Whilst the intended end location is Wilton (for delivery to the Redcar Bulk Terminal [RBT]), the developers also considered the Ports of Hull and of Immingham to the south.

[7] A pipeline would have involved turning the potash and polyhalite into a slurry[8] which would have required a more labour and technically enhanced process at both ends of the transport system.

[11] The company, now Sirius Minerals, agreed to pay £130 million to the North York Moors National Park Authority to "protect and enhance the environment".

[12] To avoid damaging aquifers across the route, the tunnel is designed to stay deep within the Redcar Mudstone Formation.

[17][18][19] In July 2016, the UK Government awarded Sirius Minerals a Development Consent Order[20] for the harbour facilities on Teesside.

[22] Whilst preparatory work was started in 2016, a ceremony to "break ground" at the Wilton site was held in June 2018 with Jake Berry, the MP for the Northern Powerhouse project.

"[10] By September 2019, progress had extended to 1 mile (1.6 km) of complete tunnelling with rails, connections and concrete interiors.

[27] Initially, an Austrian company, Strabag, were awarded the first tunnelling contract for the 8.1-mile (13 km) section from Wilton to Lockwood Beck.

[30][31] Three ventilation shafts will be constructed: at Lady Cross Plantation, near Egton, at Lockwood Beck, and at Tocketts Lythe.

Lockwood Beck and Lady Cross plantation will be larger caverns to accommodate the crossover in conveyors and for the passing of maintenance trains.

It then turns in a more north/north westerly direction through Tocketts Wood and under first the A173 road and then the A174 until it arrives at the Materials Handling Facility (MHF) at Wilton.

[41] After granulation, the finished product will be taken on another conveyor (this time above ground) to the export site at Redcar Bulk Terminal.

The company stated that this will allow for minimal visual and environmental impact as well as avoiding any significant construction obstacles on the way.