Off topic, Napier Deltic engine.

I love railroads. Thus when visiting other countries I like to at least do one leg of the travel on rails. And before boarding the train, I go to see the locomotives.

Back in the late 1970s, I visited the UK and travelled vía Brit Rail.
When nosing around the locomotives, I noticed a significant amount were Diesel powered. But the noise they would make was significantly different from the one I had heard in North American engines. The British engines produced a deep rumble that was nevertheless very fast, like a gigantic cat purring.
No Google back then, and the conductor wasn’t very helpful.

Fast forward 40 years, and I was having some beers with some acquaintances. One of them was a Vietnam vet, and he mentioned some boats had an extremely powerful, yet very odd British engine, whose sound resembled a purring cat. The Napier Deltic.

Of course arriving home I immediately Googled it. What an awesome engine! Really out-of-the-box thinking and a prime example of outstanding British engineering.

If you are not familiar with the Deltic please search some YouTube videos.

Yes the Napier Deltic was a very interesting and complicated engine which was originally developed for use in small fast naval boats.

As you mention there are some good u-tubes about the deltic, I was looking at one a couple of days ago, there was even a deltic engine used in a big New York fire engine, the idea being to squirt water up high to put out fires in high rise buildings.

As for the deltic locomotives in the UK, they are all retired from service, but there are one or two which have been preserved and are used for pulling "rail fan specials".

Last time I travelled to London on the train, there was a deltic parked up outside the National Railway Museum at York.

JimB

I'm not a "rail fan", but I am very enthusiastic about outstanding engineering and designs - and I've alway considered the Deltic engine to be a work of art.

I remember them from when I was a teenager & the engine sound is absolutely unique. The Deltic locomotives use two detuned 18 cylinder engines, giving around 3500 HP total. They were the most powerful locomotives in the world when first introduced to service.

An example from youtube, starting both engines, around a minute and a half apart:

Then now often only use one engine at a time when possible, to minimise wear & maintenence requirements.

I also discovered a couple of years ago that there is a UK "Deltic preservation society" - and it keeps its locomotives near Stavely, only about a 20 minute drive from where I live!
I now donate to the society, but have never had chance to visit or do any work on them yet due to a combination of the Covid outbreak and pressure of my own work.


I thing there are six? still preserved & either running or being restored, including the prototype. Not all have the newer signalling equiment fitted to allow them to run on the main UK rail network.

They are also somewhat infamous for "clag" (thick, dense smoke), as apparently stray oil accumulates in the exhausts at lower engine power, and burns off when power is increased and the exhaust heats up!
Not by any means the only British Rail locos to have that particular quality.

JimB said:

Yes the Napier Deltic was a very interesting and complicated engine which was originally developed for use in small fast naval boats.

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It's was a very clever idea - and a fine example of 'thinking outside the box'

It was also a stroke of genius thinking of using a boat engine in a train - I'd like to think that the people who come up with these ideas get rewarded for it, but I suspect they rarely do.

For me the stroke of genius was to have one of the three crankshafts rotating backwards to allow proper piston “phasing”.
As told, the German company Junkers initially had a dual crankshaft design, but could never, ever figure out how to phase the pistons on a triple crankshaft.

Remember, this was before computer simulation. One had to somehow figure out the mechanical ballet in the imagination!
Even now, even after watching the YouTube videos, it takes a while to understand the intricacies of the mechanical design.

Nigel Goodwin said:

It was also a stroke of genius thinking of using a boat engine in a train

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A bit like using an aircraft engine in a tank (Rolls Royce Merlin & it's de-rated land version, Meteor).

One of my customers restores and makes replacement parts for Rolls Royce Gryphon engines, the successor to the Merlin. Those are another example of amazing engineering.