FAQ
Better understand Minrail Inc
 
 
Frequently Asked Questions 
 
 
We compiled the following set of frequently asked questions to help you get the answers you need about SAMS™, the Shallow-­‐Angle Mining System. 
 
 
SAMS™ is the result of extensive R&D efforts and firsthand field experience of mining professionals, but more importantly, it addresses expectations, concerns, suggestions, frustrations, and safety issues voiced by industry stakeholders. 
 
 
Shallow dipping deposits are perhaps amongst the toughest geometries to work with, mostly because of the few tools and techniques available. When using our Shallow-­‐Angle Mining System, the workers are standing on a firm work floor and can take advantage of tools and equipment normally used for other mining techniques. We developed a very comprehensive line of equipment, tools and techniques that brings shallow dipping mining to an unprecedented level of mechanization. 
 
 
What is so innovative about SAMS™? 
 
The innovativeness of our Shallow-­‐Angle Mining System rests on its ease of installation and use in underground mining applications. The system is comprised of modular mining equipment riding on a suspended rail, bolted to the roof of the underground workings. Our railing unit is literally the backbone of the system. It is extremely strong and rugged, and yet, light enough to be manipulated safely by a single worker with the appropriate lifting equipment. It is also fairly inexpensive to buy, operate and maintain. 
 
 
Can the system be installed in a large mechanized mine? 
 
Yes. Although we designed our product with the objective of mechanizing small underground operations, any part of SAMS™ can be installed and used in large mines as well. If the equipment is intended for production mining, the geometry of the ore body has to be within specified shape criteria 
(i.e. fairly flat or dipping at + 10 up to + 45 degree). If the equipment is used for other purposes, such as general excavation work (pump room, crusher room, workshop, etc.), then there are no real limitations. 
 
 
Can the system be installed in a small, track drift type or narrow vein minei? 
 
Yes, of course. The equipment is designed specifically for small mining operations. It can be used either for production mining or for miscellaneous excavation work (pump room, crusher room, workshop, etc.). 
 
 
 
For transportation purposes, what is the size of the largest component? 
 
The telescopic platform is the largest component. Its dimensions, including the hoisting trailer, are 66 inches high by 53 inches wide by 19 ft long. These dimensions generally comply with the available space found in a typical three-­‐compartment shaft infrastructure. 
 
 
For transportation purposes, how heavy is the heaviest component? 
 
The telescopic platform is the heaviest component, weighing 6,000 lbs. 
 
 
How long does it take to install a stoping setup? 
 
From what we have seen so far, 10 hours or less are needed for a two-­‐person crew to set up the entire system. 
 
 
Looking at SAMS™ components, they seem quite rugged and heavy. How can two persons manipulate them so easily?
 
SAMS™ components are lifted in place using a very simple yet efficient group of hoisting motors mounted on the work station rail units. Since these hoists are battery-­‐powered, the installation crew can install the system right away. And thanks to the unique installation workflow we developed, no worker needs to exert unnecessary efforts or perform dangerous manoeuvres, because the bulk of the load is handled by our hoisting system. This system is so efficient that a single operator alone can carry out the system assembly. That being said, we recommend however that the setup be carried out by a two-­‐ person crew for safety reasons. 
 
 
How much electrical power is required for a typical work site? 
 
Power load for each work station is 30 horsepower or 22.4 kW, which is less than 40 amps at 600 volts. 
 
 
Does the system need special electrical hardware or requirements? 
 
SAMS™ comes with its own electrical sub-­‐panel. A “jumbo drill” or welding machine power outlet is usually the only specific electrical device needed to connect to the mine’s electrical grid. 
 
 
Is the rack and pinion mounted on your railing system really something new?
 
No, not really. In the early 19th century, trains ascending steep hills were equipped with rack and pinion (or cog wheels) propulsion system. Later on, North-­‐American and European countries applied this principle in different applications (e.g. passenger railways and coal mining). For the past few decades, various machines, including a few mining equipment, are making use of this concept to transmit power to a load handling device. 
 
 
 
Any chance of clogging the rail with packed dust or stones? 
 
No, if installed to specifications, the upside down rack (teeth pointing downward) cannot collect any debris. Ambient dust and humidity found in underground mining environment can cause dirt to build-­‐up on the rail surfaces, but this should not affect the effectiveness of the traction system. However, a daily visual inspection as part of the normal work site inspection routine is highly recommended. Prevention is your best strategy for avoiding problems. 
 
 
What is the load capacity of the railing system? 
 
The ultimate yield load capacity of each rail section is 120,000 lbf or 533.8 kN (i.e. almost 60 tons). Such capacity is necessary to sustain the tremendous forces and vibrations transmitted to the rail by the mining equipment modules. 
 
 
Are stabilizers needed to move a load around when using the telescopic module? 
 
No. Minrail’s double rail system is designed to distribute loads in virtually any direction. Therefore, no stabilizers are required to pick a load up, move it around and even up or down the stope. 
 
 
Can a load be moved even with the boom fully extended? 
 
Yes, as long as the load is within the recommended limits. 
 
 
What is the safety factor of the telescoping boom equipped with the work platform? 
 
The safety factor will vary between 10 and 6 depending on whether the boom is fully retracted or extended. In other words, you can safely load close to 2,000 lbs on the work platform, extend the boom fully, travel up or down the stope, and still be well within the safety limits. 
 
 
What happens if the platform is “overloaded”? 
 
Load cells were placed on the hydraulic system to monitor the loads on the boom. Upon reaching the maximum load, the platform’s LED projectors will “flash” to warn the operator that the load capacity is near its limit. If the load keeps increasing, the boom will slowly descend or stop moving to avoid damage or breakdown. 
 
 
How is the rail held in place?
 
We are using a Dywidag®ii anchor bolt that has a mechanical thread along its entire length so that the rail can be installed perfectly leveled, regardless of the shape of the roof. The bolt has a nominal length of 60 inches with a diameter of 19 mm. It is inserted in an appropriately sized hole and grouted in place with a two-­‐part epoxy resin. Another benefit of the Dywidag® bolt is that it can be extended using couplings when the ground conditions are rugged, broken, or uneven. 
 
 
 How strong is that Dywidag® bolt? 
 
When correctly installed, Dywidag® bolts can sustain tension loads of up to 15 tons and shear loads of about 10 tons. 
 
 
Can the rail be reused once a stope is mined out? 
 
Yes. The rails can simply be unbolted from the roof and stacked aside for further use. This however is not so for the anchor bolts, because the only way to remove them is by breaking them. 
 
 
Can a damaged rail be repaired or recycled? 
 
Yes. Each rail unit has four parts that can be replaced provided that you have the appropriate tool to fix them. Components are fastened together with crimped sleeve bolts that require a special tool to remove them. Rails can be repaired by the operator or exchanged for new or refurbished factory units. 
 
 
How is the first section of rail installed in the work station? 
 
Firstly, four sections of rails are laid on the floor and bolted together. Secondly, that rail assembly is hoisted and lined up with reference lines painted on the walls. Once proper alignment is set, the rails are anchored to the roof with Dywidag® bolts using proper scaffolding and drilling equipment. 
 
 
Can the pitch of the rails be changed once the initial setup is done? 
 
Yes. We not only have strait rails, but curved ones as well. Pitch change can either go up or down from “0” up or down to +/-­‐ “45” degree using combinations of curved rails. The available curves are 3.0, 7.5 and 11.25 degree in positive or negative pitch. 
 
 
What is the shortest distance for the rail to pitch from “0” up to “45” degree? 
 
Four rails of “11.25” degree bolted together will pitch the system up within a horizontal distance of 20 ft (6 m). 
 
 
Can the rail be installed at or near 90 degree angle? 
 
The rails and propulsion system can sustain the published loads even at 90 degree, but the mining modules are not designed to work in this attitude. SAMS™ is designed for a specific range of applications that do not go steeper than 45 degree. 
 
 
 
How is the rail transported, supported and manipulated during its installation in the stope? 
 
At the work station, one rail unit is hoisted up to allow the working platform to move underneath it. The rail unit is then lowered to rest on the hand rail of the platform that is equipped with specifically designed holding struts. From there, the rail unit becomes part of the working platform until it is brought into place using the telescopic boom. The rail is then lined up in front of the railing system and with a jack (screw type), the “nose” of the rail is raised to fit the railing alignment. The rail is then bolted in place. 
 
 
How do we proceed to line the rail up and fasten it properly during its installation in the stope? 
 
A new rail section is set into place and bolted to the previously installed section. Forward and aft mounting holes, located on each brace, have to line up close enough for the mounting bolts to slip in. This is achieved by micro-­‐movements of our telescopic boom. Once fasten, the new section of rail will support and align itself in both “pitch” and “direction”. The front brace of the rail has guiding holes through which the operator will drill off the anchor bolt holes. Finally, resin cartridges are inserted, followed by the anchor bolt and the stack of washers and nuts. Once the anchor bolts are installed, the front of the rail is levelled by tightening the nuts so as to prevent the railing from “rolling” on its axis. A carpenter level can be used to carry out this task. 
 
 
How are the modules riding on the railing system? 
 
We developed and patented a device called a “support beam module” or “SBM”. It is made up of two carriage units mounted with top and bottom cam followers. The top cam followers rest on the top surface of the lower rail flange. The railroad wheel-­‐shaped bottom cam followers, which barely touch the lower surface of the rail, keep the carriage aligned. A pair of carriage units connected with a specially designed cross member completes the support beam assembly. An SBM can even be equipped with two hydraulic motors if a given module needs self-­‐propulsion and braking capability. The motors are actuated by the power unit located behind the main SAMS™ mining component. Every SAMS™ mining module is connected to either one or two SBMs. 
 
 
How much time does it takes to install a support beam module? 
 
Installing a complete SBM unit should take about 20 min. 
 
 
 How heavy is the support beam module? 
 
The weight of a complete SBM unit is around 1,000 lbs, depending on whether one, two or no motors are installed. 
 
 
 
What type of drilling equipment is used for developing the inclined drift? 
 
We designed a development rig to drive the inclined drift (sometimes called a “draise”). Our drilling unit is built around a well-­‐known piece of equipment called “Long-­‐Tom”. Simply put, the rig is composed of two independent pneumatic cylinders, each mounted with a pneumatic drilling unit. Given the small size of the drift (or draise) section, the Long-­‐Tom drill rig was chosen for its simplicity as well as its low acquisition and maintenance costs. 
 
 
Why isn’t a “Jumbo” drill used? 
 
For the moment, the Long-­‐Tom machine is more than sufficient to handle the rather small drift section of the SAMS™ technique. Trying to fit a Jumbo rig in such a small opening, which is rarely larger than 
3.0 m by 3.0 m, would be quite difficult and cumbersome. However, we are working on a Jumbo unit that we plan to manufacture for application when much larger initial cut sections are required. 
 
 
What is the typical mine service layout in the draise? 
 
While developing the draise, mine services are installed alongside the railing system. Those services are distributed using regular “victaulic” type of piping. A 3-­‐inch Ø, sched 20 pipe is used to distribute compressed air, while industrial water is delivered through a 2-­‐inch Ø, sched 20 pipe. A 16-­‐inch fan pipe is installed alongside the rail for ventilation as well as a “leaky feeder” coax cable for communication, data transmission and blasting control. 
 
 
What drilling equipment is used for production blast holes? 
 
As opposed to its “development” counterpart, the production drill rig is a far more sophisticated piece of technology. SAMS™ mining technique requires specific drilling patterns that are somewhat unusual for normal underground drilling rigs. The drill chassis was designed entirely by Minrail, because none could be found that met our needs. Besides, we insisted on designing equipment that would minimize the need for frequent equipment change when different drilling needs are encountered. For instance, our chassis can drill rows of holes precisely along a given line even with a double dipping axis and on the same set-­‐up be quickly reconfigured to drill vertical upholes for cable bolts. Our unique rig is also designed to be flexible enough to be mounted with inexpensive off-­‐the-­‐shelf pneumatic drill heads or powerful hydraulic units. 
 
 
Can grouted cable bolts be installed in the stope? 
 
Absolutely. We are currently in talks with a Canadian company to adapt one of its product into a cable bolting module. The module will be mounted with a large spool of cable, which will be fed through an inserting head. The operator will only need to control the inserting head and attached the grouting and breathing hoses. Bulging and trimming of the cable is done by the inserting head. 
 
 
 
 Aside from regular rock bolts or rebars, can specialized ground support material be installed in the stope? 

Yes. There are virtually no limits to the type of ground support material and techniques that can be applied. Shotcrete application, Super Swellex®, grouted cable bolts are just a few of the specialized material we proposed. 
 
 
What type of drilling equipment is used for cable bolting? 
 
As explained above, the very same production drill rig is used for cable bolts drilling. 
 
 
Can shotcrete be applied in a draise or in the stope? 
 
Yes. However, a shotcrete machine module is still in the works and should be available shortly. 
 
 
Is it possible to communicate with the worker even if the drills are running? 
 
Yes. All workers, supervisors and members of the technical department are provided with a miner’s lamp equipped with an integrated FM radio. Contacting a work site person at work is done by dialing the call code that will cause the stope LED spotlights to flash and signal an incoming call. 
 
 
Is it possible to reach the work site (at the face) without forcing the worker to de-­‐setup his equipment?
 
Yes. Each work station is equipped with a utility nacelle that is installed at its far end. It is connected to its charging station for the entire duration of the stope mining cycle. If a supervisor or a maintenance crew need to reach the work site, they simply need to climb onboard and “drive” their way up. The unit is battery-­‐powered and ready to be used, at all times, in case of a power outage or an emergency. 
 
 
What happens if there’s a power outage or worse, the worker is believed to be unconscious and stuck in his work site? 

A power outage is regarded as a fairly benign event considering that the utility nacelle can easily tow the platform out safely back to the work station. If a worker is unconscious, a state of emergency is declared and the appropriate rescue protocol is initiated. Once again, the utility nacelle can be put to use since it was designed specifically for such a situation. The mine rescue team will reach the work site and evaluate the general state of health of the worker. Then, the nacelle will serve to carry the rescue team and the wounded worker back to safety. 
 
 
 
What type of remote control is SAMS™ using? 
 
A wireless system is used for convenience’s sake. The remote controls used are quite compact and specifically designed for underground application. The battery-­‐powered remote can easily be replaced by a freshly charged if need be. 
 
 
What if the worker stumbles and loses control of the remote? 
 
The remote is equipped with an internal tilting switch. The switch is fully adjustable with an angle and tripping timeout. If the remote control is held in an awkward position for a given period of time, the power unit will turn itself off. Should the worker stumble and fall down, the hydraulic pump will cease to operate until the worker resets the power unit. 
 
 
What is the minimum mining height? 
 
1.2 m or 4 ft is the minimal thickest. We do need to drive a draise having at least 2.8 m in height but the production stope part, standing laterally, may have as little as 1.2 m. 
 
 
How can the operator work in such a small opening (i.e. 1.2 m)? 
 
The operator never needs to expose himself to such confined space. All the rockwork is done remotely. With the help of cameras, monitors and telescopic boom implements, the worker is standing safely aside the confined area and operates the equipment remotely. 
 
 
What is the maximum mining height? 
 
From a practical point of view, we figure that 6 m is the maximum height at which we can safely operate. Although we haven’t mined a stope that high yet, SAMS™ mining workflow is meant to carry out rockwork in such conditions. If the ore zone to be mined is thicker than 6 m, we would probably mine it in two or more passes. 
 
 
What is maximum mining width? 
 
Best practice dictates to design a given mine plan with stopes ranging from 12.5 to 15 m in width. We realized from experience that stopes wider than 15 m provide much more challenging work conditions. The expected gain in productivity with wider stopes will most likely be offset by tougher work conditions and perhaps compromise the stope stability and integrity. 
 
 
What is the typical mining cycle of the draise? 
 
The draise is driven following a standard “drill-­‐blast-­‐support-­‐muck” workflow. Some other tasks are also required to complement this by installing the mine services as well as all the piping for compressed air, 
 
 
water, ventilation and communication. The draise is driven all the way up for the entire length of the stope. Once completed, the development rig is removed and replaced with production equipment. 
 
 
What is the expected development rate in the draise? 
 
Given that no real field test has yet to be done, we expect similar progress rate one would observe in similar situation like driving a raise with a mechanized raise climber. For planning purposes, we are considering taking a 10 ft long round (broken at 9.5 ft) within a ten-­‐hour shift. Additionally, we systematically apply an efficiency factor of 85% to derate the estimated figure and make it more realistic. 
 
 
What type of explosive is used for drifting? 
 
Explosive type is pretty much the same as the one used in similar rockwork activity. Holes are loaded with a primer and filled pneumatically with AN/FO. 
 
 
How is the broken rock removed from the face? 
 
We have designed an excavator blade that fits at the front of the telescopic boom. When it is time to remove the pile of broken rock, the excavator is used to dig and scrape the place out. The rock material is then brought down to the sill drift using a single drum slusher equipped with a scraper. 
 
 
Is there a chance of getting hit by a falling rock during the ground support installation? 
 
SAMS™ includes a comprehensive range of mining equipment that are meant to provide the safest work environment possible in this field of application. Ground support installation is indeed quite challenging in shallow dipping mining, but with SAMS™ any risk of exposure to falling rocks is virtually eliminated. 
 
 
What type of explosive is used for production blasting? 
 
Contrary to development blast holes, production blast holes are loaded with emulsion explosive. The blasting agent is stored in a specially designed container, equipped with a pump, and towed by the working platform up to the work site. 
 
 
What type of detonator is used? 
 
We prefer to use electronic detonators instead of electric or Nonel type. We believe that electronic detonators provide much better fragmentation control and are much safer to use. 
 
 
 
Is there any specialized equipment for loading and timing the production blast? 
 
We use a specially designed emulsion container equipped with a loading pump. This container is filled and transported to the work station by a service vehicle. It is then manipulated very much the same way as with any other SAMS™ module; it is hoisted in place, secured and then towed up to the work place and put into service. The blast timing is programmed using a laptop connected to an interfacing blasting module for each detonator. A special software is used to link the IP address of each detonator. Once the blast is encoded, simulations are run to make sure that the blast will set-­‐off properly. 
 
 
How is the broken rock removed from the stope? 
 
Broken rock material is handled much the same way as the broken rock produced during the development phase. Material is brought down to the sill drift using the excavator module in combination with a slusher. For stopes that are 3.5 m high or less, a single drum slusher unit will suffice to pull the material down. A double drum unit as well as transfer and guiding pulleys are required for higher stopes. 
 
 
What is the expected production rate in the production phase? 
 
Production rate may vary from one mine to another because no two mines share the same geometry and conditions. Nevertheless, the minimal production rate should not fall below 50 tons per men-­‐shift (tpms) on average. This figure may be expected in very narrow vein conditions since development phase last as long as the production phase. On much larger stopes, say 3.5 m and up, then production rates can go as high as 150 tpms. 
 
 
How many pieces of equipment will be required to accomplish the disclosed productivity rate? 
 
To answer that question, we need to further explain how SAMS™ works. Given that SAMS™ components (telescopic platform, drill rigs, etc.) are modular, they can be shared between work sites depending on their development or extraction stage. For example, one stope may be in its early stage of development, while another is at the production drilling stage or in its last hours of the mucking stage. A fairly small group of equipment could be sufficient to keep things moving. On the other hand, if mining throughput is to be much higher, then the group of equipment will obviously be larger and the number of active stope will also need to be higher. As an example, we figured that a 600 ton per day (Tpd) mining rate can be handled with a group of equipment made up of two Long-­‐Tom modules, two Long-­‐ Hole drill rigs, two telescoping platform with the associated accessories, three slusher units and approximately 350 rail units. 
 
 
 
Is special training required to operate SAMS™? 
 
Yes. A training program is available for every position, including miners, maintenance personnel, mine engineers, mine technicians and supervisors. Minrail will assign a training crew to provide training to the client’s personnel. The training period should typically last three months or so. 
 
 
Is it possible to use backfill to maximize ore volume extraction? 
 
Yes of course. Backfilling the stope is perhaps the best option to maximize the mine call factor. Backfilled stopes also promote stability and integrity within the mine infrastructure, thus reducing the risks of losing part of its precious reserve. 
 
 
Is backfill absolutely necessary? 
 
No. From an economic point of view, backfilling the stopes may not be possible, so leaving rib pillars between adjacent stopes is perhaps more appropriate and perfectly acceptable. Although this method has proven its merits, the risk of losing part of the deposit is possible if the mine isn’t designed properly. Therefore, a thorough rock mechanic study is recommended in order to evaluate and define the stope shape and mining criteria. 
 
 
With respect to mine design, is the stope layout always the same regardless of its size? 
 
No. As explained earlier, no two deposits are alike. Therefore, each and every deposit needs to be evaluated with respect to its unique features before its final design. This said, similarities between different mine designs are however expected since they share a common attribute; a shallow dipping geometry. 
 
ii Dywidag is a registered trademark of DYWIDAG-­‐Systems International (DSI)