DICK DURHAM
Motor-sailing
Sail-cloth and engines have never really been great bedfellows. With headsails furled, and the main sheeted amidships, you can gripe to windward to save that pint, thanks to your ‘auxiliary’, but you are luffing yourself into a false sense of ‘sailing’. Engines themselves, functionally square, squat uncomfortably in the functionally curved lines of a sailing hull. They sweat and rust in the salt air, they choke on the bug which thrives between water and fuel, and their pretty factory paint blisters off after one season. Perversely the bug itself has been created by industry efforts to make diesel-burning more ecologically acceptable by adding ‘bio-fuel’. It’s a bit like an impatient gardener trying to torch his cuttings while they’re still too green, creating more smoke than heat.
These thoughts ran through my mind this spring as I prepared my 25ft pitch-pine planked cutter for the season. As the east wind sucked the salt from her bilge, and the May sun started to shrink her timbers, the only thing holding up my launch was a new prop shaft. Some said it was due to a Brexit hangover, others that ‘it’s always busy at this time of year’, but whatever the reason my shaft was late. The irony of it: a sailing boat falling apart because of an engine!
When the shaft finally turned up, I hurtled along the A12 to Clacton-on-sea, Essex with the old one, its folding propeller resting on the boot shelf.
At Bruntons’ factory, established in 1868, I met the very helpful and enormously knowledgeable products manager, David Sheppard, who politely explained that my idea of removing my varifold prop with a blowtorch and a club hammer and sticking it on the other end of my worn prop shaft, was the kind of engineering that belonged to the era of a blacksmith in a Thomas Hardy novel. The fact my prop had 10 different working parts and was custom made, as are most of the company’s wares, had not dawned on me until I watched it being removed.
David gave me a tour of the factory while my prop was being fitted to the new shaft. He talked of thrust, vibration and controlling pitch, of manganese bronze, nickel aluminium, and stainless steel, and that the biggest prop they make is a whopping 45-inch four-blader. We walked past pallets loaded with golden, glowing bosses, huge tarantula-like props, and glistening silver shafts. David talked about the ‘singing prop’: how a prop hums like a wine glass wiped with a claret-dipped finger and how all propeller makers strive to eradicate such unwanted submarine crooning.
He talked of reducing RPM to make fuel systems more efficient and how all French Customs craft are fitted with his company’s props; how the Oyster and Kraken range of large ocean-going yachts, to name but two, are fitted with the company’s Sigma drive, which was adopted from the Italian train system, which allows engines to be less rigidly mounted.
And then he spoke about the coming generation of electric engines, how hybrid eco-style electric drive systems are reducing fuel consumption. There are such systems still on trial: at present catamarans are the most suitable craft because they sail faster and ‘regeneration is the key’ to such hybrids. One Dutch circumnavigator used a 10kw system on each float of his multihull giving him 23 HP which was used ‘just to get in and out of port’.
Some yachtsmen are beginning to have their diesel engines removed in order to have such systems fitted.
‘Not long ago we received one or two enquiries a year about electric drives,’ said David, ‘now it’s every month.’
Perhaps sail-cloth and electric engines will be the bedfellows of the future. Whether they sleep more easily than Dacron and diesel remains to be seen.
Bruntons used to receive two enquiries a year about electric drives, now it’s every month