Dubai Aviation Engineering Projects (DAEP) has received bids from contractors for the contract to build a tunnel at Al-Maktoum International airport.

The tunnel will be over 4 kilometres long, 33 metres wide, 15 metres high, and will be used for the airport’s baggage handling system. It will link the airport’s West Terminal building with the concourse buildings.

The tunnel tender is the latest sign of infrastructure activity on the $33bn expansion of Al-Maktoum International airport.

In December last year, a joint venture of US-based Lane and Sharjah-based National Contracting & Transportation Company (NCTC) was awarded a $125m infrastructure contract. That work involves building and installing temporary fences and gates, utilities and site offices, as well as site security.

In mid-2016, the local Tristar was awarded the contract to complete the enabling works, which covers earthmoving works for the entire 36-square-kilometre site.

An expansion to the existing terminal at the airport is also under way. In March, the local Alec was awarded the construction contract. The work involves increasing the airport’s built-up area from the existing 66,107 square metres to 145,926 sq m by June 2017.

The overall expansion project involves building new terminal facilities, concourses, runways, roads and tunnels. Once completed, the expanded airport is expected to accommodate more than 220 million passengers a year, making it the world’s largest in terms of size and passenger capacity by 2050.