Surface Equipment Timing

Surface Equipment Timing schedules through surface pits and blocks based on equipment mining rates in accordance with a calendar. The mining rate is typically based on volume of overburden but may also be based on tons of key strata. The calendar is set by the user to indicate when entire days or individual shifts within a day are down for holidays, time off, or other reasons. The pits themselves must contain key strata and overburden information which is placed in them through use of Surface Reserves, Import Timing Grids, or Assign Timing Data. Surface Equipment Timing is distinct from Surface Production Timing by requiring use of quantities or grids stored in the pits, use of a calendar, and defined rates of production for equipment. The Calendar, Equipment and Crews are defined in the Surface Project Manager.

The Project Manager also appears at the start of Equipment Timing.  The purpose of the timing project database file is to provide a single place where everything related to the timing project is stored. This includes equipment definitions, reporting settings, pit and panel information and reports produced. This also includes other data such as calendars, equipment options, date and weight tables, text block definitions. Basically everything except for the grid files, which will be referenced. This means that reviewing or even repeating results of a schedule done previously will be much easier if everything including the last results is stored in the same place.

The left side of the dialog has a tree control which displays the categories of items on the top level, with either set of items or actual items underneath. Depending on what is selected on the left, the buttons on the right will reflect the functionality available for the current selection. The sets of items showing in bold reflect the current set when applicable: i.e. the project can have multiple sets of equipment defined, but the one showing in bold is one used in calculations. By double-clicking on the item the Edit function can be executed if applicable. For equipment, the user can edit, add, copy or remove entire sets of equipment. Use the Set Current button to set a particular item current. Equipment can be imported from an older Equipment Definition file or from another project. It can also be exported to another file. A number of different data can be output to an external data source or brought up in the report formatter.

Following is a detailed description of each function on the Surface Timing window and subsequent windows. After that is a step by step procedure for setting up for the Surface Equipment Timing.


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Timing can be run from this window by selecting the Report button. It brings up the window with the finish date, where the Report or the Detailed Report are selected. Choosing Detailed Report brings up the Report Options and runs the schedule, and hatches the pit blocks in the drawing.

The program uses the SURFACE grid as a starting elevation and the thickness of each block is relative to the volume of material assigned to each bench in the pits. Benches with more volume will show up thicker than others with less. The color scheme is based on the bench you are on.  For better viewing of complex pits with separate bench polylines in 3D, surface attribute for each bench can be defined with attribute name SURFACE_BENCH# and value equal to the bench bottom elevation grid. If these attributes are defined the program builds the 3d pick view from top-down calculating the thickness on each pit vertex as elevation difference between two consecutive benches. The red text indicates the grids are moved and cannot be found at that path. There is a reset folder button to address it.
 

The Schedule Effect on Delay gives four choices:
  1. Pure Calendar delay, where if the calendar has it off already, then that is all it will do. It will not take it off additionally.
  2. As Scheduled delay, where the delay will take affect when the equipment is working. If the calendar has the equipment off at that time, then the program waits until it starts to work again, then schedules the delay.
  3. Pure Calendar Delay after precedence is satisfied.
  4. As Scheduled Delay after precedence is satisfied. 
The Due To option provides Drawing Event Types to choose from. Choose the button with "..." next to the Due To, to open the Drawing Event Types window. To Add or Edit a type, the Capture/Timing Event Definition screen provides names and productivity options. Anywhere the text drawn in the Capture Layer is encountered in the drawing, the equipment will be delayed by the Event Delay Length in shifts. The Productivity Effect is the result of the delay. Not working is where the equipment is completely down. Working is no change, and Not Producing is where the equipment is in use, but no quantities are being mined. There is also an option to apply a delay only for additional units which are specified above.

 
A report shows the amount added by unit.


This report can be saved as Excel file or can be exported to MS Project (csv) file for the further analysis.


Report Options. Each item on the dialog box is defined below.

Multi-Bench Mining Example Setup:
The defining of equipment, crews and equipment calendar are (potentially) one-time operations. Similarly, the making of the "Pre-Calc Grids" geologic model need be done only once in advance of numerous timing runs. Surface Equipment Timing, also distinct from Surface Production Timing, allows multi-bench mining by use of different equipment or the same equipment mining different benches, with different production rates. Since single-bench mining is a subset of multi-bench mining, this will illustrate the command with a multi-bench example. Surface Mine Reserves is one of three methods to place quantity and quality information into the pits, by bench. This example will use Surface Mine Reserves. If there are two benches,  Surface Mine Reserves must be run twice, one time for each bench. The dialog within Surface Mine Reserves should be completed as follows for Bench 1:

The key is to choose "Selected" strata (for benching) as well as "Use Named Pit Areas" and "Store Results in Pits". You should also select "Calculate Strata Qualities" to assign quality information to the pits. If single-bench mining is conducted, you may omit the "Selected" option. Other items in the dialog are set according to user preference. Note the option "Output Thickness Grids". If this is not selected, total quantity and composited quality information is placed in the pits, and mining across a single pit is proportional. However, if the "Make Thickness Grids" option is selected, mining across the pits picks up the varying of the overburden thickness, coal thickness and quality information. For small pits or "blocks" as they are sometimes called, storage of total information will still lead to reliable results. Thickness grids are recommended for large and long pits, where the thickness will vary. The choice of "Selected" strata requires that the user select which strata will be mined in Bench 1. The following Choose Strata dialog at will appear:

Holding the CTRL or SHIFT key down, will select Overburden and C1 to mine down to the bottom of the first coal (C1). Bench 2 would be comprised of Parting and C2. Following two runs of Surface Mine Reserves, new information has been added to the pits. Pits contain up to three categories of information: pit name (verified by using "Identify Pit Polylines"), pit direction and pit quantities/qualities organized by bench. Pit quantities and qualities are needed only for Surface Equipment Timing, and can be verified using the command "Edit Pit". For example, the information in Edit Pit is shown below. Select the "Attribute" option to reveal the quality attributes.



You will note that Bench 2 has Bench 1 (referred to as TOPO-A-1-B1) as a "precedence" bench. In other words, you cannot mine Bench 2 unless you first mine Bench 1. Lower benches are automatically set to require prior mining of upper benches (The ordering of the mining comes later!). The Pit Attributes show any attributes set by Define Pit Attributes. Some may be seen here.

Assuming that a calendar has been established (multiple calendars can be saved and recalled), and assuming that equipment has been defined, we are now ready for Surface Equipment Timing. After selecting OK on the Mining Project screen, this is how the dialog appears prior to making any selections.
The first step is to "Add Equipment". In our two-bench mine, we will use one piece of equipment for the upper bench (overburden) and different piece of equipment for the lower bench (parting). Technically, separate equipment would probably be used to remove the coal, but in this example, the coal is not included in the schedule quantities, just uncovered reporting. In fact, a 4-bench mine could be set up that considers each of the two coal seams as separate benches. In reality, however, the overburden and parting removal rate will typically govern the overall progress of the mining in this example. When "Add Unit" is selected, the following dialog appears.

Select the equipment and add them one at a time. The equipmet used here are defined based on two, 12 hour shifts. The "Availability" option can be used to de-rate the mining speed in the Edit Equipment. Any of the above items can be revised from within Surface Equipment Timing. The next step is to assign "Prestrip Fleet" to Bench 1. It is best to Sort by "Bench, Pit" and then Select "Bench 1", using the options at middle right in the Surface Timing Dialog. These leads to the following appearance:

It is also important to note the option "Skip Coal for timing" at the lower right of the dialog box. Here you can base all progress on the NonKey overburden and parting only, on the assumption that the loaders or other equipment digging the coal will "keep pace" with the equipment removing the overburden and interburden. If "Skip Coal for timing" is not selected, the coal volume will be included in the total quantity mined by the equipment. We can add a second piece of equipment, then highlight it within the Surface Timing dialog and assign all the remaining pits and benches to it (Select All or by bench number, then Assign). Note also that we can add a delay between completing the Bench 1 pit and beginning the Bench 2 pit. Delays are automatically inserted below the highlighted pit, so if a pit is highlighted, a delay will be added below it that can be moved up or down also. There is a prompt to add this as a calendar or schedule delay (described above).  Shown below is the assignment for the additional benches.

To complete the calculation, fill in the Starting Date (if the default is not correct), then click on Calculate. This leads to a completion date and the option of a unit report or going directly to the Report Options screen. The Unit Report is very instructive because it highlights when equipment has been idled. Our Bench2 equipment is waiting each time for the "slower" Bench1 unit to complete bench 1 before it can launch into bench 2. The planner could try lower rated equipment, or reverse the assignments of the equipment, or simply re-shuffle the assignments in any desired manner to maximize efficiency. The last step is to choose "Report" when returned to the Surface Timing dialog which brings up the Report Options dialog.

This example will show the first days of months.  This leads to the final hatching shown below as bench 1(the bench 2 layers were frozen for better appearance), as well as the quantity report which can be formatted many different ways and exported to Excel or Access:

Notes and Comments on Equipment Timing:
Equipment Timing can mimic Surface Production Timing through selection of "Custom Amount Table" at the base of the Report Options dialog. This would be an alternative way of getting to custom table amounts, since the equipment is removed from the equation and is therefore irrelevant. This will target tons of coal, yet report out how many dragline hours need to be scheduled to uncover the coal.

If there are multiple seams (both Key and NonKey) assigned to one bench, the program will report a tonnage and volume factor that applies to each strata. This factor can be used in the User Attributes to calculate the tonnage and volume of each separate strata instead of just a composite number of Key and NonKey.

While Surface Production Timing reports total quantities broken out by seams or specific strata, Surface Equipment Timing only reports totals for all key strata (eg. coal) and overburden, unless Split Report by Strata Fractions is turned on. However, Surface Production Timing does report specific quantities (composited) for each bench. Therefore, a 2-bench mining example will report quantities for Bench 1 (coal C1) and Bench 2 (coal C2). With sufficient benching, the individual strata quantities are retained. For one-bench mining, all multiple strata are composited in the final report.

To practice "what-if" scenarios, use "Undo Report" within the Surface Timing dialog, which will remove the colored hatching, allowing revision of equipment assignments and another practice run.

Prompts
Select all pit polylines.
Select objects: Pick all polylines

Pull-Down Menu Location: Surface Mining menu, under Surface
Keyboard Command: timepit
Related Commands: Surface Mine Reserves, Assign Directions, Surface Project Manager, Assign Timing Grids, Import Timing Data, Define Pit Attributes