At 10AM ET on March 30th, the US Navy’s gigantic floating hospital ship, the USNS Comfort, arrived in New York City where it has been sent to help relieve the pressure on the city’s hospitals that are overwhelmed with coronavirus patients.

The Comfort’s 1,000 beds and 12 operating rooms will largely be used for non-coronavirus patients, freeing up much-needed space at the city’s overtaxed hospitals. The ship is typically used to support military campaigns and humanitarian crises abroad, along with earthquake and hurricane relief. Most recently, it was deployed to Latin America, helping countries with inadequate health care systems. It was last stationed in New York City after the 9/11 terrorist attacks where it helped treat hundreds of first responders.

The ship has been around for over four decades and been deployed all around the world. Here is everything else you need to know about the USNS Comfort.

It’s a converted oil tanker. The ship didn’t start out as a hospital ship, but as a San Clemente-class oil supertanker called the SS Rose City. It was built by the National Steel and Shipbuilding Company in San Diego in 1976. The US Navy purchased it in 1987, along with another supertanker, with the goal of converting both into Mercy-class hospital ships. The Comfort’s sister ship, the USNS Mercy, is currently being deployed to the West Coast.

It’s a converted oil tanker, so moving patients around can prove difficult

But as a converted oil tanker, moving patients around can prove difficult. The bulkheads used to separate the oil weren’t removed during the retrofitting, nor were hatches added to improve horizontal movement through the ship. Most of the movement of patients from one area to another must be made by going up to the deck first and then back down.

Painted white with several prominent red crosses, the ship’s look is designed to illustrate its purpose and protect its crew and cargo against hostile attacks. The Geneva Convention protects hospital ships if they carry no munitions or weapons; any country that fires on one is charged with an international war crime.

Welcome to New York, @USNSComfort.



We knew from the outset that expanded hospital capacity was critical.



We asked and the federal government answered.



This ship is a step forward in our fight against Coronavirus. pic.twitter.com/r6Hj8NL9JH — Andrew Cuomo (@NYGovCuomo) March 30, 2020

Comfort is a big ship — like, really big. The ship is around 100 feet tall, which is the size of a 10-story building. It has a deep draft — it displaces 70,473 tons of water — and, in many ports, it has to stand at least a mile offshore. Over 894 feet long (272 meters), the Comfort is about the length of three football fields and can travel at a speed of 17.5 knots (20.1 mph).

To receive patients, the Comfort has a large helipad, with the capacity to land large, military-grade helicopters. The ship also has the ability to accept patients from other ships docked alongside. Comfort can be fully activated and crewed within five days.

the Comfort is about the length of three football fields

It can take a lot of patients. The Comfort has 1,000 beds, 500 of which are designated for minimal case needs, another 400 for intermediate cases, 20 for surgical recovery, and 80 for intensive care patients. Though the Comfort will be docked while in New York City, it was designed with a large rounded hull for improved stability for surgeries and other intensive procedures that needed to be performed at sea.

But there’s a lot more to the Comfort than just beds. According to MilitaryFactory.com (which uses female pronouns to describe the ship):

She is a complete medical facility that even includes a dental clinic, four x-ray machines and a CT scanner. A pair of oxygen-producing plants, an optometry lab and coolers to hold 5,000 units of blood are all part of her tool box. Comfort is a hospital that can sustain up to 2,000 people onboard, crew combined with patients, and supply much-needed water to both as she maintained a fresh water plant making up to 300,000 gallons of water a day. Other onboard services include a satellite lab and a central area for sterile causality receiving. A medical supply depot, along with a well-stocked pharmacy, are all included. Due to the nature of her work she has a large laundry operations and her own morgue.

Amazing video captured by @madnessnyc of USNS Comfort arriving in New York Harbor @NY1 pic.twitter.com/hvlrPGmVje — Amanda Farinacci (@amandafarinacci) March 30, 2020

The Comfort has been to war zones and disasters alike. The ship has been to Haiti at least twice in recent years: once in 1994 to help process migrants who wanted to escape the unrest and again in 2010 after a magnitude 7 earthquake laid waste to the nation’s capital of Port-au-Prince.

It has also been deployed to the Persian Gulf several times over the years. Stationed near Kuwait and Saudi Arabia in 1990, Comfort saw 8,700 patients, 2,100 helicopter landings, and 337 surgeries in its 12 operating rooms. It was also stationed there in 2002 during the US invasion of Iraq.

In addition to 9/11, the Comfort has been deployed in US waters to help respond to various disasters

In addition to 9/11, the Comfort has been deployed in US waters to help respond to various disasters. In 2005, the ship was sent to New Orleans and Mississippi after Hurricane Katrina devastated the region. The ship helped treat 2,000 patients during the seven weeks it was stationed in the Gulf of Mexico.

Before arriving today in New York City, the ship was undergoing maintenance in Norfolk, Virginia, which the Pentagon originally estimated would take weeks to complete. But the Navy, working with the Army Corps of Engineers and the State Department, got the job done in eight days, according to New York City Mayor Bill de Blasio.

The need for additional hospital capacity in New York City is enormous. In addition to the Comfort, the city is also building field hospitals at the Javits Center and in Central Park.