Why do 180s sound the way they do?

londonmidland · 22 Dec 2018

Despite having the same engines as Voyagers and Meridians (Cummins QSK19), what in particular makes these sound different?

One specific thing that sounds different (on the interior) is the constant ‘humming’ sound and high pitched scream when accelerating. They almost sound identical to the Class 175s in my opinion.

I know the same can be said for the Class 185s, too.

Is the difference in sound something to do with the type of transmission the train uses?

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robbeech · 22 Dec 2018

180’s are a straight forward DMU. The voyager family are Diesel Electric so the way they drive the wheels/motors is completely different.

hexagon789 · 22 Dec 2018

londonmidland said:
Despite having the same engines as Voyagers and Meridians (Cummins QSK19), what in particular makes these sound different?

One specific thing that sounds different (on the interior) is the constant ‘humming’ sound and high pitched scream when accelerating. They almost sound identical to the Class 175s in my opinion.

I know the same can be said for the Class 185s, too.

Is the difference in sound something to do with the type of transmission the train uses?

Voyagers/Super Voyagers/Meridians all use electric transmission with two traction motors per car, one on one axle of each bogies.

Class 180 Adelante's use a three-stage convertor-coupling-coupling hydraulic transmission. With the hydraulic transmission the engine revs will die back a bit and then slowly pick-up again when changing between the stages as with other Diesel Hydraulic Multiple Units.

185s have hydraulic transmission as well though I'm not sure if it is the same 3-stage one as the 180s or a different possibly two-stage one.

driver9000 · 22 Dec 2018

185s are a 3 stage transmission changing around 55 and 80mph. Both 180s and 185s have the same Voith t312 hydraulic transmission but their exhaust stacks differ with a 185 having a wide bore single pipe and 180 having thinner twin pipe arrangement.

TT-ONR-NRN · 23 Dec 2018

One can easily identify a Voyager by its unique rumbling sounds as it starts up and departs, whereas IMO a 180 just sounds like any old diesel train, if I heard one I certainly wouldn’t be able to tell if it was a 175, 185 etc.

Journeyman · 23 Dec 2018

driver9000 said:
185s are a 3 stage transmission changing around 55 and 80mph. Both 180s and 185s have the same Voith t312 hydraulic transmission but their exhaust stacks differ with a 185 having a wide bore single pipe and 180 having thinner twin pipe arrangement.

The exhaust stack passing up through the inside of the vehicle, and taking up quite a lot of space, is about the only glaring design flaw on the 185, which is otherwise a pretty decent train.

CosherB · 23 Dec 2018

Make the most of how they sound. I would imagine/hope that Grand Central are frantically writing an ITT for a fleet of replacement bimodes. 180s should make a one-way trip to Rotherham or Kingsbury.

darylyates17 · 23 Dec 2018

Journeyman said:
The exhaust stack passing up through the inside of the vehicle, and taking up quite a lot of space, is about the only glaring design flaw on the 185, which is otherwise a pretty decent train.

The exhaust stacks on the 185 gives them that very meaty sound (Im sure they must be close to a straight pipe) without them they'd probably sound identical to the 180s but they do take some space on the inside.

alangla · 24 Dec 2018

AIUI, the setup on the Voyager/Meridian is pretty much unique- instead of RPM increasing with driver power demand as per most diesel electrics, they increase to max rpm rapidly, then increase throttle to maintain that speed as demand and alternator field strength increases. This produces a totally different pattern of sound to the Alstom and Siemens diesel hydraulics.

craigybagel · 24 Dec 2018

Journeyman said:
The exhaust stack passing up through the inside of the vehicle, and taking up quite a lot of space, is about the only glaring design flaw on the 185, which is otherwise a pretty decent train.

Apart from their being massively over engineered - so they carry around big heavy engines that they have both derated and try to keep switched off as much as possible, and mean it can't run at Sprinter/Multiple Unit Speeds, which reduces their options got places they can be cascaded to when TPE get their replacements.

Lovely units to travel on though - my own TOC was suggested as a possible future home for them and I was actually a bit disappointed when that turned out not to be the case.

Getting back to 180s, the 175s do sound almost identical inside. They only have a 2 stage transmission and not 3 like on the 180s however.

Tynwald · 24 Dec 2018

A lot of the noise you hear is from the hydrostatic alternator drive, which is located in the cooler group, class 175 share exactly the same system, as they are vitualy the same train. They were refered to as the coradia 1000 when built by asltom. There was intended to be a 3 car 125 mph version for North Western. It is, or was, possible to operate class 180 & 175 in multi.

47271 · 24 Dec 2018

craigybagel said:
Lovely units to travel on though

Agree with this on the 185s, of the three types under discussion here they're the ones least prone to internal vibration. 180s are shockingly bad in my experience, the big error having been not to attach seats and tables properly to the walls which causes fittings to buzz with directly taking up every underfloor vibration going. Oh and having them badly built obviously.

alangla said:
AIUI, the setup on the Voyager/Meridian is pretty much unique- instead of RPM increasing with driver power demand as per most diesel electrics, they increase to max rpm rapidly,

This might explain why I get on so badly with vibration on Voyagers, to the extent that it makes me queasy, I've never really thought it through before. It reaches really quite a high frequency at starting speed meaning that you feel nothing but vibration, rather than having the buzz mitigated by other movements created by the train's motion.

I'd still rather a Voyager over a 180 any day. Thankfully I don't have to travel on Grand Central anything like I used to.

darylyates17 · 25 Dec 2018

Tynwald said:
A lot of the noise you hear is from the hydrostatic alternator drive, which is located in the cooler group, class 175 share exactly the same system, as they are vitualy the same train. They were refered to as the coradia 1000 when built by asltom. There was intended to be a 3 car 125 mph version for North Western. It is, or was, possible to operate class 180 & 175 in multi.

Is this to do with the cooler group wine when both units are idling or is it just a normal fan? as ive been keen to find out what it is as it sounds nice with the exhausts rumbling on idle.

TheWalrus · 25 Dec 2018

What is the future looking like for the 180s? Will GC take on the Hull Trains sets?

59CosG95 · 26 Dec 2018

TheWalrus said:
What is the future looking like for the 180s? Will GC take on the Hull Trains sets?

Seems likely. Though, given the amount of trouble the fleet is having since the move from OOC to Crofton (Wakefield), oxyacetylene may be on the cards too.
HUll Trains certainly weren't keen on the move to Crofton, as the staff there let one of HT's 222s slip off the jacks a few years ago...

krus_aragon · 26 Dec 2018

Tynwald said:
A lot of the noise you hear is from the hydrostatic alternator drive, which is located in the cooler group, class 175 share exactly the same system, as they are vitualy the same train. They were refered to as the coradia 1000 when built by asltom. There was intended to be a 3 car 125 mph version for North Western. It is, or was, possible to operate class 180 & 175 in multi.

On that note, have a 175 and 180 ever been coupled together? I know they've been in close proximity (in Cardiff and Manchester) over the years, but was wondering if they've ever been formally introduced.

Tynwald · 26 Dec 2018

Yes they have, full multi testing was carried out, at Old Oak Common if I remember correctly. Probably happened at Washwood Heath, as they were built on the same production line together.

LOL The Irony · 27 Dec 2018

TT-ONR-NRN said:
One can easily identify a Voyager by its unique rumbling sounds as it starts up and departs, whereas IMO a 180 just sounds like any old diesel train, if I heard one I certainly wouldn’t be able to tell if it was a 175, 185 etc.

They sound different on Voyagers because they're acting as a generator where as they're directly driving the train (via a gearbox, obviously) on 175's, 180's & 185's. They have the exact same turbo whine at whatever RPM it kicks in. I actually don't really notice the differences except a voyager revs higher on start up because it has to make electricity to power the traction motors.

hexagon789 · 27 Dec 2018

LOL The Irony said:
They sound different on Voyagers because they're acting as a generator where as they're directly driving the train (via a gearbox, obviously) on 175's, 180's & 185's. They have the exact same turbo whine at whatever RPM it kicks in. I actually don't really notice the differences except a voyager revs higher on start up because it has to make electricity to power the traction motors.

175s, 180s and 185s are Diesel-Hydraulic not Diesel-Mechanical though - they have a torque convertor and fluid coupling rather than a gearbox, the engine is never truly connected to the wheels either unlike with a mechanical gearbox where the engine does directly drive your wheels.. 172s are DMMUs so do have a gearbox - a six-speed one at that, earlier BR First Gen DMUs such as the 101s or 121s had four-speed epycyclic gearboxes with the driver having to manually change gears.

37057 · 27 Dec 2018

hexagon789 said:
175s, 180s and 185s are Diesel-Hydraulic not Diesel-Mechanical though - they have a torque convertor and fluid coupling rather than a gearbox, the engine is never truly connected to the wheels either unlike with a mechanical gearbox where the engine does directly drive your wheels.. 172s are DMMUs so do have a gearbox - a six-speed one at that, earlier BR First Gen DMUs such as the 101s or 121s had four-speed epycyclic gearboxes with the driver having to manually change gears.

The mechanical drive you describe are no different, they use a fluid coupling between the engine and the epicyclic gearbox, so there is no direct coupling on them either.

There's not much different between what's regarded as mechanical and hydraulic transmissions really, people seem to like to differentiate the two for no substantial reason as far as I can tell (unless you intend to multi them which I suspect why BR seperated them). A hydrodynamic transmission is still very much a mechanical device.

hexagon789 · 27 Dec 2018

37057 said:
The mechanical drive you describe are no different, they use a fluid coupling between the engine and the epicyclic gearbox, so there is no direct coupling on them either.

There's not much different between what's regarded as mechanical and hydraulic transmissions really, people seem to like to differentiate the two for no substantial reason as far as I can tell (unless you intend to multi them which I suspect why BR seperated them). A hydrodynamic transmission is still very much a mechanical device.

Fair enough, I got my info from a technical document which described the transmission fitted to 150s and which suggested that unlike the older DMMUs, the new DHMUs' engines were never connected to the wheels.

Nevertheless, I'm not sure about 172s, they don't seem to have a freewheel capability from what I've read.

37057 · 27 Dec 2018

hexagon789 said:
Fair enough, I got my info from a technical document which described the transmission fitted to 150s and which suggested that unlike the older DMMUs, the new DHMUs' engines were never connected to the wheels.

Nevertheless, I'm not sure about 172s, they don't seem to have a freewheel capability from what I've read.

I believe that's correct regarding 172s. I'd expect the 195s to be the same too. The older DMUs (101s etc) had a free-wheeling device fitted to the driveline between engine (+ fluid flywheel) and gearbox. I've no idea why these units prevent coasting.

You could say that the only technical difference (and I know it's obvious!) between a 172 transmission and a 185 transmission is that each gear-set is replaced by a converter/fluid couplings, as you already know. Granted there are variations in efficiency characteristics and the later is much larger and heavier!

If you were to look at them though, they both have an input and an output, both have constant mesh gears inside, both are fully automatic electronically controlled with sensors and solenoids, both have a hydrodynamic retarder, both have a heat exchanger attached and both require fluid to drive and control them.

At least there's not a great deal of difference between them from my view of maintaining both (though I've never worked 172s, the transmissions are the same as on the buses I have!)

hexagon789 · 27 Dec 2018

37057 said:
I believe that's correct regarding 172s.

Which is very strange, I've read that despite being more fuel efficient on longer runs that is negated by the inability to coast properly.

37057 said:
You could say that the only technical difference (and I know it's obvious!) between a 172 transmission and a 185 transmission is that each gear-set is replaced by a converter/fluid couplings, as you already know. Granted there are variations in efficiency characteristics and the later is much larger and heavier!

I think a hybrid might work, start off with a torque convertor then switch to a gearbox for higher speeds, retaining a fluid flywheel or something to allow freewheeling.

37057 said:
If you were to look at them though, they both have an input and an output, both have constant mesh gears inside, both are fully automatic electronically controlled with sensors and solenoids, both have a hydrodynamic retarder, both have a heat exchanger attached and both require fluid to drive and control them.

Didn't realise 172s had retarders.

37057 said:
At least there's not a great deal of difference between them from my view of maintaining both (though I've never worked 172s, the transmissions are the same as on the buses I have!)

I often wonder if the similarity to bus transmission is a good or bad thing.

Why do 180s sound the way they do?

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