While the Sandvik Axera DD421 two-boom development drill rig is technically designed for drilling tunnels, in Australia and New Zealand (much more so than overseas) it is often used to install rock bolts for ground support, which creates a lot more wear and tear on the boom than may have been intended.

Early failure of original bolting cylinders

Customers have been reporting the early and frequent failure of original bolting cylinders, coupled with unexplained cracks forming in feed cradles and DPUs that are also forming cracks earlier than would be expected.

MASPRO has identified the major components that struggle to cope with the demanding task of bolting, and our engineers have redesigned a number of these components used for this demanding operation giving much improved performance.

Even in normal development drilling activities, bolting cylinders face extreme force. After all they are placed in the full extension position during bolting activities which exposes them to bruising from falling debris, corrosion from drill cuttings and harsh UG water, just to name a few.

While bolting cylinders are often replaced through regular operation – the most common failures being leaking seals, damaged rods from external debris and in some cases bent rods  – our customers were losing time, money and productivity with failures way ahead of normal maintenance intervals. Some reports were well below 1000 percussion hours.

Using advanced equipment and techniques including linear static analysis and finite element analysis (FEA) – a computerised method that predicts how parts react to force, vibration, heat and fluid flow – MASPRO engineers analysed precisely where the rods and cradle were excessively stressed at minimum and maximum loads.

MASPRO now offers, as part of an improvement upgrade for use when rock bolting, a modified bolting cylinder which is a direct replacement for the standard design. This part alone alleviates a lot of the issues identified.

By analysing, identifying and redesigning the part to relieve the stress caused by bolting, MASPRO has delivered exceptional performance improvements to our customers.

Vastly better performance, same cost

Together, these improvements add up to significant savings in maintenance, downtime and part costs. The best part is that MASPRO’s modified bolting cylinder is available at a price point equivalent to the standard bolting cylinder, so you can improve your lifespan many times over without increasing costs.


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