Guns, missiles and stealth technology may be the headline makers of military prowess. But propulsion – and its associated power sources – has always been instrumental in giving the Royal Navy a tactical advantage on the water.
We take a look at a few of the most important historic transitions – from steam, coal and oil, to diesel and nuclear power.
Steam and sail
From the beginning of the 19th century, when sail power was the norm, the Royal Navy began developing steam-powered ships. As well as removing the need to harbour during adverse wind conditions, steam-powered vessels let the navy navigate the dangerous estuaries and other inshore areas that had long been difficult with sails alone.
In response to the threat of France’s steam-based Napoleonic ships, the Royal Navy developed its first dedicated steam-powered vessel, the HMS Agamemnon. Capable of speeds of around 11 knots (or just under 13mph), steam ships gave the Royal Navy a clear advantage in terms of manoeuvrability during times of low wind when compared to their sail-based counterparts.
Oil and the First World War
In the early years of the 20th century, coal was still the primary source of power for naval vessels. In fact, Welsh coal was the top choice for fleets all across the globe. But it was also a logistical nightmare – moving hundreds of tonnes of coal from shore to ship was a dangerous and exhausting exercise. And refuelling at sea was near impossible.
But in the years leading up to the First World War, Winston Churchill, supported by Admiral John Fisher, began the transition towards oil as a fuel source.
Oil contains as much as 40% more energy when compared to the same volume of coal, so oil-powered naval vessels could be built smaller, lighter and faster. And with considerably less smoke produced from oil than from coal, British ships were able to go undetected by the enemy for longer.
Most importantly, oil-powered ships were able to attain top speeds that allowed them to outmanoeuvre the German fleet of that time. Experts predicted that a speed of 25 knots (29mph) was required to give British ships the advantage, which was 4 knots faster than what was possible using traditional, coal-powered vessels.
The switch to oil power helped create a swift and responsive British fleet, which may have led to a number of triumphs over its German adversaries.
The modern age
As you might expect, technology has come a long way in the last hundred years. With new sources of fuel come major increases in power, speed and energy efficiency. A Type 23 Frigate, for example, can travel over 9,000 miles in 30 days on just 600 tonnes of diesel.
And, following the Second World War, the advent of nuclear power allowed some submarines to run for up to 20 years without needing to refuel. The Royal Navy’s nuclear-powered Astute Class submarine is capable of submerged speeds of up to 30 knots (35 mph), despite its massive weight of roughly 7,000 tonnes fully loaded – that’s as much as the metal structure of the Eiffel Tower.
As the demands for naval technology grow, so do the Royal Navy’s feats of engineering.