Sound of Three-Cylinder Loco

[Nearholmer]

3 hours ago, Steamport Southport said:

3/4 is three beats per bar, so 1,2,3 / 1,2,3, etc

I warned you I didn’t understand this ……. , if there are three beats in a bar, where does the /4 come into it? 

And, is a “bar” simply the cycle-time? (if it is, it might be more readily understood if expressed in seconds, but I guess this has a history that goes back longer than measurement in seconds.)
 

(LNER4479’s explanation of the /4 is, how can I put this kindly? Shall we say “not hugely illuminating”.)

[Compound2632]

Just now, Nearholmer said:

I warned you I didn’t understand this ……. , if there are three beats in a bar, where does the /4 come into it? 

And, is a “bar” simply the cycle-time? (if it is, it might be more readily understood if expressed in seconds, but I guess this has a history that goes back longer than measurement in seconds.)
 

(LNER4479’s explanation of the /4 is, how can I put this kindly? Shall we say “not hugely illuminating”.)

 

Yes, in engineering terms you can think of a bar as a cycle.

 

3/4 says there are three crotchets (quarter notes) in a bar - waltzing along, ONE-two-three, ONE-two-three... - as opposed to simple march time 2/4: LEFT-right, LEFT, right - or common time 4/4: ONE-two-three-four, ONE-two-three-four.

 

6/8 says there are six quavers (eighth notes) in a bar - which means that each cycle has more scope for rhythmic flexibility, since two quavers can be replaced by a crotchet, or the stress can be placed in different places in the bar:

"It's hard but I can do it, it's hard but I can do it..."

[Nearholmer]

So, how long is a crochet, or a quaver come to that?

 

And, I notice emphasis on the first unit in each cycle in the way you describe it. Is that a given for all of this, or is the notation somehow telling us that?

[rodent279]

2 hours ago, LNER4479 said:

Twice as quick, in fact ...

 

From the dim n distant days of O level music*, I recall 6/8 time being described as 1,2,3 / 4,5,6. It has much more of a rhythmical lilt to it and better mimics that lovely 3-cyl sound than strict 1,2,3 waltz time.

 

The poor ol' V2 at Steele Road is so off-beat that it's more of a 1...2..3/456, 1...2...3/456. Glorious stuff ... but only if you're a railway enthusiast (as opposed to a running shed fitter)

 

(*nerd alert. The base unit of '4' time is a crotchet and four of them make a semibreve (whole note). In '8' time, it's a quaver - half a crochet - so eight of them make a semibreve

https://en.m.wikipedia.org/wiki/Whole_note)

I need to listen to radio 3 more!

[LNER4479]

1 hour ago, Nearholmer said:

So, how long is a crochet, or a quaver come to that?

 

Er … it’s as long or short as you want it to be (sorry!) In classical music, the speed is set by the conductor (assuming an orchestra is involved), according to how fast he/she waves the baton. The musicians speed up or slow down at the conductor’s command (on a good day) to place emphasis etc. In pop/rock music, you can sometimes (endearingly) hear the lead singer counting the band in or the drummer tapping his sticks together before the song starts to set the pace.

 

And - yes - generally in music there’s emphasis placed on the first beat of the bar … which is sort of where we came in.

Edited November 10, 2021 by LNER4479

[rodent279]

Ah, right. So 3/4 means 4 beats to the bar, and we are sounding 3 of them? So 6/8 means we sounding 6 of them, and because there are more of them, each note is shorter?

[Nearholmer]

50 minutes ago, LNER4479 said:

it’s as long or short as you want it to be

OK, I get that.

 

Does the notation tell the musician what the composer intended the ‘base unit’ (length of a full note) to be for a particular composition?

 

(If this is all too annoying here, I’ll seek tutorial in a purpose-built thread)

[LNER4479]

SOME sheet music comes with a recommended speed, usually beats per minute, eg 120. A metronome was traditionally used to mimic that so you have an aubidle 'click' to play along to.

(Not annoying from my point of view, but we could be accused of )

[Poor Old Bruce]

18 hours ago, Wickham Green too said:

Then of course there's the mysterious exhaust sounds of three-cylinder compound locos which can start as a simple with different-sized cylinders and then run exhausting from the low-pressure only !

 

What's mysterious about it? The HP cylinder exhausts into a the steam chest for the LP cylinders. Only the LP cylinders exhaust to atmosphere so it doesn't matter whether the loco is running compound or simple, it can only give four exhaust beats per revolution. On the Midland and LMS Compounds the outside cranks were set at 90 Degrees with the inside crank at 135 degrees.

[LMS2968]

8 minutes ago, LNER4479 said:

(Not annoying from my point of view, but we could be accused of )

Personally, I love listening to various types of music, but as to making it, I have all the talent of a blocked nostril! Much as I enjoy debating the beats of two-, three- and four cylinder steam locos, the technicalities of music are way beyond me.

[rodent279]

On 08/11/2021 at 23:55, Andy Kirkham said:

 

In this video of a three-cylinder locomotive, it is noticeable, especially from about 6:09, that the exhaust beat is audibly in "6/8" time. Is this always the case with three cylinder machines, and if so, why? I appreciate that there will be six beats per revolution of the wheels, but why should one of those beats be more emphatic than the rest?

 

 

So how have they got that Br44 sounding so perfectly in time? 123/456|123/456 compared to the slightly out of sync rhythm of a Jubilee or Royal Scot?

[Compound2632]

35 minutes ago, Poor Old Bruce said:

What's mysterious about it? The HP cylinder exhausts into a the steam chest for the LP cylinders. Only the LP cylinders exhaust to atmosphere so it doesn't matter whether the loco is running compound or simple, it can only give four exhaust beats per revolution. On the Midland and LMS Compounds the outside cranks were set at 90 Degrees with the inside crank at 135 degrees.

 

Ah, but that's only one case; a four-cylinder compound (Webb, de Glehn) will be the same, essentially sounding like a two-cylinder simple. But a Worsdell-von Borries two-cylinder compound (the last of which in the British Isles ran until 1946 on the Ballymena & Larne section of the NCC) or a Webb three-cylinder compound, both with a single low-pressure cylinder, will have exhausted only twice per revolution. The Webb three-cylinder compounds are said to have quite a soft exhaust, wuffing along. This leads to some ill-informed captions to photos of double-headed West Coast expresses in the 1890s / early 1900s, where the pilot engine - usually an Improved Precedent - is said to be doing all the work, on the grounds that it is volcanically and wastefully chucking a great cloud of incompletely-combusted fuel out of the chimney, whereas the Teutonic or Greater Britain is economically spouting a gentle plume of white steam; a misapprehension reinforced by contemporary lineside observations that the simple was making all the noise. Of course it would be!

Edited November 10, 2021 by Compound2632

[Mallard60022]

May I suggest getting some Handford Recordings and listening to the sounds (beat/rhythms) of various locomotives. If you don't know how many cylinders a loco had/has then use Googley thingy,  or an Ian Allen ABC. Start with Western Region 2 Cylinder jobbies and then find some 4 Cylinder ones. Those are solid and what is called sharp beats of exhaust and gets you attuned.

You don't need to know about 'Music', but it does help. Try listening to a Waltz and a March but don't bother with Holst's Mars, or Ravel's Bolero or Dave Brubeck's Take Five (until your ear is attuned to beats and rhythms).

 

Next, for 3 Cylinder machines, attempt to get SR Spams (very distinctive and a sort of muffled exhaust and sound like old Lavatory Cisterns refilling), ER V2s (odd to say the least, especially when not 'tuned'), A4s quite a strong exhaust IMO), Jubilees and Scots and so on, and just listen to them........ a lot. Preferably starting off or at slowish speeds, working really hard, as all locos working at speed just sound like a very long Raspberry, or as In Tornado or The Duke's case, like a Diseasel or are coasting on fine cut off. 

It is fun but comes with experience.  When you get experienced then play a KIng then a Duchess (both 4 Cylinder Loco's) and hear the difference.

Experienced Railway footplate Staff (and others of course) could listen to the exhausts and determine certain issues or when to use the Cut OFF etc. I am no expert but it is certainly fun finding out. I actually know and you can see from some posts here, that many can recognise and describe the sound of an Engine when it isn't in sight. I used to be able to in Plymouth, when I was a kid, but the mysteries of the sounds of stuff operating east of Exeter, Bristol and London and anywhere north of Watford, bar some Whistle sounds, was beyond me. 

This is why most DCC Sound for Steam engines sounds ####. It may be the right beat but the sound? Nah!

Phil

[Nearholmer]

11 minutes ago, Mallard60022 said:

SR Spams (very distinctive and a sort of muffled exhaust and sound like old Lavatory Cisterns refilling),

 

Very colourful description.

 

They are about the only big locos I can remember in the wild, and they did not sound how a boy had been taught that engines sound. Belting along, tearing down the track towards the station, the sound was really odd, almost like a muffled helicoper at very high speed, or several horses galloping hard over soft ground.

[LNER4479]

1 hour ago, rodent279 said:

So how have they got that Br44 sounding so perfectly in time? 123/456|123/456 compared to the slightly out of sync rhythm of a Jubilee or Royal Scot?

Valve setting has a lot to do with it, a mysterious art known only to the artful and mysterious

(all other things being equal)

[Wickham Green too]

4 hours ago, Poor Old Bruce said:

 

What's mysterious about it? The HP cylinder exhausts into a the steam chest for the LP cylinders. Only the LP cylinders exhaust to atmosphere so it doesn't matter whether the loco is running compound or simple, it can only give four exhaust beats per revolution. On the Midland and LMS Compounds the outside cranks were set at 90 Degrees with the inside crank at 135 degrees.

Which suggests that we have - in this case - two cylinders giving a conventional 90 degree thrust and a third cylinder ( whether in simple or compound mode ) giving a very out of balance thrust ........... doesn't seem to make a lot of engineering sense to me !

[LMS2968]

33 minutes ago, Wickham Green too said:

Which suggests that we have - in this case - two cylinders giving a conventional 90 degree thrust and a third cylinder ( whether in simple or compound mode ) giving a very out of balance thrust ........... doesn't seem to make a lot of engineering sense to me !

Maybe, but that's how it was. And the Midland Compound was a very successful design, at least on the Midland Railway and pre-LMS.

[Wickham Green too]

I'll have to have a good look at / listen to No.85 next time I get a chance !

[Compound2632]

1 hour ago, LMS2968 said:

Maybe, but that's how it was. And the Midland Compound was a very successful design, at least on the Midland Railway and pre-LMS.

 

As, indeed, was the LMS Standard Compound wherever it didn't run into anti-compound prejudice: ex-Caledonian and ex-GSWR sheds, for example. 

[Artless Bodger]

On 10/11/2021 at 11:31, Nearholmer said:

 

Very colourful description.

 

They are about the only big locos I can remember in the wild, and they did not sound how a boy had been taught that engines sound. Belting along, tearing down the track towards the station, the sound was really odd, almost like a muffled helicoper at very high speed, or several horses galloping hard over soft ground.

That observation recalls an incident one afternoon at work. Our office overlooked the line near Overton station, on the afternoon in question a Jubilee (can't remember which, maroon livery) passed with an excursion. One of the managers challenged me (as the office anorak) that it could not have been a real steam engine as it wasn't chuffing. A quick approximation provided the following:

Wheel diameter approx 2m, circumference 6m, 3 cylinders = 6 beats per revolution, ie 1 beat per 1m of travel. Assume 60 km/h so 1000m/min gives 1000 beats per min or about 16/sec. Even my manager who was a better scientist than the challenger and a musician too could appreciate it would be a purring sound rather than discrete chuf chuff. Most difficullt bit was to explain why 3 cylinders (wheres the 3rd?) and how a steam engine had double acting cylinders so two exhaust beats per stroke (most of the office denizens being petrol heads). It just re-inforced my 'anorak' tag though.

[asmay2002]

On 09/11/2021 at 23:20, jim.snowdon said:

The ouzzle is why Gresley stuck, almost religiously, to three cylinder engines with conjugated gear for the middle cylinder instead of adopting, as Peppercorn finally did, independent gear for each cylinder. Was the saving by not having a middle valve gear really worth the effort?

Presumably because he was pocketing patent fees for every loco fitted with his patent valve gear.

[Andy Kirkham]

7 minutes ago, asmay2002 said:

Presumably because he was pocketing patent fees for every loco fitted with his patent valve gear.

Would he have been entitled to fees from his own employer, if his invention had been developed in the firm's time?

[Nearholmer]

I don’t think so. In that case the IP belongs to the firm, I believe.
 

Two things that I worked on were patented under my name, but in both cases the IP rested with my employer, otherwise, I’d be stupendously rich on the royalties, to the tune of about £10.

 

 

Edited November 19, 2021 by Nearholmer

[Poor Old Bruce]

On 10/11/2021 at 10:38, Compound2632 said:

 

Ah, but that's only one case; a four-cylinder compound (Webb, de Glehn) will be the same, essentially sounding like a two-cylinder simple. But a Worsdell-von Borries two-cylinder compound (the last of which in the British Isles ran until 1946 on the Ballymena & Larne section of the NCC) or a Webb three-cylinder compound, both with a single low-pressure cylinder, will have exhausted only twice per revolution. The Webb three-cylinder compounds are said to have quite a soft exhaust, wuffing along. This leads to some ill-informed captions to photos of double-headed West Coast expresses in the 1890s / early 1900s, where the pilot engine - usually an Improved Precedent - is said to be doing all the work, on the grounds that it is volcanically and wastefully chucking a great cloud of incompletely-combusted fuel out of the chimney, whereas the Teutonic or Greater Britain is economically spouting a gentle plume of white steam; a misapprehension reinforced by contemporary lineside observations that the simple was making all the noise. Of course it would be!

 

Point taken Stephen. I should have mentioned the Webb 3-cylinder compounds with only two exhaust beats per revolution. Two-cylinder compounds similarly gave two beats per rev. I did see a little 2-6-0T 2-cyl compound somewhere in Europe (Austria perhaps, not sure without digging) which gave out two beats and sounded very 'different'.

 

On 10/11/2021 at 14:36, Wickham Green too said:

Which suggests that we have - in this case - two cylinders giving a conventional 90 degree thrust and a third cylinder ( whether in simple or compound mode ) giving a very out of balance thrust ........... doesn't seem to make a lot of engineering sense to me !

 

Well, the Midland and LMS compounds worked quite well, to the extent that they could be argued to have been the most successful compound locos in this country, having had a life span covering almost 60 years.

 

Don't forget that the driving axles of the Webb LNWR 3-cyl compounds were not coupled at all. The two HP cylinders drove the trailing driving axle while the LP cylinder drove the leading driving axle.

[Compound2632]

21 minutes ago, Poor Old Bruce said:

Don't forget that the driving axles of the Webb LNWR 3-cyl compounds were not coupled at all. The two HP cylinders drove the trailing driving axle while the LP cylinder drove the leading driving axle.

 

Various theories have been advanced either by Webb or on his behalf, to the effect that the low pressure system would slip into its optimum position relative to the high pressure system, and of course the avoidance of the additional friction introduced by coupling rods - a very real issue with the manufacturing tolerances of the 1880s. But what the uncoupled driving axles really gave was a longer wheelbase than was practicable for a coupled engine at the time - 9'8" on the Dreadnaughts and Teutonics as against 8'3" on the Precedent 2-4-0s - and hence an enormous (for the time) grate area of 20.5 sq ft, compared to the Precedent's 17.1 sq ft. The compounds had boilers pressed to 175 psi vs 150 psi for the Precedents. So altogether a much more powerful engine, which was what Webb knew was needed, even before the benefits of compounding were taken into account.