Steam en­thu­si­asts make up a small but colour­ful seg­ment of the coun­try’s recre­ational boat­ing fra­ter­nity. Revered as some­thing of a mystic among them is the chap who builds en­gines for the ves­sels – from scratch.


Asteam engine, Auck­land’s Wayne Larsen will tell you, is a rel­a­tively sim­ple piece of tech­nol­ogy, with far fewer moving parts than any in­ter­nal com­bus­tion engine. But, he will add, it’s also a won­der­fully el­e­gant in­ven­tion, a fluid song of shin­ing me­tal, ro­tat­ing with grace. A move­ment he never tires of watch­ing.

Scores of steam-pow­ered launches op­er­ate around New Zealand to­day – and a num­ber of them are fit­ted with en­gines Wayne has built. These are not re­stored en­gines – they are built from the ground up, start­ing with de­sign, cast­ing and ma­chin­ing, through to as­sem­bly and fine-tun­ing. All from a back­yard garage.

Though a trained au­to­mo­tive en­gi­neer, Wayne has al­ways been fas­ci­nated by steam en­gines. His love af­fair be­gan, he says, as a boy watch­ing the synchronised move­ment of the engine in the ferry that took his fam­ily on out­ings to Mo­tu­ihe Is­land in the 1960s.

The steam ex­per­tise and pre­ci­sion ma­chin­ing skills were largely self-taught, though he learnt a “hel­luva lot” from the old-timer en­gi­neers who tack­led the 1980 restora­tion of the Wil­liam C Daldy – the his­toric tug that steams around Auck­land’s Waitem­ata Har­bour as a tourist at­trac­tion.

“I vol­un­teered to help with the restora­tion. Many of the chaps who’d op­er­ated her en­gines over the years were also in­volved, and one them – Gra­ham Wilkin­son – taught me most of what I know to­day.”

Since then Wayne has gained a for­mal steam qual­i­fi­ca­tion, and is of­ten the old tug’s chief en­gi­neer for her trips around the har­bour – a man­tle he’s happy to have ‘in­her­ited’ from his teach­ers.

“She’s a fas­ci­nat­ing ves­sel. Her twin, triple-ex­pan­sion en­gines – rated at around 900hp each – are the largest in any New Zealand steam ves­sel to­day. They sound small by mod­ern stan­dards, but bear in mind the torque they de­velop is as­tro­nom­i­cal – and max­i­mum power is avail­able in­stantly. The en­gines are very slow revving – they swing 11-foot 6-inch di­am­e­ter props, with an 11-foot pitch.” [3.5m by 3.3m.] BUILD­ING A STEAM ENGINE

As his ex­pe­ri­ence and knowl­edge de­vel­oped, so Wayne’s in­ter­est ex­panded and even­tu­ally em­braced the no­tion of build­ing steam en­gines rather than sim­ply oper­at­ing them.

He be­gan – 22 years ago – with an engine for his own boat – the 20-foot Vic­to­ria. “I bought the hull third-hand and I’m afraid I still don’t have a clue who built her or how old she is. But she was per­fect for my engine.”

Wayne ini­tially con­sid­ered im­port­ing the var­i­ous engine com­po­nents from Bri­tain but de­cided against this be­cause they were over-priced and also clashed with his no­tions of what con­sti­tuted good de­sign. In­stead, he elected to de­sign and build the engine from scratch – engine bed, fly­wheel, crank­shaft, cylin­ders, pis­tons, pis­ton rings, con­rods, bear­ings, valves, con­denser pump – every sin­gle piece.

“The process in­volves mak­ing wooden pat­terns for each of the dif­fer­ent parts, which I send to Pa­pakura’s South Auck­land Foundry. I tell them what the cast­ings are for, and leave it to the met­al­lur­gists to make sure the qual­ity of the cast-iron is suit­able for build­ing an engine.”

While the engine’s ma­jor com­po­nents are cast-iron, items such as the crank­shaft and con­rods are ma­chined from high-ten­sile steel. The con­denser pump, bear­ings and valves are ma­chined from phos­phor bronze, and there is plenty of cop­per tub­ing.

Wayne’s garage is equipped with two lathes, a milling ma­chine and a 13-tonne hy­draulic press – and there’s an im­pres­sive se­lec­tion of

mi­crom­e­ters and Verniers in at­ten­dance. He op­er­ates each of these with the fi­nesse and del­i­cacy of a neuro-sur­geon, work­ing to tol­er­ances of a “few thou”.

Vic­to­ria’s engine is a twin-cylin­der model. It looks sur­pris­ingly small for a 20-foot timber launch, but at its max­i­mum 350rpm it pow­ers her to a com­fort­able six knots – her dis­place­ment speed. And even though it ap­pears to be a fairly ba­sic engine, with the re­volv­ing crank­shaft and con­rods clearly vis­i­ble, there are in­trigu­ing fea­tures.

It’s direct drive, for ex­am­ple, with the prop shaft at­tached to the fly­wheel. “Be­cause max­i­mum torque is avail­able in­stantly,” says Wayne, “there is no need for a re­duc­tion gear­box. You ad­vance the throt­tle to in­tro­duce the steam into the cylin­ders and away she goes.”

And, um…..re­vers­ing? Well, it’s just a mat­ter of shift­ing a lever – steam en­thu­si­asts know it as a Stephen­son Link – from ahead to astern. It quickly and smoothly re­verses the di­rec­tion of the engine’s ro­ta­tion.

The crank­shaft is an­other un­usual piece of de­sign. Un­like many twin-cylin­der petrol/diesel en­gines where the pis­tons fire 180o apart – the in­ter­val be­tween the pis­tons on Wayne’s engine is only 90o. Be­cause…?

“It en­sures that one of the pis­tons will al­ways be on a down­ward or up­ward stroke, which makes for im­me­di­ate op­er­a­tion and ef­fec­tively de­liv­ers two power pulses in each

rev­o­lu­tion. If they were 180o apart, one at top-dead-cen­tre and the other at bot­tom-dead­cen­tre, the engine may strug­gle to turn over.”


The only part of the power train that Wayne doesn’t build is the boiler. “In New Zealand, recre­ational steam boats are gov­erned by var­i­ous boiler codes and they’re lim­ited to an oper­at­ing pres­sure of 100psi. Boil­ers have to be fab­ri­cated by a cer­ti­fied boil­er­maker – it’s not a DIY project.”

Vic­to­ria’s boiler is fired by coal. Many steam boat own­ers pre­fer to run their boil­ers on used cook­ing oil, which Wayne con­cedes is prob­a­bly more ef­fi­cient and a lit­tle cleaner. “But I pre­fer coal be­cause it’s more tra­di­tional.”

He is very par­tic­u­lar about the coal he feeds into the boiler. “It usu­ally comes from Huntly and it’s gen­er­ally pretty good, but oc­ca­sion­ally it’s con­tam­i­nated with stones, and I care­fully pick them out be­fore feed­ing the boiler.”

Steam en­gines have rea­son­able ef­fi­ciency, says Wayne. “Vic­to­ria’s engine uses a small amount of coal, and al­most zero water be­cause the water’s con­tin­u­ously re­cir­cu­lated. It’s a closed-loop de­sign, with the steam con­dens­ing back into water. The only time I re­ally need to top up the water is when my pas­sen­gers use Vic­to­ria’s steam whis­tle with too much en­thu­si­asm.”

You ad­vance the throt­tle to in­tro­duce the steam into the cylin­ders and away she goes...

FAR LEFT Valves are ma­chined from phos­phor bronze, as is the con­denser pump.

LEFT Vic­to­ria’s engine seems small for her length, but it pow­ers her to a com­fort­able six knots.

ABOVE Every com­po­nent of the engine is man­u­fac­tured from scratch and ma­chined to pre­cise tol­er­ances.

RIGHT Ban­ished to the garage by his wife, Wayne finds so­lace in build­ing an­other engine.

BE­LOW A rare, colour­ful – and noisy – breed, steam­boat en­thu­si­asts cel­e­brate a by­gone era of marine trans­port.

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