ENGINE REVOLUTION
– a century of the internal combustion engine at sea - where to next?

Early days
At the beginning of the 20th century the internal combustion engine was in its infancy and nobody, apart from a few visionaries, could have anticipated the revolutionary effect that it would have on the whole of the marine industry.
In 1876 a 44 year old German engineer, Nikolas August Otto, invented the internal combustion engine through a sequence of operations referred to as the ‘OTTOCYCLE’. Twenty one years later Rudolf Christian Karl Diesel, a fellow German, demonstrated the first ‘compression ignition engine’ which he proved to be twice as efficient as steam.
It would have been unimaginable, even to the visionary, that ocean liners and warships, the great strongholds of the steam engine, could ever be propelled around the world by ‘Diesel’ engines; but it happened.
End of the steam era
For the wealthy and more leisured classes, large yachts abandoned the use of expensive, ungainly and slower steam for the comparative compactness, safety and simplicity of the diesel. Press the button and, hopefully, it would start; keep it topped up with fuel and you could run it all day and all night - and you only needed one member of the crew to make it go. No more stokers, no more coal, no more smuts and smoke from the funnel, no more large areas dedicated to steam which always offered the threat of blowing up.
In 1913 Camper Nicholson broke the mould by building the 149ft. ‘Pioneer’ and installing a pair of 250BHP Polar Diesel engines.
It was the start of a new era where designers could move the engines out of the way to the stern, so they didn’t interfere with the cabins or the saloon, and where they could also accommodate, in the engine room, a generator to assure an adequate domestic power supply. And the boatbuilders needed only supply one set of beds per engine and then concentrate on the far more lucrative business of fitting out bigger and more luxurious accommodation.
Yachts and small craft
At the other end of the boating world the petrol engine would reign supreme. Small cast iron masterpieces with heavy flywheels to make them run as smooth as butter. The Stuart Turner (most popular ever two-stroke auxiliary), the four-stroke Albin or Thornycroft’s heavyweight, ‘Handy Billy’, would become some of the workhorses of the inshore fisherman and many a shipyard would use them to power their workboats.
But of far greater importance to the longer term prospects of boatbuilding was the effect that these small, affordable marine petrol engines would have on the leisure craft market and the vital role they played in an attempt to bring small boat cruising to the masses. Further up the market four-stroke petrol engines found their place either as ‘marinised’ or specialist marine versions of automobile engines.
Petrol engines eventually lost favour because of the flammable nature of the fuel and the susceptibility of electrical circuits to salt water but, if intelligently and properly fitted and maintained, their reliability can be equal to a diesel and, if handled with due respect, the fire risk should not be over emphasised. Considerations of weight and cost still make them worthy candidates for small yachts particularly as outboards and to power high speed, smaller motor boats. Outboards particularly benefit from a good power/weight ratio which gives them portability, easy installation, small space requirement and enables them to be tilted for the shallows.
New generation diesels
On the other hand diesels were heavy, smelly, full of vibration and expensive and World War II had left the industry desperately short of materials with a lot of inferior quality African mahogany being grabbed by many boatbuilders faced with few alternatives... that was until we got to the fifties when two major developments would revolutionise the small craft scene. The advent of the small, high-speed, marine diesel engine coinciding with the introduction of GRP and ‘production line’ manufacturing can be seen as the revolution that reincarnated the small boat industry.
This new generation of small diesels emerged as beasts of a very different colour with better power/weight ratio and the ability to start ... “even when wet”. With the technical and marketing expertise of such manufacturers as Volvo Penta, Gardner, Kelvin and Perkins, the small marine diesel became clean and desirable.
Over the last twenty years Japanese manufacturers have grabbed the market by the throat and developed highly sophisticated, lighter weight, smoother and less expensive small engines which today dominate the small diesel market and rightly so.
The gains that we have made are freedom and flexibility for designers, reliability and lower costs for owners and an unprecedented expansion in the market for the boatbuilder not forgetting the invention of the modern marina.
That magic combination of small, high-speed, reliable ‘clean diesel’ engines and shiny, low maintenance GRP also led to the creation of today’s ‘weekend sailor’.
Step aboard and go..
The vast majority of those who put to sea these days can be properly described as ‘weekend sailors’.
He/she expects to step on board without getting the ‘Docksiders’ wet, ‘drive’ a boat (packed full of ‘goodies’ such as a refrigerator, TV, electric lighting, showers, air conditioning, fully kitted galley, electric winches, bow thrusters and enough electronic navigation equipment to make NASA jealous) with power to spare probably against the tide and wind. The pressures of ‘modern living’ mean getting out on a Friday evening and being back on Sunday ready for the office on Monday morning.
The combination of that engine, that material and the enormous expansion of marinas (which is a direct result) can make all this possible and if the English weather forgets the plot then we can stay on the pontoon and enjoy the surrounding facilities and amenities.
This culture benefits the small craft industry right down the line from designers, builders and marina owners to chandlers, marine engineers, sail and rigging makers, insurance companies, banks and finance houses and, of course, yacht brokers and small craft surveyors.
And the whole industry of charter and flotilla holidays is built solely on this mindset.
Internal combustion reigns supreme
By the end of the twentieth century the internal combustion engine had taken over the world and, with it, the marine industry. Now we must look for alternatives that will benefit future generations.
Sadly, our long love affair with the piston driven internal combustion engine must go into decline because it is not an efficient mechanism. It does not achieve complete combustion and therefore expels polutants. It burns fossil fuels thereby creating nitrogen oxides, carbon monoxide and carbon dioxide all of which seemingly add to the greenhouse effect. It is smelly, noisy, vibrates and, with a multitude of metal-to-metal parts, is inherently unreliable and wears out.
And, if we want to bang a final nail into the coffin, the internal combustion engine that we are likely to have fitted in our next floating dream (assuming it to be in perfect tune and condition) will only transfer about a third of the available energy in the fuel into useful thrust from the propeller.
So to suggest that heavy, longer term R&D investment should be put into the internal combustion engine, particularly piston driven machinery, for the benefit of future generations would seem to be foolishness in the extreme. In the short term ‘next generation clean diesel engines’ is a worthwhile attempt but in reality it is only smoothing the path towards the day when this century old technology draws its pension.
We need the next breakthrough in motive power. Just as Nikolas Otto and Rudolf Diesel revolutionised engine design and thinking at the turn of the last century, we too need some radical thought backed by strong R&D and a willingness for the application.
One thing is certain - the next generation is going to demand a ‘greener’ solution than the internal combustion engine will be able to supply. It’s time for the engineers to get back to the drawing board.
Roger Josty (May, 2005)