Tenders Are Invited For Preparation Of Technical Documentation And Construction Of A Hole From The Grubenthall Longitudinal To The Hegger Transverse

3. Subject Of The Order.3.1. The Subject Of The Order Is The Design And Construction Of A Ventilation Opening From The Grubenthal Longitudinal Section, Position Iv To The Hegger Transverse On Level Iii In The Underground Workings Of The Wieliczka Salt Mine, Hereinafter Referred To As Mining Works. 3.2. The Aim Of The Mining Works Is To Supply Air From Level Iv To Level Iii To The Transverse Hegger Area. The Ventilation Hole In Question Will Be The Main Fresh Air Flow Route For Ventilation Of The Planned Decommissioning Works Carried Out At The Southern Border Of The Deposit On Levels Iii, Iv And V.3.3 The Subject Of The Order Will Be Implemented In Four Stages: 1) Stage I Including: Preparation Of A Technical Design With Technology For Mining And Drilling Works, 2) Stage Ii Including: Reconstruction Of The Grubenthal Drilling Site On The Basis Of The Above-Mentioned Documentation At The Location Of The Drilling Site, 3) Stage Iii Including: Securing The Hegger Transverse At Position Iii, Along With Drilling In The Location Of The Planned Hole, And Drilling A Pilot Hole To The Drilling Site Located At The Hegger Transverse. 4) Stage Iv Including: Widening The Hole At An Angle Of 90 Degrees, With A Length Of No More Than 39.0 M, And Then Encasing It With Mutually Screwed Steel Pipes, With An Internal Diameter Of Not Less Than 1,220 Mm And A Wall Not Thinner Than 10 Mm, Cemented Along The Entire Length To The Rock Mass. Details Of The Scope Of Implementation Of Individual Stages Are Described In Annex No. 2 To The Contract Template.