I captained a sea-faring ship like the Dali for 13 years. Here's a breakdown of what happens in a crisis like this.

A former ship captain steering large vessels describes the complicated process of port entry and exit and what happens in an emergency.

• Sachin Saxena is a former ship captain who spent 13 years navigating the globe on large ships. 
• He breaks down the processes of entering and exiting ports in big vehicles like the Dali.
• In emergencies like power failures, a ship can't just stop and there's a lot of pressure onboard. 

This as-told-to essay is based on a conversation with Sachin Saxena, a 45-year-old former ship captain from Singapore. It has been edited for length and clarity.

I captained ships transporting liquid petroleum gas from Asia to the United States for 13 years, from 1997 to 2010. Entering or leaving a port is one of the most challenging parts of any voyage. When you enter a port, you need to consider everything from currents to shallow patches and bridges.

When I saw the news about the MV Dali hitting the Francis Scott Key Bridge in Baltimore, I wasn't worried about the crew. I knew the crew would be safe because the ship was still floating. I was more concerned about people outside the ship.

Hitting a bridge would be a navigation team's worst nightmare. If the MV Dali's power had failed after the vessel had passed the bridge, I believe nothing would have happened.

It's not unusual for a ship to hit a bridge, but there are protocols to prevent it

It's not unusual for a ship to hit a bridge. Bridges are a real concern in the United States, which has so many sea bridges. Seeing the MV Dali incident, the crew couldn't do much as there was little distance between the vessel and the bridge and it was the result of a power failure.

When I was a captain and used to pass bridges, I would stand on the top of what sailors call "monkey island": a deck in front of the navigating bridge and the uppermost accessible part of the ship. I'd stand there to ensure we had clearance and everything went smoothly.

We used electronic charts to navigate in and out of ports, but I also used to double-check the calculations myself. The reason I would do this was because I used to sail on ships carrying liquid petroleum gas. If my ship ran into a bridge the entire city would be blown away, so the safety factor was very high.

The procedure when an incident like this happens

If my ship suddenly lost power, the first thing I'd do would be to drop the anchor. You don't need power to do this. However, anchors aren't always effective if the ship is moving fast. Each ship, whether a container ship, dry bulk, chemical, or LPG ship, will have an emergency generator. This will start about 45 seconds after the ship's power has failed.

This doesn't give you full steering, but it gives you emergency steering that you can use to get into clear water and anchor. It takes time to slow a ship down. If you're moving at five knots and put on the brake, it will slowly come down to 4.8 knots, 4.6 knots, and so on — It won't just stop. There isn't a single solution to such a situation. Each case is different.

There are several questions that an internal auditor would want the management of the ship to answer

After I stopped working as a captain, I became an internal auditor for a shipping company, where I carried out internal audits on health, safety, and environment on merchant ships going worldwide.

When you first hear that an incident like the Baltimore crash has occurred, there are several questions that, as an internal auditor, I'd want the management of the ship to answer. I'd want to know whether the bridge was mentioned in the passage plan meeting — a meeting before the voyage attended by the captain and senior officers from the navigation team and engineering. You also have another meeting about the next port while at the previous port and will discuss situations such as currents.

I'd also want to know what triggered this power failure. Has it happened before, and how often has the ship received maintenance?

There is something called the Planned Maintenance System. In the same way that a car manufacturer guides you on what you need to do to the car after 50,000 miles, every piece of equipment on the ship has a guideline on how it should be maintained. So, I'd want to check whether routine maintenance and long-term preventive maintenance guidelines were followed.

How a shipping company would manage a collision

In the event of an incident, the shipping company would establish an emergency control room at the company headquarters in their own country. It will be manned 24/7. They will have everything about the ship in that room, such as drawings of the vessel. The shipping company's staff will communicate with the ship and the agent on the ground who is nominated to speak on their behalf.

They will also take a look at the black box on the bridge, which contains the voice recordings of everything that was said on the bridge between crew members and what they said when speaking to the authorities or the engine room.

Sitting so far away from an event like this makes it easy to comment, but you think about the captain on that ship and what pressure they must be going through.

We cannot change what happened, but thousands of vessels trading worldwide can learn from this and become educated about what happened to ensure that such accidents do not happen again.