Ballast challengePublished 17/5 at 13:04
In a quarry near Canosa di Puglia in the southern Italian region of Apulia that produces railway track ballast, an Indeco HP 25000 hydraulic breaker proves to be the best alternative to drilling and blasting when explosives are not an option.
The Pozzelle quarry is characterized by the occurrence of Ambrato and Serpeggiante marble typical of the area. Active since the late 1980s and managed by the company CO.MA, the quarry has potential for the production of crushed stone for track ballast.
A set of surveys and laboratory analyses indicated that the deposit also contained metamorphic carbonate rock with dolomitic characteristics dating back to the formation of the Apulia platform during the Cretaceous period. The rock is considered ideal for the production of ballast thanks to its good compression strength, resistance to abrasion and frost, and absence of harmful fibres such as asbestos.
The quarry’s proximity to a key provincial road, plus the need to protect the surrounding agricultural activity from dust, precluded drilling and blasting. That prompted CO.MA to consult a company with the experience and machinery to perform the full quarrying cycle, the primary and secondary crushing, as well as its stockpiling.
Production was contracted out to D’Oria Giuseppe e C. from Andria, which has experience operating in the road works and concrete sector. To best handle the task of quarrying a material of such hardness and unconfined compressive strength with very little fracturing, D’Oria purchased an Indeco HP 25000 FS and a 90t Hitachi 870 excavator, which it paired up with another 33t Hitachi Zaxis 350 excavator mounted with an HP 14000 the company already owned.
The second breaker is used to reduce the blocks designated for ornamental stone, which whether due to imperfections or cracks must instead be used as a material for ballast production. The second breaker works to reduce material designated for ballast produced by the HP 25000. The Indeco HP 25000 is having success in markets where drilling and blasting has seen a gradual decrease. Currently Indeco is the only producer to offer a breaker with 3,390Nm.
Despite the large size and high performance, the HP 25000 also has the advantage of being coupled with 90t excavators, a feature that translates into higher mobility in the quarry and lower fuel consumption, and higher profitability. With a striking rate that can get up to 460 blows/min and a 250mm chisel, the HP 25000 can ensure impressive productivity.
The HP 25000 also boasts a ratio between input and output power highly favourable for achieving optimum efficiency. The breaker also comes with the anti-blank firing system, which considerably improves efficiency and extends the life of the breakers.