Deltic

I'd always thought the 'Deltic' was a type of British Rail diesel locomotive from the 60s and 70s, but tabbing around Wikipedia today I find the loco took its name from an engine, made by engineering firm Napier & Son. I've long had a bit of a soft spot for Napier, partly because in the popular imagination they and their magnificent Sabre played second-fiddle to Rolls-Royce with their flashy Merlin and Griffin -- pity Bristol and the workmanlike radial Centaurus -- and partly because, in my book, engineering firms should be called things like 'Napier & Son.' 'Bristol-Siddeley' was pretty good; 'Armstrong-Whitworth' one of the best company names of all time. Who wouldn't rather have an Armstrong-Whitworth toaster than, say, a Tefal? But I digress...

Turns out, the Deltic wasn't just another big diesel engine, it had an entirely radical piston arrangement. Pistons were arranged in pairs, opposed in a shared cylinder, then three such piston pairs were coupled in a triangular arrangement via three shared crankshafts. Timing issues were resolved by having one crankshaft contra-rotate, geared into the common output shaft.

The design allows each valve to be unidirectional. It's not entirely unlike a Wankel Rotary, but retaining pistons rather going the whole hog and adopting a rotor. There's a nifty little animation on the Wikipedia page, but what I really want to know is -- what would a small one of these sound like?

(other Wikipedia finds of the day: a list of Rainbow Codes for British military projects -- my favourite remains 'Blue Circle,' but that's a bit of a cheat -- and details on Miss Shilling's Orifice. Which, perhaps surprisingly, is entirely safe for work. Why we never covered the eponymous inventor for Local Heroes is beyond me. Also: I never knew it was possible to fly to Ascension Island and the Falklands via RAF Brize Norton, though it's still unclear quite how one goes about booking travel; mentions from RAF Mount Pleasant entry, Ascension Island entry. Oh, and this part of the entry on the F-4 Phantom II jet fighter:

On 10 May 1972, Randy "Duke" Cunningham and William P. Driscoll flying an F-4J with the radio call sign "Showtime 100" shot down three MiG-17s to become the first flying aces of the war. Their fifth victory was believed at the time to be over a mysterious North Vietnamese ace Colonel Toon, now considered mythical. On the return flight, the Phantom was damaged by an enemy surface-to-air missile. To avoid being captured, Cunningham and Driscoll flew upside-down (the damage made the aircraft uncontrollable in a conventional attitude) and on fire until they could eject over water.

Emphasis added.)