FreightWaves Classics: Malcom McDowell’s containership begins first journey in 1956

Malcom McLean in the foreground with a Sea-Land container behind him. (Photo: Maersk)

On this date in 1956 the first commercially successful container ship began its maiden voyage on a route from New Jersey to Texas. The Ideal X and its 58 intermodal containers began a revolution in shipping that is still echoing around the world today.


A McLean Trucking Company patch. (Photo: NC Historic Sites)
A McLean Trucking Company patch. (Photo: NC Historic Sites)

Malcom P. McLean recognized the potential to haul motor freight when he was just a teenager. The native of Maxton, North Carolina, purchased his first truck in 1934 and began hauling dirt for the federal Works Progress Administration’s road construction projects. Later, he transported tobacco, textiles and other goods in his McLean Trucking Company trucks. By the mid-1960s, his company had become the fifth-largest trucking company in the United States, with a fleet of 5,000 trucks and trailers and 65 terminals scattered across 20 states. McLean’s Winston-Salem terminal was the world’s largest when it was built in 1954. He sold his trucking company in 1955 for $6 million. 

If he had done nothing else in his life Malcom McLean would have been considered successful. But luckily, he had other plans.

Containers and container ships

The Ideal X began its career as a World War II oil tanker that had been named the SS Potrero Hills. The ship was built in the early 1940s. After World War II the Potrero Hills was purchased by Malcom McLean. It was the first ship in what became his Sea-Land fleet.  

Malcom McLean. (Photo: PBS)
Malcom McLean.
(Photo: PBS)

McLean realized the potential of containerization, particularly in terms of loading and unloading time and costs. He had delivered cotton bales from North Carolina to New York Harbor in 1937, and had waited several days while longshoremen manually loaded the cargo on a ship. The time and cost to load standard break bulk cargo was a barrier to cost-effective trade and shipping. In 1956 McLean calculated that loading a medium-sized ship the conventional way cost $5.83 per ton. Comparatively, loading containers on a ship the size of the Ideal X cost less than $0.16 per ton! 

McLean’s original goal was to create an integrated transport system along the Eastern Seaboard in which coastal shipping would complement road and rail transportation. However, the goal was difficult to achieve because each mode of transport was segmented. Also, the continued construction of the Interstate Highway System (IHS) during the 1960s improved trucking efficiency. 

But McLean pioneered the use of shipping containers that were of a uniform size and could be used on multiple modes of transportation – from ships to railroads to trucks. McLean owned the Pan-Atlantic Steamship Company (later Sea-Land) and the Potrero Hills was modified in 1955 to carry McLean’s new shipping containers on its decks. Engineers reinforced the flat upper deck and added specially designed grooves to accept the aluminum containers. The Potrero Hills was renamed the Ideal X. (For more information on McLean, his career and the containers he popularized, see this earlier FreightWaves Classics article.)

The Ideal X. (Photo:
The Ideal X. (Photo:

The first voyage of the Ideal X

However, the Ideal X was not the first container ship. The Clifford J. Rodgers, operated by the White Pass and Yukon Route, had made its debut in 1955. Nonetheless, the Ideal X is the ship that proved the concept of container shipping.

On this day in 1956, the Ideal X left Port Newark, New Jersey with its regular load of 15,000 tons of bulk petroleum on board bound for Houston, Texas. The Ideal X also carried 58 containers that were 35-feet long, 8-feet wide by 8-feet high. The containers were loaded on board the ship in less than eight hours. The containers were 35-feet long because that was the standard truck size in the United States at that time. Construction on the first sections of the IHS had just recently begun; there were very few highways and the turn radius on standard roads did not allow for longer trailers.

The five-day trip was incident-free; the Ideal X made its way down the eastern seaboard, into the Gulf of Mexico and then on to Houston. When the 58 containers were off-loaded at the Port of Houston, there were 58 trucks  waiting to transport them. There were also five containers waiting to be taken back to New Jersey.

What success meant

Based on the voyage of the Ideal X, McLean expanded his business and launched a new method of transporting cargo via ship (and later by truck and rail). Ports began to invest in bigger cranes and improved their infrastructures to handle new containerships that came online. 

While break bulk cargo of different sorts is still transported, a very large percentage of the world’s cargo is now transported in containers that are upgrades of McLean’s early versions.

Standardized container sizes and features followed over the next few years; soon ships built to carry hundreds (and now thousands) of containers were built and sail all of the world’s oceans and trade routes. In addition, railcars built to carry containers (and then double-decked containers) came along, as did specialized truck trailers. 

Homage to Malcom McLean. (Image: American Maritime Heroes)
Homage to Malcom McLean. (Image: American Maritime Heroes)


Malcom McLean is widely hailed for his trailblazing role in the use of containers. Before McLean popularized shipping containers, all goods were manually loaded into sacks, barrels and/or wooden crates loaded directly onto/into cargo vessels as break-bulk shipping. Prior to McLean’s introduction of containers, it could take as long as three weeks to unload and load each ship.  By comparison today’s massive containerships can be unloaded and loaded within 24 hours.

In addition, using shipping containers allowed cargo to be transported and transferred between road, rail and sea.

McLean’s Sea-Land Corporation grew very quickly after he proved the worth of container shipping. He sold his portion of the company in 1969 for $160 million. SeaLand is now part of Maersk, the largest container shipping line in the world.

McLean died in 2001 at the age of 87. He is considered one of the most important figures in transportation history.

However, the Ideal X did not “live happily ever after.” The ship was purchased by a Bulgarian shipping company in 1959 and sailed for another five years under the name Elemir. In 1964 the ship suffered severe damage in a storm and was sold for scrap later that year. 

Another tribute to Malcom McLean. (Image:
Another tribute to Malcom McLean. (Image:

The impact of shipping containers on global trade

In 1968 the International Standards Organisation standardized the shipping container to the dimensions of 20-feet long, 8-feet high and 8-feet wide. (There are now 40-foot, 45-foot and 53-foot containers as well.) Ships were completely redesigned around the dimensions of the containers they were destined to carry. Shipping costs plummeted, which led to the manufacture of goods in other nations and on other continents that were then shipped via containers to their destinations. Since then, ports, rail networks, ships, trucks and other equipment have been redesigned to more effectively and efficiently move containers.

According to The Economist, “the shipping container has been more of a driver of globalization than all trade agreements in the past 50 years together.”

Container ships constructed within the past few years are capable of carrying over 20,000 TEU (Twenty-Foot Equivalent Units) shipping containers (and more). Currently there are over 20 million shipping containers traveling among countries all over the world. Experts gauge that over 90% of items purchased globally were transported inside a shipping container.

That is the shared legacy of Malcom McLean and the Ideal X.

Author’s note: FreightWaves will be honoring Malcom McLean in the near future. 

A Maersk container ship entering Port of Los Angeles. (Photo: Port of Los Angeles)
A Maersk container ship entering Port of Los Angeles. (Photo: Port of Los Angeles)

Source: freightwaves - FreightWaves Classics: Malcom McDowell’s containership begins first journey in 1956
Editor: Scott Mall