SHAFT SINKING
The Redpath Deilmann Nezhinsky team completed the whole sinking and equipping of both shafts ahead of schedule with a Herrenknecht SBR while registering just one reportable accident ( finger injury )
and geological problems below the initial freeze section – along with ongoing COVID-19 restrictions – to complete the project ahead of schedule .
The fact it did so while breaking a company record is astonishing .
Made up of a combination of German , Belarussians , Russians and other nationalities , the team is now putting the final touches to the 8-m diameter shafts ( one 750 m depth and one 697 m depth ) at Nezhinsky . Shaft # 2 , the service shaft , is now fully equipped , and will be used to transport muck from underground development work – expected to take upwards of a year – at the potash project .
“ We ’ re more or less finished with the ‘ shaft sinking ’ side of things in Belarus ,” Greinacher said . “ This means we have a really good team available ready to be deployed elsewhere .
“ Yet , this is a double-edged sword . We need good people to run a project , but we also need a project to employ those people .”
In terms of a potential project involving an SBR , only one remains out there in the territories that Redpath Deilmann is focused on ( Europe and Russian-speaking countries ), according to Greinacher .
The potential work in Poland to sink shafts for a coal project – mentioned in this same feature last year – has been hit by incoming EU regulations around thermal coal developments , while most other sinking projects up for tender are from metal mines where the SBR , which has a cutting mechanism suitable for soft-tomedium-hardness-rock , would not be considered .
This isn ’ t to say the SBR ’ s days are numbered . Far from it .
Greinacher , in reviewing the team ’ s and SBR ’ s performance in Belarus , said : “ On average , we advanced a little more than 3 m / d under some very difficult conditions . I think the peak performance was 7.4 m / d , or 150 m / mth , the latter of which was averaging 5 m / d . By that point , we were in the bottom section of the shaft where conditions were optimal .
“ The team was perfectly aligned , and the machine performed very well – we made some modifications to it at the beginning , as is typically done on such projects – and the rock conditions were very good .
“ We achieved records later , when the SBR was in rock salt , and there is nothing better than rock salt for such sinking work .
“ Yet , there is still room for improvement . If we were to undertake a project under similar conditions , we could probably exceed the performance we achieved in Belarus by about 20 %.”
Such a benchmark means the SBR is likely to crop up in future projects outside of Woodsmith in the UK ( see Watching Woodsmith boxout ).
When it comes to rock cutting , the Nezhinsky team might soon
SEPTEMBER 2021 | International Mining 107