July/August 2020

36 n TRANSPORTATION July/August 2020 www.drivesncontrols.com Broads sailors are happy to touch electric propulsion with a barge pole S ailors on the Norfolk Broads have traditionally used long poles called quants to push traditional wooden sailboats when the winds are unfavourable, and to manoeuvre them through narrowwaters or under bridges. The Hunter’s Yard boating company runs a rental fleet of these vessels, but in recent years, it began to see a drop in business as older customers found the rigours of quanting increasingly difficult, and younger families with children wanted the convenience of motorised propulsion. It was clear that auxiliary motors would be needed, but it had to be done in a way that would not affect the boats’sailing characteristics or destroy their historical appearance. After considerable research, the boatyard installed a electric propulsion system on a trial boat. The package consists of a electric pod motor with a folding propeller, a pair of batteries, a fast charger, a shore power box and a combined controller and display system.“We refer to it as an ‘electric quant’,”says Philip Bray, secretary of the Hunter’s Trust, which owns and operates the fleet of sailboats. The task of fitting the electric propulsion systems to 80-year-old wooden boats presented challenges.“The boats were built to the unique Norfolk Broads pattern with flattish bottoms, a very shallow bilge, a long keel and a large oval rudder that swings through 360 degrees,”Bray explains.“In addition, they were built by eye by craftsmen without written plans or drawings, so the installations had to be very carefully thought out for placement of the internal components and connecting cables.” Facing resistance Initially, there was considerable resistance to the idea of retrofitting the historic vessels with electric motors.“Our boats are very traditional and our customers likewise, and when the idea was first made public at the annual general meeting of the Friends of the Hunter Fleet in April 2016, there was a great drawing of breath that nearly sucked the roof down,”Bray recalls. But it didn’t take long to change their minds. “Our customers obviously approve, because our bookings are increasing and the boats with engines are the first to be booked,”Bray reports. “There is a waiting list for them too.” The electric drive systems were supplied by a German company, Torqeedo, which specialises in electric mobility systems for boats. Founded in 2005, it develops and manufactures electric and hybrid drives in ratings from 0.5–100kW for both commercial and recreational craft. The Cruise 2.0 pod drives that power the Broads boats are fitted inconspicuously below the vessels’hulls. They deliver a thrust equivalent to a 3.7kW (5hp) engine, achieving a maximum propeller speed of 1,300 rpm, capable of propelling vessels at speeds of up to 6 knots (11.1km/h) and for distances of up to 24km (depending on the operating speed). The 24V motors are said to operate with an efficiency of 56%. The electric propulsion systems are not intended for prolonged use on the boats, whose primary means of propulsion remains their sails.“When we installed the first boat, it was coming back after a week with typically 60- 70% of the charge remaining on the battery,” Bray recalls.“Typically, we can fully recharge the boats in about two hours during the cleaning period on change-over days.” The first electrified boat was an hit with renters, and more boats were fitted with a similar propulsion assistance system the following year. There are now five vessels fitted with the system, and more are planned. “We have 14 cabin boats in three classes – two-berth, three-berth and four-berth – and our plan at the moment is to install engines in all but one of each class so that one of each is available for the purists,”says Bray. He believes that once the benefits are realised, all of the company’s boats will probably be motorised.“After all, just because an engine is fitted it doesn’t have to be used.” n Electric motors are being used to replace the barge poles that were traditionally used to manoeuvre wooden sailboats out of trouble on the Norfolk Broads.