Mario Pietromartire, founder, and MD of Bomar Projects, passed away on 11th May 2021, aged 88. Born in Italy, he trained in the Italian military flying school before coming to South Africa to attend the State School of Mines. After a period in the gold mines, aged 36, he was appointed by JCI/Dipenta as underground manager at the Outlet section of the 83 km Orange-Fish project. Mario showed great leadership under the watchful eye of Commentatore Pasquale himself. Involving shallow cover tunneling he strove to win the floating trophy for best production.

In the early 1970s he formed his first company with colleagues, Bodo Wentzel and Rudi Mulhbauer. Their first contract was two railway tunnels at Delville-Wood in Natal, followed by two at De Doorns, and then many more. Recognised as a “go-getter” during his 50-year career in contracting, his passion and solutionist thinking led to significant contributions in the industry. His patents include an integrated system to excavate steep decline shafts (MMS), a tunneling system to continuously fill a span of hoppers to reduce cleaning times (HLS) and a mining machine to extract chromite and platinum in narrow tabular ore bodies (Megamole).

He was the first in South Africa to introduce consolidation ‘ground freezing’ in 1976, during the exploration stage of the Huguenot road tunnel, Du Toits Kloof. In 1982 he consulted on a large footprint, 42-m-deep below surface basement section, of the Mass Transit Railway in Hong Kong. In mitigation of time over-run, due to unforeseen ground conditions, his ‘mining’ solution using shafts, hoists, scrapers et cetera for the excavation, was implemented.  Described by the Umgeni Water Board as a “superb tunneling feat” a 3.3 km tunnel under Westville, Natal, was completed ahead of schedule by Mario, using a 3.03-m-diameter tunnel boring machine (TBM).

During the late 1980s and early 1990s, three raise-bored and continuous slipform concrete lined ventilation shafts for Sasol were carried out in a JV. On one occasion, poor ground conditions resulted in a fall of material in the sidewall approximately 110 m from the surface. Mario’s proposal for consolidation, by means of lowering a custom designed prefabricated steel pipe form and cementitious grouting from surface, was successfully implemented. At BRPM mine in 2000, to establish ‘cutter’ consumption cost, he successfully introduced a 2.1-m-diameter gripper TBM to bore a 2.1-metre-diameter, 340-m-long raise in UG2 reef.

Cross-border projects, amongst others, included an exploration shaft and drives for De Beers in the sands of the Central Kalahari; large x/section diversion, outlet tunnels and intake shaft at the Maguga Dam project, Swaziland - with commendation for completing in a short time; sinking and equipping in Mozambique and Zimbabwe; and three prospect shafts and drives in the DRC with extensive grouting to mitigate ground water inflows. Locally and cross border Mario delivered nearly 50 projects, in both the Mining and Civils sectors. A person who worked with Mario said: “What a Man!” Mario leaves his wife Tersia, two sons and three daughters.

- David Easton