electric drive systems, slightly OT

[kiha40]

Ok, so this is only semi-railway related but I thought some of you might be interested. I certainly am. I decided to post it in here because 1) there's no off-topic forum, 2) I usually post in here, and 3) because electric railways seem a lot more common in outside the US than within.

So, here we go: http://hutnyak.com/Trolley/trolleyphotos.html . Most of you are probably familiar with mine trucks, used for moving earth containing ore. You may also know that the majority of these (less Caterpillar products) have a diesel/electric drive system like a lot of North American-built locos. Here's are some examples of something I'd like to see tried on railways. These mines have the standard diesel/electric trucks, but they've also got pantographs. On hills, there's a caternary line, and in order to reduce strain on the diesel, or perhaps to extend the trucks' carrying capability beyond what the diesel could do, the trucks connect while on the hill. Very interesting, I think.

I'd love to see some passenger-use GP40s or maybe even some SD-MACs try this out. Presumably they've got all the power they need, but if they cover track that's both electrified and not, they could use the overhead when available to reduce noise/pollution. Just and idea. Have a look.

On topic: in the next several months, JR East will begin to replace the Chuo Line's utilitarian, obviously-old 201 Series EMUs with the new E233 Series... I can't wait to see them...

[David Benton]

I guess these are what 's known as a diesel electric hybrid . These were proposed for New Zealands Noth island main trunk line in the 90's . The middle section is Electrified , the 2 ends not . But nothing came of these ideas , Nz in the end brought no new trains .
the traction motors arent much different on deisel electric and elecric locomotives . wether there's room on a loco for a diesel engine and a transformer ,plus the more complicated controls , i don't know .
but it would be ideal for extending passenger services beyond the cantenary , and for helper service in mountain sections . The diesel engine reaches the limit of what it can supply before the electric motors reach thier limit of what they can handle (short term ) , so cantenary assistance on mountain sections would be ideal .

[george matthews]

I guess these are what 's known as a diesel electric hybrid . These were proposed for New Zealands Noth island main trunk line in the 90's . The middle section is Electrified , the 2 ends not . But nothing came of these ideas , Nz in the end brought no new trains .
the traction motors arent much different on deisel electric and elecric locomotives . wether there's room on a loco for a diesel engine and a transformer ,plus the more complicated controls , i don't know .
but it would be ideal for extending passenger services beyond the cantenary , and for helper service in mountain sections . The diesel engine reaches the limit of what it can supply before the electric motors reach thier limit of what they can handle (short term ) , so cantenary assistance on mountain sections would be ideal .

The class 73 series in Britain are classified as Electro-Diesel. They were deisgned to replace steam for freight trains on the third rail network where the third rail didn't go into the goods yards. So they use third rail where it exists and switch to diesel where it doesn't. Of course there is now no freight and no good yards. So they have mostly been used a electric locos on the Gatwick Express. They are now nearly all redundant.

I have once been on a train, in BR days, that used this capability. It took an InterCity train with Mark 2 coaches from Bournemouth to Reading. It was a replacement for a class 47 diesel which was presumably unavailable. It used the third rail supply to Basingstoke and then switched on the diesel to Reading, where it was replaced by a Class 47 to go on to Birmingham.

A few remain as rescue locos.

[David Benton]

thanks George , i remember seeing one parked at Clapham junction , back in the eighties when i was living in London . And of course on the Gatwick expresses .

One application in NZ that would suit , The otiria tunnel . 8 k.m of 1 in 30 , i think . Used to be electrified at 1500 volts d.c , but the loco change in the middle of nowhere , maintenance of cantenary , supply problems , meant they ripped the cantenary system out , and put a huge fan system in to allow diesels to do the job . But it is a limiting factor to the coal trains on this route . the diesel electric / electric hybrid would work well , with the 1/2 hour trip through the tunnel .
I have thought they could use a compressed air type system to provide propulsion and introduce air into the tunnel , but a massive amount of air and pressure would be required .