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giobox

That "deltic" engine just for the water pumping is incredible, I'd never seen that cylinder layout before.

> https://en.wikipedia.org/wiki/Napier_Deltic

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Napier was on the cutting edge of certain kinds of IC engines for a long time.

https://en.wikipedia.org/wiki/Napier_Sabre (1938).

Powered the absolute monster that was the Tempest (up to the Mk 2 - they did have reliability issues they never quite solved but 3000+HP out of an engine that weighs barely more than a tonne dry will do that)

https://en.wikipedia.org/wiki/Hawker_Tempest

Was happy to see the name re-used for our upcoming fighter.

We also called the Eurofighter the Typhoon and the (WW2) Typhoon (also a Sabre engine) was the predecessor of the Tempest - it started as a re-wing of the Typhoon but enough changes where made to give it a new name.

Just a devastating superprop in its day.

The type 55 "deltic" locomotives, named after army regiments used to do the east coast Edinburgh-London train run, there were 22 of them in service and one in the science museum London. They had the first 100mph rating for diesel passenger service.

The engine had a unique characteristic whine or whistle. As an avid train spotter at Waverley station in edinburgh I loved hearing it, saw every one and was in the cab of two thanks to long suffering kind engine drivers.

There was a mini deltic too. I'm not sure it went beyond a testbed loco.

Those are amazing engines. It's a pity that in the future we'll just be using magnets and coils, there something about these designs that moves me in a way that nothing electrical ever will. And I'm a great fan of renewable energy, and realize that the pollution that has been created (and is still being created) is absolutely unsustainable.

There are people working on internal combustion engines with a very similar design currently, for many applications (military, trucking, etc) diesel or diesel electric is the only realistic option for the foreseeable future: https://achatespower.com/

A series of 10 "baby deltics" were built and ran for some years, although they weren't particularly successful on the whole.

They were basically out of service by the time I was out of short trousers. I made special trips south to see the "warship" class 43 hydromatic transmission in Western Region out of Old Oak Common in London, the type 44 "peak" series and the diminutive type 3 diesel shunter at Birkenhead. The baby deltics were probably parked in a yard waiting scrapping.

I have dim memories of being held up over a bridge to watch steam trains pass, but by the time I was obsessively writing down numbers they were special trains like "Sir Nigel Gresley" and "the Flying Scotsman"

I left britain before the east coast electrification. I do still see my favourite type 8 Diesel shunter, the most ubiquitous kind in Britain, when I pass by.

If you want sheer power, It's a Deltic every time. That high pitched whine, it's unmistakable.

> avid train spotter at Waverley station in edinburgh

We probably met. I was there every day traveling to and from school but did casual trainspotting on the side. Oblivious someone would one day write a book with that title..

If you're the guy who flung a football pie at my head from a train window, I remember that pie crust.

Hahaha. Proto-DC-sandwitch-thrower. Not me though. I'd be eating the pie.

About 12 years ago they used to use 55022 as a shunter at Springburn yard, because it was "road legal" and could couple up to older carriages that were being taken in for refurbishment. Nice cushy retirement job, easy shifts and a well-appointed engine shed to park up it at night ;-)

I used to hear it all the time, working in a nearby industrial site. I'd maybe just take five minutes to sit outside and drink my coffee, listening to that weird shimmering howl.

There are no good recordings of it on Youtube and I suspect like a lot of things you have to experience it for yourself.

Piston engines got pretty wild before turbines eventually took over the world. The most efficient ones were more efficient than today's turbines in terms of BSFC[0]. One of the most interesting to me was the Napier Nomad[1], which used turbo- and super-charging. However, the turbo had secondary fuel injection and effectively ran as a turbine to drive the compressor.

[0]https://en.wikipedia.org/wiki/Brake-specific_fuel_consumptio... [1]https://en.wikipedia.org/wiki/Napier_Nomad

Napier Nomad is one of my favorite engine designs. More info at https://oldmachinepress.com/2019/08/05/napier-nomad-compound...

Those exhaust driven turbines didn't just drive the compressor like is typical with turbochargers, but was also mechanically linked to the crank shaft so the turbine contributed to the overall power output of the engine directly, not just by forcing more air into the cylinders. That's what made them "turbo-compound."

The youtube channel "Greg's Airplanes and Automobiles" has a nice video about turbo compound engines.

Speaking of turbines and fire apparatus, back in the 60's a few jet turbine powered engines and one ladder truck were made: https://www.aeroflap.com.br/en/when-fire-trucks-used-boeing-...

Gas turbines aren't generally noted for their efficiency, but rather:

- Power-to-weight ratios. Critical in aerospace applications.

- Long duty cycles. Everything spins, reducing wear-and-tear relative to reciprocating designs. Maintenance on piston engined aircraft during WWII was a major logistical concern.

- Raw speed. Supersonic flight requires high rotary speeds, and the few propeller-driven aircraft which achieved this had ... issues. Ground crews and pilots suffered health effects from the noise alone, and notoriously often flat refused to work with the XF-84H "Thunderscreech": <https://en.wikipedia.org/wiki/Republic_XF-84H_Thunderscreech...>. At near-supersonic speeds and above, propeller blade tips themselves break the sound barrier, losing aerodynamic flow over the blades, making quite a racket, and greatly reducing efficiency.

Propeller-driven planes remain more efficient than jets in many instances, though last I checked US military forces rely on turboprops over reciprocating engines in virtually all instances, possibly excepting some civilian-based (e.g., Cessna / Piper, etc.) trainer or observer variants.

They're unique. Originally designed to power fast torpedo boats during WW2, three of these powerful and compact engines would churn out plenty of power for the boat up to 50 kt.

https://everythingaboutboats.org/napier-deltic/

They're still in use by our UK navy. Nine minesweepers still on active duty.

I just realised they re-engined them with cat engines in 2008. Pity.

There are numerous "atypical" piston engine layouts, though I cannot recall precisely where I'd seen a reference, probably on YouTube ~10 years ago.

The basics are a single piston, dual (often opposed at an angle or flat-head design as on older BMW motorcycles), in-line (usually 4-cylinder), or V (as in V-6, V-8, V-12, etc.)

Then there are radial engines used in piston-driven aircraft. These virtually always have an odd cylinder count, to prevent locking (there's always an unbalanced force in the direction of intended rotation, or so one hopes).

<https://en.wikipedia.org/wiki/Radial_engine>

There are various rotary engines, with the Wankel design best known. Very high power-to-weight ratios as a result of having three combustion chambers per rotor, but a relative short lifecycle due to wear, and some compromises in efficiency. "Flying car" company Moller International, out of Davis, CA (and apparently inactive since 2015) had at its core a Wankel-based powerplant, with four pairs of counter-rotating engines powering four ducted fans. It sounds like all the angry hornets in operation.

<https://en.wikipedia.org/wiki/Moller_M400_Skycar>

Wikipedia lists some other unusual designs as well: <https://en.wikipedia.org/wiki/Reciprocating_engine#Miscellan...>.

I believe that the axial engine may have been featured in that video mentioned in 'graph 1:

<https://en.wikipedia.org/wiki/Axial_engine>

> The Napier Deltic engine is a British opposed-piston valveless, supercharged uniflow scavenged, two-stroke diesel engine

Any tech that includes the word “scavenged” must be cool and efficient

Scavenging here means getting the exhaust from the previous cycle out of the cylinder and replacing it with fresh air. Technically all internal combustion engines do it one way or another, but usually you hear the word in relation to two stroke engines. Two strokes don't have discrete "suck" and "blow" steps so those need to be done at the same time. With two stroke diesels, that was done using blowers to basically force out the exhaust by blowing in fresh air.

Generally speaking at least, two stroke diesel engines weren't super efficient, but did offer great power output relative to their size.

Two of the three crankshafts rotate in the same direction, whereas the third one moves the other way around!

It amazes me what we manage to figure out on the mechanical side of things. Just look at motorcycle engines. Screaming along at upwards of 20k RPM and just taking it in stride and moving people down the road at what might as well be supersonic speed.

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