Picture this…
You’ve been wanting to visit Palawan for some time now. Convenience and budget are of utmost concern, so you book the cheapest travel option with a trip just over an hour long and with a short wait time. After arriving at Manila Harbor, you spot the watercraft docked on the edge. But the vehicle that is mooring is not like any ship you have ever seen before: sleeker, more modern, and are those jet engines? You board it and observe from a wide window the beautiful Manila Bay, abounding with all its cargo ships, yachts, and ferries. The transport you have gone on starts its engines and sails out after being towed out. However, as it lurches forward, it starts to get faster and faster, becoming swifter than first that of a regular ferry, and then a jetski, all the while nervousness creeps in. As your heart races, so does the ship, increasing its speed to almost unnatural levels. You think a fiery and watery collision with the seawater’s surface awaits you. However, the only thing that does is silence, and you start to not hear the sound of waves crashing against a hull. You look out and see the boat skimming over the water level. You are taking a ride on an ekranoplan.
Ekranoplans, also known as ground-effect vehicles (GEVs), seem to be a mix between a boat and a plane, combining the waterborne nature of a boat with the speed of an airplane. This is reflected in its design, with both a hydrodynamic and aerodynamic hull and large wings. As it speeds up, it transforms from a motor yacht to a jet plane as it lifts its body out of the water and races barely above the surface. These vessels are not small, in fact, they can get huge. The Soviets created an ekranoplan, called the KM but better known as “The Caspian Sea Monster” after the lake it operated in. At the time the largest and heaviest craft in the world, it had a weight when empty of 240,000 kg, full weight of 544,000 kg, and was longer than a Boeing 747 (Gunston, 1995; Komissarov, 2002). What is even more insane is that it was designed and built in the ’60s. But what’s behind the name “ground-effect vehicle” and what’s the point of designing one in the first place?
The key to answering those two questions lies in understanding a few important aerodynamics concepts. According to the FAA, drag is the force that goes against the direction of a craft in the air due to airflow disturbances caused by the aircraft itself. Drag is one of the main forces that must be overcome by the engines and is the reason why designers craft streamlined planes. One of the types of drag is called induced drag, which is drag caused by the wings in flight. Yet, when an aircraft flies just over a flat surface such as a body of water, the airflow which causes lift-induced drag is instead redirected to form a high-pressure area under the body of the aircraft. This is the ground effect and is the reason why pilots often experience a mysterious force resisting touchdown when flying low over the ocean, or upon landing on an airport runway. Nonetheless, one man’s inconvenience is another man’s boon, as with the lessening of drag comes a decrease in energy output required to generate lift and sustain flight, and as such, much greater fuel efficiency at high speeds. Massive ekranoplans such as the KM were made to utilize the ground effect to its fullest extent, with their large masses and wing areas able to compress more air and generate more lift and thrust. In fact, the name “ekranoplan” is the English transliteration of the Russian “экранопла́н”, meaning “screen plane” and derived from the Russian word for the ground effect.
The scenario described at the beginning of this article is not exactly a vision of the future of public transport in the Philippines, but it does give a good sense of what the ekranoplan experience would be like. Despite rough typhoons in the south and east and competition against budget airlines, our nation’s calm inter-island seas, flourishing tourism industry, and the ekranoplan’s ability to carry large loads demonstrate that the idea of them being used in operating domestic tourism routes is not entirely impossible. But beyond the viability of this option, what is most important is the exercise of thinking outside the box in a world of norms. Who knows, you just might be the one to devise the next ekranoplan.
Photo for reference
Reference:
Gunston, B. (1995). The Osprey Encyclopedia of Russian Aircraft, 1875-1995. Osprey.
Kommissarov, S. (2002). Russia’s Ekranoplans: The Caspian Sea Monster and other WIGE Craft. Midland Publishing Ltd.