Submarines vs Surface Ships: A Comparative Analysis for Commercial Transport

While submarines have been employed in various specialized roles, their utility when compared to surface ships for commercial transport remains highly discussed. This article explores why submarines are not typically used for this purpose, focusing on factors such as capacity, cost, and operational logistics.

The Role of Aircraft Carriers

Aircraft carriers, a quintessential surface ship, play a significant role in modern naval strategy, particularly in terms of diplomacy and projection of naval power. Unlike submarines, aircraft carriers are highly visible, serving as a manifestation of a nation's willingness and capability to engage in overseas operations. They also serve as floating airbases, enabling the deployment of fighter jets, attack helicopters, and other assets.

It is crucial to understand that the primary function of aircraft carriers involves providing a powerful and mobile logistical platform that can be easily detected by adversaries. This transparency enhances communication and diplomatic relations, ensuring that allies and adversaries alike are fully aware of a nation's intentions and capabilities.

The Challenges of Submarines for Commercial Transport

Submarines, while highly versatile in certain naval operations, face significant limitations when it comes to commercial transport. The primary obstacles include limited tonnage capacity, cost, and the practical logistical challenges associated with loading and unloading cargo.

Limited Tonnage Capacity

One of the fundamental limitations of submarines is their tonnage capacity. Unlike surface ships, which have large open decks and suitable cargo holds, submarines are designed to carry a much smaller amount of cargo. They are constrained by their hull design, which must balance the needs of crew, equipment, and missile systems with cargo space.

The main displacement of a submarine is determined by the volume of water it displaces when on the surface or submerged. Any additional weight, such as cargo, would cause the submarine to sink, necessitating additional buoyancy to maintain its desired depth. This makes it impractical to transport significant amounts of cargo without significantly altering the design of the submarine, potentially turning it into a surface ship.

High Costs and Operational Logistics

Another significant factor is the cost associated with submarines. A nuclear submarine can cost upwards of one or two billion dollars, whereas a modern container ship generally costs in the range of tens of millions. This cost difference is a major barrier to the use of nuclear submarines for commercial transport. Additionally, the operational and maintenance costs of submarines are considerably higher due to the complexity of their design and the need for specialized crews and facilities.

Furthermore, the logistical challenges associated with loading and unloading cargo on a submarine are considerable. Submarines have limited cargo holds and must adhere to strict buoyancy and balance requirements, making the process of receiving and discharging cargo both time-consuming and logistically complex. In contrast, container ships are optimized for quick and efficient cargo handling, making them far more practical for commercial transport.

Historical Context

There have been a few limited examples of cargo-carrying submarines, such as those used by Germany during World War I and by several nations during and after World War II. These ships were often specialized for specific missions, such as breaking blockades or providing resupply during sieges, and were not designed for extensive commercial transport. Even in these cases, the purpose was driven by extreme necessity and not practicality in the contemporary context.

An infamous example is the effort to resupply Malta during World War II, where submarines played a crucial role in maintaining supply lines under dire circumstances. However, these operations were the exception rather than the norm and were developed as a response to exceptional conditions, not as a standard practice.

Conclusion

In summary, while submarines offer unique advantages in certain naval operations, their suitability for commercial transport is limited. The combination of limited tonnage capacity and high operational costs makes them impractical for widespread use in commercial transport. Traditional surface ships, such as container ships and bulk carriers, remain the most cost-effective and efficient solutions for global trade and transportation.

Given the advancements in modern container shipping, it is unlikely that submarines will replace surface ships for commercial transport in the foreseeable future. However, advancements in technology may open up new possibilities in the future, potentially leading to hybrid or specialized submarine solutions.