Empathic Design
Brace yourself it’s going to be long. But It’s worth a read!
This is a story of how bad the design caused a ship’s crew to lose control of the vessel, costing the life of ten people onboard and 100million.
” In the early hours of Aug. 21, 2017, McCain was 20 miles from Singapore, navigating one of the world’s busiest shipping lanes. Captian Sanchez was on the bridge to assist in the complex maneuvers ahead. He ordered sailor Bordeaux to take over steering the warship while another sailor controlled its speed.
The idea was to avoid distractions by having each man focus on a single task in the heavy maritime traffic.To check that he had control, Bordeaux tugged the ship’s wheel slightly to the left. The McCain did not alter its course. Bordeaux rotated it slightly to starboard. Again, the McCain maintained its track. Bordeaux suddenly realized that the McCain was steaming uncontrolled toward the cargo ships sailing through the Singapore Strait.
“Loss of steering!,” he called out.
The McCain began to turn mysteriously to the left, slowly at first, and then faster. The ship drew closer and closer to the vessels plying the strait. Three minutes and 19 seconds after Bordeaux’s cry, the McCain collided violently with a 30,000-ton Liberian-flagged oil tanker. Ten Navy sailors were killed and scores more were injured. It was the Navy’s worst accident at sea in 40 years.
Navy blames the crew for the incident. “
What happened exactly, why the ship did not alter its course? Why the sailor call out Loss of Steering?
First lets understand the fundamentals To operate a ship you control the speed by throttle and direction by rudder. For propulsion, the ship has two main shafts connected to propellers.
The two shafts can operate independently, moving at different speeds if needed for sailing or maneuvering. The Ship’s controls are a digital system with touchscreens.
The image below is what the digital controls for the ship’s throttle looks like. The vertical sliders allow the user to drag the throttle up and down to increase or decrease speed.
Sitting below these controls is the $100 million checkbox called a gang.
If the checkbox is checked the controls for the right and left propellers are connected, so both sides of the speed will be the same. When unchecked, you can move either slider without affecting the other.
So you can also run the propellers at different speeds, if the gang is unchecked. If the right propeller spins faster than the left, the boat will turn left. If the left propeller spins faster than the right, the boat turns right
Where everything went wrong?
When sailor Bordeaux was trying to test the steering from console, it was not working because steering was not assigned to him and he was not aware of the information.
When transferring the speed control to the sailor Mitchell the gang checkbox got unchecked and the sailor was not aware.
Since it’s unganged only the left shaft was working, when sailor Mitchell reduce the speed only the left side got reduced and the ship was turning to sharp left.
However, the captain thought the steering was the problem and he checked the steering control, but it was in ZERO Position.
But the actually reason of ship turning to left is the speed difference on the two propellers. A slow speed on the left side and high speed on the right side, so the right side propeller turns the ship direction towards the left. Before realizing the fact, the ship went close to another oil ship and crashed on it.
Based on this incident I want to indicate the design flaws which cost 10 sailors life and 100million dollars.
- Information about the ownership of the control should be emphasized rather than using it as a secondary information. Bordeaux should have understood that he does not own the steering control at the time testing. He should have not called it as “Loss of Steering” where the entire confusion begins.
- A single check box on a touchscreen is the heart of the whole incident.Which person in the universe use a checkbox on a touchscreen?
- Is that checkbox is the right interface to be indicate the both shaft’s are connected?
- When it is ganged there should be only one slider in the console rather than showing two sliders and moving it parallel. Show two sliders when it’s unganged. By doing this, Mitchell should have understood the shaft was not ganged, by looking at the console itself.
- When it’s unganged and sailor reduce the speed, there should be an indication that the ship direction is changing on this course of action. Consider direction is one of the most important action.
This incident clearly says, design in the touchscreen created the whole problem and users executed it very well.
Good design is not only about choosing the right interface. Designer should understand the user and their environment. By empathizing with the person using the interface, a designer can prevent errors, reduce cognitive strain, and help people recognize and recover from mistakes if they should happen.
Design plays critical roles in our everyday lives. Design responsibly and having the empathy in mind.
Read the whole story of the incident here :
