Step 3. The Mechanical Equipment Calculator

In this step, you'll estimate how much of the spilled oil you could skim off the sea surface during the time remaining before the oil is predicted to reach the sensitive site. You have on hand a single, small skimmer vessel, a Sandpiper (skimmers are boats and other devices that can remove oil from the sea surface before it reaches sensitive areas along a coastline). Here's how to use the Calculator to make the necessary calculations:

1. Create and name a new scenario. To do this, click New Scenario, type in the name of your scenario, then click OK.

2. Assign the Sandpiper platform to your scenario. To do this, click Go to Platform, click on the Sandpiper in the list of skimmers, then click OK. You will see information about the characteristics of the Sandpiper. Next, click Scenario Assignments, click on the name of your scenario, click >>Move>>, then click OK.

The Calculator shows you information about the Sandpiper obtained from the manufacturer or estimated by oil spill response experts, including its Service Type (the mechanism it uses to skim oil) and Operating Environment (the environment it is designed to function in). Note in particular the Nameplate Pump Rate, shown in the lower left corner of the window. This is the maximum rate at which the Sandpiper can skim fluid from the water surface, under ideal conditions (in real life, consider reducing this value if you are attempting a skimming operation in rough seas). When using the Calculator for a real response, adjust Offload, Transit, and Utilization Times to match your situation. These are the times taken (a) to offload collected fluids from the skimmer and (b) to complete a one-way transit to the transfer point, and (c) the time available to collect and recover fluids, transit to and from backup storage, and offload recovered fluids. For more details about the information you see on your screen, click ?.

Change Utilization Time to 10 hours, since you have an estimated 10 hours before the oil slick reaches the sensitive site.

Graphic: Program window snapshot

3. Return to your scenario: from the Scenario menu, choose the name of your scenario, then click Go to Scenario.

The Calculator will add the Sandpiper to its list of skimmers used for this scenario, and its UT, Utilization Time.

4. Fill out the boxes in the Calculator to describe your spill scenario, as shown below.

Graphic: Program window snapshot


5. Click Calculate. The Calculator will use the information you entered to predict

(Cost per Barrel [Cost/bbl], the cost in U.S. dollars per recovered barrel of oil, would be estimated if you had entered the hourly cost of operating the Sandpiper.)

Questions

  1. About how much oil could the Sandpiper recover during the operational period? ____ barrels
  2. What percentage of the total volume of the slick is this? ___%
  3. Is skimming with the Sandpiper a realistic option, given the time you have available?
  4. The Sandpiper is a relatively small skimmer. What if you also had available the ACRU2, a larger skimmer? (the ACRU2 is the name of a particular skimmer in the Recovery 1 class). How much oil could the two platforms recover during the operational period? ____ barrels (Hints: (a) be sure to reduce the Utilization Time for this skimmer to 10 hours, and (b) once you've added this platform to your scenario, press Calculate again.)
  5. About what percentage of that oil would be skimmed by the ACRU2? ___ %

 Check Your Answers


Scenario | Step 1 | Step 2 | Step 3

Revised: April 16, 2001
Office of Response and Restoration, National Ocean Service, National Oceanic and Atmospheric Administration