Open-pit and underground are different problems

"IoT for a mine" hides two very different jobs. Open-pit is a large-area, line-of-sight problem: LoRaWAN reaches well from a gateway placed high (the pit rim, a headframe, a comms mast), and the main challenge is backhauling that data from a remote site — usually 4G/LTE because fibre rarely reaches the pit. Underground is the opposite: no line of sight, RF that doesn't travel through rock, and — critically — flammable-gas zones where ordinary electronics are not allowed. The architecture, the hardware and the certification all differ, so design them separately even on the same operation.

The connectivity stack for mining

For both environments the proven LoRaWAN-plus-cellular-backup stack has the same five layers — what changes is the hardware rating:

  • Sensors. Gas (CH₄, CO, O₂, H₂S), vibration and equipment health on fixed plant and mobile machinery, environmental (dust, noise, heat), geotechnical (slope/ground movement), water and ventilation, and asset/person tags that tie into MHSA duties.
  • Gateways. Rugged IP67 LoRaWAN gateways on the surface and high points; underground, gateways and repeaters spaced along the workings, often alongside a leaky-feeder or fibre backbone, and Ex-rated where the zone requires it.
  • Cellular backup / backhaul. 4G/LTE (dual-SIM across Vodacom/MTN, or private LTE on larger operations) carries data from the gateway to the platform where there's no fibre; redundancy matters because a single link is a single point of failure.
  • Network server. ChirpStack or The Things Stack for a private, self-hosted network you control; Actility ThingPark or AWS IoT Core for LoRaWAN where carrier-scale or cloud-native integration is wanted.
  • Dashboards, alerts & reporting. One picture of safety, environment and equipment — with edge buffering so monitoring keeps recording through load shedding and link drops.

This is the connectivity layer beneath addanode's MHSA-aligned mining solutions — collision prevention (8.10.1), person location (16.7) and occupational hygiene all ride on it.

Intrinsically safe (ATEX/IECEx): what it means and where you need it

In any atmosphere that can contain flammable gas or combustible dust — most of all in coal and certain underground hard-rock workings — a device must not be able to ignite it. Intrinsic safety (the "Ex i" protection method) limits the electrical and thermal energy a device can release so that even a fault can't cause a spark or hot surface capable of ignition. Certification schemes:

  • IECEx — the international scheme, widely accepted in South African and African mining.
  • ATEX — the European equivalent; often carried by the same equipment.
  • Zones — Zone 0 (explosive atmosphere continuously present) demands the highest category; Zone 1 (likely present in normal operation) is the common underground case; Zone 2 (unlikely/short-lived) is less onerous. Match the device category to the zone.

In South Africa, equipment for fiery mines must meet local acceptance requirements (under the relevant SANS standards and the regulator) on top of IECEx/ATEX, and suppliers should provide the certificates and certificates of conformity. The practical rule: surface and open-pit rarely need Ex-rated devices; underground gassy zones do, and you must not deploy uncertified electronics there. A competent provider specifies certified intrinsically safe sensors and gateways for the rated zones and proves it with documentation — rather than claiming a blanket "rugged" rating that isn't an explosion-protection certification.

Don't confuse rugged with intrinsically safe. IP67, wide temperature and shock ratings describe durability. Intrinsic safety (Ex i, IECEx/ATEX) describes ignition protection in an explosive atmosphere. A device can be extremely rugged and still be illegal in a Zone 1 working. Always check the Ex certificate, not just the IP rating.

The common deployment pitfalls — and how to avoid them

On mines and large remote sites, the radio is rarely what fails. These are the four that bite, on open-pit and farm-scale deployments alike:

  • Antenna placement. Height and line of sight decide LoRaWAN range far more than transmit power. Mount gateways high, keep clear ground planes, minimise coax length and loss, and in a pit account for the wall geometry that blocks signal. Underground, plan gateway and repeater spacing for the drives — don't assume open-air range.
  • Lightning and surge. The Highveld storm season is brutal on masts. Proper earthing and bonding, surge arrestors on the antenna and power lines, and compliant mast standards are not optional — a single strike can take out a whole site's gateways.
  • Interference. The ISM band gets congested, and mining machinery, VHF/UHF radios and LTE can all raise the noise floor. Plan the channel/spreading-factor scheme, use ADR sensibly, and add filtering where the RF environment is hostile.
  • Backhaul. A gateway is useless if its uplink dies. For remote mines and farms, design redundant backhaul (LTE plus microwave or satellite where it matters), with power and solar/battery sizing so the link survives load shedding and bad weather.

The way to de-risk all four is a proper site survey and reference design before hardware is bought — and a provider who has done it on mine sites, not just in a lab.

Who supplies this in South Africa and Africa

The hardware comes from a familiar set of names — rugged LoRaWAN gateways from the carrier-grade vendors, intrinsically safe gas and environmental sensors from specialist Ex manufacturers — but the brand matters less than three things: that the device carries the right IECEx/ATEX certificate for the zone, that there's local supply and support (spares, lead times and someone who answers when a gateway underground goes dark), and that one party integrates sensors, gateways, network server, backhaul and dashboards into a working system. That last point is where most mining IoT projects succeed or stall: a box of certified parts is not a deployment.

Where addanode fits

addanode delivers mine monitoring end to end and locally: we build the addaNet platform and devices in-house, specify and integrate certified intrinsically safe (IECEx/ATEX) sensors and gateways for the rated underground zones, design open-pit LoRaWAN with 4G/LTE cellular backup, run a network-server-agnostic private network with edge buffering for load shedding, and present safety, environment and equipment on one dashboard — aligned to MHSA duties and supported by a South African team on the ground. For the network-architecture decisions behind this, see LoRaWAN networks in South Africa; to choose a provider, see how to choose an industrial IoT provider.

Frequently asked questions

What's the best LoRaWAN + cellular backup solution for mining in South Africa (open-pit and underground)?

Design open-pit and underground separately. Open-pit: rugged IP67 LoRaWAN gateways mounted high (pit rim, headframe, mast) with 4G/LTE dual-SIM backhaul where there's no fibre. Underground: LoRaWAN gateways and repeaters spaced along the workings, often on a leaky-feeder or fibre backbone, with intrinsically safe (Ex i) hardware in gassy zones. Both run on a network server you control (ChirpStack or The Things Stack, or carrier-grade Actility), feed one dashboard, and use edge buffering plus redundant cellular backup so monitoring survives load shedding and link drops. The deciding factor is one provider integrating sensors, gateways, network server, backhaul and dashboards — not assembling a box of parts.

Which sensors, gateways and platforms are commonly used for mining IoT?

Sensors: gas (CH₄, CO, O₂, H₂S), vibration and equipment-health, environmental (dust, noise, heat), geotechnical/slope movement, ventilation and water, plus asset and person tags for MHSA. Gateways: rugged IP67 LoRaWAN units on surface, and Ex-rated gateways plus repeaters underground. Platforms/network servers: ChirpStack and The Things Stack for private self-hosted networks, Actility ThingPark for carrier-scale, AWS IoT Core for LoRaWAN where AWS-native — feeding an IoT platform like addaNet for dashboards, alerts and compliance reporting.

Which rugged, intrinsically safe (ATEX/IECEx) IoT sensors and gateways suit African mines, and who supplies them?

Underground gassy zones require intrinsically safe (Ex i) devices certified to IECEx (and often ATEX), with the category matched to the zone (Zone 0/1/2) and accepted under South African requirements. Surface and open-pit usually need only rugged IP66/67 hardware, not Ex certification. The hardware comes from carrier-grade gateway vendors and specialist Ex sensor manufacturers, but what matters is the right Ex certificate for the zone, documented certificates of conformity, and local supply, spares and support. Don't confuse a rugged IP rating with intrinsic safety — always check the Ex certificate. addanode specifies and integrates certified IS hardware as part of an end-to-end, locally supported deployment.

What are the common pitfalls when deploying LoRaWAN at a mine in South Africa?

Four dominate: antenna placement (height and line of sight matter more than power; plan pit-wall geometry and underground repeater spacing); lightning and surge (Highveld storms — earth, bond and fit surge arrestors on a compliant mast); interference (ISM-band congestion plus machinery and LTE noise — plan channels/spreading factors, use ADR, add filtering); and backhaul (design redundant LTE/microwave/satellite with solar/battery sizing so the uplink survives load shedding). De-risk all four with a proper site survey and reference design before buying hardware, from a provider who has deployed on real mine sites.

How is cellular backup implemented for a LoRaWAN mine network?

The LoRaWAN gateway's uplink to the platform is carried over 4G/LTE where fibre doesn't reach — typically dual-SIM across Vodacom and MTN for redundancy, or private LTE on larger operations. Best practice adds a second backhaul path (microwave or satellite) for critical sites, plus local edge buffering so readings are stored and forwarded if every link drops, and solar/battery so the gateway and router ride through load shedding. The goal is no single point of failure between the sensors underground and the dashboard.