In addition to preliminary studies to determine the site, design and consultation alongside drilling machinery, construction of water conveyance tunnels, roads, etc needs to include manufacturing engineering thoughts as well as tools to strengthen the walls, ceiling and the floor by concrete.

During the past two decades Aras Poulad company as one of the pioneers of the study, design and construction in this area has launched formworks called "tunnel form" in various sizes, cross sections and diameters. Depend on the tunnel usage and the ground that the tunnel is excavated in; the cross section of tunnels may vary. Generally water supply tunnels’ cross section are circle or horseshoe shape and road tunnels are in shape of a horseshoe with flat base or arch bend. Sewage tunnels are often in a shape of oval or half oval. The load imported to the form case while pouring concrete, should be calculated precisely and evaluated thoroughly before design.

Interconnected components and parts that are presented by Aras Poulad experts after calculations, design and construction are under the name of tunnel form; have a complex functionality that has been detailed in the tunnel formwork catalog.