site to handle the significant amount of construction materials, counting the many pipe sections. Varying between 350mm and 25mm in diameter, they include 712m of piping for the fire-fighting system and 519m of piping to convey fuel to the new tanks. The various construction materials are delivered to a portion of the staff parking that was made available to the contractor to be used as a laydown area.
Vees Moodley, Executive Director of Efficient Trotech, remains impressed by the extent of innovation deployed on this project, especially in terms of ensuring very high levels of safety are maintained on site.
“Efficient Trotech has retained its competitive edge in the fuel infrastructure market by, among other traits, an unwavering commitment to HSE on all of our projects. We are working with a company with similar values, which have created excellent team dynamics that are critical to the successful delivery of complex infrastructure projects.”
Raghubir concludes that he is proud of his team’s participation in yet another project that is demonstrating M&D’s leadership in the energy infrastructure market.
“Oil and energy projects have become a significant focus for M&D moving forward. Our Oil & Energy Division also intends participating in the construction of wind and solar farms, as well as positioning itself as the construction partner of choice in Engineer, Procure and Construct contracts. This is in addition to deploying our extensive skills and experience in steel, mechanical, piping and plate work construction, as well as electrical and instrumentation in these markets.”