Tabriz Metro – Line 3 Project

Project Overview

Tunnel Saz Machine (TSM) was responsible for the complete overhaul, reassembly, testing, commissioning and initial operational support of two NFM EPB Tunnel Boring Machines for the Tabriz Metro Line 3 project.

The two machines, named Sahand and Sabalan (Model NFM 1331/372/S9), were received in dismantled condition and underwent comprehensive overhaul and refurbishment by TSM. Both TBMs were assembled within the same common shaft and commenced excavation from that shaft. Sahand was completed and commissioned first, followed by Sabalan.

The two machines were assigned to excavate two parallel tunnels, with a combined planned tunnelling length of approximately 10 km, serving six metro stations between the provisionally identified as Bus stand Terminal and Rizwan city station.

Geological Conditions

The ground conditions consisted mainly of very dense sand containing boulders and very large rock blocks, together with lenses of clay and dense sandy soil. The tunnels were excavated above the groundwater table, and no groundwater was encountered at the excavation face. No significant ground settlement was reported.

Cutterhead Configuration

The soft-ground cutterheads featured a 31% opening ratio and were equipped with a combination of buckets, scrapers, knives, rippers and drag bits. Each cutterhead was also fitted with two copy cutters.

TSM Scope of Work

1. 1. Complete overhaul and refurbishment of two dismantled EPB TBMs.
2. 2. Cutterhead repairs, welding works and replacement of cutting tools.
3. 3. Reassembly of both TBMs within the common shaft.
4. 4. Testing and commissioning, with Sahand completed first and Sabalan afterwards.
5. 5. Technical supervision and operational support during the initial excavation phase.
6. 6. Completion of the contractual warranty excavation of 100 rings (approximately 150 m) per TBM.