The economic and energy diversification programmes of countries in the Middle East and North Africa have provided an impetus for physical infrastructure projects such as tunnels, which have become emblematic of the region’s transition towards a more interconnected and sustainable future.

In some cases, tunnelling projects in the region also extend beyond their utilitarian functions – in addition to decongesting cities and improving water networks, they embody diplomatic overtones and regional cooperation.

Some of the biggest tunnelling projects in the Middle East have historically been executed in the GCC, especially in Saudi Arabia and the UAE. These two countries also promise the most robust future project pipelines.

Neom tunnels

In line with its strategy of redefining sustainable urban living, the integration of tunnels is key to shaping the landscape at Neom in Saudi Arabia.

Tunnels are core components of the integrated transportation network at Neom's The Line, Oxagon and Trojena developments.

According to regional projects tracker MEED Projects, about $6.9bn-worth of schemes with tunnel components are at the pre-execution and execution phases at Neom.

Tunnel projects worth over $4.6bn are in the execution phase. These include the backbone infrastructure tunnels for The Line project, which involve constructing two railway tunnels in parallel using the drill-and-blast method, one for passengers and the other for goods.

In June 2022, Neom awarded $2.7bn-worth of main contracts to the joint venture of Shibh al-Jazira Contracting, China State Construction Engineering and FCC Construction for lots two and three of this scheme.

A separate contract worth about $1.8bn was awarded by Neom for lots four and five to a team of Archirodon, Samsung Engineering and Hyundai Engineering.

The pipeline of projects with tunnel components at Neom is worth about $2.3bn. Some of the major upcoming projects include the time-travel tunnel and funicular railway at Trojena and a package of works for the Spine railway network at The Line. The main contract bids for both packages are in the evaluation phase.

Other upcoming projects include the Spine's desert coastal west cut-and-cover tunnels for The Line, which are under design, and packages one and two of the delta junction tunnel at Oxagon. Neom expects to receive the bids for both packages by 27 August.

Dubai Deep Tunnels Portfolio

In Dubai, meanwhile, the Deep Tunnels Portfolio includes a series of interconnected deep sewage tunnels and associated facilities. The project involves the construction of two sets of deep tunnels terminating at two pump stations located at sewerage treatment plants (STPs) in Warsan and Jebel Ali.

A conventional sewage and drainage collection system and STPs will be built in Hatta.

First announced in 2015, the Dubai Deep Tunnels Portfolio project has faced delays over the years. The tender for consultancy services was first issued in 2015 and was awarded the following year to US-headquartered Parsons.

In June 2017, Dubai Municipality appointed Dutch consulting firm KPMG to assist with preparing the project under a public-private partnership (PPP) model instead of the conventional engineering, procurement and construction model.

There was no significant progress on the project after Dubai Municipality conducted a geotechnical investigation in late 2017.

This changed in June of this year, however, when Dubai’s Executive Council approved the project and said it would require an investment of about AED80bn ($22bn).

It added that the project has been designed to serve the needs of the Dubai population for the next 100 years, in alignment with the Dubai Economic Agenda D33 and the Dubai Urban Plan 2040.

In August, Dubai Municipality invited firms to express interest in bidding for the contract to provide project management consultancy services for the scheme. It expects to receive prequalification applications by 25 August.

Jeddah stormwater system

Jeddah Municipality is also taking steps to improve the city’s water infrastructure, and is investing in stormwater drainage and management systems.

The latest project under this programme is the King Abdullah Road-Falasteen Road (Kafa) tunnel, which is being developed in two phases. Phase one involves the construction of two main storage tunnels, one 5.3 kilometres (km) long and the other 3.4km long.

The scope of phase two includes constructing a terminal pumping station, a marine outfall and all necessary online and offline shafts.

In March, Jeddah Municipality invited contractors to prequalify for the contract to build the tunnels. It is understood the client received responses to the request for qualifications in June.

US-based Aecom is the consultant for the project.

Morocco's undersea rail link

In June this year, the Spanish government revived the Morocco-to-Spain undersea rail link project after allocating about $2.5m for a renewed design study. 

The project was launched in 2003 but was put on hold after the 2008 financial crisis. It has undergone several rounds of feasibility studies but remains in the study stage after nearly two decades of funding-linked delays.

The plans involve a double-rail track and additional service line stretching 38.5km between Tarifa in Spain and Tangier in Morocco. A 28km section will run under the Mediterranean Sea at a maximum depth of 475 metres.

The maximum depth of the tunnels will be 300 metres. Each single-track tunnel will have an inner diameter of 7.9 metres, while the service gallery will be 6 metres in diameter.

The two countries are developing the project jointly through Morocco’s National Society for Strait of Gibraltar Studies and the Sociedad Espanola de Estudios para the Comunicacion Fija a Traves del Estrecho de Gibraltar.

In 2006, Swiss engineering company Lombardi Engineering was selected to design the tunnel and the preliminary studies for the project were completed two years later.