D8142: Louder than Bombs!

[lewisner]

I walked this bit of line from Ruabon to Corwen before they put the track back.Great to see it used again.

[tr4ins]

Great sound.

[RustedBovine]

You can see why they call them choppers!

[wisdomstar1981]

good stuff.

[toonmag50]

great vid-where abouts is this line-country side looks good

[tpickthall]

The Dee Valley, Llangollen, North Wales

[littlepouser2]

what an enginge noise fandabbydozy

[Shahidnabibullah]

great stuff mate!

[pcgenius9]

We get this with D8001 going up the EVR's 1 in 27 incline!

[simonpilk]

Wonderful little engines and a very sturdy design... plus superb noise..

[Trainbuff2008]

Excellant sound, felt like i was vertually on the footplate you've got a quality camera with excellant mic there pal.

[tpickthall]

Cheers! You're feet away from the exhaust port on a 20, so there's always plenty of thrash. Still day and slow speed meant no wind noise on the mic as well. Just a shame we can't repeat this at Llan any more : <

[tpvalley]

Is thew driver just banging the power handle to maximum and leaving it there?

[choirboyfromhell1]

Field diverters=Electrical gear transition?  Series to parallel? Wonderful video. Keep restoring 'em!

[tpvalley]

field divert is basically a resistance in paralel to the field windings of the traction motors, this has the effect of allowing motor to spin faster for a given power, something to do with the motor generating current that resists the current being fed into it...or something!

[choirboyfromhell1]

CSX predecessor Chessie System used glorified reostats in their locos to limit current per engine/gen RPM's, could this be what you mean?

[tpickthall]

Cheers for the comments. You're both basically correct. The diverts put resistance across the traction motors to stop them generating back emf, i.e. as they spin faster they will act like a generator themselves and work against the field you apply to turn the motor. It's a similar principal to gear changes, but done entirely differently for an eletrical transmission.

[tpvalley]

No.

Instead of fixed magnets the traction motors use electro magnets aswell as the windings on the armature/s.

The electro magnets have a resistor connected between the + and - , this resistor is connected to divert field when the balancing voltage reaches a certain level, this has effect of being able to run motor faster, even electric locos use field diverts.

The engine slows as there is more load on the generator, like when u turn lights on in car, roughly!

[choirboyfromhell1]

But something makes transition, we have contactors or power relays in the electrical cabinet that drop the resistors as traction motor speed is gained. Something switched over at 0:44.

[tpvalley]

Yes of course, when the divert is switched on the resistances r connected by means of huge big switch things that u mention.

I dont think british locos switch between series to series parallel and all of that stuff but I am not sure.

I know in old american locos u have a transision control to switch between series and series paralell which will also adjust total resistance of traction motors which will effect engine rpm.

We need an operators manual! there r some on the web for USA loco's!!

[tony4790]

HELLFIRE !!!! You must have a good knowledge of locos to notice the field divert . Nice one !!!

[madmax200769]

Throbtastic!! :)

[37427]

Choptastic!!

[47807]

A pair through "Prestatyn" in 2008 Hellfire!!

[tpickthall]

There was certainly a Chopper on the A55 last Saturday morning....

[37chief]

Didnt these used to work in pairs through Prestatyn in the early 90s ???

[boswellchrome]

great cab view

[fgh456pc]

MY LORDS!!! LOL

[D335Media]

Hmm - If I were blind, I think that were a helicopter on wheels =P

[tpickthall]

LoL, they don't call 'em Choppers for nowt!

[tpvalley]

track is very close to edge!

[tpickthall]

Makes for an exciting climb and descent!

[rickskateboard]

That's me shouting in the tunnel!

[tpickthall]

Nice bellow - LoL!