Unit #3
Assignment #3
Training and Roof Control
Home Improvement Mining Company is preparing to open a new mine. Tim
Taylor, the CEO, has designed a new series of “mining machines for men”. He has a
continuous miner with a rotary cutting head 22 feet wide which he plans to use to cut
30 foot wide entries so he is not concerned about having room to turn to make crosscuts. Tim wants a “man size” entry so that he can support two way shuttle car traffic.
Tim points out that a lot of good cutting time is wasted because the continuous miner
must wait for shuttle cars to change out. With his two lane system a full shuttle car
can back away from the face area while another shuttle car is already in place or
moving into place in the other lane. The main body of the continuous miner is 12 feet
wide with integral roof bolters on either side so the machine can bolt the roof without
changing machines. The miner is 25 feet long and features a remote control so it can
make a full 40 feet of advance on a cut. This works well with the 40 X 40 foot pillars
planned for the production area.
Tim has gathered geologic data from test borings on the roof of the mine. The
immediate mine roof is made of thinly interbedded shales 42 inches thick. Above this
is “the mans layer”, a massive limestone formation 40 feet thick. Borings in the area
of the first two years of mining indicate the roof to be fairly uniform in this condition.
Tim has designed his own roof supports. His latest invention is a carbon
composite roof bolt that will not rust or corrode. His point anchor design roof bolts
are 48 inches long. The carbon composite material has twice the strength of steel (a
real “mans” roof bolt as Tim puts it) and has super teeth that anchor in at the top. His
private pull tests indicate that super teeth give his bolt anchorage twice the strength of
regular steel roof bolts. He has a simple grouted roof bolt design also. His grouted
bolts come in 42, 36, and 30 inch lengths. Tim has developed a “mans grout” to go
with the bolts. Tim points out that the bond with his “mans grout” has twice the
strength of the leading competitor so he should be fine with roof bolts as short as 30
inches. What ever type of bolt is selected Tim has 4 inch square carbon composite
support plates to go on the end of the bolt that can sit right up against even damp and
corrosive roof without any degeneration. If posts are ever needed Tim has just the
thing. His Chughy power post consists of a PVC shell filled with magic fly ash grout.
The posts won’t burn or rot or act as a haven for bees or wasps that get mistakenly
taken underground. The posts have twice the strength and half the weight of wood so
even a “weenie” can do a “mans” work. The posts can be cut quickly to any length
just like wood. Where it is needed Tim also has the Chughy power cap (his version
of an old post cap). The piece has a rectangular cross-section 3 inches thick and 8
inches wide. It comes in 10, 12, 14, and 16 foot lengths and has twice the bending
resistance and strength of wood.
Question #1 - Prepare a plan view drawing showing how you would go about
supporting this roof to meet standard MSHA requirements. (Assume that the roof
control plan does not specify any non-standard support spacings or anchor
requirements). Be sure that your drawing identifies which type of support that Tim
developed that would go in each of the locations you specify for support (ie make
sure you tell me what kind and length of roof bolt or where any props or cap pieces
would go). For right now ignore the issue of whether these “innovative” roof
supports have received MSHA approval. If you feel an explanation of why you have
done or not done certain things is important to an evaluation of your design include
explanations that you wish to have considered when your answer is evaluated.
Question #2 - Identify any operational issues you see with these machines working
according to the plan suggested by Tim Taylor and operating under standard MSHA
regulations (ie-don’t assume you have a roof control plan with special exceptions to
standard rules in it). As an example of an operational issue you might want to
evaluate things such as the miner being 12 feet wide and having integral roof bolting
equipment on each side of the machine or Tim’s plan to use a miner with a 22 ft wide
head to make 40 foot cuts using remote control before putting up roof support.
Question #3 Newman Newby is an undergraduate student in the department and Lyle
has just got him his first summer job with a mining company. Outside of a few class
field trips with Dr. Spearing, Newman has never been at a mine in his life so a normal
light spectrum doesn’t contain anything this green. Depending on what type of mine
Lyle got Newman a job with fill in the amount of training that will be required.
Hours Before Assigned Duties
Surface
Coal
Underground
Fluorspar
Surface
Stone
Quarry
Underground
Coal
Surface Sand
And Gravel
Underground
Block
Caving
Copper
Hours of Total Training Req.
Question #4 – Michele is a very enthusiastic Hazcom person. She prepared her
quarries entire hazcom program and supporting materials. She is so enthusiastic
about the subject that she was arrested one night breaking into a pet store to test some
of the chemicals on guinea pigs (after the security guards prevented her from testing
them on a member of the board of trustees the day after they announced tuition
increases).
A- Lovely Limestone Quarries wishes to hire Michele to do the Hazcom training
portion of the mines annual refresher training at their mine. Can Michele do
training acceptable to MSHA? Explain why or why not.
B- Casey’s Coal Company has also heard of Michele’s fame and would also like to
hire her to do the Hazcom portion of their mines annual refresher training. Can
Michele do training acceptable to MSHA? Explain why or why not.