What goes up, must come down

This quilt shares the ship heave data experienced during our 49 days underway for Expedition 390.  Heave is the up-and-down (vertical) motion of the ship. The first day of data is in the upper-left corner, then moving across the top row to the right are for days 2-7. The start of the second row on the left side represents data from Day 8, then moving across to Day 14, and so on moving down the quilt. The color of the large rectangles represents the numerical value for the average heave that day, and the small colored stripe through the middle represents the maximum heave value for the same day. The small stripe is lowest in the rectangle when the maximum heave was recorded as 1 through 5 feet. The stripe is moved higher in the rectangle when the maximum heave was 6-10 feet, etc. The color scale is on the left side and repeated on the right side, with units in feet. Starting on the bottom, the gray represents one foot, the dark blue represents two feet, going up to 20 feet. There are three blanks in the color scale for 16, 18, and 19, as those values were never the result of an average heave calculation or recorded daily maximum value.

Quilt measures 41 inches wide by 51 inches tall and was completed July 1, 2023.

Hanging quilt with colorful rectangles

Quilt showing average and maximum daily ship heave values, from JOIDES Resolution during IODP Expedition 390

Out on the ocean, a ship experiences wind, currents, and wave action. These ocean and atmospheric dynamics will cause a ship to move in six different types of motions, including heave . This video from Nautilus Live defines and explains each of these motions (sway, surge, yaw, roll, pitch, and heave) and how they can influence a ship at sea. 

On JOIDES Resolution, the ship heave is recorded by three Motion Reference Units (MRUs). Two are located down by the moon pool, one is at the heave compensator.

Colorful rectangles in a hanging quilt

Section of upper-left corner of the quilt

Colorful rectangles in a hanging quilt

Average and maximum values, including the color representing the highest maximum heave value

Activity for classrooms

If you are a classroom teacher or informal educator, you can use this quilt as a starting point for a student investigation. See this resource document for ideas on how to have students work with ship heave data.

All ship heave values collected during Expedition 390 can be found in this Google Sheet.

Full quilt description (click to read)

Out on the ocean, a ship experiences wind, currents, and wave action. These ocean and atmospheric dynamics will cause a ship to move in six different types of motions – heave, sway, surge, yaw, roll, and pitch. This video from Nautilus Live defines and explains each of these motions and how they can influence a ship at sea. It is important for the crew on board JOIDES Resolution to understand and track this information, as the data determine ship safety and the ability to drill for deep-sea sediments and oceanic crust.

This quilt is a data visualization of the ship heave during Expedition 390. The heave of a ship is defined as the linear, up-and-down (vertical) motion of the ship due to swells and wave activity lifting and lowering the entire ship.

JOIDES Resolution has three motion reference units (MRUs) that measure the absolute motion of the ship, including the heave. Two MRUs are located down by the moon pool and one is at the heave compensator. The realtime ship heave values are important, as if there is too much vertical motion, then the driller or tool pusher makes the call to suspend drilling. The ship then enters a period of WOW – Waiting On Weather.

So how much heave is too much? JOIDES Resolution can still core on days when the heave is 15 feet or less (from JR Ship Brochure). The ship has a heave compensation system for coring and logging, which lessens the impact of ship motion from either the drill string or the wireline logging tools. A passive heave motion compensator is used for drilling. The top drive, which rotates the pipe and drill bit, is attached to the motion compensator. As the ship rises and falls with the waves and swell, pistons keep the drill bit on the bottom. During logging operations, compensation is provided by the wireline heave compensation (WHC) system. (*see YouTube video for demonstration)

This quilt shares the ship heave data experienced during our 49 days underway (not tied to the dock) for Expedition 390 as measured by the MRUs. The first day of data is in the upper-left corner, then moving across the top row to the right are for days 2-7. The start of the second row on the left side represents data from Day 8, then moving across to Day 14, and so on moving down the quilt.

The color of the large rectangles represents the numerical value for the average heave that day, and the small colored stripe through the middle represents the maximum heave value for the same day. The small stripe is lowest in the rectangle when the maximum heave was recorded as 1 through 5 feet. The stripe is moved higher in the rectangle when the maximum heave was 6-10 feet, and so on. The stripe is the highest when the maximum heave was recorded as 17 or 20 feet, the two highest values recorded by the MRU.

The color scale is on the left side and repeated on the right side, with units in feet. Starting on the bottom, the gray represents one foot, the dark blue represents two feet, going up to 20 feet. There are three blanks in the color scale for 16, 18, and 19, as those values were never the result of an average heave calculation or recorded daily maximum value.

The majority of the fabric for this quilt was purchased at Old Country Store Fabrics (Intercourse, PA). A 3 Cats Shweshwe fabric, a Da Gama Textile manufactured in South Africa, was used to mark the maximum recorded heave value of 20 feet, keeping with my intention to include a 3 Cats Shweshwe fabric in each Expedition 390 quilt. The long-arm quilting was completed by Old Country Store Fabrics. Quilt measures 53 inches tall by 42 inches wide and was completed on July 1, 2023.