A couple of days ago visited a brilliant museum celebrating a maritime dynasty of commercially energetic Scots and a wonderful walk back through time (www.scottishmaritimemuseum.org/sites/dumbarton/). William Denny, in 1882, created the first commercial towing tank for his shipyard with exquisite clarity of purpose; “to determine with commercially acceptable accuracy the power required to achieve the contract speed, and to reduce that power for any installation to a minimum.”

Associated with feathering paddle wheels and 20 kt paddle steamers, helicopters (development of airscrews in 1900 to a flying tethered prototype in 1913), America’s Cup yachts (Shamrock II, 1901), the Irrawaddy Flotilla Company (with ~600 river boats in Burma in the 1930s), fin-stabilisers from the 1930s to the 1950s, and hovercraft in the 1960s, this commercially enterprising family company and its employees must have been one of the world’s most innovative companies in the UK before succumbing to commercial pressures in the early 1960s.

Integrator In addition to the test tank, the museum includes precision machinery, such as the model cutting machine invented by Froude,  and instrumentation such as the all-mechanical dynamometer to measure tow-tank model forces, and a pallograph (a mechanical device to mechanically measure vertical structural vibration, also compensating for ship roll).  The  drawing office includes tools of the trade such as cylindrical slide rules and a mechanical integrator, based on the principles of a planimeter, for calculating moments of area from drawings (see photo).

The whole place is a wondeful insight into engineering and commercial innovation from a world before electronics.


Who needs sparkplugs?

July 24, 2015

P1070701 (Who needs sparkplugs)

Have a look at the photo above – a 1908 Mors Grand Prix car that was at the 2015 Goodwood Festival of Speed. Spot anything odd? Well, you can see the insulated conductors that obviously are attached to the spark plugs (far left and far right), right? But what are the funny little lever arms just to the right of the left hand “spark plug” and to the left of right hand “spark plug” and why do they both have a connecting arm downwards?

This, believe it or not, is a make-and-break that is actually inside each cylinder to create a spark from the low-tension ignition system. Each driven by a cam below and a push/pull rod. Actually there are two camshafts, one for starting and one for running, so the moment it starts you jump out and run to the side of the engine to pull a lever that slides in the operating cam to replace the starting cam. Who needs advance / retard?

Oh yes, and the little cup visible on the top of the right hand cylinder? Well, you fill these cups on each cylinder with fuel and turn the tap, so dispensing a known quantity of fuel in before starting. Four cups for cold and 1.5 for a hot start. Crank it – and stand well back.

Don’t you love the experiments in early automotive engineering? (BTW – the spark plug had already been invented and I’m not sure why Emile Mors didn’t adopt it.)

And many thanks to the friendly and tolerant team from the Revs Institute (https://revsinstitute.org/the-collection/1908-mors-grand-prix-car/) who were working on the car and happy to explain obscure technical details.